Observations on bike fit

[jmoore]

I shipped my main bike to AZ last week for the upcoming TMB BBQ Sufferfest v5.

This weekend I pulled down my Merckx Strada that was my main bike for years prior to getting the custom Bedford. I've riddent this bike multi-thousands of miles through all types of terrain. I did 25 miles on both Sat and Sun. Pretty much the regular route that I've ridden countless times.

About 1/2 way through the ride Sat I started getting a bit of pain in my lower back, near the pelvis. No amount of stretching or fidgeting around seemed to help. When I finished my upper back between my shoulder blades was tighter than usual. I did some concentrated stretching on Sat evening to try and alleviate.

Sunday morning I rolled out again and set off on the same route on the Strada. The bike setup was unchanged. This time I felt slightly better but still had the pelvis and upper back pains during the ride. I pulled out the fit sheet for the Bedford and compared them to the Strada. The Strada bar drop was about 1 cm lower and 1 cm more stretched out. That had to be it.

Since I got the Bedford I have not had these pains. Thinking back I likely had some of this pain on the Strada before but not to this extent. These minor changes have proven to me (yet again) the value of a good fitter and a good builder working in tandem. I thought I knew my fit numbers inside and out and was fully dialed in. Apparently not. It also tells me that I could likely do some more stretching and core work :)

[tigoat]

I used to have pain in various parts of the body when I do an endurance ride but being a tough dude I did not pay attention to it too much. About two years ago, for some reason I decided to try a wider bar, going from 40cm to 44cm and it made a huge difference. Little did I realize that a wider bar would make such a dramatic difference in comfort. FYI, I am only 5'7" and skinny.

[fogrider]

...can make a big difference....the older we get, very small changes can make a big difference. Sometimes it hurts, sometimes, its an improvement. I have five bikes that I ride, three regularly and the other two not so regularly. Good fit is always paramount. obviously, they are pretty much the same size, but there are many differences, some by design and a few things not so much yet they all work. I use a wider handlebar for my "climbing" bike because I like more room on the top of the bar for long climbs. and for stiffness and lightweight, I went with a frame that is slightly smaller and use a 13cm stem and longer seatpost.

[jtakeda]

I'm curious to pick your collective brains.

I'm young and while saddle height is the same on all my bikes, bar reach and drop are different among all of them. I know I will "hurt" my way into finding which one is ideal at some point in my life, but for now I can ride 50+ miles on any of my bikes and be fine.

When you bought your custom
-Did you have a set bar reach/drop on all your bikes?
-Had you had a fit before or did you work with the fitter to determine size?
-Were you well versed in how angles affected position and how seatpost setback affected position (beyond the basic KOPS)?

Just curious as one day I would like a custom and want to know what kind of information I should have 100% dialed in. Basically, I don't want to get some simple measurements done and geometry drawn up and end up selling my bike a year later because I don't like the fit.

Another side point:
The bike I pull out for most longer rides is set up a little funky making me think it's slightly too big for me. Its incredibly comfortable for me and I can do 100+ miles on it pain free. BUT my saddle is almost all the way forward on a non set back post and the steer tube has a little more stack than I would prefer.

I know I could size down and use a setback post and longer stem but than my stack would be SUPER big. These are the kind of things that lead me to asking these questions as I am no bike fit pro.

[TMB]

I shipped my main bike to AZ last week for the upcoming TMB BBQ Sufferfest v5.

This weekend I pulled down my Merckx Strada that was my main bike for years prior to getting the custom Bedford. I've riddent this bike multi-thousands of miles through all types of terrain. I did 25 miles on both Sat and Sun. Pretty much the regular route that I've ridden countless times.

About 1/2 way through the ride Sat I started getting a bit of pain in my lower back, near the pelvis. No amount of stretching or fidgeting around seemed to help. When I finished my upper back between my shoulder blades was tighter than usual. I did some concentrated stretching on Sat evening to try and alleviate.

Sunday morning I rolled out again and set off on the same route on the Strada. The bike setup was unchanged. This time I felt slightly better but still had the pelvis and upper back pains during the ride. I pulled out the fit sheet for the Bedford and compared them to the Strada. The Strada bar drop was about 1 cm lower and 1 cm more stretched out. That had to be it.

Since I got the Bedford I have not had these pains. Thinking back I likely had some of this pain on the Strada before but not to this extent. These minor changes have proven to me (yet again) the value of a good fitter and a good builder working in tandem. I thought I knew my fit numbers inside and out and was fully dialed in. Apparently not. It also tells me that I could likely do some more stretching and core work :)

Two things:

1). It will only be a sufferfest if zMud insists on making it so.

2) you have been training. That is against the rules.

[Peter P.]

I know I will "hurt" my way into finding which one is ideal at some point in my life...

It shouldn't be that difficult. Your body is capable of adapting just fine to a RANGE of fit dimensions.

When you bought your custom
-Did you have a set bar reach/drop on all your bikes?
-Had you had a fit before or did you work with the fitter to determine size?
-Were you well versed in how angles affected position and how seatpost setback affected position (beyond the basic KOPS)?


-When I bought my first custom many decades ago, I had no clue you could merely send body measurements to the builder and they would figure out the rest. Instead, I sent the frame measurements I wanted and surprise-the frame didn't fit well. What I learned from the experience was you should be REASONABLY comfortable on your existing bike before ordering a custom. That way you can compare any numbers a builder might suggest with what you know works/doesn't work.

-Yeah; I would say the reach/drop on all my bikes was pretty close. I'm always wary of having too MUCH drop and reach vs. too little.

-No. I read a few books on fit and pretty much knew instinctively when I my reach and drop, or fit in general, was good. I basically used ownership of stock frames to finalize what I thought was a good fit (after that first custom frame mistake). That helped me narrow down where I should go with regard to a custom frame. This was 30 years ago when there was little information available. Today, I think with all the fit systems, fitters, and books out there it should be a lot easier to determine what dimension range works.

-I used to get all wrapped up in seat angles and such and truly believed it was necessary to change seat angle with frame size but after decades of following this stuff I've concluded seat angle is less important than it seems. It's crank length that should be adjusted to fit femur length (That's my opinion and it's not meant to start a discussion here.) However, I've also concluded that seat angles were settled upon and frames designed around setback seatposts. Using zero setback seatposts (IMO) requires a change in seat angle. You could say I follow the Cervelo school of thought: Their bikes are 73 degree seat angles across the size range except for the RC5a I think, which used a 72 degree seat angle and zero setback post (to save the weight of the offset seatpost clamp). Lennard Zinn's writings convinced me of the unvariable seat angle/change the crank length concept.

Just curious as one day I would like a custom and want to know what kind of information I should have 100% dialed in. Basically, I don't want to get some simple measurements done and geometry drawn up and end up selling my bike a year later because I don't like the fit.


There's not a lot of mystery in frame fit as most of us could fit on a stock frame. You won't need to have your fit dialed 100%. A good builder can look at your body measurements, your favorite frame measurements, and will likely suggest something that if not perfect, you can fit into with adjusting seat fore/aft and a change of stem.

Another side point:
The bike I pull out for most longer rides is set up a little funky making me think it's slightly too big for me. Its incredibly comfortable for me and I can do 100+ miles on it pain free. BUT my saddle is almost all the way forward on a non set back post and the steer tube has a little more stack than I would prefer.

I know I could size down and use a setback post and longer stem but than my stack would be SUPER big. These are the kind of things that lead me to asking these questions as I am no bike fit pro.

When I read stuff like that I think either the rider has set themselves up improperly on the bike or they have injuries or other problems that prohibit them from riding a "normal" bike.

In your case the only way (and the best way) you're going to find out is to buy a bike one size down to address the stack issues. Going down ONE size can't make the stack change that drastic.

As far as your seat fore/aft, you should run you and your existing bike through a couple DIFFERENT fitters or use a couple different books out there to see if they agree that you NEED such a non-standard position.

[fuzzalow]

In response to the OP, I do not find that having to get used to, or be in shape to ride, different frame setups is in any way ideal. Whatever fit & position a rider has adapted to on the bike should be effortless. And that effortlessness is seamless between however many number of bikes owned by the rider. The transition is seamless because there is no change in the rider's own physical geometry from one bike to the next.

In almost all cases the fit numbers taken off of each bike will be slightly different. However, the crucial, unifying condition of each bike is that they accommodate the balance point of the rider's fit & position without any requirement of the rider to alter in any way his/her own rider geometry to fit into any bike. The bike's contact points are always brought to the rider. The rider never contorts to interface with a fit & position dictated by where contact points happen to be located on a bike. And any rider position that does not incur a relaxed, balanced position on a bike is by definition a contortion and an artificial contrivance of position.

In response to a question concerning custom bikes, that is a very big topic to explore. In general, I do not think it is correct to expect a builder to be knowledgable about rider fitting (they should be expert at frame fitting) and I do not think it is fair to expect a builder to cure the fit & position maladies of their clients. The builder must be able to construct a frame that will have a range of adjustability in its hard points (i.e. headtube height & location; seat tube height & location; seat tube angle/setback from the BB) that should not require extremes of stem or post to dial in a fit. That basic frame chassis is handed off to the client, or to the client's fitter, and the fit & position is dialed in from that point forwards.

A rider must know their own fit numbers. That is the one constant carried from bike to bike.

[dekindy]

I would interpret this to mean that you have not adjusted your old bike to the new position or is that not possible? I know that I was going to have to purchase a new fork for my Schwinn Paramount to raise the front end to an acceptable height. Decided to get a new bike.

[carpediemracing]

To the OP - as an above reply mentioned, did you update the Merckx to reflect the Bedford fit?

It brings to mind a short clip of Jeremy Powers prepping for a cross race. Someone filmed him in a parking lot. He was rolling up to his mechanic on one bike, he'd switch to the other bike doing a moving dismount-remount, pedal away, then return and mention this or that needs to be changed. He repeated the process over and over until the two bikes were identical (I assume). It seemed to be mainly lever/bar stuff since he had identical frames, stems, bars, etc.

I have two custom frames but I hadn't done that. However when I rode one bike to the pits and then jumped on the other bike I realized there were small differences between the two.

[carpediemracing]

When you bought your custom
-Did you have a set bar reach/drop on all your bikes?
-Had you had a fit before or did you work with the fitter to determine size?
-Were you well versed in how angles affected position and how seatpost setback affected position (beyond the basic KOPS)?

Just curious as one day I would like a custom and want to know what kind of information I should have 100% dialed in. Basically, I don't want to get some simple measurements done and geometry drawn up and end up selling my bike a year later because I don't like the fit.

Another side point:
The bike I pull out for most longer rides is set up a little funky making me think it's slightly too big for me. Its incredibly comfortable for me and I can do 100+ miles on it pain free. BUT my saddle is almost all the way forward on a non set back post and the steer tube has a little more stack than I would prefer.

I know I could size down and use a setback post and longer stem but than my stack would be SUPER big. These are the kind of things that lead me to asking these questions as I am no bike fit pro.

For me I've gotten my position pretty well dialed in over the years (decades). When I spec'ed out my frame I asked for frame dimensions, I did some rough measurements for reference, but I knew what I wanted.

As far as the various contact points go, I wanted the greatest range of adjustment with my "ideal" position in the middle of the range.

So, for my seat tube angle, I held a straight edge between the BB and the center of the saddle rails and measured the resulting angle with a compass. I have short quads - the angle ended up 76 degrees. The builder said to go with a 75.5 so I did. Of course my saddle is slightly forward of centered but it's not like before, where I'd just slide the saddle all the way forward and hope it was forward enough.

For my top tube I figured on a 12 cm stem with a regular reach bar. This puts a good amount of weight on the front wheel, leading to a very stable bike in corners. This makes the bike feel really stable when I'm in the middle of a packed field. With a compact handlebar I need a 14-15 cm stem to get the same weight over the front wheel.

I used the front end off my Cannondale (73 deg, 43mm rake) because it worked for me.

I started with a normal 40.5 cm stay but reduced it to "as little as possible" (39 cm) after the first frame. I had too much weight over the front wheel and the rear would chatter in aggressive turns, even if I wasn't pedaling.

The only fit dimension which is not centered is the head tube height. After some discussion I realized that I'd simply need "the shortest head tube possible". My goal was to be able to use an 80 or 90 degree stem, giving me the widest range of adjustment (73-90 degrees). However this would require a 3 cm head tube, give or take, so that was out of the question.

For your long distance bike I whould map your contact points, using a decent margin for any future adjustments. Saddle position, bar position, relative to BB. I imagine that you'll find that you can map out tubing that works much more efficiently, without maxing out various adjustment ranges (like saddle rails). Based on your short description the head tube would be longer, the seat tube more vertical. Not sure of the other stuff.

A final thought - people tend to fit riders with fits that mirror the fitter's fit. For example Lemond has long quads so his bikes had a pretty laid back seat tube. I don't know about now but back then I couldn't move the saddle forward enough so the frames were out of the question for me. I tend to ride forward (short quads, long torso) and I favor my back so those are my biases.

Disclaimer: I've fit riders but I'm nowhere near as qualified as some/many of the folks here.

[jmoore]

I would interpret this to mean that you have not adjusted your old bike to the new position or is that not possible?

To the OP - as an above reply mentioned, did you update the Merckx to reflect the Bedford fit?

The Merckx setup was not adjusted. I have not ridden it in nearly a year. I have been almost exclusively on the Bedford. I didn't even think about the reach measurements until about 1/2 way through the ride on Sat. And really didn't put all this together until after the ride on Sunday. I will align the fit between the Bedford and Merckx before I ride it again. But frankly, the Merckx is really too small, since it's a 61cm and it was my only option if I wanted to ride this weekend. I should probably sell it and get something else that fits better, but I really love it. And it's purdy :D


Two things:

1). It will only be a sufferfest if zMud insists on making it so.

2) you have been training. That is against the rules.

1. zMud loves to make people suffer

2. I'd hardly call what I've been doing training.

3. We will have fun regardless.

[jtakeda]

Thanks for the replies ( and sorry to jack the thread)

I have sized down and I end up with too much drop.

My conclusion was I need a bike that is slightly smaller but with a longer headtube to accommodate the 10-11cm bar drop. I have longer legs than torso so it makes my saddle height too high on specific frames.

Anyone want to confirm or deny my hypothesis?

EDIT:
Maybe I should give some numbers.

"Too big"=56cm sq. 100mm stem.

In my mind I need a 55-56cm ST with a 54-55cm TT.

Also a headtube that allows me to ride at about 7-9 cm of drop at 74cm saddle height.

[benb]

One observation.. working on core strength and flexibility seems to widen the "window" of acceptable fit. Maybe Not by many centimeters, but certainly by millimeters or even a centimeter or two.

It is easy to go down the trap of needing "compensation" via the bike or some aid since that is all buyable/consumable stuff but sometimes the answer is elsewhere.

[fuzzalow]

I have sized down and I end up with too much drop.

My conclusion was I need a bike that is slightly smaller but with a longer headtube to accommodate the 10-11cm bar drop. I have longer legs than torso so it makes my saddle height too high on specific frames.

Anyone want to confirm or deny my hypothesis?

EDIT:
Maybe I should give some numbers.

"Too big"=56cm sq. 100mm stem.

In my mind I need a 55-56cm ST with a 54-55cm TT.

Also a headtube that allows me to ride at about 7-9 cm of drop at 74cm saddle height.

I don't know where you had measured from-where-to-where for a drop of 10-11cm as mentioned above but you can't get that much drop with a 56 frame at a 740mm saddle height. You should try to localize on standard euro measurements such as given by Claude Genzling in Bernard Hinault's book "Cyclisme sur Route"

https://lh5.googleusercontent.com/-Zqu8EvmGqNM/UFs8Ldc4mqI/AAAAAAAAAH4/hgkZLCp348Q/s512/hinault-genzling.jpg

In answer to your question, if you know how much bar drop you must have, it becomes the long pole in the tent that drives your frame size requirement. As such, a 55cm will max out around 8cm drop so you will have to go smaller still to a 54 to see 9cm drop. These are guesses on my part but I long ago rode a 750mm saddle height and the most drop I could squeeze out of a 55 frame was 8cm. My old Della Santa had 8cm drop:

https://lh3.googleusercontent.com/-BCUL7jlaPeY/T2ORVnXFvzI/AAAAAAAAADg/hr02WLNDASo/s640/Della_Santa55STx56TT%2520008.jpg

I'd SWAG that you should look into riding a 54.

One observation.. working on core strength and flexibility seems to widen the "window" of acceptable fit. Maybe Not by many centimeters, but certainly by millimeters or even a centimeter or two.

Firstly, no criticism of benb in quoting and responding to his discussion point. We know we are all trying to contribute positively and help each other out.

I don't agree with this approach because any time the words "flexibility" and "core strength" are used, it says to me that the rider is stretching, straining and exerting to scratch out another precious few millimeters of bar drop. I ask everyone here to please not do this. That very method is painful, laborious and most importantly, injurious to long-term spinal column health. That added drop did not come free and is the result of additional curvature of the spine which means greater compression in the spinal discs to make the tighter curve. Please do not do it this way. Ride with a reasonably straight back. Done this way allows one to age gracefully to be the mythical old rider in the small Italian town still riding a drop bar bicycle in the style of Cancellara.

No one wants to destroy their back because they didn't know better when they were young, youth allowed riding in this way and back pain was a faraway consideration about how to ride.

[zmudshark]

The Merckx setup was not adjusted. I have not ridden it in nearly a year. I have been almost exclusively on the Bedford. I didn't even think about the reach measurements until about 1/2 way through the ride on Sat. And really didn't put all this together until after the ride on Sunday. I will align the fit between the Bedford and Merckx before I ride it again. But frankly, the Merckx is really too small, since it's a 61cm and it was my only option if I wanted to ride this weekend. I should probably sell it and get something else that fits better, but I really love it. And it's purdy :D




1. zMud loves to make people suffer

2. I'd hardly call what I've been doing training.

3. We will have fun regardless.

Hey, I'm a really nice guy, and have mellowed considerably.

I can't help with your fit, I hurt all over ;)

[benb]

Firstly, no criticism of benb in quoting and responding to his discussion point. We know we are all trying to contribute positively and help each other out.

I don't agree with this approach because any time the words "flexibility" and "core strength" are used, it says to me that the rider is stretching, straining and exerting to scratch out another precious few millimeters of bar drop. I ask everyone here to please not do this. That very method is painful, laborious and most importantly, injurious to long-term spinal column health. That added drop did not come free and is the result of additional curvature of the spine which means greater compression in the spinal discs to make the tighter curve. Please do not do it this way. Ride with a reasonably straight back. Done this way allows one to age gracefully to be the mythical old rider in the small Italian town still riding a drop bar bicycle in the style of Cancellara.

No one wants to destroy their back because they didn't know better when they were young, youth allowed riding in this way and back pain was a faraway consideration about how to ride.

You read way too much into what I said. Regardless of whether you want to ride straight backed, straight up like you're riding a hybrid, or contorted like Cancellara you should still be paying attention to flexibility and core strength.

What is worse, the old guy who can miraculously still ride a crazy position like Cancellara or the guy (probably not even that old) who just rides his bike all the time and is all out of wack on the bike and can't even do a pushup anymore cause he neglected everything but turning pedals? If you're that guy you can probably order custom frames till the cows come home you're still going to have pain.

I highly doubt someone like Cancellara has damaged his spine from riding that way.

[BobbyJones]

what I've found interesting on matching fit between two bikes is agonizing over making sure my contact points are identical (or as close to it as humanly possible in my realm) and some how they still feel different.

Solution: Ride as many different bikes as often as possible!

[jtakeda]

Without completely jacking the thread.

My fit question wasn't so much a complaint or issue as much as it was a question.

At this point, if I'm comfortable on everything I own with wildly different fits, which fit should I build a custom around?

[fuzzalow]

You read way too much into what I said. Regardless of whether you want to ride straight backed, straight up like you're riding a hybrid, or contorted like Cancellara you should still be paying attention to flexibility and core strength.

What is worse, the old guy who can miraculously still ride a crazy position like Cancellara or the guy (probably not even that old) who just rides his bike all the time and is all out of wack on the bike and can't even do a pushup anymore cause he neglected everything but turning pedals? If you're that guy you can probably order custom frames till the cows come home you're still going to have pain.

I highly doubt someone like Cancellara has damaged his spine from riding that way.

OK, I will concede that I misunderstood what you were talking about in your first post. I will also add that I am not sure what you are trying to get at in your response above ^. You also are incorrect in describing riding in the style of Cancellara as "contorted" and "crazy" - it is anything but that at all and is effortless and the position is not injurious to the spine.

Backtracking to your first post:

One observation.. working on core strength and flexibility seems to widen the "window" of acceptable fit. Maybe Not by many centimeters, but certainly by millimeters or even a centimeter or two.

Then exactly what are you trying to say here? Because I originally misinterpreted what you are referring to here as saddle to bar drop, just where are you tossing around all these measurements and saying it still makes a good fit? To my experience, slopdash never makes for a good fit.

what I've found interesting on matching fit between two bikes is agonizing over making sure my contact points are identical (or as close to it as humanly possible in my realm) and some how they still feel different.

Solution: Ride as many different bikes as often as possible!

HaHa! Very true. All kidding aside, in fixing you remark it would be correct as the reverse of what you posted:what I've found interesting on matching fit between two bikes is agonizing over making sure they feel the same (or as close to it as humanly possible in my realm) and some how my contact points are not exactly identical.

At this point, if I'm comfortable on everything I own with wildly different fits, which fit should I build a custom around?

Well if you say so. Then for you, any number can play.

Respectfully, your descriptions in this thread are contradictory and all over the map. What we have here is a failure to communicate; which I have tried to remedy in "speaking Genzling" as it were. It sounds like you want answers where you don't quite understand the question. Good luck.

[thwart]

what I've found interesting on matching fit between two bikes is agonizing over making sure my contact points are identical (or as close to it as humanly possible in my realm) and some how they still feel different.

Solution: Ride as many different bikes as often as possible!

True dat.

I've had chronic rotator cuff issues since '09. It's improved to the point where I can now comfortably ride a bike with a 5-7 cm drop… but not day in, day out. My big-mile bikes have a 2-3 cm drop.

Great argument for more than one bike. :banana: :banana: :banana:

[jtakeda]

I'll just get a fit and see what they say.

If the numbers seem wacky I'll come back:p

Sorry for the confusing posts.