- Sram force compact to double
you wouldn’t be able to put a double chainring on as the bolt pcd is different. you can get compact chainrings in larger than 50 though – from the likes of TA and Stronglight. doubt you can get a sram OEM in bigger than 50. shifting would get worse so might be worth going for a bigger inner too, maybe 36 or 38, or even a 39.
it seems a bit odd that you soon out ob the flat yet go to low ratio on the climbs. are you using those low ratios because they are there or because you need to? maybe just man up a bit ob the climbs?!Posted 4 years agonjee20Subscriber
1. you didn’t spin out at 36mph, that’s 100rpm in 50-12
2. 50-11 is a bigger gear than 53-12, so if you’ve got a 12-up cassette change that first.
3. 34-53 won’t work nicely at all, you’ll dump the whole cassette to keep up with the change and you’ll get all sorts of rubbing issues.
Edit: and as said the BCD is different, although TA and Rotor do larger rings with a 110mm compact BCD.Posted 4 years agoDT78Member
Okay replace spin out with “maintain higher than100rpm for 2.5 minutes”. I am a grinder not a spinner so whilst I can go over 100 I can’t maintain it for long but I could easily reduce the rpm and push a slightly bigger gear. 70 to 80 is my comfortable rpm.
Cassette is an 11 28.
iit sounds like overall it is a bad idea, like I thought.
To be honest it is rare I am in the shortest gear, somewhere like blissford which you can push a bigger gear if need be. I don’t like putting too much strain on the drive not that I’ve snapped a chain on the road bike yet, I have on the mountain bike and it hurt a lot hitting the deck. So, sounds like a proper double is the best idea and save the compact chain set for when I go somewhere with proper hillsPosted 4 years agoDT78Member
Currently using a 34/50 11/28 combo. My rides are pretty flat around Winchester / new forest but I do end up using the small combination for some of the bigger hills. Thing is I am regularly spinning out. Yesterday on the flat with a tail wind I was holding 36mph at 160bpm, so definitely more in the tank but I couldn’t spin any faster.
Would I be able to swap the big ring to a 53 from a double? Front shifting seems very sensitive to setup and I’m worried it would be too big a jump?
And secondly, what are the rings called on crc or Merlin? Doesn’t appear to be force chainrings unless I’m being a muppet (entirely possible)Posted 4 years agonjee20Subscriber
50-11 is a bloody tall gear. If you’re honestly finding that too small then stop messing about with a compact and just buy a double. I can’t believe you’re wanting higher than that but feel a need for 34-28.
That’s about 90rpm though, being able to spin a bit quicker would almost certainly be beneficial.Posted 4 years ago
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