Extremely hooked front sprocket teeth acting on innocent new chain

The final drive chain* has been clunking and scrawping for some time,  like it did last summer in the Alps just before it took out the cush drive bearing. If that bearing goes again, I can fix it (just about) but more of a worry is the output shaft bearing. If that goes it could write off the whole bike.

Serious stuff so I’ve only ignored the noises for about three weeks. The juddering of the old front tyre (hopelessly out of balance) distracted from the imminent self-destruction at the back. The new front tyre is making the rest of the bike look bad. A bit like when you paint the skirting boards but can’t be arsed with the door.

The good people at http://www.gunnisonmotorsports.com had nothing in stock but got me an EK O ring chain with patented screw link for 10am next day and fitted for less than the price of the tools I’d’ve needed. I’m more of a DID man, usually, but this was significantly cheaper.

I spoke to the mechanic about leaving extra slack in the new chain to account for the slightly long rear shock. He overruled me and insisted that normal tension would be fine. I’ve since checked it with me and Helen on the bike and the thing is pulled to bearing screaming tension. I shall loosen the chain before we go out again.

If you have an ounce of mechanical sympathy, you should be waving your arms in the air and shouting “what about the sprockets?” The front is totally shot but may be useful in a martial arts movie. I will phone ahead to the Triumph dealer in Denver and order a genuine part (genuine one has chunk of nylon incorporated into it for additional cushioning). Rear sprocket looks okay and has probably only done about 30,000 miles. I have been known to replace brake pads a single pad at a time. There’s another place in Denver that could do me a larger than standard rear sprocket. This could tempt me.

*just called a drive chain in the USA, not final drive chain. Note that, secret agents.