Author Topic: thorn mecury chain line  (Read 154 times)

pinkbunnyok96

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thorn mecury chain line
« on: December 05, 2018, 01:27:36 PM »
trying to fit a shimano xt chainset to a mercury how to check chain line any sugestgon's the advice given is 1 * 2.5mm shim on drive side 2*2.5 mm on non drive side, if i do this crank arm has to much free pla. using just 1*2.5 mm shim on non drive side sorts that problem but i get a horibel sound that gets worse if you start exerting efort through the pedals and vibration through the poedals new kmc chain new bb shimano xt bearings no play in the wheel rim side to side with the chain off no noise or vibration coming from rohloff hub , its no worse no mater how i arange the shims on the b/brkt

Dave Whittle Thorn Workshop

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Re: thorn mecury chain line
« Reply #1 on: December 06, 2018, 09:42:02 AM »
Can you post some photos of the bike so I can see if there are any obvious issues?

With the correct XT MTB external bracket 1x2.5 drive side and 2x2.5 non drive is 100% correct and should have no play, so something is wrong, did you buy it new?

Is part #13 on this schematic in place? http://www.sjscycles.com/Drawings/Shimano/Shimano_Deore_XT_FC-T781_Tech_Doc.pdf 

pinkbunnyok96

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Re: thorn mecury chain line
« Reply #2 on: December 06, 2018, 01:22:16 PM »
the problem is not the spacers the problem is new chain ring new chain new bottom brkt nearly new thorn rear sprocker (less than 2000 miles) it makes a horibel noise and there is a trembel through the pedals if you coast down hill and slowely rotate pedals all is fine the bike was a customer reject bought from sjs cycles bridgwater

Dave Whittle Thorn Workshop

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Re: thorn mecury chain line
« Reply #3 on: December 06, 2018, 01:24:19 PM »
I'd try reversing the rear sprocket, also wind the eccentric back a bit and run the chain a bit slacker and see if the noise goes away.

pinkbunnyok96

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Re: thorn mecury chain line
« Reply #4 on: December 07, 2018, 03:11:25 PM »
do not know how or why. but pulled the entire transmission apart relaced chain chain ring rear sprocket bottom brkt bearings with brand new bits totally sorted but still can'nt get more than 5mm worth of shims on thanks for your prompt and helpful advise