Bike set up / geometry and saddle fitting

edis

Do you find that most cycle shop staff dont seem to know what they are talking about when it comes to bike set up?

I have cycled for years mostly on bikes that probably didnt fit me that well, and i think the time is coming that i will have one made to fit me.

Can anyone explain the science of bike fitting, the more technical the better and the longer you have been riding the better.

Finaly many of you have probably seen the specialised saddle fitting system in some shops.
For those who havent i will explain. You basicaly sit on a neoprene pad with your thighs slightly rising, which is all about getting your sit bones to make an impression in the pad. then the distance between is measured and this is supposed to help in choosing a saddle, all makes sense to me. that is untill i found my sit bone width is greater than the width of all the saddles buy a fair bit. can anyone shed any light on this?

Ed

dennisn

edis wrote:

Do you find that most cycle shop staff dont seem to know what they are talking about when it comes to bike set up?

I have cycled for years mostly on bikes that probably didnt fit me that well, and i think the time is coming that i will have one made to fit me.

Can anyone explain the science of bike fitting, the more technical the better and the longer you have been riding the better.

Finaly many of you have probably seen the specialised saddle fitting system in some shops.
For those who havent i will explain. You basicaly sit on a neoprene pad with your thighs slightly rising, which is all about getting your sit bones to make an impression in the pad. then the distance between is measured and this is supposed to help in choosing a saddle, all makes sense to me. that is untill i found my sit bone width is greater than the width of all the saddles buy a fair bit. can anyone shed any light on this?

Ed

If you think the bike shops don't know how to fit you, why would you trust anyone to build a frame to "fit" you? Why would you think he knows any more about fitting a bike than the next guy? So what if he builds bikes, that only makes him someone who knows how to make a frame. Plenty of those people around. As far as fitting a bike goes I'm
really starting to think that no one knows how to do this. I would be willing to bet that
if you went to ten different fitters you would come out with ten different ideas as to frame size. There are people out there who claim to know all about bike fit and there are
computers out there that claim to give you that perfect fit(how a computer knows is beyond me). There are also many fitters on this web site forum who will also give you
perhaps another 100 or so top tube dim's., seat post angles, crank arm lengths, head tube lenghts, stem angles, handlebar widths, seatpost setback dim. and the list goes on and on. Just because something works for someone else doesn't mean it will work for
for you. If I were you I would go to a good bike shop(ask around), tell the shop what type of riding you intend to do(touring / racing), find the frame(for your type of riding) that catches your eye in you preference of materials(although I don't believe materials are anything critical). Have them order your correct size if they must(plenty of people out there on non custom frames and they love them and there are plenty to pick from). Spend as much as you have in the budget for the frame, wheels, and components. The shop you bought this thing from WILL be more than happy to make sure you're happy. I guess
what I'm trying to say is that this is a bicycle not a lounge chair or a feather bed and if
you are expecting great comfort, smooth as silk, etc. as all the ad's claim you are going to be disappointed.

Dennis Noward

meagain

Find a copy of "The Bicycle Racing Book" by William Sanders - bet his fitting guide is as good as most and better than many!

For the rest.....I'm with Dennis.

synchronicity

I'm almost 31 now and started cycling more seriously back when I was 15. I've ridden quite a few bikes now, in many sizes. Ive also been lucky enough to supply bikes for people ranging in height from 152cm to 203cm (5'1" - 6"8").

It's not an exact science because there is no one standard sized frame, body shape or "ideal position". Different frames having the same seat tube length will have different top tube lengths. Look around and you will see that some manufacturers are reknowned for this. I still haven't figured it out.

I'm probably in the minority here, but in my humble opinion, fitting services (including machines) aren't ideal either as they don't give you a feel of how it feels to actually ride that particular sized bike that they are suggesting for 5 or more hours.

For instance, a 140mm stem might be what you require on paper & it might even feel great on a stationary bike. Ride it, and you'll soon discover the extreme difference it makes to the handling compared with a 120mm stem.

I'm a big believer in finding proportional length cranks, stems, wheels, etc. Unfortunately, people are STRONGLY biased in favour of 700c wheels. For small riders, 650c is a better choice, if only because of the toe-overlapping-the-front-wheel issue. If someone doesn't agree, they're most likely taller than 5'6" (I am 5'11"). :roll:

On forums, I've noticed that some people tend to suggest a 110mm stem on a road bike, regardless of the size of the bike (somehow thinking it's the "magical stem length"). Again, they're being somehwat biased, based on their own size. 110mm is not what smaller and larger riders request in practice (and 90% of my clients know what they're doing already). I've seen people ask for everything from a 61cm frame with a 100mm stem, to a 53cm frame with a 120mm stem.

Even changing something as simple as your pedals can alter your whole position on the bike. Going from traditional Look pedals to vista pedals will lower your position on the bike by ~30mm. You'd even need to consider lowering your handlebars if the difference is that great.

Lastly, many cyclists forget about assymmetry. I have a leg length discrepancy, and so do a lot of people. Technically, you need to be measured and then fitted for each side of your body independantly. I have a hunch that a lot of "fitters" don't do this, don't have time, or forget.

For me, you can only obtain your unique "100% fit" by gaining your own experience - that only comes with time. Lastly, the position you decide upon will depend on the bike and the type of riding you expect to be doing. For example, my DH rig vastly differs from my road bike.