Cyclocross frame sizing

trekker12

I'm considering a switch to the muddy side!

Is it usual to ride a slightly smaller frame than you would on the road? For example my road bike is a 52cm and my old mountain bike is 16" which is considerably smaller.

Is it normal to er towards the mountain bike size? I'm just thinking it will be a little easier to dismount and carry a smaller bike.

Obviously I'm going to try a few and see what I like but my budget is for second hand so some idea of where to start would be good.

I'm 5'4" small if that helps!

Pseudonym

stick to your current frame size is my advice. CX frames generally have a slightly shorter top tube anyway...

FransJacques

Random thoughts:
Firstly, go off road bike. I'm 6' and ride a 17" Cannondale MTB which is only a size bigger than yours, so MTB not a good proxy.

2 schools of thought: a) you need a TT high enough that when grasping the TT near the seat cluster you can pass your elbow through the front triangle clearing the BB/chainrings for portaging - I personally think that's a little extreme b/c there's nothing wrong with the right hand grasps ST/left hand grasps handlebar approach (unless it's a long portage like 3 Peaks).

b) other school is a ST length 1 - 2 cm shorter than your RB with the TT 0.5-1 cm shorter. CX HTs look small but don't forget the front end is based on a 400mm as opposed to 367mm fork measurement.

Maybe look for something used or cheap: those Forme Hiver frames look nice (maybe it's just the white paint) also Paul Milnes on eBay has tons of nice frames.

MikeWW

Agree on those Forme Hiver frames
Got 3 of them (one son has 2 and the other has 1) and plan to get a couple for myself at the end of the season
Good clearances, no fork judder, look nice and good VFM
I tend to go for the same frame size as road

FransJacques

MikeWW wrote:

Agree on those Forme Hiver frames
Got 3 of them (one son has 2 and the other has 1) and plan to get a couple for myself at the end of the season
Good clearances, no fork judder, look nice and good VFM
I tend to go for the same frame size as road

Did you ever weigh a bare frame? Please tell me you did - one without the BB or headset?

MikeWW

FransJacques wrote:

MikeWW wrote:

Agree on those Forme Hiver frames
Got 3 of them (one son has 2 and the other has 1) and plan to get a couple for myself at the end of the season
Good clearances, no fork judder, look nice and good VFM
I tend to go for the same frame size as road

Did you ever weigh a bare frame? Please tell me you did - one without the BB or headset?

Sorry I didn't
May be able to find out from you as I think we have some technical details somewhere
The Kinesis EVO 4 is slightly lighter I would say

Here are a couple of ours

VamP

Oh they look yum!

andyp

They do look good but, for some reason, there is no geometry information on the Forme website so it's hard to assess what the sizing is like.

trekker12

ooh they are nice, rethinking budget!

MikeWW

I have all of the Forme Hiver dimensions
If you PM me with your email address I will send them through to anyone interested

amclinden

I am 14 and ride a CAADX 5 2012 54cm which is huge My dad rides a 56cm road bike and it is probs a bit big for him (I only have it so I don't grow out of it). Generally you go 1 or 2 sizes smaller as has been said...

mentalalex

its all about the top tube length really, find a frame size that matches the top tube you ride, 54cm fit me fine, those are my cross bikes above, very good frames, there only a few more grams heavier than kineses evo 4,

there's not point in being on a frame that is the wrong size for you! my cross bikes have all had a bike fit through CADENCE SPORT, which has made a world of difference,

FransJacques

MikeWW wrote:

I have all of the Forme Hiver dimensions
If you PM me with your email address I will send them through to anyone interested

Or you could just post it here for everyone to benefit from...

mentalalex your pic looks like it was Koksijde or somewhere else they like sand. I saw the U23 race aka, the Dutch CX Team Time Trial Championships, but I didn't get there early enuf to see you, sorry about that.

andyp

mentalalex wrote:

its all about the top tube length really, find a frame size that matches the top tube you ride, 54cm fit me fine, those are my cross bikes above, very good frames, there only a few more grams heavier than kineses evo 4,

I agree, the top tube length is important, but the head tube length should also be considered, as getting your bar height right is equally important (as I found out to my cost recently).

mentalalex

@andyp how did you have yours to high or to low?

Monty Dog

CX bikes generally ride 'high' due to the fatter tyres, clearances and higher BB, therefore riding the same size as your road frame may result of inadequate toptube clearance should you need to get a foot-down on rough terrain. Also running them shorter and less extreme bar drop helps with control - very rarely do you reach a speed where aerodynamics becomes a factor, but losing rear wheel traction because you can't get your bum off the back of the saddle is far more important IME. My road race position is a little deeper and more-stretched out in comparison i.e. toptube is 1cm longer.

MikeWW

Best I can do
Have it on an Excel file

model Size (cm) s/tube mm (centre to top) s/tube mm (centre to centre) t/tube mm (centre to centre) s/tube angle h/tube angle w/base mm b/b height mm c/stay length mm rake
(A) (B) © (D) (E) (F) (G) (H) (I)
Hiver 52cm 520 480 517 74.5 72 1005 65 425 45
Hiver 54cm 540 500 529 74 72 1008 65 425 45
Hiver 56cm 560 520 546 73.5 72 1010 65 425 45
Hiver 58cm 580 540 565 73.5 72 65 425 45







7005 Aluminium Frameset
Carbon Fibre Fork
BIG' Mud Clearance
Seatpost 27.2mm
F/Derrailleur Clamp 31.8mm
Steerer 1 1/8"
Headtube 45/45 (Campag)

explosifpete

just noticed mike say the forme frame gets no brake judder? really? I've got one and the bike is great but there is masses of fork judder and you cant fit a anti judder hanger as there is no fitment hole

explosifpete

http://i226.photobucket.com/albums/dd20 ... 11/001.jpg