velodrome track race - kissena queens new york

Wednesday, June 04, 2008

Handlebars, stems, top tubes, and bike fit

Establishing the correct amount of reach and drop seems to be one of the more challenging aspect of proper bike fit.

For me, not enough reach means nether regions, hands, and fingers might go numb. Too much reach and the bike rides like a torture device for stretching out the back, neck, and shoulders.

I've not yet shelled out three hundred dollars for a professional bike fit, as much as I would like to do so. I have great respect and appreciation for some of the more in depth fit methods like wobble-naught, but for that same amount of money I can buy a lot of parts like stems and maybe a different saddle. Having parts on hand can be useful for experimenting, and I feel that bike fit can sometimes be a dynamic attribute.

Bike fit formulas seem at best an approximation of what works. After trying a number of the formulas I have always required small adjustments to make the fit work for me. I usually (always) carry an allen key when I ride and use it to make small adjustments. As a rule of thumb, adjustments are made in very small increments. The rule is as follows: adjust only 1/2 as much as seems necessary.

It would be easy to go on and on about the finer points of bike fit but there are many others with more knowledge and experience in this aspect of biomechanics than me.

Different handlebars have widely different dimensions. These dimensions are width, drop, and reach. For the most part width remains constant. A 38cm handlebar measures 38cm wide, and a 46cm handlebars measures 46cm wide even though some manufacturers measure from center to center and others measure from outside to outside. Still that's not the meat of the issue.

The meat of this post is that a bar with 4cm longer reach will make the bike feel 4cm longer in the cockpit and consequently should call for a shorter stem for the same feel while riding in the drops. A bar with 4cm more drop will require a few more spacers under the stem, or a different stem angle, etc, etc. This little calculator can help figure out stem length and angle. So if a bike feels like it almost fits, don't give up until trying a different set of handlebars.

Below is a table describing what has and hasn't fit me based on what I've been using. My bikes are
* 54cm Felt TK2. 53.5cm top tube
* 51cm Lemond. 53.2cm top tube
* 49cm Lemond. 51.5cm top virtual tube (too small for me)

Handlebar Drop Reach Sum(TT+Stem+Reach) Experience
DedaPista 173mm 109mm 734mm-752 Doesn't fit on Felt with 90mm stem or on 51cm Lemond with 110 stem. Too deep.
Nitto 123 170mm 108mm  
3T Zepp XL 170mm 100mm 752mm Feels a bit deep on lemond with 120mm -8 degree stem but is working ok for now.
Nitto 125 150mm 88mm 733mm Fits pefectly on Felt with 110mm -6 stem and some spacers.
Ritchey WCS Logic 144mm 82mm 734mm A bit too wide for me (42cm), but felt ok with 120mm -8 stem.
Ritchey Biomax II 130mm 75mm 733mm Love these bars! Was very comfortable on 49cm Lemond with 140mm -6 stem but geometry and handling felt off. The width is 39 on the hoods and 41 at the drops. But it doesn't have enough drop on 51cm Lemond.
[Highlighted rows had good fit.]

It seems obvious. In addition to measuring the top tube and stem length, the handlebar should also be factored in for proper fit. I should probably try a shorter stem with the Zepp XL handlebars.

Lemond Tete De Course Titanium BicycleThis leads me to offer one of my bike up for sale. It's a 49cm Lemond titanium bike. It's one hell of a ride, for a medium/small sized person. I'll accept any reasonable offer. :)


casual entropy said...

those Ritchey bars really are great - they are, i think, what locks in the fit on my road bike. and you're completely right on - handlebars are a very oft-overlooked aspect of bike fit. like how Felt stocks Deda Pista drops even on the 52cm TK2.

when I put the b125s on there yesterday, at the QBB while waiting for niki and andras, the first thing I felt when I got back on the bike was that finally it fit.

small movements in the arms lead to surprisingly big movements in the torso, and corresponding comfort in the muscles. I see a lot of people on the track riding a lot lower than maybe they'd be comfortable with, and I speculate that handling suffers, too, when people's arms are straight down and their weight is leaning on the front end.

40x14 said...

I'm glad you're liking the Ritchey Biomax handlebars Mattio, it was fun seeing you race the Felt yesterday at the Velodrome, that bike has such tight geometry!