New chainring for Sora 9speed
06-11-20, 09:10 AM
#1
Senior Member
Thread Starter
New chainring for Sora 9speed
Hi! I have a Surly LHT with a Shimano Sora triple chainring, 50-39-30. Can I, and would it be advisable, to put a smaller chainring on the small end, say a 24? I'm old, fat, bad knees, bad disposition, and a beer gut, if any of that matters!
06-11-20, 09:43 AM
#2
Really Old Senior Member
What's the BCD of the smallest ring?
It may be large enough that you can't go as small as you want, if at all.
It may be large enough that you can't go as small as you want, if at all.
06-11-20, 11:46 AM
#3
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https://wickwerks.com/bolt-circle-diameter-bcd/ cheat sheet near bottom
06-11-20, 02:02 PM
#4
Senior Member
Thread Starter
It seems that the chainring setup I have has asymmetric bot spacing. 4 bolts, 64-ish between 2, and 45-ish between two. That, I am sure, complicates things a bit. 
Is my answer a new crankset, if I want the small gear bad enough?
Is my answer a new crankset, if I want the small gear bad enough?
06-11-20, 04:53 PM
#5
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Yes. Shimano specs are 110/74 but judging from the pic that doesn't mean what it once did.
Shimano has made various "Trekking" cranks through the years with useful chainring sizes. AFAIK the 9 and 10 speed versions weren't sold in the US but were sometimes available on ebay. I think the 9 speed was T661.
Shimano has made various "Trekking" cranks through the years with useful chainring sizes. AFAIK the 9 and 10 speed versions weren't sold in the US but were sometimes available on ebay. I think the 9 speed was T661.
06-11-20, 05:08 PM
#6
Banned
replace with a Sugino 110 74 5 arm then you certainly can fit a 24t on the granny gear 48, 36, 24 12 t jumps..
