Hi All,

I am thinking about buying a CX bike and wondered what folks opinion was on sizing. Is there a standard formula, same size as my road bike or a bit smaller? I do plan to go to the shop to try it but am looking at online stock to see if it is worth the journey.

Cheers

Dogsby

I usually use top tube length as frame size can be measured in a variety of ways

I was told slightly smaller than a road bike, not that that helped as I didn’t have a road bike. When I was looking at cx bikes from the reading I did seems size varies wildly (same as mtb I guess). Maybe phone the shop tell them your size and see what they say?

Old school advice used to be 1″ smaller than your road bike but the last time I tried roadbikes I was anywhere from a 58cm to 62cm and ‘Medium’ to ‘Large’ so I would definitely try.

depends what you’re using your CX bike for
the racier types go for the same size as their road bike, maybe with a slightly shorter stem
if you’re using it for more mucking about on and off-road then a bit smaller for chuckability

1cm shorter top tube or stem as your road bike works well, especially for racing

Some people go a size smaller for the added crotch clearance as CX bikes have a higher BB + fatter tyres so less standover. Worth noting that some CX frames have a longer top tube per given size to increase the wheelbase for added stability.

Cheers All,

Off to CRC tomorrow to have a look and a quick try.

Dogsby

Cannondale recommend going one size (2cm) down, so if their 54cm Supersix road fitted you, they’d recommend the 52cm SuperX CX bike.

Just to throw a spanner in there, I personally would take a 54cm in both. The same size CX would normally have a shorter top tube, and less standover as the higher BB raises the whole frame.

A couple of cm’s less reach than your road bike (can be achieved with shorter tt or stem).

I aimed for same dimensions as my road bike (Effective top tube, reach etc.)

With road bikes being compact frames these days you can pretty much use the same size. Being different brands makes it harder. My road bike is 55cm and my CX bike a 54. I aimed for a slightly shorter reach on my cx bike achieved through the shorter TT and a raised stem. Could just as easily fit a 10mm shorter stem.