A forum for owners of Yamaha TTR250 trail and enduro bikes!

JOHNYBOY · Super Guru

sprocket teeth

Cubber · Super Guru

I've had sprocket teeth missing before now, but not just after previous adjustments. smile

A well looked after transmision is essential, as your son must now be realising.

This is what can result if no maintenance is done.

Well maintained .jpg

Martyn

JOHNYBOY · Super Guru

maintenance done by me regulary adjust & lube up before each ride spin wheel & check must have been a stone or has anyone had this

Cubber · Super Guru

I am sorry, John, but I wasn't inferring that your maintenance was suspect.

Despite regular maintence and adjustments things can, and DO, go wrong.

I am sure your diagnosis of stones is correct, what else could there be other than a faulty sprocket? confuse

Even factory maintained bikes have problems like this - Agostini's chain broke 1967 within sight of the finish when he was leading! bleh

Martyn

JOHNYBOY · Super Guru

you are dead right martin these things happen but ive never seen one as bad thats the trouble with alluminium rear sprockets ive fitted a metal one might last a bit longer pal

peteBLUEttr · Super Guru

Woahh! Jeez I've never seen any like in that picture before Martyn! Thats crazy it has completely torn them off.

All I can say is john your's and the ones in the picture must be a really really soft cast of alloy to do that. I think nice carbon steel sprockets are the best way. Most of them are to be fair.

Never scrimp on such important items like the sprockets or chain.

JOHNYBOY · Super Guru

yes pete i have never seen one as bad just fitted a metal rear & a metal self clean to front inspected the chain for tight links 3 times to make sure & lubricated i think i am going to lube up with oil on a paint brush ive tried every chain lube i think the only way to go is good old oil on enduro bikes different senareo on road bikes such as my gsf 1200 bandit too much oil thrown near rear type good old engine oil not old new

pug · Guru

I'm well happy with this Tutoro manual oiler it fit's on the bike a treat strapped to the rear shock boost bottle and as the chain dry's out in the day on the lanes you can up an down the flow to what ever you want with a bit of filtering on old engine oil an I cant see why you could not use it in the oiler. had many a long ride back on the road after a day in the mud last year before the oiler with a dry chain slapping round the sprockets

www.tutorochainoiler.com/collections/tutoro-manual-chain-oilers-1

Pug

ttboof · Super Guru

May be a case of a worn chain and alloy sprocket

Was the chain and sprockets changed as a set when last done

Steel sprockets tend to bend and hook the lighther alloy ones tend to snap off teeth if the chain is worn (moves the center of the roller higher on yhe tooth)

Not to rule out a foreign object