DIY bike fitting

[lph]

(maybe not "bike maintenance" as such, but still "tinkering around with bike")

I was doodling around at home thinking how to dial in the fit on my road bike and wanted to measure the basic angles and lengths on my two quite different mtbs as well, to compare and see how much variation I can ride comfortably.

But you only connect with the bike at 3 points; hands, butt, feet. And if you use the knee-over-pedal-spindle and heel-on-pedal method to place your saddle, can't you assume that your saddle has the same relationship (height/setback) to your pedals, no matter bike? Assuming here too that the bikes are somewhat comparable, not completely upright bike vs. drops.

And if that is a given, you only have to look at the relationship between hands and feet. Since I have the same pedals and the same crank lengths on all 3, I used the crank center rather than the pedal as a stable starting point.

So I just measured the vertical distance between the crank center and the handlebars (actually I measured from the floor to both, then took the difference), measured the direct angular distance between the two and calculated the horisontal distance, the reach.

I have to doodle some more with the numbers I came up with (which won't be til next time I'm home with a cold, I suspect , but anyone have any comments on my reckoning? I'm hoping to come up with a kind of a comfortable range that suits me.

[alpinerabbit]

At the clinic I went to on sunday, they said the heel-on-pedal thing should make your leg almost straight on the road bike, and a little more bent on the mtb. Or the orther way round.

[lph]

Hm.

Oh, I forgot to say - I use the same mtb shoes on all 3 bikes too.

[velogirl]

Heel on pedal is a very outdated methodology. With a huge variety of pedals and shoes available these days (with different stack heights), it's not a particularly accurate method to use.

Because of varying fork and seat post rake/angles, the most accurate way to set up multiple bikes would be to match the angle at the knee and hip at the DBC and 9:00 positions. This would be done with a goniometer.

Lorri

[divingbiker]

Because of varying fork and seat post rake/angles, the most accurate way to set up multiple bikes would be to match the angle at the knee and hip at the DBC and 9:00 positions. This would be done with a goniometer.

My guess is that someone doing a DIY bike fit doesn't have a goniometer sitting around.

[SouthernBelle]

My guess is that someone doing a DIY bike fit doesn't have a goniometer sitting around.

Isn't yours in the drawer in the kitchen with the spatulas?

What the hell is a goniometer?