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[Closed] Cyclocross bike sizing

 td75
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Sorry, I know this topic has been done before. I'm thinking of getting a cyclocross bike again. I used to have a 58cm crosscheck. Older second hand Kona Jake's seem cheap with canti's. I was wondering about sizing?

I've been looking at the geometry and it's either a 56 or 58cm. Now the 58cm gives me 57.8cm TT. The 56cm is a 56.3cm TT.

I'm thinking the 58 but does anyone 6'2" 34" leg ride a 56cm crossbike? Do you feel cramped? Would it mess the handling up if I put a long stem and layback seat post on it to give me a more stretched out position?

Cheers Tim


 
Posted : 15/07/2014 9:45 am
 nre
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I'm 6'2" with 34" inside leg and ride a 'Large' Boardman CX which has a 58cm 'conventional' seat tube measurement (BB centre to top of seat tube) and sizing feels about right.


 
Posted : 15/07/2014 10:22 am
 JoB
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i know it means nothing but i'm 5' 10" and ride a 56 CX bike, with a long stem and layback seatpost, so i'd imagine you might find a 56 a bit cramped

what was the geometry of your Crosscheck, if you were comfortable on that then go with the one that's closest


 
Posted : 15/07/2014 10:29 am
 td75
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The crosscheck had a 58cm top tube. But I always seemed to get a bit of lower backache on longer rides. I always wondered if I was too stretched out?

Seems like I should just stick to a 58.


 
Posted : 15/07/2014 10:34 am
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I think about 1-2cm shorter in the top tube than your road bike is about right - assuming your road bike is correctly fitted of course! Depends what you are using it for too I guess - is it going to be one of those rare beasts and a cross bike used for cross or a commuter, a tourer, a bridleway bike, a bit of everything?


 
Posted : 15/07/2014 10:39 am
 JoB
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i get lower back ache on bikes that are too short, jusayin ๐Ÿ™‚


 
Posted : 15/07/2014 10:43 am
 td75
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Yeah thats right. I want something that I can take through the woods one minute but go out on a road ride as well. I wouldn't be racing and I don't have a road bike at present. So it would be a bit of everything.

I was just wondering if I could dial a small size frame in to suit. Maybe with a longer 120mm stem and 20mm layback post for road rides.


 
Posted : 15/07/2014 10:47 am
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'Sizing down on CX bikes' is oft-repeated but (imo) unwise advise unless you're racing CX and have ridden bikes since the days when they had square geometry.
With an 'I don't race cross disclaimer' - I prefer to shorten CX bikes by using a shorter stem. Handles better in many situations, less likelihood of a too-low front end that can come from sizing-down and less issues with toe-overlap from shorter / smaller front triangles.
CX bikes tend to have a load of weight over the front axle as it is, fine for what CX bikes were originally designed for but not so great for general off-road riding. The only issue with a shorter stem on a road/drop bar bike is less weight on the front wheel when cornering but off-road tyres and hard cornering on tarmac aren't a good mix anyway.


 
Posted : 15/07/2014 10:48 am
 JoB
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i'd get a bike that fits in the first place rather than buy a smaller frame that's a bargain and somehow making it fit


 
Posted : 15/07/2014 10:49 am
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My CX bike has a 1cm shorter top tube and 3 cm shorter stem than my road bike. It's also a fair bit higher at the front. It's spot on for CX though.

(58cm frame, 57.5 TT, 11cm stem, I'm 6'5", 35" inside leg, 82cm BB to top of saddle w/175mm cranks).

I personally wouldn't want to be messing with saddle position to get extra reach - I'd get a longer CX frame and then have two different stems if I really wanted to be able to get a 'proper' road position for road riding.


 
Posted : 15/07/2014 10:50 am
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I would say a post with setback is pretty standard. It would be odd to put a zero offset post on either a road bike or a cross bike. So that's not buying you extra space.

I have a cross bike and I do play with stem length as well as stack height depending on if it's being a winter training bike, a tourer or an actual cross bike. For reference 5'11" and a 56cm top tube and stems from 100-120mm.


 
Posted : 15/07/2014 10:53 am