Cyclocross sizing, 56 or 58??

[ambitionator]

Hi I'm new to this and want to buy a cyclocross bike over a road bike as the roads are not to great near where it live and I would like the option to ride on gravel, bridal paths etc. The bike I have chosen is the Cannondale CaadX 105 Disk 2015 model, any good?
My biggest problem is which size frame to go for! I'm 6'1 with an inseam of 33.5". I've decided a 58 size frame would be perfect if I was going for a road bike, but I have been doing research and some people say cyclocross frames should be the same, and some say drop down a size? (Why is this?) I can't find a definite answer and can't test ride as no shop near has any.
Could someone shed some light on this please and help me pick the right sized frame?
Thank you

 

[raleighnut]

Test ride both and see which feels better, it'll be you riding it after all.

 

[Venod]

Can't coment on Cannondale road bike sizes but I ride a 54 cross & 54 road bike (Kinesis) 5' 10" 32" inside leg, the. Cross has a short headtube compared to the road, so compare the geometrys before you decide, if your not planning on doing any cx racing I think the same size as your road bike would be fine, just to add to the confusion I ride a large Cannondale MTB, the medium felt too small :-/

 

[ColinJ]

I can comment on Cannondale road bike sizes because I own one and happen to be the same height as Barnard01! A 58 cm frame is perfect for me.

The only reason I could think of for going down a size for cyclocross would be to get a lower top tube, but that seems like an odd thing to do.

Test rides would make sense, but if you can't do them then the 58 cm frame will be fine. You can fine-tune your position by changing the saddle height/setback and/or the stem size/orientation.

 

[ambitionator]

Thank you all for your comments. Colin, do u have a similar inseam measurement? Do you have plenty of stand over clearance?

 

[Sharky]

I recall a road test in Cycling Mag a few years ago using two identical bikes, but different sizes. With adjustments to saddle and stems etc, they achieved identical positions. There was very little difference between the two, but I think preference was for the smaller frame as it gave a more lively and responsive feel.

If making a choice between a road and cx bike, have a real study between the two. A cx bike may sound if it is better suited for bridal paths, but apart from tyres, probably not much different. A cx bike will be designed to be thrown over your shoulder and won't have cable runs in the way. A cx bike may have the extra set of brake leavers the might be useful, or just get in the way of strapping lights on the bike. A cx bike won't come with mud guards, so need to make sure they can be fitted.

A road bike will probably have 23mm tyres, too lightweight for non Tarmac, but you can probable fit more suitable tyres up to about 28mm tyres, depending on mudguard clearance etc.

An audax or touring bike might be a better option. The Ribble winter training bike is pretty rugged. It's a confusing market, so best of luck.

Keith

 

[Supersuperleeds]

I am a 58 on my hybrid, tricross and road bike (all specialized)

 

[Berties]

when i bought my cx bike last year ,as i mainly ride road i bought a 60 as i am 6 foot 4 ,but was told to ride it for cx comps a 58 would be a better fit,so maybe have a sit on a few,and it all goes down to individual bike geometry,

 

[Venod]

The cross bike will have way more clearance for bigger tyres than the road bike, I have ridden mine with 30mm tyres & guards on some very rough tracks, bigger tyres would have fitted even with the guards on, without guards I could have gone even bigger.

 

[ColinJ]

Thank you all for your comments. Colin, do u have a similar inseam measurement? Do you have plenty of stand over clearance?

I thought I was 32.5" but I just checked and am 33.5", like you.

I don't consider standover clearance to be particularly important. I have never had an issue with it on any of my bikes, but I don't spend much time standing over them!

I can stand over my Cannondale's top tube without crippling myself and that is good enough for me. There is probably an inch of space between tube and 'nads!

 

[ambitionator]

I'm going to try one out tomorrow at a local shop, they only have the 56 in stock so I'll see how that fits, if it's to small I'll order the 58 in.

 

[loother]

Hi Barnardo1. How did you get on? I ride a '12 Caadx size 56. I am a tad under 6ft with 32+ inside leg. For a better fit I fitted a 90mm stem and flipped it. I would think the 56 might be OK for you. Good luck.

 

[youngoldbloke]

Some useful advice here #1. A lot depends whether you are actually going to race the bike. If the CX frame has a higher bottom bracket a 56 may be the same or close to a 58. It all depends. Worth comparing the frame geometries, esp top tube length.

 

[ambitionator]

Tried out both sizes, the smaller size definitely was the one to go for, but wasn't really sold on the bike to be honest! So I ordered the 58" 2015 specialized diverge sport a1, which is apparently replacing the specialized tricross range, which looked, felt and sounded more suited to me.