the jerk's advice: stems getting longer

[dbrk]

Our pal the Senor is a cleaver fellow, as we know, and I have recently experimented with his notions of stem length, to wit, I have added some length, on the order of 1cm, and moved (just a tiny tad) forward on my saddle. Since I routinely sit way, way, way behind the spindle (some 3cm in some cases), I can easily come forward. To work this experiment I chose two bikes that are designed as true race bikes, which in my mind means a saddle/bar drop that places slightly more weight forward and into the front end. The drop I have in mind is about 3cm or so. I also am happy to be even a bit more stretched out. I hate feeling "short" or cramped in any way and I can _much_ more easily adjust to being longer in the front. The bikes are my French blue Sachs and my silver Rivendell. Both got Nitto Pearl 12cm stems which are more like 12.7cm because Nitto measures on the side (side of the stem to center of the open clamp) rather than across the top (from bolt to center). These are long stems but not silly long. They are well down below their max line. The Sachs shows more post than the Rivendell and is slightly quicker up front.

The results are all very positive. The ever so slight bit of weight forward makes the Sachs even more direct, steady, and rock solid. The extra reach gives me the chance to push my butt waaay back onto the saddle (this being very good for the lower back, btw). I put the saddle forward less than 1cm, so that's not much of a change, but I still feel like there is a bit more forward weight. The Rivendell in comparison just feels longer, with no change I can perceive in the way that it handles. The Riv ordinarily wears the fatboy Dugast 28c silk tubulars so it is impossible, imho, to improve on the ride. But I am even more comfortable just one centimeter more extended though I can't surmise any difference in the front end.

The Sachs is clearly the more "pure" racer and it's happier bike for this move. Actually I did this on the TdF CSi awhile ago but forgot to mention it: in that case I didn't lower the stem or the saddle, I just made the bike longer and that was a good thing. I love being long in the cockpit, I suppose. To each his own.

I just got a 13cm Ibis stem for my Ibis, now by a longshot my smallest bike (originally listed as a 55cm but c-c, so more like a 57). Report (a better one than this) to follow. The moral of this story: your stem is too short. I hear you, Senor jerk.

dbrk

[saab2000]

....I had been thinking of writing specifically on this topic! Today I installed a Cinelli Grammo threadless stem onto my Croll, the one for which DWF last year created a new fork.

What a difference it made!!! I had had a 13 cm Ritchey WCS. In addition to looking out of place on the bike, it was a bit too short and a bit too high. The Grammo is a 14 cm and sits a bit lower on the bike. There are no spacers.

It is perfect. I really feel like it is a racing bike again. I get low and aero and have no pain anywhere. The only thing I need to do now is to work on the ol' beer gut thing..... The handling is improved, as the Jerk says it should be.

DBRK is right when he says that the Jerk is right!

[Dr. Doofus]

Is my stem long enough?

Before spending money on expensive, and sometimes painful, stem enhancement from ITM, Deda, Ritchey, Nitto, or Cinelli, try this simple test:

Drop a plumb line (or yardstick-length carpenter's level) from *two* locations: the center of the brake hood, and the curve of the drop.

If the plumb line for the curve of the drops bisects the front hub axle, or (ideally) falls up to, say, 1 cm in front, and the plumb line from the hoods falls 1-2 (?) cm in front of the hub, your stem is long enough to put sufficient weight on the front wheel, and your steed will handle like a racing bike (unless it is made by Giant or by a small Russian company trying to make use of leftover titanium tubing from recycled MIGs, and is simply junk to start with).

If the plumb line falls behind the front hub, forget it. Your stem is too short, or your top tube is too long, and it ain't gonna handle like a racing bike cause yer pushin that front wheel around like a Wal-Mart shoppin cart.


Now, this is just a *proposed* test... The Doc couldn't sleep last night, and started goofing around with photoshop with some pro bike pics from cyclingnews.com, and observed the relation of the curve/hoods to the hub...got the Doc thinking that if your hands are over or in front of the hub, there's enough weight there for it to handle like it should...so the test would be to see where that contact point with the bike lies with relation to the front hub...but then again, the doc got D's in science classes, and although he is a Doc, he is a Doc of Literature, which, last time we checked, got nothin to do with bike design.

Dave Kirk? ERitchie? Jerk? Does the test pass muster, or have no validity at all...?

[coylifut]

I think stem length has become is a phallic symbol around here

[eddief]

Not too many posts on the board from racers it seems. So what is the formula for stem length for the vast majority of serious recreational riders? I really enjoy riding 50 miles on my Rex/Walmart shopping cart. I fail miserably at the plumb line relative to front axel formula. With relaxed seat and ht angles, 8 bb drop, and level to saddle bar height, 9 cm stem; the shopping cart is wonderful riding cycle.

[Dr. Doofus]

Exactly Eddie. Its only an issue if you want to ride fast. If you lack the flexibility to ride in a low position, your bike won't handle like a racing bike anyway, and if you lack the flexibility, you're not trying to see how fast you can take a corner, because, as you accurately point out, that's not why you're riding.

We can talk about rake, trail, and front center until we're blue in the face, but the weight distribution of the rider is a crucial part of the picture....

If one is a "serious recreational rider" I and he think that the formula is "does my back hurt or not" -- becuase if you can't get the weight on the front wheel due to flexibility, its a total non-issue.

[eddief]

All points of view appreciated.

[coylifut]

I use a somewhat substantial saddle to bar drop and stem length. I've been toying with brining it up a bit. The biggest hammer in my district sits relatively upright as did Indurain. Maybe you guys are talking about bars that sit up much farther than I'm seeing in my minds eye, but from where I sit, wattage is the key.

[Dr. Doofus]

The reason I mentioned "low" was that low and *long* tend to go together -- its hard to run a long stem with the bars even with the saddle, unless the top tube is pretty short.

We're not talking about aerodynamics. Wattage is also a dead issue here -- its not speed while pedaling here, its how much speed can the bike take while still giving the rider a feeling of control while *coasting* through a turn (pleeeeease don't say fast guys pedal through corners -- the only reason pedaling through corners is the fast way in the U.S. is because if you actually take the fast line through the turn you move out of the draft, because you have to follow all the idiots who have never taken a corner flying like hell in a kermesse *where they don't pedal through corners*). We're talking about handling. As for Indurain, yes, he had a fairly upright position for a pro. He also ran a stupidly long 150 stem to keep the front end of his bike short and to tear down those descents as fast as he hammered up them (but more about that later).

When most people talk about stem length and handling, the first thing they think about is steering axis, and how a long stem makes a bike "steer" slowly. Indeed, a 140 or 150 stem gives an articulated feel when you turn the bars (you don't need to go that long unless you're riding a 58 or bigger, and depending on what handling you're shooting for). However, that's just part of the picture. The length of the stem also affects the amount of weight over the front wheel, which is another part of the handling stew, along with rake, trail, and head angle. Weight behind the hub, you're pushing the bike and the front end will feel loose in bad way, like the wheel is drifting (because it is). Weight too far in front of the hub, and you'll have an equally screwed up situation....

Look at this picture:

Bike A: 58 cm seat tube, 57 top tube, 73 head angle, 43mm of rake, 130 stem

Bike B: 58 cm seat tube, 59 top tube, 73 head angle, 43mm of rake, 110 stem

The same rider could "fit" on both bikes. They have the same length from seat to stem center. They could have identical stack heights. Bike B would steer like a dog, while Bike A would be a responsive race bike. Why? Bike B is going to be longer in the front-center, and because of the short 110 stem, the rider will have less weight over the front wheel, regardless of bar drop. Bike A will be shorter in the front center, and have more weight on the front wheel. A very talented builder informed me that trail is a bit more important than f-c, and I'll take his expert word for it. However, if two bikes have identical trail, and one has your hands well behind the hub, and the other has your hands over it, the latter bike will handle more responsively and securely, tracking and "sticking to the road" better. Look back in ProCycling when Marcel Wurst rode Moncoutie's Decathlon. For some sick reason, Moncoutie ran a long top and a 110 stem, giving his 58cm bike a 60cm f-c. Wurst said he was scared to push it on a descent, and that a climber (and allegedly poor bike handler) like Moncoutie must not worry too much about handling switchbacks, only getting up them....


Think of it this way. Stem length isn't a fit issue. Top tube length and head tube length should set the front end of the bike up so it fits. Stem length is a handling issue -- how much weight do you want over the front wheel and why. Obviously, a tourist and a racer (or a club racer) have different desires for how the bike should handle. I wouldn't do a double century on my CSi with a 130 stem and 9.5cm of drop. I wouldn't take a Rambouillet to a crit.


I may be off base here -- if I am, I hope jerk/kirk/ritchie will correct me....

[ericmurphy]

My Legend is 58 X 57, 73 + 73, 120 mm stem with a -10 deg rise. My plumb bob (a toenail clipper hanging from three feet of dental floss; my daily display of adaptability) shows that the center of the brake hoods is about half a centimeter in front of the hub axle, and the front of the drop is half a centimeter behind it.

So at least I'm not riding a shopping cart...

[eddief]

Sounds like we might be about the same dimensions in body and bike. How tall are you, what length sleeve and pant legs do you have? Just curious to find out if I was more flexible if I'd ride a similar bike to yours.

[soulspinner]

Please compare and contrast this with the greatest rider of all time and his insistance that a well balanced bike have a 110 stem. What other factors contributed to this...longer chainstays?

[ericmurphy]

Sounds like we might be about the same dimensions in body and bike. How tall are you, what length sleeve and pant legs do you have? Just curious to find out if I was more flexible if I'd ride a similar bike to yours.

Let's see. I'm almost exactly six feet tall, 34" inseam, and I wear a 16 1/3 - 33 shirt. Does that mean my arms are an inch shorter than my legs?

I'm amazed that the dimensions on my Serotta are so close to the dimensions on my previous bike (within a cm or so for most dimensions) and yet the fit on the Legend is infinitely better. Amazing what a difference such minor dimensional differences can make.

BTW, my bars perfectly obscure the front hub when I'm on the hoods. That's supposed to be a good rule of thumb for stem length.

[Dr. Doofus]

Please compare and contrast this with the greatest rider of all time and his insistance that a well balanced bike have a 110 stem. What other factors contributed to this...longer chainstays?


Hey, I and he said it was all speculative....

Anyway, the colnago charts have Eddy on 120s....

[jerk]

thanks for coming to the dark side kids. told ya the jerk is always right...
front center and balance....race bikes are designed around long stems...that's the deal they handle better with'em and handling is more important than just about anything including fit....you need your hips rotated forward to use the most powerful muscles in your body (try to stand up out of your chair without bending forward.....can't do it? how the hell are you supposed to ride a bike balls out looking like the wicked witch of the west?) so for the jerk low, long and the front wheel nice and tucked....not that it's going to matter on the painfully slow century the out of shape jerk is doing tomorrow....but my bike does have a 140 stem on it...

[ericmurphy]

A friend of mine used to race the Spring Classics in Belgium probably 20 years ago (he's in his mid-forties now). He told me once that at the time everyone raced small frames with stems at the UCI limit. Is that still true with the likes of Lance, Jan, etc.?

[Dr. Doofus]

Stems:

Jan -- 150
Lance -- 130
Bobby J -- 130
Ale-Jet -- 140
Hincapie -- 140
Kirsipu -- 130
Mayo -- 130
Moreau -- 140


A variety of rider sizes, but you see some consistencies...most pro biks are set up with 120+ stems (a little guy runs a 120...five nine or over, odds are the guy runs a 130+).

If you look at 70s-80s riders, the stems were about 1 cm shorter...but saddles were also lower, and the bars were higher, a less stretched out position. Into the 90s, more speed came as the result of better aerodynamics (lower stem) and more power (higher saddle). Longer reach could be done with top tube or with stem. These guys are getting custom made bikes. They ride 20,000 a year. If their bikes handled better with long top tubes and 110 stems, *they would ride them that way*. They don't. Even 70s setups (go back and look at those Colnago charts again) the hands are over the hub, even though the stems are in the 125-120 range....


At first I was speculative, but now the Doc is telling me he's convinced: for a "fast" setup, hands over or ahead of the hub, bub. For a tourist, its a different deal....

[vaxn8r]

Where do you get this information?

I seem to recall that LA uses a 120 mm stem...I'm thinking I read that somewhere this year???

[Dr. Doofus]

the bikes of all those cats were profiled in VeloNews, Cyclingnews.com, TopVelo, Velo, an Italian mag the doc ran across in D.C....Bici (?)...early this year LA was running a shorter stem, but last year it was 130....


hands over the hub, bub

[vaxn8r]

I placed a loooonnnng quill polished ti Ibis stem on the classifieds (130mm) if anyone wants to make their clasic bike way faster....and prettier. ;) ;)

[zap]

Jan uses a shorter stem on mtn stages. Doesn't want to fly over the h/bars when he hits the brakes on descents.

I seem to recall Lance using 11-12 cm stems as well.

[bulliedawg]

Doc Doofus:

Plumb line goes straight through the hub axel. Is this why I sometimes feel cramped in the shoulders?

[Dr. Doofus]

I'm not that kind of Doctor, and niether is he. But, we do have an extensive and expensive line of theraputic sports-medicine home products that might be able to address your problem. Please send us a 59 Terraplane with a 74 seat angle and a 58 top, and we'll send you our starter home treatment kit.

[Russ]

the bikes of all those cats were profiled in VeloNews, Cyclingnews.com, TopVelo, Velo....

Doc,

Thanks for the info, but IMHO, I don't trust anything I read unless I can verify it myself or via a credible source! (and no, I don't think most news media, sports or otherwise are credibe sources).

I have noticed that cyclingnews.com in particular, is often inaccurate about the bike specs they post. Let me give you and example:

http://www.cyclingnews.com/tech.php?id=photos/2004/giro04/tech/bikes_climbing/CN-girobike09
The caption says: "...that's a proto FSA Plasma integrated bar/stem."

Obviously, the person taking the pictures is not the person writing the captions. The bars and stem on Simoni's bikes, as verified by Tom Armstrong of Cannondale were FSA's K-Force. You can also see that the stem and bars on pictures where Simoni is racing, his stem shows a cap.... integrated bars and stems do not need a stem cap!

To get some clarificationon on this issue, I e-mailed cyclingnews.com and asked them to correct this error and to see if they could give us readers, actual measurements of the Pro bikes they feature, however, their response was: "Well, the photographers do not have time to measure bikes or ask questions..." Go figure! Why would CN just decide to post innacurate information, I wonder!

Again, this is just an example... I recal other instances of information beign wrong in several mags, but I gave up keeping track. IMHO, the magazine that does the best job is Bicisport of Italy. In more than one occasion, if they don't know something, they will admit it....

Cheers!

[alembical]

Not sure how to post a picture, but .....
http://www.cyclingnews.com/photos/2004/tour04/tech/?id=specialized/CN-TDF04-Tech06

is one long stem with a huge drop.

alembical

[jerk]

Jan uses a shorter stem on mtn stages. Doesn't want to fly over the h/bars when he hits the brakes on descents.

I seem to recall Lance using 11-12 cm stems as well.



the 140 is jan's "short" stem. most of the time he uses a 150 but he has used a 160 as well. the jerk is going to try raising the dura-ace hoods on his d/a 9 equipped bike and will probably need a longer stem to compensate. got any 150s lying around?

[jerk]

[QUOTE=Dr. Doofus]Stems:


If you look at 70s-80s riders, the stems were about 1 cm shorter...but saddles were also lower, and the bars were higher, a less stretched out position. Into the 90s, more speed came as the result of better aerodynamics (lower stem) and more power (higher saddle). Longer reach could be done with top tube or with stem. These guys are getting custom made bikes. They ride 20,000 a year. If their bikes handled better with long top tubes and 110 stems, *they would ride them that way*. They don't. Even 70s setups (go back and look at those Colnago charts again) the hands are over the hub, even though the stems are in the 125-120 range....


QUOTE]

the main reason for what the doc says is that road conditions are considerably better than they were in the 1970's. so....stays are shorter...front centers are a bit tighter so stems can be longer to keep the same fit. the bars are lower and the saddles are higher because the roads are better. what's sort of funny is that old man cinelli predicted this stuff in the early sixties....he thought that as european roads got better bikes would get tighter and lower....he also thought that by now we'd all be riding on 650 wheels for the same reason. oh well.

[zap]

Sorry, still using both my 150 stems.

[jeffg]

from Hampsten cycles:

A properly fitted bicycle is centered around the stem, which we think of in terms of sizes: small (100-105mm, for frames in the 50-54cm range), medium (110-120mm, for 54.5-57cm range), and large (120-130mm, for 57.5cm and up range). A bicycle built around the proper stem length will have optimal weight distribution and handling characteristics. We believe that the cure for a poorly fitting bicycle is not a longer/shorter stem, but rather a well-built frame using the correct length stem.

I ride a 55X57 with an 11cm stem, though I suppose it could be a 12. That said, my bikes handle wonderfully with 6-7cm bar to saddle drop and an 11 cm stem. I will try the doc's plumb bob test tonight.

[Russ]

from Hampsten cycles:
....A properly fitted bicycle is centered around the stem....
Glad you brought up the real issue, Jeff! This has always been the key issue that the people that have fitted me in the past (LeMond, Guimard, and not long ago, Kiefel) have always said.

....I will try the doc's plumb bob test tonight.
I am curious, what numbers did you come up with? I know the Doc Doofus would be proud of me ;)

CSI: TT 54.6, Stem 120
Drop (from curve): 1.2cm (from hood) 3.8cm
Legend: TT 54.8, Stem 120
Drop (from curve): 1.5cm (from hood) 4cm
Ottrott: TT 54.9, stem 120
Drop (from curve): 1.5cm (from hood) 4.2cm

By the way, I don't think I need a longer stem... or need to be positioned like Cipollini or Petacchi.... Those animals are of a different breed! :p

[Dr. Doofus]

By and large, most Serottas the Doc and I have seen have the rider's hands over the hub, unless its for a rider with poor flexibility who couldn't get there, and (the fitter wisely noticed) probably shouldn't try.... All that said, our CSi was designed for a 120 stem, but we moved out to a 130 (as well as moving the saddle up 5mm and back just a tad) because although the Fit Cycle position was dialed in "by the numbers" we were more comfortable the way things were before (the doc is both open to suggestion and the victim of a gnat's attention span...he always wants me to piss around with something on the bike)...the longer stem didn't detract from the handling...a shorter stem would have, but then again that's all in the context of 9.5cm of drop, so longer is going to be more complimentary with the whole Gestalt....

jeffg, there's no one right answer to your question. I and he think that the top tube and head tube should dial in the fit, and that the stem is to dial in handling -- the question is, what kind of handling do you want? neutral race? responsive/nervous race? neutral touring? randonneur? quick randonneur? The Doc's Merckx was bugging him, and after some emails with Dave Kirk and some reading up on how trail works with front center, head angle, and rake, the mouse and the Doc concluded that a good builder can manipulate all those factors to design a bike that will handle however you want it to, and then the stem is the icing on the cake.....

Although I'm inclined to agree with the Doc that an 11cm stem is a little short if you're running a 57TT, it ain't that simple...we'd have to see you on the bike, know your riding style, your injury history, blah blah blah (all that important stuff that Seven ignores...they just plug the numbers into a damn chart and tell you what your new position should be...weiners)....

As for Hampsten...he's a God. Those numbers seem in the ballpark for an 80s-early 90s race bike, or for most recreational rider consumer bikes. The Doc will not say anything bad about Hampsten or his bikes...the cycling Gods fry your nuts in peanut oil for **** like that....

[dbrk]

The Doc is correct that a long stem is de rigour for a race bike fit and that the stem length and weight distribution are a feature of the bike's _style_, that is, different bikes (randonneur, nervous race, this or that) handle accordingly. It is also the case that we have to look to a person's flexibility because folks who are not flexibile can't ride "racer style" but can often ride randonneur stylel, which means that the stem length might _not_ be longer since weight is distributed differently and the bikes handle wonderfully. I would venture to say that I am as flexible in body as the most flexible racer on this Forum (or nearly anywhere else). But I also only occasionally care to ride in the race style. My bikes are designed each according to their purpose and style. My point here is that longer stems suit _certain_ bikes and a certain style, and that many (MANY) folks who are riding for fun (and not racing) would benefit from not taking up a racer's style but looking into other sorts of designs and fits. I have the sensation that this thread has evolved to notion that longer stems and lower saddle/bar drop is somehow "correct" or better---which is true only on a racer style bike. The three of us agree on that, I am sure about Doc.
The fact that we have lost stack height and headtube length in the threadless era has caused more hassle and expense than it has solved any problems.

dbrk

[Dr. Doofus]

The Yogameister looks up fromthe shadow of his bo tree and speaks the truth once again....

Dr. Brooks, threadless stems suck. I and the mouse would nudge our quills up and down during the year...a mil here, a mil there...and they looked cool...in retrospect, the doc was stoopid for not getting his CSi with an F1, threaded (which was still possible)...and the Flandrian Gods probably gave me this cold because there's a threadless stem on the Corsa...at least the ol' Moser still has an Eclypse on it....

uh-oh, new thread direction

[Andreu]

........"this thread has evolved to notion that longer stems and lower saddle/bar drop is somehow "correct" or better---which is true only on a racer style bike". Moreover, it is a very interesting & refreshing break from all the Tdf threads.
However, out of interest what would be the "feel" of a bike with hand position very much forward of the front hub compared to the "feel" of a bike with hand position very much behind the front hub. I am also thinking of Obree´s superman position on the track - you would have a really sensitive handling bike (with the stem acting like a lever?)...probably not a huge problem when going in circles. Any thoughts?
Thanks
A

[eddief]

My back was starting to ache from reading about longer stem extensions. I was actually allowing myself to be talked into doing more situps and working on my core, rather than continuing to enjoy the heck out of the riding position and 9 cm stem on my Rex. The "sit back and up" with the subtlety of the low bb, riding position of the Rex is always more comfortable than the race-bred geo of my other bike... for the type of riding I do.

[jeffg]

jeffg, there's no one right answer to your question. I and he think that the top tube and head tube should dial in the fit, and that the stem is to dial in handling -- the question is, what kind of handling do you want? neutral race? responsive/nervous race? neutral touring? randonneur? quick randonneur? The Doc's Merckx was bugging him, and after some emails with Dave Kirk and some reading up on how trail works with front center, head angle, and rake, the mouse and the Doc concluded that a good builder can manipulate all those factors to design a bike that will handle however you want it to, and then the stem is the icing on the cake.....

Although I'm inclined to agree with the Doc that an 11cm stem is a little short if you're running a 57TT, it ain't that simple...we'd have to see you on the bike, know your riding style, your injury history, blah blah blah (all that important stuff that Seven ignores...they just plug the numbers into a damn chart and tell you what your new position should be...weiners)....

As for Hampsten...he's a God. Those numbers seem in the ballpark for an 80s-early 90s race bike, or for most recreational rider consumer bikes. The Doc will not say anything bad about Hampsten or his bikes...the cycling Gods fry your nuts in peanut oil for **** like that....

Docs --

Too busy last night to check my bikes (7 sleep-over family guests in a NYC 1-bedroom+ wife and baby); however, I will do so tonight and would bet my hands are well-positioned over the hub). As for desired handling, both Kelly B. and Steve Hampsten approved of the 11cm stem for DC riding. I have to say, riding from Santa Rosa to the Alps has shown the setup to handle very well for me, and I certainly don't tend to lose ground on DCs during technical descents. So, the handling is definitely not nervous race, though I would suppose the bike is race worthy. The only opinion for a 12cm stem seemed to be from the shop and motivated by a desire to keep a "stock" 56X56. When I asked Kelly whether a 56cm TT +12cm stem or 57cmTT + 11cm stem would be better, he chose the latter. Oh well, it works for me! Numbers to follow ...

[MadRocketSci]

what kind of racing are we talking about here? flats and cobblestones? or screaming down switchbacks? i have the notion that if you put a 14 cm stem on my 56 tt i'd do a '01 Ullrich a$$ over tea-kettle in the ditch the next time i rode down page mill...

http://www.paloaltobicycles.com/gradeslocal.html

[Dr. Doofus]

exactly, Mad, and if you're not over six feet (like Petacchi or Ulrich) you don't need a 140 stem.... Grimpeur, Sprinteur, Barodeur, Rouleur...there are many different racer styles and setups...as a rule, hands over the hub...how far over is up to the style of rider, build, flexibility, all the things that have been discussed.

niether the jerk nor I and Me have ever proclaimed that everyone needs to go change their stem...just that, in general, if you want a tight front center and "modern" response, you go with a longer stem and shorter tt....also, most long-stem setups are counterbalanced by kicked-back saddles...those cats on 140 stems are also riding frames with 15cm of post showing, and the saddle all the way back...more weight out front, you need to move some weight back to keep the center of gravity...the Doc only runs 6cm of saddle setback (to be 1cm behind the spindle), and if he rode a stock 59cm Coppi, he'd run a 150 stem, and have 55% of his weight over the front wheel and flip our ass over constantly...the only reason I and I moved up from the 120 Kelly spec'd was because we also moved the saddle back (the fitter had us right at KOPS)...I could still stretch our front a bit more, so he put on a 130...the center stayed the same, just each point moved out a bit....

jeff echoes the point we tried to raise earlier this morning...that most Serottas are set up as they need to be, for that rider's strength, flexibility, riding style, goals, and skills....

no hard and fast rules...but in general, hands over the hub, bub....

[William]

This is an interesting thread and it may explain some differences that I've felt between my CSI and other bikes that I've had. I took Doc's suggested measurement from the center of the hoods on the Serotta and find that it almost exactly bisects the center if the front hub. Obviously if you put it on the drop it's going to put it behind the hub. Now, I know this is going to sound blasphemous to many of you so grab hold of your computer tables.....this may explain why my Serotta doesn't seem to feel as crisp as my first road bike (gasp!!), a Fuji Roubaix. Don't get me wrong, my Serotta has a MUCH nicer as well as stiffer ride where it counts. But I could rip that Roubaix around any corner at speed with more confidence (confidence being a subjective word) than almost any bike I've had since. It was a 63 cm (c2c) as is my Serotta, but it had a shorter TT which I had to compensate for with a longer stem (I don't remember the exact length) with a slight rise which I know fell forward of the front hub. I also dumped the original 105 components for a mix of Ultegra and DA, 180 mm DA cranks, Flite saddle, Mavic wheel set etc... The Serotta has a 63 cm ST and a 63 cm TT center to center. I'm running a 120 mm Cinneli stem with no rise. It's set up with a DA gruppo. The height difference between the top of the TT and the top of the stem is 10 cm. From the top of the TT to the center of the saddle is about 22 cm. So there is a 12 cm difference between the top of the stem and the top of the saddle. This positioning allows me to stretch out but I probably could go a little bit longer if I wanted to try it. BTW, these measurements were all determined on the Serotta fit/size cycle.

Don't get me wrong, I've won and placed in a lot of races on the Serotta. It's a great handling bike and I probably won't ever sell it. But, it still doesn't have that crisp, tight feel that that Roubaix had and I'm beginning to wonder if the stem differences could be the reason? I suppose it could also all be in my mind?



William

[Dr. Doofus]

a tough call...63x63 is a loooong bike, regardless of ST angle. See the jerk's earlier threads on the old board about long stems and big bikes.

Its the great debate between front-center and trail (which the Doc had recently with his Merckx)...some contend that if the trail is set up right, you'll still have responsive steering. Others contend that if the front of the bike is loooong, then yeah, it'll feel like your driving a big rig, not a sports car. Ask six brilliant builders, you'll probably get three brilliantly different answers...some cats would say its the trail, some would say its the front-center...that's why there are differences in geometries...I'd say getting it "right" is about a meeting of the minds between a knowing rider and a knowing builder.

And here's the next problem. E-Ritchie, Dave Kirk, Kelly Bedford, Gert at Merkcx (the Gert who designs the bikes...not the Gert who paints or the Gert who locks the doors at night, or the Gert who...), and Dario Pegoretti would all build you slightly different frames, this Doc would be willing to bet. They're knowing. The problem is whether or not the customer (who is not a veteran pro who rides a bike 4 hours a day and knows what s/he wants) is knowing. Hence why E-Ritchie takes your measurements, tells you to leave him alone, and then builds your bike. Really, its best that way.

So really, what we all need to do is everybody has to get their own "bespoke" Sachs, Kirk, Serotta, Merckx, Pegoretti, and hell why not a Nagasawa too, and then, when you find the one that's *it*, you know how your bikes need to be made. Or you'll be confused and broke. Or you'll be friggin Brooks.

[William]

It is a looong bike, but I’m a big guy. One thing I will point out between the two is that I can take my hands off the bars on the Serotta and it will track straight at higher speeds. Taking my hands off of some other shorter TT bikes that I’ve had (including the Roubaix) and the handler bars will start to oscillate and quickly get worse to the point of loosing control. I always felt a little funny with those longer stems on those frames but it worked. It’s possible that I learned to use that “twitchiness” to an advantage that gave the perception of a crisp handling bike?

BTW, how do I get to the old forum?

Like I said, my Serotta is still a great handling bike. Here you can see me using it to avoid a crash in a hairy stage race I’m currently racing in…incognito. :rolleyes: :D :rolleyes: :D

William

[Fixed]

Nice thread

[William]

Wholly time warp Batman!!!:eek:





;):)
William

[thwart]

Hey, it's nostalgia week! ;)

These threads are certainly worth reading... thanks!

[jr59]

Is it zombie week?

[mjb266]

Hells yeah...educative.

All new members should have to read some of these classic posts. The centralized fit and fitness knowledge in the archives is fantastic.

[mister]

sick thread bump fixed!

[zap]

fixed dude, that's some dredging.

[witcombusa]

There a so many other variables that affect weight distribution on a bike that this is but a wee part. Not a cure all by any stretch!

Should have let this one be.....:no:

[Ahneida Ride]

There a so many other variables that affect weight distribution on a bike that this is but a wee part. Not a cure all by any stretch!

Should have let this one be.....:no:

Just what we need. Another 20 page thread about short stems,
bad leather saddles, low gears and upright riding styles.

I ride to clean out the few brains I have left.
How fast I get from point A to point B is mostly irrelevant to me.

[TPetsch]

Funny, I was just studying this image the other day trying to glean some understanding about professional racer "Fit". Hard to find side views like this one.

http://tourdefrance2012.net/wp-content/uploads/2012/06/2010_tour_de_france_stage20_paris_eiffel_tower_alb erto_contador_peloton1.jpg

[Bruce K]

I am pretty sure there is no real value in dredging up an 8 year old thread.

BK

[Bruce K]

Let's see where this goes.

BK

[firerescuefin]

Let's see where this goes.

BK

Bruce... Thanks for reoPening. Interesting takes from the past and interested on input frOm current crowd

[Chris]

Not necessarily having to do with length, but more position, Gerard Vroomen has written some good stuff on today's trends about stem height and rider position. His point about how a rider will generally end up with his back in one position regardless of how low the stem is was a point that really hit home with me. I raised my bars 5mm and have felt some difference. Most notably has been a decrease in the hand tingling that comes from ulnar compression.

http://gerard.cc/category/bike-equipment/

[fourflys]

Not necessarily having to do with length, but more position, Gerard Vroomen has written some good stuff on today's trends about stem height and rider position. His point about how a rider will generally end up with his back in one position regardless of how low the stem is was a point that really hit home with me. I raised my bars 5mm and have felt some difference. Most notably has been a decrease in the hand tingling that comes from ulnar compression.

http://gerard.cc/category/bike-equipment/

that link was worth reopening this thread for sure, thanks! There are some great points in his postings... makes want to try a Cervelo...

[Rueda Tropical]

Can you talk about stem length without talking about handlebar reach?

Nowadays a reach of 75-85 is the norm -my 3ttt Gimondi has a reach of 105 which was not unusual not so long ago. If you subtract 20mm from the bar reach you will need to add it to the stem.

My 110 stem plus 105 bar setup = 215 reach. If I switched to a compact bar or a modern traditional bend bar like the 3T Rotundo I'd need around a 130 stem.

[soulspinner]

Can you talk about stem length without talking about handlebar reach?

Nowadays a reach of 75-85 is the norm -my 3ttt Gimondi has a reach of 105 which was not unusual not so long ago. If you subtract 20mm from the bar reach you will need to add it to the stem.

My 110 stem plus 105 bar setup = 215 reach. If I switched to a compact bar or a modern traditional bend bar like the 3T Rotundo I'd need around a 130 stem.

+1 No fit can be done without knowing bar reach, bars vary greatly...........

[SPOKE]

If all you do is install a longer stem (maybe even increase the seat to bar drop also) there will only be an extremely small % increase in weight on the front wheel. Now this may be just enough to help improve handling a bit. But to get a bit more weight shifted forward you may have to let the "mother nature" of cycling work some magic. Over time (miles) your pelvis will rotate forward a bit and this is the magic.....

[oliver1850]

Has anyone ever checked how much the weight distribution changes with the amount of adjustment in horizontal dropouts? It seems to me that for a given rider and his given ideal position relative to the BB spindle, the best way to change his weight distribution is to move the rear wheel. Obviously there are limits and tradeoffs, but I'm wondering how much the rear wheel has to move to change the weight distribution, say from 58/42 to 55/45.

[MadRocketSci]

from a free body diagram weight distribution is mainly affected by the bike's front-center and rear-center (or, chainstay length)...increasing stem length will affect this distribution if it causes your upper body to get lower, thus moving your cg forward a bit. If you maintain the same upper body position your weight dist will be unaffected (except for an insignificant bit of influence from your arms stretching forward more)

[Dave]

Has anyone ever checked how much the weight distribution changes with the amount of adjustment in horizontal dropouts? It seems to me that for a given rider and his given ideal position relative to the BB spindle, the best way to change his weight distribution is to move the rear wheel. Obviously there are limits and tradeoffs, but I'm wondering how much the rear wheel has to move to change the weight distribution, say from 58/42 to 55/45.

That's simple to figure, with reasonable accuracy. If the wheelbase is approximately 100cm, then moving the wheel forward by 1cm adds 1% to the rear wheel percentage and takes 1% off the front. 3% would require a lot of movement.

There are few modern frames with horizontal dropouts. Most chainstays are now very short, in the 40-41cm range, at least for racing bikes. You can't get the rear wheel any closer without contacting the seat tube.

I like to see a weight balance of about 55/45 when I'm in an aggressive descending position. That's what I get with my off the shelf 51cm LOOK frames, even using a lot of saddle setback.

[oliver1850]

Thanks Dave, that's what my intuition said but I wasn't sure on the physics. I was really thinking of it in terms of custom frames, not off the shelf ones. I just thought there might be enough adjustment in horizontal dropouts to make a measurable difference in weight distribution, and thought maybe someone had tried it.

How does weight distribution affect straight line stability? I'm more interested in having a bike that inspires confidence, as opposed to ultimate cornering capability. The bike I rode tonight (modern carbon) is twitchy at high speeds. Over 30 mph it becomes hard to keep it going in a straight line on bumpy pavement. I'm more comfortable on my 1991 SLX Serotta at 40 mph than this bike at 30. Both have relatively short stems, but I haven't compared the geometry of the frames. I plan to try a longer stem just to see if it makes the bike more stable. My guess is that the way the bike feels is more a function of HT angle and rake than other factors, but I'm interested to see if I can make it suit me any better by changing my position.

[Pete Mckeon]

Besides arms a key ingrediant is one or all of the below

- rider's flexibility which improves and streteches thru the season you probably prefer a longer stem than winter time
- torso length
- original atarting point on lenghth
- preferred position when you ride
- as you get older and less flexible things change

Pete

ps the below has worked for many years for me and was used mostly decades ago. Don't spends money unless it puts a smile on your face AND gets you to ride more. Over the years i have used 12 all the way down to 10cm. Most are at a 110 today. A sachs i rode some was speced at 120


Let a good fitter like smiley look at youon bike and go from there.
10stem or a 12 stem is 6/8s of an inch difference by specs but each mft is somewhat different in how they size to place the stem size






Is my stem long enough?

Before spending money on expensive, and sometimes painful, stem enhancement from ITM, Deda, Ritchey, Nitto, or Cinelli, try this simple test:

Drop a plumb line (or yardstick-length carpenter's level) from *two* locations: the center of the brake hood, and the curve of the drop.

If the plumb line for the curve of the drops bisects the front hub axle, or (ideally) falls up to, say, 1 cm in front, and the plumb line from the hoods falls 1-2 (?) cm in front of the hub, your stem is long enough to put sufficient weight on the front wheel, and your steed will handle like a racing bike (unless it is made by Giant or by a small Russian company trying to make use of leftover titanium tubing from recycled MIGs, and is simply junk to start with).

If the plumb line falls behind the front hub, forget it. Your stem is too short, or your top tube is too long, and it ain't gonna handle like a racing bike cause yer pushin that front wheel around like a Wal-Mart shoppin cart.


Now, this is just a *proposed* test... The Doc couldn't sleep last night, and started goofing around with photoshop with some pro bike pics from cyclingnews.com, and observed the relation of the curve/hoods to the hub...got the Doc thinking that if your hands are over or in front of the hub, there's enough weight there for it to handle like it should...so the test would be to see where that contact point with the bike lies with relation to the front hub...but then again, the doc got D's in science classes, and although he is a Doc, he is a Doc of Literature, which, last time we checked, got nothin to do with bike design.

Dave Kirk? ERitchie? Jerk? Does the test pass muster, or have no validity at all...?

[Fixed]

Nice posts........or should I say stem?
Cheers

[roguedog]

This was a great dig, Fixed. Thanks for unearthing these two threads. Really enjoyed reading them.

[Pete Mckeon]

Besides arms a key ingrediant is one or all of the below

- rider's flexibility which improves and streteches thru the season you probably prefer a longer stem than winter time
- torso length
- original atarting point on lenghth
- preferred position when you ride
- as you get older and less flexible things change

Pete

ps the below has worked for many years for me and was used mostly decades ago. Don't spends money unless it puts a smile on your face AND gets you to ride more. Over the years i have used 12 all the way down to 10cm. Most are at a 110 today. A sachs i rode some was speced at 120


Let a good fitter like smiley look at youon bike and go from there.
10stem or a 12 stem is 6/8s of an inch difference by specs but each mft is somewhat different in how they size to place the stem size






Is my stem long enough?

Before spending money on expensive, and sometimes painful, stem enhancement from ITM, Deda, Ritchey, Nitto, or Cinelli, try this simple test:

Drop a plumb line (or yardstick-length carpenter's level) from *two* locations: the center of the brake hood, and the curve of the drop.

If the plumb line for the curve of the drops bisects the front hub axle, or (ideally) falls up to, say, 1 cm in front, and the plumb line from the hoods falls 1-2 (?) cm in front of the hub, your stem is long enough to put sufficient weight on the front wheel, and your steed will handle like a racing bike (unless it is made by Giant or by a small Russian company trying to make use of leftover titanium tubing from recycled MIGs, and is simply junk to start with).

If the plumb line falls behind the front hub, forget it. Your stem is too short, or your top tube is too long, and it ain't gonna handle like a racing bike cause yer pushin that front wheel around like a Wal-Mart shoppin cart.


Now, this is just a *proposed* test... The Doc couldn't sleep last night, and started goofing around with photoshop with some pro bike pics from cyclingnews.com, and observed the relation of the curve/hoods to the hub...got the Doc thinking that if your hands are over or in front of the hub, there's enough weight there for it to handle like it should...so the test would be to see where that contact point with the bike lies with relation to the front hub...but then again, the doc got D's in science classes, and although he is a Doc, he is a Doc of Literature, which, last time we checked, got nothin to do with bike design.

Dave Kirk? ERitchie? Jerk? Does the test pass muster, or have no validity at all...?

[Fixed]

This was a great dig, Fixed. Thanks for unearthing these two threads. Really enjoyed reading them.

Thanks
Thanks William for the peg thread
Cheers

[dustyrider]

It seems to me the handlebar's specs is as big a variable to consider, as your bike's spec, in your determining your stem length, but I don't seem to see anyone mentioning this.

I've been looking at picking up a Nitto Noodle and it's reach is about 13mm longer than the bar I currently ride, and love, so in my mind I'd want to lessen my stem by about 10mm, in order to keep everything relatively the same.

I'm not sure drop is as big a factor, and in fact there is only a 4mm difference(shorter) between the bars I'm comparing, so I haven't given that much thought.

I'll have to give this thread a once over later it seems...

[rounder]

I went to Smiley. He said try this. He shortned my stem by 1 cm, raised my saddle by 1 cm, lowered my stem by 1 cm. They seemed like negiligible differences, but afterward the bike felt fine.

[Chance]

Would like to comment on dr doofus' theory of hands over front hub but not sure what his status means. He, Eric Murphy, and Andreu are listed as "guests". Anyone care to remind me again what that means. May have asked before but don't recall if they can reply to comments about their previous posts.

[William]

Would like to comment on dr doofus' theory of hands over front hub but not sure what his status means. He, Eric Murphy, and Andreu are listed as "guests". Anyone care to remind me again what that means. May have asked before but don't recall if they can reply to comments about their previous posts.

When the migration to the spot across the hall began, some folks just left and didn't come back. A few others tried to remove themselves completely and wipe out their presence. Since they are no longer "members", their old posts remain and appear as "guest". I can think of a couple of oldies who went back and started removing their old posts but apparently gave up after a while...probably to time consuming to do when you have thousands of posts.

Hey, to each their own. http://forums.pcpitstop.com/public/style_emoticons/default/shrug.gif





William

[Fixed]

A lot of those posters don' t post across the hall any more or rarely .
A lot frame builders over there though
Cheers

[William]

A lot of those posters don' t post across the hall any more or rarely .
A lot frame builders over there though
Cheers

Yep. There is there, here is here. It's all good.:beer:





William

[zap]

It's a package deal.

Stem/tt/wheelbase...........

I stand by an old rule of thumb, no stem should be shorter than 100 (say 45 c-c frame) and progressively go up from there to 150 for the taller est folks.

[witcombusa]

It's a package deal.

Stem/tt/wheelbase...........

I stand by an old rule of thumb, no stem should be shorter than 100 (say 45 c-c frame) and progressively go up from there to 150 for the taller est folks.

And I would and do respectfully disagree with you. Without knowing any of the riders particulars you can't plug in a formula equation, one size fits none answer. Completely case by case compromises needed.