Sloping top tubes - are they becoming a thing of the past?

[dd74]

Maybe it's my imagination, but it feels like I'm seeing less sloping top tube frames these days. Or not as steeply sloping. I definitely feel there are less sloping top tube custom frames out there.

Is there some sort of a reason, style or conspiracy behind this? Maybe the sloping top tube isn't all it's been lauded to be functionally? Thoughts? Observations?

[wallymann]

the slope is less pronounced these days.

i personally prefer a classic look, but a sloping frame can look pretty tough too.

[jmoore]

We can only hope to see less slope. But with the proliferation of generic carbon frames, the slope is here to stay.

[MattTuck]

My incoming custom has a sloping TT. for the contact points, I wanted to show a bit more seat post, so I went with sloping. I have very little seat post on the current bike, and feel it is too harsh. Wanted something different.

As far as the big manufacturers, these things come in cycles. I'm sure after the seat mast craze finally dies, and level TT become the 'in' thing, then sloping top tubes will make a resurgence... always gotta be selling something new and improved over what people currently have.

[Mikej]

No. They are a thing of the present and will be forever. Alot of people really like the look and fit with todays taller ht's. 6-7 degrees seem to be norm, with a "level" tt still having 2-3 deg. slope. But a full level tt? Mostly on lugged steel.

[rePhil]

I changed from liking lugs and level top tubes to tig and sloping top tubes. I helps with standover for us vertically challenged.
I like the slope of my Moots Compact, as well as the tig work. It's just right for my tastes. We all like what we like.

[David Kirk]

2° is the new level.

dave

[Ahneida Ride]

2° is the new level.

dave

I think Dave is correct.

My Bedford is 2 deg slope ..... almost imposable to notice.

[Chance]

...........

Is there some sort of a reason, style or conspiracy behind this? Maybe the sloping top tube isn't all it's been lauded to be functionally? Thoughts? Observations?

Firstly, nobody needs +/- 20 cm of seat post showing in order to have adequate top-tube clearance when standing. That “look” came more from pros riding tiny frames compared to what most of us should be riding. In my opinion of course. Small frames for them handle faster, weight slightly less, and allow for them to have huge saddle-to-bars drop. For average riders that’s more of an image “want” than a functional requirement.

Secondly, there was also the idea that sloping top tubes would lead to fewer frame sizes to stock. Don’t think that worked out as well as they wanted. The initial small/medium/large and maybe extra-large sizes quickly became almost as many as before. The market (that is buyers) drove much of that. Would guess lower cost manufacturing helped out a bunch too. Once volume picked up it was also cheaper to produce and stock more sizes. With more sizes the advantage of a deep slope to aid in standover is reduced.

Thirdly, a long seat post flexes more which in theory produces some “vertical compliance”, which should improve ride somewhat. However, due to simple geometry, if there is appreciable flex it’s mostly in the undesirable back-and-forth direction instead of the more desirable up-and-down. It also puts more stress on the frame, which becomes more of a problem as frames are made lighter.

A little is probably good, but like many things too much of anything can ruin it.

[SPOKE]

2° is the new level.

Dave

+1!!!!

[mike p]

The less slope the better...right up to level which is perfection!

Mike

[Black Dog]

You see, the move to sloping top tubes was to increase lateral stiffness and vertical compliance, and now the move back is to increase lateral stiffness and vertical compliance...and around the marketing carousel we go.

[Bob Ross]

I wish I'd taken better notes when Carl Strong was designing my custom road bike back in 2010. The subject of level versus sloping came up, and I said "all things being equal I would prefer a level toptube purely for aesthetic reasons, but I'm willing to be convinced if there are actual benefits to a sloping toptube."

And then Carl proceeded to give me a 5 minute explanation of all the benefits of a sloping toptube for my particular application

...none of which I remember!

The fact that it's an S&S coupled frame may have had a lot to do with it; sloping toptube certainly makes fitting the frame in the case easier. But I'm pretty sure Carl mentioned some actual performance or functionality advantage (and it wasn't standover height, which is a non-issue for 6' me).

[dekindy]

Why, after all these years, does this myth that sloped top tubes were developed to reduce the number of stock sizes, continue to persist? Really! Will this never die?

OP, yes it is your imagination.

[roydyates]

2° is the new level.

dave

So the OP is seeing fewer sloping TT's because he is seeing more 2° slopes that he perceives to be level?

[Black Dog]

There is no evidence, actual facts that is, that a sloping top tube does anything other than offer a different look and some savings on frame materials in terms of cost to the maker and less mass (good for marketing) but even that is a red herring because a longer seat post is heavier than a shorter one in a traditional frame. People used to argue that there was a lower centre of gravity and that made swinging the frame back and forth while out of the saddle easier, again nonsense since the longer seat post is heavier. Other arguments were about a stiffer frame do to shorter tubes and so on the nonsense went...

Really, if you like it great, if you don't that is fine too.

[spaced_ghost]

i've always been a classic, steel, level top tube and lugs kind of guy. for years. and suddenly in the last six months I want TIG, fat tubes, and steep sloping TT. have no idea why. a change, I guess.

[Len J]

There is no evidence, actual facts that is, that a sloping top tube does anything other than offer a different look and some savings on frame materials in terms of cost to the maker and less mass (good for marketing) but even that is a red herring because a longer seat post is heavier than a shorter one in a traditional frame. People used to argue that there was a lower centre of gravity and that made swinging the frame back and forth while out of the saddle easier, again nonsense since the longer seat post is heavier. Other arguments were about a stiffer frame do to shorter tubes and so on the nonsense went...

Really, if you like it great, if you don't that is fine too.

After my broken back, my saddle to bar drop changed from 9+ to just over 5........a 2% slope allows me to have a slightly longer HT, have the drop I need and not need spacers. So, there are other reasons to slope. IME.

Len


Sent from my iPad using Tapatalk HD

[palincss]

Secondly, there was also the idea that sloping top tubes would lead to fewer frame sizes to stock. Don’t think that worked out as well as they wanted.


And totally meaningless for a made-to-order custom anyway.

[b_drum]

From a strictly aesthetic perspective, I will almost always side with level tts, but damn do I love to look at Rob English's stuff.

[93legendti]

From a strictly aesthetic perspective, I will almost always side with level tts, but damn do I love to look at Rob English's stuff.

http://www.englishcycles.com/custombikes/rays-v3-eps/

I believe he is the same Rob English who designs for Bike Friday...

[Chance]

Why, after all these years, does this myth that sloped top tubes were developed to reduce the number of stock sizes, continue to persist? Really! Will this never die?


And you don’t?

Next you’ll tell us man didn’t actually land on the Moon.:rolleyes:

[CunegoFan]

Why, after all these years, does this myth that sloped top tubes were developed to reduce the number of stock sizes, continue to persist? Really! Will this never die?

OP, yes it is your imagination.

Whether it was the original motivation or not, it was the result. By pure coincidence it also saved mucho dinero all throughout manufacturing and retailing.

[dd74]

Whether it was the original motivation or not, it was the result. By pure coincidence it also saved mucho dinero all throughout manufacturing and retailing.
This is sort of where I stand; the money saving aspect. Far too many builders have told me that the sloping top tube otherwise has no advantage to a bicycle frame in stiffness, weight saved of or overall performance. As to why I perceive I've seen fewer sloping top tubes, I can't say. Things come and go in the fashion industry, why shouldn't it be the same in bicycle manufacturing?

[sante pollastri]

the body of evidence :hello:
http://mangiapolenta.it/wp-content/uploads/2010/09/Marco-Pantani2.jpg

[cat6]

The story takes place on the planet Grool, a planet inhabited by mostly short, anthropomorphous felines. The idyllic and mundane lifestyle of the feline aliens is interrupted when an alien invader known as Kat of Nine Tails kidnaps Grool's sentient populace, inadvertently leaving one of them, Squeak, behind. Shortly after, Squeak encounters a human boy known only as Bubble who agrees to rescue Squeak's captured populace.

[dd74]

I'm almost a foot shorter than you. I'm also no engineer, so I can only go by what I am told. I do know that my Serotta CDA (with a 5-degree slope) feels stiffer than all my other frames with horizontal TTs, including a Serotta-built Ti frame. Funny thing is the Serotta is even stiffer than the carbon Ridley I have. Sure, the Serotta is custom, but the parameters are not much different than the Ridley.

So the question is with a 51-53cm frame, would a sloping top tube even matter as far as stiffness goes (or even weight savings), only because there's not that much frame material there to begin with.

Meanwhile there's the larger question of the top tube in general, and if horizontal is now vogue.

[jpw]

The age of the sloper must have been informed by the rise of the mtb, non?

[alancw3]

i'm 6'4 and just about every builder i've chatted with has recommended a sloping tt. i guess we're talking to different builders. how tall are you?

i'm in the tom kellogg camp and agree with what he has to say about compact frames and climbing.

"Compact Frames


Compact frames are developing a sizable following in the cycling community. As a compact frame owner myself, I appreciate the nimble liveliness afforded by the design. Like all bicycles, the handling characteristics of compacts starts with the geometry so let's take a look.

In designing the our first compact prototype back in mid '98, we wanted to discover what if any the real world differences there would be between traditional and compact frame designs. Our first compact frame (still my favorite frame) was an exact replica of my then current titanium frame in materials and geometry save for the sloping top tube. I designed it with a severe (17 degree) slope to ensure that any differences would be as obvious as possible. We had assumed that the new frame would be somewhat stiffer and lighter. It was lighter (about 4 ounces) but it was not appreciatively stiffer. Although we were able to measure a slight increase in stiffness, it was too slight to feel. The big change came when I stood to accelerate or climb. As I stood up, the bike appeared to loose three pounds. The inertia of the bike as I rocked it back and fourth was reduced so much that I felt as though I was on a twelve-pound bike. Interestingly, when seated, a compact frame feels exactly like a traditional design. The compact design has no effect on handling beyond the increases responsiveness during climbing and accelerating."

http://www.spectrum-cycles.com/geometry.php

+1 this is my experience exactly. climbing is where a compact frame shines.

[victoryfactory]

2° is the new level.

dave

Is it because a builder can get the 2* with stock lugs?

I had my '03 Legend built with ~4* which got me the stand over
I needed. I really have never noticed any issues and am convinced
that the anti sloping tube people are just reacting to the look of it
and the concept that the big bike companies are doing it to fit
more people on fewer sizes. Both valid positions but please don't
confuse those reasons with any real world technical problems with
sloping tubes and please don't discount them for people like me who
have really short legs. The slope enabled me to get a proper HT height and standover.
Not everyone is 6' and 170 lbs with a 32" inseam.
A very big part of why cycling has become so big today is because more
"normals" can ride comfortably with the changes in geometry, improved
saddles and components.
Everone has always wanted to ride. But back in the day, you would get
a one type fits all road bike and you either could deal with the racing
position of the day or your bike would end up in the basement.
Look what happened when the MTB craze began. All of a sudden you
could get a bike with standover and a more upright position! no wonder
everyone went out and bought them. People love to ride. make them
comfortable, let them see up the road without neck pain, pedal without
foot issues and sit without a pain in the ass and they will.

VF, aka Old chimp legs

[soulspinner]

You see, the move to sloping top tubes was to increase lateral stiffness and vertical compliance, and now the move back is to increase lateral stiffness and vertical compliance...and around the marketing carousel we go.

Yep. Now we go to full length seatposts with toppers cause its more rigid. I just run a Thomson post which is plenty rigid.

[oldpotatoe]

Why, after all these years, does this myth that sloped top tubes were developed to reduce the number of stock sizes, continue to persist? Really! Will this never die?

OP, yes it is your imagination.

Giant was the first, and it was to reduce SKUs, painted as some sort of hogwash marketing pablum about fitting better and being lighter, stiffer, blah, blah. They went from about 10 sizes to S/M/L/XL.

VERY similar to the hype about threadless, easier to adjust, lighter, better, blah.

Y'all can think what ya want but I was in the trenches for both iterations and knew the 'philosophy' behind both.

[mcteague]

With custom builders, sloping the TT allows for a good bar height along with stand over clearance. Imagine the tube pivot point in the middle. When the front comes up, to accommodate the desired bar height, the rear drops and you have slope. It is a nice, practical solution to the disappearance of height adjustable stems.

My old Seven Axiom has a 5 degree slope. With my new order, I asked for 8 degree just to more closely match the angle of the stem. I actually prefer a flat TT on a lugged frame for that classic appearance. Once you move away from the skinny tubes and lugs I am more open to a non-traditional look.

Tim

[sante pollastri]

Giant was the first, and it was to reduce SKUs, painted as some sort of hogwash marketing pablum about fitting better and being lighter, stiffer, blah, blah. They went from about 10 sizes to S/M/L/XL.

VERY similar to the hype about threadless, easier to adjust, lighter, better, blah.

Y'all can think what ya want but I was in the trenches for both iterations and knew the 'philosophy' behind both.

the slope is not marketing,it's a geometry that avoids useless complications,it's genial;)
I don't think that mr Marco Pantani rode his sloping Bianchi for marlketing,he wanted that bike because he tested everything to climb better.

[fuzzalow]

I agree that the new modern standard when referring to a level TT is actually a very modest slope of 3 degrees or less. Maybe this has something to do with the new math.

I took delivery of a custom frame last year where I specified a level TT. It came built to a ~2 degree slope in the TT. Don't matter what I want, the builder builds 'em the way he sees best. :) And he was right. Very modern but not dopey sloped like a MTB or a Giant.

I have a much more difficult time with the look of enormo-tall head tubes on the modern bikes. Curvy downwards TT so there can still be lotsa post. Now that's racer sharp.

[oldpotatoe]

the slope is not marketing,it's a geometry that avoids useless complications,it's genial;)
I don't think that mr Marco Pantani rode his sloping Bianchi for marlketing,he wanted that bike because he tested everything to climb better.

The sloping top tube on Giants were not about marketing, but about saving money in production(like threadless) THEN painted as some sort of performance and fit 'advantage', by the marketeers. Like shoe companies making whole sizes only and then saying 'more people' fit these fewer sizes..Whih is true if that's all they offer..fewer people fit well, but more can be shoehorned into the single size, than before.

Pantani didn't ride/like that bike just cuz it has a sloping top tube. The guy was teeny, I doubt his standover would dictate anything else.

BTW-Giant 4 size gig happened before Pantani. 1995, vs 1998 for Pantani's wins.

[sante pollastri]

The sloping top tube on Giants were not about marketing, but about saving money in production(like threadless) THEN painted as some sort of performance and fit 'advantage', by the marketeers. Like shoe companies making whole sizes only and then saying 'more people' fit these fewer sizes..Whih is true if that's all they offer..fewer people fit well, but more can be shoehorned into the single size, than before.

Pantani didn't ride/like that bike just cuz it has a sloping top tube. The guy was teeny, I doubt his standover would dictate anything else.

BTW-Giant 4 size gig happened before Pantani. 1995, vs 1998 for Pantani's wins.

Pantani was a racer,first of all,and that was his Job.
He was able to change more than 20 frames per year only to look for his own perfect geometry.
Bikes are made for races,and races are made for teens,not for old & fat men.
keep in mind that a sloping geometry can be custom,not only xs,s,m,l and xl.
last but not the least,the aheadset-carbon stem-carbon fork combo save a lot of weight.

[Ahneida Ride]

for me the 2 deg slope works

I have clearance and can get the bars up to saddle height.

so I have a 65 in the back and a 67 up front.

https://www.dropbox.com/s/2o7pof3sbpja01z/DSC_0821.JPG

[Black Dog]

I have both types of bikes and have no preference one way or the other, but when I hear that slopping climbs better than traditional I have to call out BS. Perception and reality are not the same thing. Even if Tom Kellogg says there is a big difference this is simply and argument from authority and not evidence. No disrespect meant to Tom but everyone is subject to observational bias.

The notion of reduced inertia while swinging the bike laterally would be great if there were some actual data to show that the difference is there, and if so, that it is substantial. Tom says that the frame was only 4 ounces lighter and the over all bike weight and stiffness was not really different. The question that needs to be answered is this: How much less force is required to swing the bike and this will be a function of the centre of gravity. The longer seat post in a sloping bike will be a heavier per inch than the tubes. Some of the mass saved on the frame is taken back buy the longer and heavier seat post. What is the net difference? Has anyone measured this. Sorry if I sound like a curmudgeon but, until there is some empirical evidence that a sloping top tube makes a bike faster up hill I will call this one out. Claims require evidence.

[93legendti]

Tom Kellogg is a fan:

"...As a compact frame owner myself, I appreciate the nimble liveliness afforded by the design...

In designing the our first compact prototype back in mid '98, we wanted to discover what if any the real world differences there would be between traditional and compact frame designs. Our first compact frame (still my favorite frame) was an exact replica of my then current titanium frame in materials and geometry save for the sloping top tube. I designed it with a severe (17 degree) slope to ensure that any differences would be as obvious as possible. We had assumed that the new frame would be somewhat stiffer and lighter. It was lighter (about 4 ounces) but it was not appreciatively stiffer. Although we were able to measure a slight increase in stiffness, it was too slight to feel. The big change came when I stood to accelerate or climb. As I stood up, the bike appeared to loose three pounds. The inertia of the bike as I rocked it back and fourth was reduced so much that I felt as though I was on a twelve-pound bike. Interestingly, when seated, a compact frame feels exactly like a traditional design. The compact design has no effect on handling beyond the increases responsiveness during climbing and accelerating..."

http://www.spectrum-cycles.com/geometry.php

[Chance]

i have both types of bikes and have no preference one way or the other, but when i hear that slopping climbs better than traditional i have to call out bs. Perception and reality are not the same thing. Even if tom kellogg says there is a big difference this is simply and argument from authority and not evidence. No disrespect meant to tom but everyone is subject to observational bias.

The notion of reduced inertia while swinging the bike laterally would be great if there were some actual data to show that the difference is there, and if so, that it is substantial. Tom says that the frame was only 4 ounces lighter and the over all bike weight and stiffness was not really different. The question that needs to be answered is this: How much less force is required to swing the bike and this will be a function of the centre of gravity. The longer seat post in a sloping bike will be a heavier per inch than the tubes. Some of the mass saved on the frame is taken back buy the longer and heavier seat post. What is the net difference? Has anyone measured this. Sorry if i sound like a curmudgeon but, until there is some empirical evidence that a sloping top tube makes a bike faster up hill i will call this one out. Claims require evidence.

+1

[Chance]

Tom Kellogg is a fan:

"...As a compact frame owner myself, I appreciate the nimble liveliness afforded by the design...

In designing the our first compact prototype back in mid '98, we wanted to discover what if any the real world differences there would be between traditional and compact frame designs. Our first compact frame (still my favorite frame) was an exact replica of my then current titanium frame in materials and geometry save for the sloping top tube. I designed it with a severe (17 degree) slope to ensure that any differences would be as obvious as possible. We had assumed that the new frame would be somewhat stiffer and lighter. It was lighter (about 4 ounces) but it was not appreciatively stiffer. Although we were able to measure a slight increase in stiffness, it was too slight to feel. The big change came when I stood to accelerate or climb. As I stood up, the bike appeared to loose three pounds. The inertia of the bike as I rocked it back and fourth was reduced so much that I felt as though I was on a twelve-pound bike. Interestingly, when seated, a compact frame feels exactly like a traditional design. The compact design has no effect on handling beyond the increases responsiveness during climbing and accelerating..."

http://www.spectrum-cycles.com/geometry.php

With due respect to Mr. Kellogg, have read this opinion dozens of times over the years and every time it raises the same issues for me.

If the bikes were built otherwise identical and the weight savings was only 4 ounces, how big a difference is that really? How can 4 ounces make a bike swing side-to-side like if it weighed a few pounds less? If that were the case, wouldn’t you feel the same advantage when you used a smaller water bottle instead of a larger one? Or when a bottle is half empty? We are only talking about 4 ounces after all. Don’t know about the rest of you guys, but when one of my bottles is empty my bike doesn’t suddenly feel all that different than when it’s full. Not as far as feeling so much lighter as it swings side to side.

And if the issue is that the 4-ounce weight savings lowers the center of gravity and reduces moment of inertia about pavement, wouldn’t a 4 ounce reduction (that’s just over 100 grams) in saddle weight make an even larger difference? Or removing a heavy tube from a saddle bag? Have tried both and it doesn’t make my bike feel all that different either.

Any of us can test this theory for ourselves by removing 4 ounces from the saddle area and see if it really makes that much difference. It’s easy enough to decide for ourselves.

Obviously since it’s so subjective, he (or others on his behalf) can claim that Mr. Kellogg has unusual abilities to discern such minute differences. Or you can call it mostly BS. Either way it’s highly doubtful it will help the rest of us mere mortals that ride real bikes and don’t worry too much about whether we have a full bottle or whether we are hauling around an extra tube in our saddle bag.

[wallymann]

...If the bikes were built otherwise identical and the weight savings was only 4 ounces, how big a difference is that really? How can 4 ounces make a bike swing side-to-side like if it weighed a few pounds less?

moment-of-inertia. look it up. the lower weight is secondary to the fact that a meaningful proportion of the frame's mass was closer to the ground when going to a sloped geometry.

its like when a figure-skater pulls their arms in and the spin speeds up even though no new energy is introduced into the spin. same principle here, the axis of rotation is the line along the ground twixt the tire contact-patches. the tubes were moved significantly closer to the ground/axis, thus a meaningful reduction in the MOI even if the bikes had the same mass. that the sloped bike was 4oz lighter the effect is even greater.

take a 10lb length of re-bar, which would be a few feet long thus a large MOI, very difficult to twist back and forth in your wrist. now take a 10lb plate at the gym, and maybe 8" across and a low MOI in comparison, and its very easy to twist back and forth in your wrist. distribution of mass relative to the axis of rotation is whats at play.

[CunegoFan]

moment-of-inertia. look it up. the lower weight is secondary to the fact that a meaningful proportion of the frame's mass was closer to the ground when going to a sloped geometry.

its like when a figure-skater pulls their arms in and the spin speeds up even though no new energy is introduced into the spin. same principle here, the axis of rotation is the line along the ground twixt the tire contact-patches. the tubes were moved significantly closer to the ground/axis, thus a meaningful reduction in the MOI even if the bikes had the same mass. that the sloped bike was 4oz lighter the effect is even greater.

take a 10lb length of re-bar, which would be a few feet long thus a large MOI, very difficult to twist back and forth in your wrist. now take a 10lb plate at the gym, and maybe 8" across and a low MOI in comparison, and its very easy to twist back and forth in your wrist. distribution of mass relative to the axis of rotation is whats at play.

Bull. We're talking about a very small portion of the overall bike weight being moved a few inches down. As Chance points out, putting a 100 gram tube in a saddle bag would have equal or greater effect. No one talks about how much livelier their bikes feel after they use their spare tube. Two large, full water bottles weigh about three pounds. That is real weight, not vaguely perceived, mostly imaginary weight. I don't know about you, but my bike does not get "livelier" on climbs after I run out of water.

When I read that "bike felt three pounds lighter" line in Kellogg text, I thought I had stumbled into a Bicycling magazine bike review. I was expecting "allowed me to ride one gear higher" to soon appear.

[Kirk007]

My two Kirks have identical angles, effective top tube lengths, forks, bb height etc. My contact points are the same. My sloping travel bike differs in 5 respects: it has couplers, it has about a 7 degree slope rather than a 1 degree slope, the chainstays seem to be a few mils shorter and I may have 2 mm additional width at where they are crimped near the chain stay brace, (but my measurements are not precise), filet brazed rather than lugged, built for short reach rather than mid reach brakes. They are meant to fit exactly the same. I've never weighed them to see if there's a difference.

I know exactly what Tom Kellogg is describing. Is it actual, measurable I don't know, but perceptions, upon which most of our enjoyment of things is based, matter.

[Ken Robb]

Would a sloper allow a rider to swing the bike farther to the side when climbing standing up? Are any riders bumping the inside of their thighs with the top tube of any bike?

[Black Dog]

My two Kirks have identical angles, effective top tube lengths, forks, bb height etc. My contact points are the same. My sloping travel bike differs in 5 respects: it has couplers, it has about a 7 degree slope rather than a 1 degree slope, the chainstays seem to be a few mils shorter and I may have 2 mm additional width at where they are crimped near the chain stay brace, (but my measurements are not precise), filet brazed rather than lugged, built for short reach rather than mid reach brakes. They are meant to fit exactly the same. I've never weighed them to see if there's a difference.

I know exactly what Tom Kellogg is describing. Is it actual, measurable I don't know, but perceptions, upon which most of our enjoyment of things is based, matter.

Perceptions only matter when they align with reality. You may think that you feel a difference because you expect there to be a difference but it may not be there. Our perceptions are a very poor measure of most things. This is why we have instruments and science to help us tease out the difference between perception and reality. No offence ment here, seriously.

[Chance]

moment-of-inertia. look it up. the lower weight is secondary to the fact that a meaningful proportion of the frame's mass was closer to the ground when going to a sloped geometry.

its like when a figure-skater pulls their arms in and the spin speeds up even though no new energy is introduced into the spin. same principle here, the axis of rotation is the line along the ground twixt the tire contact-patches. the tubes were moved significantly closer to the ground/axis, thus a meaningful reduction in the MOI even if the bikes had the same mass. that the sloped bike was 4oz lighter the effect is even greater.

take a 10lb length of re-bar, which would be a few feet long thus a large MOI, very difficult to twist back and forth in your wrist. now take a 10lb plate at the gym, and maybe 8" across and a low MOI in comparison, and its very easy to twist back and forth in your wrist. distribution of mass relative to the axis of rotation is whats at play.

Wallymann, thanks, but don't need to look it up. Really. Know enough to get by already.

On a side note that has absolutely nothing to do with cycling, but does with the physics in question: When a skater pulls their arms and legs in, and they spin faster, does the amount of energy in the spin remain the same?

Think hard before replying.;)

[NHAero]

Exactly. Dave Anderson designed several approaches for the custom he built for me, and we agreed that an 8 degree slope would give the best combo of standover height and putting the bars level with the saddle. I like the look of a level TT better, but I like how my new bike fits my aging body.

With custom builders, sloping the TT allows for a good bar height along with stand over clearance. Imagine the tube pivot point in the middle. When the front comes up, to accommodate the desired bar height, the rear drops and you have slope. It is a nice, practical solution to the disappearance of height adjustable stems.

My old Seven Axiom has a 5 degree slope. With my new order, I asked for 8 degree just to more closely match the angle of the stem. I actually prefer a flat TT on a lugged frame for that classic appearance. Once you move away from the skinny tubes and lugs I am more open to a non-traditional look.

Tim

[fuzzalow]

All the rationalizations and justifications on sloping TTs cover any angle from junk science to jaber wocky. All the perceived performance benefits are just as easily canceled out by any number of countervailing inefficiencies across either man or machine, or both.

Heart, legs and lungs. Level TT or sloping TT, don't mean a thing if it ain't got that swing. I go by what looks good.

[Kirk007]

Perceptions only matter when they align with reality. You may think that you feel a difference because you expect there to be a difference but it may not be there. Our perceptions are a very poor measure of most things. This is why we have instruments and science to help us tease out the difference between perception and reality. No offence ment here, seriously.

Really? I think very differently, but I am not so concerned with measurement and quantification. I am a trained biologist but left this concept that only things that can be measured are real long ago. Perception is reality; its the only reality that really matters to an individual. The placebo effect is well documented. And there's much in this world that we don't know and have been unable to quantify.

At the end of the day, who the F cares if there's a performance difference that can be measured and quantified other than perhaps a pro who wants to ensure that the bikes not slower. My sloped Kirk is sloped to get into a case. It also has a snappier feel to it ATMO. That's my story; my perception and I'm sticking to it. :) And I'm not a traditionalist; I like 'em both.

[weiwentg]

Sloping TTs in a limited size run was certainly a fad for a long time. I hope the fad is dying down. Underlying all that is that sloping TTs can be an element of fit, and I hope that does not die out.

[oldpotatoe]

Pantani was a racer,first of all,and that was his Job.
He was able to change more than 20 frames per year only to look for his own perfect geometry.
Bikes are made for races,and races are made for teens,not for old & fat men.
keep in mind that a sloping geometry can be custom,not only xs,s,m,l and xl.
last but not the least,the aheadset-carbon stem-carbon fork combo save a lot of weight.

Not sure of your point(s). His 'perfect' geometry happened to have a sloping top tube. I doubt he looked for one.

Bikes, via sponsorship, are made for selling. 'Win on Sunday, sell on Monday', or else bike makers wouldn't sponsor racers.

When sloping geometry FIRST came out, by Giant, it was in only 4 sizes, to save money.

When threadless First came out, early 90s, it was to save money and carbon steerers didn't exist.

Last point, I weighed a carbon stem the other day, I think from Time, and it weighed more than a Ritchey WCS aluminum stem.

Last, last point. I think sloping top tubes, unless made for a fit issue(bigger headtube, standover issues) look stoopid. For a big guy, riding a big frame with 300mm of seatpost showing, looks like he's riding his little sisters bike.

I'm in the 'would rather be dead than look bad', camp.

[Chance]

Really? I think very differently, but I am not so concerned with measurement and quantification. I am a trained biologist but left this concept that only things that can be measured are real long ago. Perception is reality; its the only reality that really matters to an individual. The placebo effect is well documented. And there's much in this world that we don't know and have been unable to quantify.

At the end of the day, who the F cares if there's a performance difference that can be measured and quantified other than perhaps a pro who wants to ensure that the bikes not slower. My sloped Kirk is sloped to get into a case. It also has a snappier feel to it ATMO. That's my story; my perception and I'm sticking to it. :) And I'm not a traditionalist; I like 'em both.

To me a perception can be real or imagined. Reality is real whether it can be perceived or not. And it's a huge difference. A flawed perception can influence a person but may not others. Likewise a real difference may be perceived by some and not others.

If a guy “perceives” his wife as beautiful, but in reality she is as ugly as sin, can he expect others to see her as beautiful too? Guess he can expected it, but few will agree.

A kid goes to bed and senses a monster under the bed. It’s not real. But to her it feels real enough to increase her heart rate. When the parents go to bed with a thief hiding under the bed, they may not be aware but the danger is real nonetheless.

Real versus imagined perceptions (i.e. – assessment, opinion, view, and so on….) can work both ways which is why science is needed to get to the “truth” for some people. Others can be happy with imagined advantages as long as it seems true to them.

[Lionel]

I like 2deg or 0 deg for looks, my bikes below are all 2 deg except the Sachs who is at, well ....0. I had a Salsa with a big slope and I admit it felt snappy but so many other variables were in the mix that no conclusion could be drawn. As I ride large frames large sloping looks weird....

http://i1068.photobucket.com/albums/u459/Lionel_B/Crumpton/DSC_0130.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Sachs/Sachs1-1.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Strrong/Strongshamal.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Zank/DSC_0012.jpg

[mcteague]

I like 2deg or 0 deg for looks, my bikes below are all 2 deg except the Sachs who is at, well ....0. I had a Salsa with a big slope and I admit it felt snappy but so many other variables were in the mix that no conclusion could be drawn. As I ride large frames large sloping looks weird....

http://i1068.photobucket.com/albums/u459/Lionel_B/Crumpton/DSC_0130.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Sachs/Sachs1-1.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Strrong/Strongshamal.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Zank/DSC_0012.jpg

Looks like you have a large amount of drop. If you were to ride with 2-3cm drop I think you would either need lots of spacers, lose stand over clearance or need more slope. Lots of us "older" folks cannot tolerate 8+cm drop any more.

Tim

[Len J]

I like 2deg or 0 deg for looks, my bikes below are all 2 deg except the Sachs who is at, well ....0. I had a Salsa with a big slope and I admit it felt snappy but so many other variables were in the mix that no conclusion could be drawn. As I ride large frames large sloping looks weird....

http://i1068.photobucket.com/albums/u459/Lionel_B/Crumpton/DSC_0130.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Sachs/Sachs1-1.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Strrong/Strongshamal.jpg

http://i1068.photobucket.com/albums/u459/Lionel_B/Zank/DSC_0012.jpg

Nice stable Lionel.

Len

[Charles M]

Casting aside all the bull***** arguements...

Back to the original question, "are sloping top tubes becoming a thing of the past"



The answer is No.

In fact sloping top tubes are more common on more frames now than 5 years ago and 5 years ago it was more common than 10.

You may not note it, but a lot more frames have a moderate slope now.




Now lets get back to group "A" telling group "B" that they should have the same narrow minded position that physics doesnt exist because group "A" can't feel the indisputable math at work..., While group "B" tells people that Small improvement "X" makes a world of difference

[Lionel]

Looks like you have a large amount of drop. If you were to ride with 2-3cm drop I think you would either need lots of spacers, lose stand over clearance or need more slope. Lots of us "older" folks cannot tolerate 8+cm drop any more.

Tim
I have 10cm, for a 6'5" guy it's pretty normal.

[93legendti]

I've bought slopers from Carl Strong, Tom Kellogg, Serotta and Dave Kirk. Pretty esteemed company.
On my hardest group rides with the most hills, I ride a sloper. All that matters is I feel a difference.

[Lionel]

Nice stable Lionel.

Len
hey thanks!
just realized the Crumpton is 4deg :)

[sante pollastri]

Not sure of your point(s). His 'perfect' geometry happened to have a sloping top tube. I doubt he looked for one.

Bikes, via sponsorship, are made for selling. 'Win on Sunday, sell on Monday', or else bike makers wouldn't sponsor racers.

When sloping geometry FIRST came out, by Giant, it was in only 4 sizes, to save money.

When threadless First came out, early 90s, it was to save money and carbon steerers didn't exist.

Last point, I weighed a carbon stem the other day, I think from Time, and it weighed more than a Ritchey WCS aluminum stem.

Last, last point. I think sloping top tubes, unless made for a fit issue(bigger headtube, standover issues) look stoopid. For a big guy, riding a big frame with 300mm of seatpost showing, looks like he's riding his little sisters bike.

I'm in the 'would rather be dead than look bad', camp.

1)you doubt,excuse but it doesn't matter,Pantani worked with the Bianchi reparto corse.
2)a bike that win and sell has got the positive feedback of both the racers and the norma cyclist,what else?
3)may be Giant did 4 sizes to save money,genial,if you also consider the advantages in riding a bike,without a lot of complicatinos.
4)now carbon forks exist,and it would be impossible to do a thread carbon fork...
last,there are a lot of carbon stems,not alu covered with a carbon lay...
apart for the weight,you have to consider that a stem/bar combo is able to absorb vibrations,alu not.

[Kirk007]

To me a perception can be real or imagined. Reality is real whether it can be perceived or not. And it's a huge difference. A flawed perception can influence a person but may not others. Likewise a real difference may be perceived by some and not others.

If a guy “perceives” his wife as beautiful, but in reality she is as ugly as sin, can he expect others to see her as beautiful too? Guess he can expected it, but few will agree.

A kid goes to bed and senses a monster under the bed. It’s not real. But to her it feels real enough to increase her heart rate. When the parents go to bed with a thief hiding under the bed, they may not be aware but the danger is real nonetheless.

Real versus imagined perceptions (i.e. – assessment, opinion, view, and so on….) can work both ways which is why science is needed to get to the “truth” for some people. Others can be happy with imagined advantages as long as it seems true to them.

I think we are in part saying the same thing: to the individual, their perception is their reality even if quantifiably wrong. Now if shown that the reality per measurement or actuality (nothing under the bed) is the case, then the individual would perhaps change their perception of the event/situation. If not then that's a whole different discussion.

My point of view is influenced by two things: in the workplace, how one is perceived can be huge: walk down the hall with a swagger, exude confidence, and that image one promotes may cause some in the workplace to overestimate the value or quality of that person's contribution, at least until they are presented with evidence (perhaps mediocre work product) that changes their perception. I've observed this for years. The second influence are scientists who insist that every phenomena in the natural world is either quantifiable and explainable by science as we currently know it or it does not "exist." There is a current view gaining favor in the environmental realm along these lines; that we should only protect resources with a measurable economic value to humans; it is currently a darling view of some "cognescenti." I find this position to be hugely arrogant and myopic. It is built on inflated egos and repeats the mistakes of the past. Charles if you are calling folks who perceive a difference even though not quantifiable as the narrow minded ones, I think it is quite the opposite.

What we know changes all the time. What could not be explained 100 years ago can now be quantified. We once thought the world was flat. We used to deny that illness could be caused by poor hygiene, bad water etc. because we didn't know any better. Perhaps what is perceived by some riders is in fact happening and we simply don't know how to quantify it yet. Or maybe its just a figment of the imagination. But if it is indeed imaginary, well, again, there's plenty of studies showing performance gains based on incorrect perceptions (placebo).

Does it matter, as long as no one is harmed and folks are happy? If folks hate the aesthetic of slopers or level top tubes or beer can pipes or tubulars or whatever, fine with me, you are entitled. Just don't be so judgmental and self righteous (and I am not calling anyone out here or suggesting that is occurring in this thread; not in the least) to tell me that I have sh*tty taste because my preferences/perceptions differ; I really don't care what anyone else thinks about my preferences, but I won't hesitate to tell said person to bugger off and mind their own idiosyncrasties simply out of my utter disdain for busy body know it alls.

[dave thompson]

^^All of the above.^^