QUOTE(valkyrie1232 @ Jan 4 2015, 12:39 PM)
Ok got another noob question for the sifus here. I am currently running a SRAM X4 RD on my tern link d8 (thanks etigge!). My wife and I are tinkering with the thought of changing to double chainrings.
My question is : would a SRAM x4 FD accommodate say, a 53/39T crank? I've read online in some other overseas forums and they said it wouldn't work.
Which brings me to my next question. Would it be then possible to change the RD to a road bike RD for my wide range 11-32T cassette? From what I know the biggest road bike cassettes are like 11-28T at most.
I went back and read sifu etigge's posts and I've seen him using Shimano road RDs like tiagra and sora. Are you using a wide range cassette as well? If it really works I would prefer to change the entire setup to a road groupset then, instead of having some weird hybrid MTB rear and Road front setup lol.
The SRAM X4 RD is OK if you want to add a double chainring for your setup. But finding a left shifter is going to be hard. You need to buy a pair both left and right. The FD is quite universal, meaning you can use SRAM or Shimano or even Microshift shifters but the rear RD , Shimano needs Shimano RDs and SRAM needs SRAM's RD. So, for yours, if you want to change double chainring, I think it is prudent you get Microshift 8 speed shifters. Then also get the Microshift's FD.
I don't know what other online forum's are saying but I have install 14, 15 , 18 and 20 speed on foldie's without problem. I even installed a 105 Shimano cassette (11/28T largest) on a 16 inch folding bike. The cassette has the same space width regardless if it is road bike or mountain bike, that is it is of the same number of gears. Eg. Shimano 9 speed Deore and the Sora 9 speed cassette are the same width. Only the ratios are different. The road bike uses smaller cassettes for smoother shifting and also road riding don't need such a big ratio difference. Point is, the cassette of
both MTB and roadbike can be used if the number of gears are the same.RD is another subject altogether. Most roadbike have short cage (the part holding the two pulleys on the RD). For smaller difference in ratio, it shifts faster and more accurately. That's why roadbike shifting is crisp. The maximum nowadays is 30T for roadbikes. They can start from 11T or 12T. THose models with 30T also comes with medium length cages to compensate for the chain slack. Mountain bike RD's of course can go to 36T maximum. But the RDs are also mountain bike. The chain length needs to be adjusted carefully though, to take up the slack and the maximum that I have tried is 34T for a 406 wheelset. 451, no problems. But for 8 speed, the max. is 32T only anyway.
Front is always roadbike setup, eg. 52/39T or 53/39 or compacts 50/34 but the rear set up can be mountain or roadbike. You need to prioritize your riding. I have used the SRAM's X5 on my Vigor and Dash before and the rear cassette was 11/34T with SRAM's X5, no problems. But I am using Shimano 105 on the same Dash now as I changed to 451 wheelset , so needs C-brakes (road bike types) and also the faster shifting of the roadbike setup. Cassette is 12/30T and it's more than enough already.
Happy Riding and also " man man lam" Hahahaaa.
This post has been edited by etigge: Jan 4 2015, 07:15 PM