# Proper Size for a Cyclocross Bike...



## caltobybear (Nov 17, 2010)

I have not been biking much, but my family is huge into a couple different areas. I am looking for guidance on the proper fit for a Cyclocross bike to mainly be riden for recreation. I am thinking about competing, but that would be a year or 2 out. Your guidance is appreciated!

Measurements:
6'0 tall
Cycling Inseam: 33" or 83.82cm

Some of the calculators out there say:
Frame Size: 
Road - 56 cm
Mountain - 46 to 44 cm

Saddle Height - 74 cm

Howver, others say I should get bigger than 56cm b/c that could be too small...


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## shapelike (Sep 13, 2009)

It really depends on your proportions and flexibility, etc. Also, one manufacturer's "56" won't fit the same as another's (never mind how S/M/L/XL sizing factors into that). Your best bet is to go to a shop you feel comfortable with and test ride a few bikes in different sizes. Aim for a more neutral fit than anything w/ an aggressive amount of drop. Don't be shy about asking them to swap out the stem for one shorter/longer (whatever will be more comfortable).


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## bodhizafa (Nov 6, 2010)

Not sure if that measurement is just for road bikes. My cross bike is a size smaller than my road bike. I measure a 54 for road (Cervelo Soloist) but 52 for Cyclocross (Redline Conquest Pro) I believe the cross bikes are measured slightly different (both bikes seem about the same size, yet different geometries) I also had a 52 Kona Jake that felt longer than both the above bikes (all have same size stem, same bars too). Maybe a higher bottom bracket accounts for the difference in size numbers (?). 

Anyways get out a test ride as many as possible.


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## frdfandc (Nov 27, 2007)

Quite a few times a cyclocross bike in a 56 (just an example) is a little smaller than a road bike in a 56. Gotta look at the geometry of the bike. Seat tube angles, head tube angles, Effective Top Tube length.


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## ChilliConCarnage (Jun 1, 2006)

bodhizafa said:


> I measure a 54 for road (Cervelo Soloist) but 52 for Cyclocross (Redline Conquest Pro).


You must be my twin. My Soloist carbon is a 54, and my Conquest Team is a 52.

Only drawback to the small CX size is problems with toe overlap. Some people also complain that smaller frames are harder to shoulder, but I'm OK with my 52.


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## backinthesaddle (Nov 22, 2006)

We are the same size. I ride a 56cm road bike with a 56.5TT. My cross bikes are both 54cm with 55cm top tubes. You want your cross fit to be a bit smaller, but very close to your road set up. 
http://www.cycle-smart.com/articles/find.php?search=31


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## shomyoface (Nov 24, 2007)

backinthesaddle said:


> We are the same size. I ride a 56cm road bike with a 56.5TT. My cross bikes are both 54cm with 55cm top tubes. You want your cross fit to be a bit smaller, but very close to your road set up.
> http://www.cycle-smart.com/articles/find.php?search=31


Did you read the article you referred us to, it's contrary to your post?

"Keep it the same as your road bike! Too many people think they should downsize their 'cross bikes because of the higher bottom bracket and lower saddle position. What they end up with is a bike that they can't raise their bars high enough on because the head tube is too short. Bottom brackets on 'cross bikes used to be very high to allow for clearance when pedaling on the backs of pedals that had clips and straps. With clipless pedals, most 'cross bike bottom bracket heights have come down to that of a normal criterium bike. So, the need for a smaller bike to accommodate standover height doesn't exist to the same extent."


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## backinthesaddle (Nov 22, 2006)

shomyoface said:


> Did you read the article you referred us to, it's contrary to your post?
> 
> "Keep it the same as your road bike! Too many people think they should downsize their 'cross bikes because of the higher bottom bracket and lower saddle position. What they end up with is a bike that they can't raise their bars high enough on because the head tube is too short. Bottom brackets on 'cross bikes used to be very high to allow for clearance when pedaling on the backs of pedals that had clips and straps. With clipless pedals, most 'cross bike bottom bracket heights have come down to that of a normal criterium bike. So, the need for a smaller bike to accommodate standover height doesn't exist to the same extent."


I knew that was coming... 

I did, and it's used for reference. If I put a tape on each of my bikes, the measurements are virtually the same, but the cross bikes are about 5mm smaller all the way around.
Myerson gives a good basis to work from. A bit smaller works better for ME, as I use the cross bikes for other things, like single track riding. 
If you're building a pure racing bike, then make everything the same.

I can promise you though, with certain manufacturers, the cross bike geos they list are fine in theory, but don't work out when rubber meets the road. Ridley, for instance, size out really big. 

A cross bike that's too big, and requires a nubby stem will ride like a dump truck.


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## ChilliConCarnage (Jun 1, 2006)

I think like in most things, there's no hard-and-fast rules you can go by, just personal preferences. 

Some people buy small and love it - others find they feel too cramped. 

Some buy big and love it - others find it feels too large.

I personally like to size down for the same reason I like smaller motorcycles - they're easier to whip around, which is an important consideration on some of the technical CX courses. As I mention above, the negatives of a smaller frame include the possibility of toe overlap and less room to shoulder. I suppose you could also have a problem getting the bars high enough, although spacers and a riser stem should theoretically take care of that.

That's why I think its a good idea to buy your first CX bike used. I understand the possibility of a used CX bike being somewhat thrashed, but you don't want to spend brand-new money on a bike that may or may not fit. I bought a Salsa Las Cruces brand-new as my first CX bike. It felt too big so I had to sell it, and somebody got a great deal on a new scandium Dura Ace race bike. My Redline frame I got used, and was way cheaper than my Salsa. It also fits just right.


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## laffeaux (Dec 12, 2001)

Do you ride a road bike already? If so, my recommendation is to look at CX bikes that have about the same top tube length (with the seat tube angle factored in) as your road bike. The same length or a little shorter (maybe a 1/2 cm) should work fine.

I'm a little taller than you - 6' 3/4" and have a 86.5 cm cycling inseam - and I ride a bike with a 57cm top tube, 73.5 degree STA, and a 120mm stem.


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## helios (Jul 22, 2010)

In my experience standover is still a bit of an issue, not necessarily because of BB drop but because of non-sloping top tubes (for easier shouldering). My 56 Tarmac has a standover height of 800mm whereas a 56 Crux has 807mm and would be too tall for me. Instead, I ride a 54 Crux with 790mm of standover for some wiggle room. I lost about 1.5cm of effective tob tube going to the 54 but got it back via stem/handlebar reach adjustments and I'm really happy with the way it turned out in terms of comfort and the way the bike feels at speed. 

I know it's said a lot, but go at least put yourself on the bikes you're considering. By virtue of the kind of riding you're doing (CX course can demand significantly more "technical" riding than riding on the road) I think _subtle_ differences in saddle height and handlebar drop/reach can be beneficial. It's nice to have a little buffer when you hit a ditch you weren't expecting to be there and things of that nature ;-) 

As it was said above, consider going used at first because its hard ot know what you're going to like/dislike until you've tried it.


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## jroden (Jun 15, 2004)

you need to determine proper top tube length. I and just a smidgen taller than you and ride bikes in the 58-60 size with a 58.5 top tube, road and cross are the same. It comes down to body dimensions. I do not think the idea of buying a smaller frame for cross makes much sense with the faster and more open courses we ride, perhaps it never made sense


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## krisdrum (Oct 29, 2007)

helios said:


> In my experience standover is still a bit of an issue, not necessarily because of BB drop but because of non-sloping top tubes (for easier shouldering). My 56 Tarmac has a standover height of 800mm whereas a 56 Crux has 807mm and would be too tall for me. Instead, I ride a 54 Crux with 790mm of standover for some wiggle room. I lost about 1.5cm of effective tob tube going to the 54 but got it back via stem/handlebar reach adjustments and I'm really happy with the way it turned out in terms of comfort and the way the bike feels at speed.
> 
> I know it's said a lot, but go at least put yourself on the bikes you're considering. By virtue of the kind of riding you're doing (CX course can demand significantly more "technical" riding than riding on the road) I think _subtle_ differences in saddle height and handlebar drop/reach can be beneficial. It's nice to have a little buffer when you hit a ditch you weren't expecting to be there and things of that nature ;-)
> 
> As it was said above, consider going used at first because its hard ot know what you're going to like/dislike until you've tried it.


Glad your set-up is working for you, but not sure I agree to make standover such a priority. Standover height is a ways down the priority list in my mind as it isn't a particularly useful measure. How often are you straddling your bike flat-footed? And if you crash or come across an obstacle you weren't expecting, is 7mm really going to make the difference between hurting yourself and not?


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## pretender (Sep 18, 2007)

Greater standover just means that much more distance to fall before contact.


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## jroden (Jun 15, 2004)

krisdrum said:


> Glad your set-up is working for you, but not sure I agree to make standover such a priority. Standover height is a ways down the priority list in my mind as it isn't a particularly useful measure. How often are you straddling your bike flat-footed? And if you crash or come across an obstacle you weren't expecting, is 7mm really going to make the difference between hurting yourself and not?


i do think a bike with much higher standover (i.e. some of the ridleys) can be a pain in the neck as they require the rider to jump up higher when remounting. Plus, to my untrained eye it suggests a higher center of gravity, which isn't helpful.


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## krisdrum (Oct 29, 2007)

jroden said:


> i do think a bike with much higher standover (i.e. some of the ridleys) can be a pain in the neck as they require the rider to jump up higher when remounting. Plus, to my untrained eye it suggests a higher center of gravity, which isn't helpful.


I'm not expert, but I don't think standover necessarily has to be tied to BB drop, which seems to be what you are talking about. Ridleys have high BBs, so for a given saddle height, you do have to jump up more to swing a leg over as well as the center of gravity comment. More often than not TT standover is probably tied to that, but I don't think it is a direct correlation.


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## helios (Jul 22, 2010)

I don't mean to suggest standover should be a top priority, but I do think it's worth considering. 

Like someone else said above, it's a matter of personal preference. My crotch sitting on the top tube when I'm standing is a point of contention for me. I prefer my cx bike just a tad on the small side PROVIDED there isn't significant toe overlap. I should have done a better job of qualifying that.

EDIT to add: don't forget about things like handlebar drop and reach (classic vs. ergo vs. compact etc) which can make a significant difference. Measuring from say saddle tip to stem clamp is great if you've got the same saddle and handlebar on both bikes, but comparing across bikes is significantly less useful if the two bikes have different handlebars. 

These are just ideas to keep in mind when shopping for bikes from different manufacturers. I learned on my own by comparing that it's not always so easy to compare apples to apples without a little work.


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