Forum

[KC1961]

Apologies if you've already seen this on the Classic Motorworks forum. Anyway, I was doing an oil change today and found what looks like some broken bits of primary chain roller stuck to the drain plug. This is quite disappointing on a 6700 mile bike, more so as it still has a stock motor and doesn't lead a hard life. Has anyone replaced their primary chain, will I need any special tools or a workshop manual? Any other advice appreciated.

[KC1961]

Forgot to mention. Bikes a 2015 Continental GT.

[Alan R]

Hi KC 1961---------- Surely at such a short distance that's go to be a Warranty issue, hasn't it?? ??......To be quite blunt about it that's *****g disgusting !!..My old Grandad's pushbike chain gave better service than that LoL !!.......... We've had another GT owner on here recently with a dropped valve head, how many more duff-uns' are out there ??....Doesn't bode well for the new 650, does it ??.......PS}-Thanks for the "Heads-up" about the forum..

[Alan R]

---Additional to that last entry}--- You'll need to check / or have a check done on the teeth of the engine sprocket and the clutch drum plus any potential internal damage to the inner and outer casings.....Those bits would have come off with quite some centrifugal force....

[Adrian]

Best get it fixed ASAP. One of the downsides of the unit construction engine is that a primary chain snapping can seriously damage the l/h crankcase casting, not just the chain case as on the older models.



A.

[albert]

KC1961 As a 2015 continental gt owner myself I would be very interested in any further posts on your outcome of this problem and would certainly follow adrians advice on this one.

[Rattlebattle]

Primary chain breakage on the CGT is not unknown; there are more examples on Classicwotsit already mentioned (an excellent forum for those of us with UCE bikes). There are two factors: the primary chains are rubbish and the automatic chain tensioner can put too much strain on it. Best put a Reynolds on; you were lucky, smashed cases are not unknown. As for removal IIRC you just need a clutch puller. As an aside, there is an excellent article in RealClassic magazine by Roger Slater ( he of erstwhile Laverda fame). Dissatisfied with the level of vibration on his C5 he removed and dismantled his engine and balanced his crank etc to the designed balance factor - it was way off, which is probably why some vibrate more than others - they’re just chucked together by disinterested workers. Anyway, the engine comes apart really easily and is actually a good, compact design. I’ve kept my copy of RealClassic as the article shows much more clearly than the official w/shop manual what needs to be removed, how to do it and what pitfalls to look out for. Interestingly he elected to bin the original, unbranded chain and fit a Reynolds. I’d do the same if I were you. The issue seems to affect the CGT more than the 500cc bikes. The balance factors for the cranks are different too, apparently. Good luck.

[KC1961]

I've just looked at Real Classic's web site and ordered the March issue (that seems to be the one, if not please let me know Rattlebattle). Hopefully I'll get the spanners out next week and find out what's all needed. Altho' I could've done without this I'm pleased that it is as it is rather than sitting at the side of the road somewhere looking at smashed cases and waiting on the RAC for a lift home.

[Alan R]

Hi Guys--------just out of interest sake but had your Warranty expired then ??

[Rattlebattle]

Yes, it’s the March issue. It is as the last in a series but the most useful. It should be straightforward, no real difference to removing the primary drive on, say, a BSA C15 or similar, except that the alternator is in the timing side. Not sure if any old puller will do, usually you’ll need one that screws into the clutch mainshaft to pull the clutch off it’s splines. I gather some of our American cousins convert the chain tensioner to a manual one. You should check to see that the crankshaft is in line with the clutch so that the primary chain is aligned. Good luck. Let us know how you get on; I’ll probably put a Teynolds on my C5 as a precaution.