Theory of Bike Fitting: Tall Riders Walk Their Own Path

Theory of Bike Fitting: Tall Riders Walk Their Own Path

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How does a cyclist lower their center of mass? Well, you can be shorter, that works pretty well. Or cut yourself off at the knees, but that has other side effects that I don’t want to get into right now. You could also lower the bottom bracket like Look and Eddy Merckx used to do (I think they raised their BB to the standard height recently).

Buth the real solution is that in most cases – at least in the cycling world, taller means lankier and that means that proportionally, the distances and angles between legs, arms, handlebars, saddles, and pedals start being very different – and should be much more extreme – than the scaled-up picture model of the 5’10” rider on a 56.

I have found over the last 23 years of riding that when I lower my bars, two things happen. First, I have better control over my machine. Second, I go faster. After having my bars as low as they would go on my R3 and consistently feeling they were a bit too high, I bought a 17 degree stem for my R3 which lowered my bars by 2cm- more than I thought I wanted. The results were astounding. Not only does my bike handle better, but I ride about 1-2kmph faster on flats and on climbs. The speed factor can be attributed to freakish bio-mechanics (that may be unique to my physiology) and/or increased aerodynamics, but the bike handling is, I believe, directly related to my lowered center of mass. In fact, John – who is also an Eros Poli-sized rider such as myself – noticed how good a low, aggressive position feels after borrowing one of my bikes during a visit to Seattle.

The bottom line is that you have to be comfortable on a bike, and that means different things to different people based on their size, flexibility, and style of riding. That said, I urge tall riders to experiment with riding the smallest frame you can while still getting enough saddle height and top tube length needed to ride efficiently – and then ride your bars as low as you can. If you need an example from the pros, take a look at Axel Merckx’s position (at the top of this post, as well as compared to Floyd Landis above), or keep in mind that Greg Rast on team Astana had Trek build him a frame with the dimensions of a 61cm frame with the head tube height of a 56cm frame – and slams his handlebar stem right down on his top tube.

It’s all about your center of mass, baby.

// Racing // Technology

  1. Pic of the bike and me back in the day.

  2. I linked to this before but feel it’s better here in all it’s visible glory.

  3. I’ll throw this one in too.

  4. Taylor Phinney’s saddle to bar drop looks pretty small to me when compared to that of Gesink, JVS and Trebon.

  5. @VeloVita
    Its working for him.

  6. @RedRanger
    Agreed certainly. I was joint pointing out that while he is a tall rider, Taylor’s position may not be the best example of what Frank was getting at with this article judging from the above photo when compared to the others.

  7. @mouse

    Pic of the bike and me back in the day.

    AWESOME! Avocet 30 on there too, from the looks of it. The hairnet is perfect as well, and I looks like a ctriterium handlebar. Love the look. Top marks.

  8. @michael
    Phinney, to my eye, looks very compact – fit very traditionally from my perspective. Obviously he’s going plenty fast so who’s to say anything about it but if I was fitting him I’d have him on a smaller frame with more extension and drop. He’d be UNSTOPPABLE.

    I’d say from the shots above, JVS is the closest to what I’m talking about.

  9. @frank

    Phinney goes well, but he has been crashing a lot. I guess like father, like son.

  10. Phinney looks like he has short arms too.

  11. Phinney is on the rivet, so he looks all foreshortened. I wouldn’t be taking any positional advice from that photo.

  12. @michael

    @frank
    Phinney goes well, but he has been crashing a lot. I guess like father, like son.

    To quote myself…

    The point of that comment was that Phinney may need to drop his bars to crash less.

  13. Ever get the feeling you’re talking to yourelf in public?

  14. I tend to disagree about the lowered-center-of-mass theory that you say would improve control. I am pretty convinced that it is more about the distribution of weight between the two wheels (which is something completely different). The moment you lower your bar you will put more weight on your front wheel. When I look at your bikes I get the impression that your seat is located almost over the rear wheel’s axle. So putting more weight on the front wheel by lowering the handlebar will of course improve bike stability and control. That’s my theory. …
    I prefer a large setback myself. Therefore my custom built frame comes with 72.5 ° seat tube angle, 41.5 cm chain stays and a rather short BB-to-front wheel distance in combination with a 135 mm stem and a slightly raised BB. Thereby I achieved a perfect biomechanical position and perfect weight distribution allowing perfect control although my center of mass is somewhat elevated (due to the raised BB).

  15. @grumbledook

    I tend to disagree about the lowered-center-of-mass theory that you say would improve control. I am pretty convinced that it is more about the distribution of weight between the two wheels (which is something completely different). The moment you lower your bar you will put more weight on your front wheel. When I look at your bikes I get the impression that your seat is located almost over the rear wheel’s axle. So putting more weight on the front wheel by lowering the handlebar will of course improve bike stability and control. That’s my theory. …
    I prefer a large setback myself. Therefore my custom built frame comes with 72.5 ° seat tube angle, 41.5 cm chain stays and a rather short BB-to-front wheel distance in combination with a 135 mm stem and a slightly raised BB. Thereby I achieved a perfect biomechanical position and perfect weight distribution allowing perfect control although my center of mass is somewhat elevated (due to the raised BB).

    Really interesting theory; I’d love to see a side-on shot of your bike. Weight distribution definitely has a good deal to do with it, and one thing I did notice when I lifted the bars by 5mm was cornering improved as before the front wheel was perhaps a bit over-weighted. With all these things, there is a balance between opposing factors and you’ve got to work them out.

    But the overall center of mass still plays a critical role and the physics is pretty clear that a lower center of mass = more stable. But to your point, a low center of poorly distributed mass is also crap. This lower center of mass is very apparent when I ride the TSX; the BB is probably 2cm or more lower than the Cervelo; aside from that, the position is almost identical. The TSX falls short in every category of cycling – less comfortable, softer, heavier, etc – but it’s handling is noticeably better. It just sits on the road like a chicken on an egg. (The geometries are also slightly different, but the same effect is noticed on the TSX vs. the Bianchi XLEV2 which have the same geometries except the XLEV2 has a higher BB – i.e the seat/head tube angles are the same.)

  16. OK. I see your point. … And when talking about superior handling, we need to keep in mind each one of us may have different preferences. E.g., I prefer a quickly reacting bike with an almost “nervous” geometry. Therefore, I like it when the BB is higher than the “classic” 7.5 cm drop. But at the same time I like to be in control under each condition, which is achieved in the case of my bike by weight distribution (i.e. long chain stays and short fw-to-BB distance) in combination with a rather long stem. I posted a pic of my road bike already. But you may have another look here.

  17. I think weight distribution vs. center of gravity is essentially a tomato/tomato potato/potato situation. Don’t ask me how that works in type.

  18. More fodder. Trebon’s new bike, presumably fitted to him already.

  19. @michael
    I’m in the market for a ‘cross bike and that Felt is giving me serious, SERIOUS carbone. Seeing it in my side, albeit with less saddle setback than I prefer, moves it from Carbone to Wantbone.

  20. @frank
    Especially considering the considerable thought I’ve given to SRAM on ‘cross, and my well-established love for Zipp.

    Do you think Trebon would mind if I “borrowed” it? Just for tonight? Just for a taste? He can even watch, if that helps close the deal.

  21. I bet if you find him in your town he would let you test ride it if you gave him you car keys, phone and wife. If you and he made it to Portland, I know a Kona pro rider who knows him who would vouch for you for the test ride.

  22. @frank
    You should look at a Ven Dessel for a cross bike. Those things are sexy!

  23. As you are talking about cx-bikes. Here is mine:

    I know, several rule violations here. But it is a great 8 kg ride.
    Looking forward to my first cx race of season 2011/2012 next Saturday!

  24. @frank
    Van Dessel – Fult Tilt Boogie CX bike

    you gonna get a bike with disk brakes?

  25. @grumbledook
    What a beauty!

    @RedRanger
    Not sure yet; the traditionalist in me screams “No!” at canti’s, but I know how much trouble they can cause…

  26. Not sure who is planning on riding this one, but check out the saddle-bar drop and stem length. Frank, maybe this should be your next bike if you’re looking for an ISP frame:

  27. Ok, that didn’t seem to work so I’ll just link to the photo

  28. @michael

    More fodder. Trebon’s new bike, presumably fitted to him already.

    Saw this bike in the flesh today, the saddle was pushed a good bit forward of what it is in the photo, but what’s a guy to do?

  29. @frank

    Ignore the cans of Australian piss water in my jersey which I had an inexplicable hankering for; but these pics here are about as close as I can find to side-shots of me on the R3. Try not to be too envious of how Awesome I am.

    Fosters?

  30. @minion
    Fuck me, I was looking for those pictures during the recent Fosters debacle. I knew they were here somewhere.

  31. Hehe, I have a feeling they’re going to be bumped a fair bit.
    It is worth noting that in the thread MArcus tried to point out that no-one in Aus drinks Fosters. All that tells me is that Marcus has been lying for a year.

  32. Okay, serious proper question about bike fitting.

    I was in a store last week and they offer a bike fit service, takes 2 or 3 hours and seems to involve all manner of measurements, lasers and video and what not, cost is £120, with follow up service after a week or two if needed.

    Is it worth thinking about ? Or do I just fanny about with my seat position etc and see how things go.

  33. If a seat position is your only problem and you are sure it’s the seat than I wouldn’t do the bike fitting.If you never did one and you are constantly unsure about your frame size,stem length etc. that could be possibly the best way you ever  spend 120 quid.

    If you need help with saddle height and/or for/aft position there are few good starting points.What’s the problem with your set up exactly?

  34. @Nate

    Nevermind Fosters,is that a fucking EPMS?

  35. @TommyTubolare Its compounding the crimes,  isn’t it. If you’ve got two giant cans of pisswater in your pocket you need an epms

  36. @minion

    Most definitely.

  37. @TommyTubolare

    If a seat position is your only problem and you are sure it’s the seat than I wouldn’t do the bike fitting.If you never did one and you are constantly unsure about your frame size,stem length etc. that could be possibly the best way you ever spend 120 quid.

    If you need help with saddle height and/or for/aft position there are few good starting points.What’s the problem with your set up exactly?

    Well tbh maybe I do not know if there IS a problem, but I think maybe we all just adapt to our position somehow, however all I can say is I shift around on the saddle a bit (for and aft) and after some time on a ride I get numb fingers. I do feel better when I move forward toward the seat nose a bit in terms of speed. It’s all a bit of a black art to me. Maybe I shall treat myself to an early crimbo present.

  38. @strathlubnaig  I did a bike fit with a local coach and bike fitter. Took almost two hours. Well worthwhile.  A mate swears by the Retul fit, but I think it’s pretty pricey.

  39. @TommyTubolare

    @Nate

    Nevermind Fosters,is that a fucking EPMS?

    It was a toe-strapped satchel briefly used while riding in a jersey a size too big before I could have smaller ones made.

    Talk about a photo that continues to haunt. Merckx bless the internet.

  40. @strathlubnaig

    @TommyTubolare

    If a seat position is your only problem and you are sure it’s the seat than I wouldn’t do the bike fitting.If you never did one and you are constantly unsure about your frame size,stem length etc. that could be possibly the best way you ever spend 120 quid.

    If you need help with saddle height and/or for/aft position there are few good starting points.What’s the problem with your set up exactly?

    Well tbh maybe I do not know if there IS a problem, but I think maybe we all just adapt to our position somehow, however all I can say is I shift around on the saddle a bit (for and aft) and after some time on a ride I get numb fingers. I do feel better when I move forward toward the seat nose a bit in terms of speed. It’s all a bit of a black art to me. Maybe I shall treat myself to an early crimbo present.

    Are you abnormally shaped at all? I think for “regular” people, they will get you close, if you are at all advanced or irregularly shaped, they may be lost and just apply all the usual rules of thumb to something that is not a thumb.

    If you have pain somewhere, definitely do it. I think that is what Tommy means by “what is wrong”. If you have no pains, then you can play around with for/aft on the saddle. It is normal to move about on the saddle, by the way, but your typical position should be on the most comfortable bit of the saddle to sit on. When you go hard, you’ll slide forward. When looking for quad power, slide back.

    Numb hands doesn’t sound good, though. Your bars may be too low.

  41. @frank We’ve had this debate before and you’re still wrong. The tendency when going hard is to slide forwards, but this is what really loads the quads, not moving back – the further back you sit (within reason) the more you recruit your glutes and hamstrings. Ideally you want to be smack in the centre to achieve a balance.

  42. @Oli

    What relation does that have to the KOPS fitting concept?

  43. KOPS is completely bogus, so nothing really.

  44. @Oli

    What do you recommend for setting saddle setback then?  I noticed I tended to be not on my sit-bones, so I have my saddle 6cm setback, at 80cm height.  I understand everyone is different and you can’t really fit over the internet, but am I doing something wrong?  This is the one part of my fit I always kinda wonder about, but I don’t have any discomfort.

  45. Reading the article it makes mention of Axel Merckx and Floyd Landis, but the picture is Thor?

  46. @frank

    Are you abnormally shaped at all?

    Are there any tips or ‘general rules’ you would recommend for someone with short legs, long arms & torso? I’m 181cm tall with a 78.5cm inseam and a particularly disproportionate 210cm wingspan.

  47. @DerHoggz Sorry, I don’t mind debunking myths with offhand calls but answering that is impossible online, I’m afraid – just off the top of my head, it could be to do with your seat height, the saddle itself, your handlebar height, your flexibility, your reach to the ‘bars, or some combination of the above.

  48. @Nate admiring how ‘awesome’ your Thoracic extension is. Tut tut for those long rides!

  49. @madcaddiekarlos If you are referring to the gentleman with cans of Fosters in the jersey pockets, that’s not me.

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