899 with 1199 rear fitted. Have a hardened alloy rear sprocket which after a few thousand miles is showing wear on every other tooth Chain is fine and correctly adjusted. Any ideas why it’s filling every other tooth?
It's to do with the sprocket sizes. If they are both even numbers the wear will be spread on the same teeth more often. I always try to have odd tooth numbers on both sprockets and never fit a 14 tooth gearbox sprocket.
Just to understand that Derek are you saying a 15/44 is ok but a 14/44 wouldn’t be and would cause the above wear?
If you go in gearingcommander website it actually tells you the best ratios to stop having the same link hit the same tooth as much as possible.
May well be the same pitch when new. Slight wear on softer sprocket causes chain whipping accelerating the wear on the softer sacrificial sprocket. Sprockets tend to wear faster on the driven face. Irregular surface hardness on one tooth beds the chain down causing the second tooth to skip and accelerate wear on every second tooth. One stiff link can cause similar wear. Chain tension should be checked over a full revolution. Too tight/slack chain and sprocket will hook on steel and break up on Ali alloys. Could of course be a poorly cut, crap sprocket
@Cream_Revenge ..... Good stuff ! Thanks for the link . I've often wondered about this , but never bothered to dig down into the facts / maths . It makes perfect sense ..... choose sprockets carefully to avoid constantly hitting the same teeth . We are already at a disadvantage with big twins , since all of the power comes in two large pulses .... .... very different from a four cylinder engine !
@Sev the pitch is 520 for chain and sprockets. The front steel sprocket is 899 o/e (15t) and the rear alloy one is 44t.
Still getting no difinitive answers on why rear is wearing oddly. Pitch and gearing is same as standard 899. Albeit with a 108 link chain; due to longer swingarm(single sided). So sitting facing the rear sprocket and holding it at the 9 & 3 o'clock position I can move it side to side a few mill. As in pulling the edge of the sprocket towards me and away from me. I take it this shouldn't be doing this? All nuts etc on hub are fine so are my 6 cush bungs knackered?
In addition to lateral movement you mentioned it's not because of which part of the chain is on which tooth is it? I notice the 'inside' chain link pair always sits on the teeth with the wear on the sides.
Update: Had new C&S kit fitted yesterday at dealers. Same make rear sprocket went on etc etc. Mech-droid then called down to show me he could move rear sprocket in and out a bit holding it at the 3 and 9 o’clock positions!! He then removed it and rotated the sprocket a bit. Tightened it all up and it’s now as firm as a very firm thing. Cush bungs are 4 years old. Will see if rear sprocket wears oddly over next 1000 miles. Went to coast for curly chips to celebrate
