CX ratios (yes, I know it’s been done)

Right, I’m building up a CX and need to think about cassette and chainrings. What are folks using?

It’s not for racing by the way, it’s for use as a commuter, offroad fun and road miles

Got any pictures?

Not at work, sorry. It’s still a frame at the moment anyway.

I would off though 50/34 chainset and 12/27 cassette would be ok if the road and commute take up the bulk of the miles. Where are you thinking off going off road with it? The normal Cotswold stuff?

Simon – YGM.
50t up front won’t be much use if he’s using it properly off-road.

“gingerflash – Member
Simon – YGM.
50t up front won’t be much use if he’s using it properly off-road.”

Which is why I phrased my post the way I did.

34/48 with a 12-27 (9sp) on mine, mostly for commuting and off-road jaunts, it works well round most of the stuff in the Peaks and Lakes that I’ve used it on. With knobbly tyres, you won’t need a 50, 48 will be just fine.
I swapped the cassette for a 12-34 for the Three Peaks though, a cunning move that allowed me to ride up stuff that others could only walk up.

Aye, normal Cotswold stuff, so nothing monster steep. Thinking about it, I might check what the ratio is on my 29er SS and go from there for the offroady stuff.

How big a difference between chainrings can I get away with?

I’ve got 34/50 and a 14/25 9 speed cassette. I went out earlier and did some lovely snowy farm tracks, I just stuck it in first and spun my ass off. I only got the 14/25 because the only other one in the shop at the time was a 12/23. It’s not too bad actually, Norfolk is pretty flat so a 27 isn’t essential, and the closer ratios are nice. I’d ideally have a 12/27 though, especially when I go back to Manchester next week and play in the hills.