What is the best chain ring combo for cranks on CX bike. Terain is moderately flat with some very short steeper grades (like over river banks) here in TX . I am planning to run 12-25 in the back. I was thinking something like 39, 48?? I tend to push gears. Is 48 quite unusual size?
Any suggestions?? (building a CX bike)
I run a 48/38 and 12/25. That seems to be the best fit for me. I tend to push big gears also.
You are in the ballpark. 46/38-42, 48/ 38-42 are probably the most popular setups. The 46/42 seems popular with the strong riders with a 11-25 in the back. I think the general idea is to have a bunch of gears that you use all the time. The 38 or 39 might be a little small for the faster courses, but I don’t think you will have any disadvantages or advantages using it . I run a 46/38 and my 2nd bike has a 42 single ring up front. Sometimes it is faster to just run the hills where you struggle to get up in a 39/25.
We can probably argue what front combos work best and bottom line is, it really does not matter as they all work pretty well. A 48/12 is plenty of gear for most any course.
Up here in the northeast, courses are usually pretty technical with rolling terrain and lots of mud and snow. I run a single in the front (42t) and a 12-27 in the rear. By eliminating the big chain ring, front shifter, and der., you can save a good amount of weight.
Jeff
Last year I ran a 38/48 up front and a 12-27 in back. This year I am running a 38/42 in front with the 12/27 in the back. I am in Ohio with some technical off camber courses with rolling terrain and some steep short hills. Running a single 42 up front is very popular here too.
any idea where to get 46/130 BCD? Nothing on ebay. I am gonna check here on ST.