I know this has been addressed before but I’m not finding it. Tried Sheldon Brown’s website but need some other opinions. Here’s my deal: I love the feel of the gearing on my road bike with 700 wheels. It has 42/52 on the front and standard 10 speed on the back with 11-24 cassette. Currently on my tri-bike with 650’s I have 39/53 in front and a 10-speed in back with 12-25. Do I change the front or the back of my tri-bike to get the closest gearing to my road bike and to what? Thanks.
change the front on the tri bike to 54/44.
That’s not going to do it. The % difference between 650C and 700C is about 8%. So you need to go to an 8% larger chain ring to get an equal gearing to the larger wheels.
39->42 is just about perfect.
1.08 x 53 = 57.24, but the biggest you can get easily is a 56, so the 56/44 combo would probably be your best bet. Shimano doesn’t recommend the 56/42, but I don’t really see any reason why it wouldn’t work.
Thanks! Why doesn’t Shimano recommend the 56/42? Is it nonstandard with 56/44 being standard?