Removing the
sprocket cover revealed an utterly horrible sight: years of sticky chain
lube plus road dirt and metal particles from the terribly worn
sprocket, all packed tight around the chain and clutch pushrod.I scraped all the muck out into some old newspaper, with judicious use of a large screwdrive. I swear, it must have weighed a kilo - like a generous portion of fish and chips.
The sprocket was loose on the gearbox output shaft - the lock washer was the only thing that had stopped it coming off altogether. Nasty. At least I didn't have to fight to remove it.Although I've seen pictures of teeth in worse condition before, I'd never come across a sprocket with more wear than this myself. The teeth were no more than a third of their original width and distinctly hooked. More like barbs than teeth. Here's a repeat of an 'after' picture for easy comparison.
2 comments:
That's impressively grubby. My CBR sprocket cover was packed after last winters salt/grit deployment. It's not nice stuff to remove is it!
Why did Triumph fit the dip stick on the sprocket side? Checking the front sprocket suddenly becomes a much lengthier process with it there. A sight glass or fitting the dipstick on the other side would have alleviated the issue easily enough. And there's no case saver fitted either so a snapped chain could take out the crank cases.
It's never going to be a nice sight under a sprocket cover, that's true. It was the quality of the gunk that surprised me with this, especially its metallic content. I'm not sure I've seen a 'case saver' before, though I think I can guess what you mean. Is it a steel bar above the chain run? And it's true - I've seen pictures of bikes with broken cases after a snapped chain.
The dipstick arrangement is a pain. I've cross-threaded the dipstick on my Daytona a couple of times though to be fair the thread is totally different on that - much coarser. No, the main pain as you said is that getting the cover off means losing engine oil.
I'm guessing the design idea was to keep the gearshift sweet by having the gear change shaft in a lubricated bearing. And it is very nice to have it supported in a real needle roller bearing. Also, on my other bikes the change shaft has suffered by being in the line of fire from chain muck as it runs exposed beneath the sprocket. This one was clean as a whistle.
Later Trophies (circa 99) have a major revision of the engine cases, following the same pattern as the 96 Thunderbird. This includes deletion of dip stick on the left and the adoption of a filler cap in the clutch cover on the right with a sight glass beneath it, together with moving then engine breather out of the clutch cover. Revisions also deleted the inspection cover over the starter sprag clutch and alternator drive gears though, which turned out to be a much bigger issue for the unlucky/weak of battery.
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