Making a frame fit

Hey everyone.

I need help…
I’ve just finished my single speed project and the frame is slightly smaller than I’m used to. This shouldn’t be too much of a problem as long as I can replicate the body position I’m used to from my road bike. What is the easiest way to measure an existing position (saddle, handlebars, offsets etc)?
Something not too technical would be great.


  1. Distance of horizontal line from saddle to handlebar
  2. Distance from top of saddle to centre of BB
  3. Amount of drop or rise of handlebar relative to horizontal line from saddle

If these measurements are the same as your road bike, you should be OK unless you have to compromise something like a really short/long stem which will affect handling.


Thanks Des.
In regards to the top of saddle/centre BB measurement- is it better to take it from the pedal because my crank lengths are different?

Probably, although I usually just use the same measurement and adjust according to feel after a few rides. Bare in mind that using different saddles will affect your saddle height too.


Don’t forget your saddle setback

  • a bit tricky first time but drop a plumb line (a bit of string with a heavy washer or something tied to the end will do) to the centre of your bb and measure level back to the tip of your saddle. You might need to adjust fore & aft a bit for comfort if your saddle is different to the one on the bike you took the measurement from (and if the frame is a lot smaller you might need to consider a seatpost swap)

Watch One Sunday In Hell and see Eddie’s technique in using a ruler on his saddle.

Or you could do what I did and stand your bike next to your other one and match the saddle height. Not very scientific, but it worked !

I think that CraigC might have a suggestion for you :-D… Sorry, couldn’t resist

Ahh! Nuts, beat me to it…


Buy a new fuck’n BMX if ya wanna a Single Speed…silly Ho :wink:

Ha ha ha ha ha ha…

An astute observation has lead to laughter… We’re all laughing…

Now it’s dying down…

Bastards, the lot of you! :evil:

But your logic is flawed since it IS A NEW BIKE ya doofuses. :mrgreen:

I win! Except the bike is hurting my back… :oops:

I have found that when back ache occurs, it is usually the result of stem length and handlebar height. If the frame is on the small size a longer stem might help with a higher ‘degree’ rise might do the trick.

Yes that sounds like an accurate synopsis of my situation. I think I’ll increase the stem from 100 to 110 or 120mm and get my ‘rise’ happening. Is 120mm dicky looking on a 55cm frame? I’d rather be in pain than look dicky after all…

This page is good for bike fit: The Colorado Cyclist | Shop for Bicycles, Bike Parts and Accessories

If you have a sore back it may be partly due to the bike not fitting and partly due to you. How strong is your core (deep transverse abdominals)? These muscles are the ones that support your lower back. I don’t mean the six pack, but the ones underneath. If you haven’t been training them, it could be your problem. Classes in mat pilates and yoga are good, or get a fitball and start a program.

That’s what hybrids are for :stuck_out_tongue:

You haven’t seen The Hor with his shirt off have you? :evil:*

*Sorry Hor I couldn’t resist!!!

Great article on bike fit, thanks. I trust their advice coz they credit this as a ‘comfortable rider’.

I found this the other day and it helped me fine tune my roadie.

It gives a 3 different riding positions so you can sort of play around here and there.

And yes, she looks comfortable…