in the early summer of 2001 i purchased a 58cm Klein Quantum Race - a very sweet ride. this was the first time i had been on a bike since 1993 when i sold my Bianchi for book money in college (a sad day). i bought the Klein i was 28 and horribly out of shape lugging around more than a few extra pounds. a decade earlier i raced and had fun, but after an hour or so on the Klein, i was done - toes asleep, shoulders aching, and sometimes a sharp pain in the knees. i adjusted my cleats, saddle position, and saddle height and things seemed to be ok enough that i rode 3-4 times a week into early winter of 2002. i wasn't 100% comfortable, but i was able to put 1-1.5 hours in the saddle.

we ended up moving the following summer and the bike landed in the shed - a painful reminder of not being active. last season i rode it a few times, but i never got going again like that first season on the bike. i was not very comfortable on the bike and basically didn't enjoy riding. this season i have been trying to ride and find myself reliving the pains of last year. i'm sure there are several issues at play, the most obvious being overweight and out of shape.

the Klein is a 58cm and i find myself pushing my butt back over the saddle an inch or more when peddling - it seems to help my toes from falling asleep and my knees from hurting. it also helps stretch out my back.

the Klein has a 74 degree seat tube with a top tube that is 57.9cm long. based on my comfort level increasing when pushing back past the saddle, it seems i should have gone with a larger frame. the problem there is my 31" inseam - i had a hard time straddling the next size up - 61cm.

i'm looking for some suggestions - i have thought about changing the crankarms from 175's to 170's or even shorter - i'm thinking this would move my body forward on the saddle in the down stroke. i have thought about using a seat post extender, but i had used one in highschool when i out grew the 56 i was riding and it seemed very flexible and dangerous.

i fear that i might have to get a new frame/bike - i really like the feel of the Klein, i just wish the seat tube angle wasn't so steep so i could move my butt back an inch or 2.

-steve

There are some seat posts out there that have a fairly extreme setback. You should be able to find something that will help. I have the opposite problem. I like my seat almost TT forward, and have to use a zero setback post. I doubt shorter cranks will help.

It is amazing how much difference loosing a few pounds will make in overall comfort on the bike. That is my experience anyway.

Good luck.

Take a look at the fit info at www.coloradocyclist.com/bikefit. They have the basics pretty well covered. You should first measure your CYCLING inseam and convert to centimeters (inches times 2.54). I doubt your cycling inseam is only 31 inches (79cm) or you couldn't straddle a 58cm frame.

Rule of thumb for saddle fore/aft position: With the bike sitting level, a plumb line dropped from the front of the knee should hit the end of the crank arm (the Andy Pruitt method). There are several variations which will all produce similar, but not exactly the same results.

For saddle height, adjust the saddle so the foot is horizontal with the leg locked at the bottom of the stroke. Most people will find an ideal height within plus or minus 1cm from this point. At least it's somewhere to start.

Frame size has nothing to do with saddle fore/aft position. That's governed by the seat tube angle and the type of seatpost chosen. The saddle height will remain the same, regardless of the frame size you choose. As someone else pointed out, you can get a post like the FSA K-force light that has a huge 35mm setback. If you do move the saddle back, you'll probably need a shorter stem, or the reach to the bars will not be tolerable.

Another point is that a 58cm frame with a 74 degree STA is quite unusual. In this size 72.5 or 73 degrees is much more common.

i have been wrestling with getting the fit correct on this bike for over a year and it just hasn't happened. i had an offer to sell the bike and i did just that. i'm now in the market for a new ride - looking at Lemond and Cannondale aluminum frames - not sure i want a carbon frame - i need to walk before i can run ;)

C-40 - thanks for taking time to help - i didn't anticipate selling the bike when i posted this. i'll use the info when setting up my new bike.

-steve