pdxtex

im nearly at wits end. i picked up a bike on CL that was going to be a winter commuter but its just turning into a winter knee wrecker. i own three other bikes and thru trial and error got them all dialed in the way i like it. im going on week 8 and i still cant get the craigslist bike to feel right. ive narrowed it down to the saddle i was using as garbage, going back to a straight post and shortening the stem. the standover height is good but it is a cross bike from the early 2000s so perhaps there is a bit of geometry oversight im overlooking. if you were to try and set up bike A to be like bike B, what three key measurements would be the same? id say, seat distance to bottom bracket, overall length from top of seat to end of crank arm too. one thing i did not consider is actual bottom bracket width or spindle length. im tall so its entirely possible my legs are too close to the bb as it appears more narrow then my other bikes.....should i just sell the thing? ill make a profit from it but i likes it.

10 Wheels

Sell it..

lazerzxr

If you have the seat pedals and bar in the same position as bikes you are comfortable on then possibly look at the width otherwise known as Q factor of the cranks. this can be a significant change particularly if your other bikes are triple chainsets and the new one is a double for example. different saddles seat you differently so that could account for some of the problem. also check for play in BB bearings / pedal bearings.

pdxtex

thats got to be it. my other bikes are triples, this one is a double and its been my mcl thats been bugging me. ive never had an inner knee issue ever until last month so that must be it. my back, neck and wrists all feel great and the reach to the controls is fine. ive had some ok success with some speedlplay x's also so maybe those have longish spindles. also i bet i could set the cleats even wider to make up any difference in Q factor...thanks for the tip....

cyclezen

Q is a very variable thing, as relates to how some react to it. some people experience significant issues when the Q is off for what they have (me) and some can ride through it with no issues.
sometimes the crankarm shape will affect the overall width as much as spindle width - I would measure the actual width between your pedal centers on the bike which 'fits' and the one which has issues.
if the pedal have a tight 'float' then issues will be accentuated.
I would not screw with the cleat placement, if it currently works for you - because you'll end up having to screw with rotation as well as placement.
if the Q delta is substantial (over 5/6mm overall) consider getting pedal extenders for the 2 ring set to match your 'good' setup - they can be had for $20 to $40 and screw between the pedals and the crankarm.

saddles and setback - saddles do come in way diff. shapes and lengths - lengths on saddles will vary from 245 to over 300 - 275 being the middle of the bell curve. I prefer to measure 'saddle setback' from where I like my sitzbones, to the vertical of the BB. Once I get a 'new' saddle I determine where my sitzbones end up on the saddle and then measure from there to the saddle nose, that determines the 'setback' from the BB.
ie - I like my setback to be 30.5 cm, and if the sitzbones land on the saddle 23.5 cm from the nose then my saddle nose setback from the BB vertical is 7 cm.
For many a saddle shape may vary your placement by as much as 1 to 1.5cm differnce (or more or less) to the saddle nose...
worth checking...

pdxtex

^^the seat i was using definitely did not work out with this set up. its a good seat but i think i like a hammocky type set up like concors or romins. i can almost definitely say its a knee alignment issue as it tracks forward thru the pedalstroke.

rogerstg

I've found the Park Road Positioning Chart to be a helpful tool when setting up bikes to have similar geometries.