Frame size advice

[jorgemartin]

Hello!
I have a 58 cm (23 inch) road frame. I am 193 cm (6.3 ft) with an inseam of 92 cm (36 inch). I find this bicycle to be kind of okay for going about town but a bit uncomfortable for touring (I am constantly sliding my ass backwards and leaving it there, suspended in the air) so I have decided to buy a new frame. I think that a 60 cm frame would be okay but I am doubting. Because the difference seems so small on paper... should I get a 62 or even 64 cm frame? The question is not what is the right frame size for me is but how do I go about finding it? I have been sold smaller frames at bike shops in the past so I'd be a bit wary of their advice. Having said that, not all shops are the same. Any advice would be appreciated. If this helps, the new bike would be a 700c tourer with drop bars... Cheers!

 

[accountantpete]

The problem is that the longer legs imply a relatively shorter upper body.

Can you not get a longer stem and get a good idea of what top tube length you need. Then all you need do is look for a frame with a shorter/longer headtube which will present the bars lower/higher as you require.

 

[02GF74]

top tube is the more important measurement - I woiould suggest looking at frame with 60 cm top tube, measure horizontally (i assume you are talking road bike frame and not mountain bike). this would be on a 60 cm frame - 64 will be too big, and probablyu 62 too,

 

[jorgemartin]

Thanks! Yes I'm talking road bike frame rather than mountain bike geometry (and specifically thinking about touring).Top tube and seat tube are the same length on my bike. The stem (quill stem, 22.2 mm clamp) is 100 mm long. Would a 110 mm stem make a difference? Anyway, sounds like 60 cm would not be a bad call, as I would have more choice of stem lengths (for Ahead, range goes from 60 to 130 mm, even more perhaps...) and this flexibility would help me find the right set up...

 

[P.H]

IMO, two measurements are critical. First the relationship between saddle and bottom bracket, height is easily adjustable, fore/aft isn't always so easy. You can use setback seatposts and saddles with longish rails but the seat tube angle of the frame may well be too steep to get it right. Then when that is right, reach needs to be correct, both length and height, the best way to get that reach would be the right size frame with the appropriate top and head tube measurements to allow a proportional stem. However with modern components it's usually possible to adjust the reach on a frame that isn't the best size, it may not look the prettiest but it will be comfortable. I think the problem of wanting to move back on the saddle is more likely to be your position over the BB. This is a result of frame geometry rather than size. As above some adjustment to the saddle may be possible. A too short reach is likely to result in shoulder and neck aches, do you suffer from these?
There's so many factors to getting it right, it's not just your size and shape, a few places offer fitting sessions that are not outrageously expensive, Paul Hewitt for example, I bought a touring bike from him 9 years ago and the fitting session was included. He made some changes to the way my previous bikes had been set up, not all of which I immediately liked, but all have turned out to be improvements.

 

[BimblingBee]

A 110mm stem would make a difference but you need to always start a fit from the saddle and go from there. A layback seat post may work as a cheap fix.

I've got a 61cm frame (Kona Honky Tonk) and am 183cm and put a shorter stem on it and its great.

 

[jorgemartin]

I don't suffer from shoulder and neck aches. I find that my rear end doesn't want to stay on the saddle and that my body is regularly looking for a different position. Also my arms and hands get weary and I feel that I want to throw my hands forward a bit... In any case, it sounds like a bike fitting session would be worthwhile. Condor cycles in London offer this service for £80 so I might just do that. http://www.condorcycles.com/workshop/condorbikefitting.html