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As per title. After 500miles of the occasional chain suck from brand new (checked for stiff chain links etc...)
I decide to swap out the drive train to see if it made a difference - older XTR cranks with brand spank middleburn rings, sram cassette and kmc chain. Now the chainsuck is even worse - I'm wondering if it could be a chain line problem? Anyone else got/had similar probelms?
have you put the right spacers in for the BB, or just a look and maybe add/delete some?
Surely a chain line issue. I just can't see how a frame can cause chainsuck. Can you check your frame? Is there any chance it is misaligned? The only effect I can see with a frame is how well it deals with chain suck. EG does the chain fall through or jam between chainset and shainstays causing damage.
no problems with mine
Haven't changed the BB so it as it came from the (reputable) LBS. It looks like it has the right number of spacers (2 drive 1 non)
Chain jams when changing from mid ring to granny under very little pressure. To the stage now that I either change well before any climb or actually stop, get off and spin the wheel to change down.
Last time it went it badly it was so jammed I had to remove the crank and it's put a dent in the chainstay. Hence why I replaced the drive to try and sort it .
How could I check the alignment?
I've had chain suck in the past, and yes, its bad when it happens (the price you pay for short chainstays and loads of mud room i think). Mine was definitely the fault of the horribly worn kit i was running on it though!
Can't imagine why you're experiencing it with new kit. Measure from the middle of the seat tube to the middle ring, mine measures about 51mm which isn't great, but hasn't caused me any problems.
Shame cause its a bike that deserves to be pedalled hard!
I've got a Duster Ti; two spacers drive side, one spacer non drive side. XTR 970 with old rings; no problems with mine other than that I'm not keen on the geometry.
Could you guys with a duster (to hand that is) post the total length of the BB (shell+spacers). I'm wondering if maybe one of the spacers is a few mm out or something. When you look at the middlering on the crankset it seems to be very little clearance.
I'll have to check mine in the morning (in the shed at the mo)
Ive just found your problem!! GRANNY RING, take it off, problem solved.
I'd need to scrape the mud off first!
I think the seat tube to middle chainring measurement is more relevant, different BBs and different axles etc. would confuse the BB measurement
Think mine is the old style XTR octalink BB with 3mm of spacers driveside, 2mm non drive.
Not sure I understand the seat tube to middle chain ring? Why would that be important? I was thinking it would be more about how far out from the frame the chain rings were sitting?
(Oh is that measurement from the top of the seat tube to the start of the middle chain ring?)
Crank is a m960 xtr with new middleburn rings, also had trouble with the LX cranks that it came with)
and lol - I wish I was fit enough to cope without a granny (not far off, but not there yet!)
Ah, sorry, didn't explain very well:
http://www.sheldonbrown.com/chainline.html
I had some wierd chainsuck type issues with middleburn rings, but it was because i'd mixed a big middleburn with a shimano middle
ah I understand now - I'll check in the morning - ta 🙂