I've always got a question, as you'll have noticed.
Attached are photos of my (1965 B40F) engine sprocket. It looks, would you agree, like the RH side is more worn than the other? I've just bought a new chainwheel and a new primary chain, but before fitting them I'm just wondering if the engine sprocket wear is evidence of some misalignment. You'll also see there are signs of a bit of wear and tear here and there, eg on the crests of some of the teeth. Any advice, please? (This is new ground for me.)
Thanks very much. Phil
By the way, when I say RH side I do of course mean the inboard side (just noticed the photos are not all the same way round, sorry.) Phil.
Further to my previous posts on this, a bit more information: I see that the crankshaft oil seal is running on what I believe is a spacer, marked "C", which I think (having read Rupert Ratio) is the thickest of three available (back in the day) spacers (sorry photo is a bit dark.) I'm not sure whether the wear on the sprocket suggests that's too thick or too thin. And of course I don't know when the wear occurred, before or after the spacer was fitted. Phil
Quote from: Phil C on 06 Mar, 2021, 15:20
By the way, when I say RH side I do of course mean the inboard side (just noticed the photos are not all the same way round, sorry.) Phil.
Sorry, I meant outboard, the side with the boss.
Anyway, I'll see what the alignment looks like with a straight edge (steel rule.)
Putting a six inch rule across the engine sprocket and the chainwheel, they look well aligned if the rule is below the teeth on the sprocket. Of course that's not the case if I try to line up with the rule on the actual teeth of the sprocket, because of the wear on the teeth. Except for the wear I think there's pretty good alignment. Do I need a new engine sprocket? Phil
Hi Phil,
As you have new clutch drum and primary chain you may as well go for the full set. The worn front sprocket will cause the chain to wear a bit more quickly and in turn this will wear your new clutch drum a bit more quickly. Also, for the sake of few more £s get some new clutch bearing rollers.
Dave.
I'm happy to do that but do you think having a new engine sprocket will mean the "C" spacer is no longer the right one and the alignment is out? Phil
If the wear is the side the spacer is, then I would say that the spacer is to thick pushing the sprocket over.
No the wear is on the outboard side, furthest from the spacer.
Quote from: Phil C on 06 Mar, 2021, 17:38
I'm happy to do that but do you think having a new engine sprocket will mean the "C" spacer is no longer the right one and the alignment is out? Phil
Anyone?
I still think the spacer is to thick.
Hi,
I would put the clutch drum and front sprocket on with the spacer that you have and see how much out it is. Lining up below the teeth is probably more reliable and it needs to be as perfect as you can get it. The difference between the spacers will only be in several thou. It looks like you may need the slightly thinner one to take the sprocket in a bit.
Also, use a longer straight edge so that fully engages on both sprockets. The back of a hack saw blade is quite good and measure any gap that you see.
What does RR say about this?
Dave.
RR (vol 1, p.119) says use a 12" rule to check the outer edges are perfectly in line. (The illustration shows a 6" rule, but anyway whatever.) RR goes on to say if they're not perfectly in line then attend to the spacer by fitting a thinner one or shimming. He also says that if the crankshaft oil seal is fitted then removal of the spacer is very difficult. Anyway, I'll order a new sprocket tomorrow (and roller bearings) and hope the alignment is spot on because I don't know how to get the spacer out. I'll let you know. Thanks again. Phil
Hi,
Have you got a couple of strong magnets? If so you may be able to tease the spacer out.
Dave.
No, but that's an intriguing idea. I guess they'd need to be very strong. Anyway, My fingers are crossed for the sprocket to line up well. If not, and in the absence of strong magnets, maybe getting the oil seal out somehow first would work. I say somehow...
Phil.
Hi,
The magnets in flashing beacons that go on a vehicle roof are very strong. A strong magnet is also useful for cleaning the bench and around the vice. Wrap the magnet in a bit of oily rag that you are going to throw away and pick up all the bits of metal and filings on to the rag. Unwrap the magnet making sure that all the bits are folded in to the rag. Discard the rag.
The magnet is clean and so is the bench and vice.
Dave.
I seem to remember that the work you started in the primary chaincase was because of an oil leak. With all that you've ended up doing it's working out a very expensive oil seal!!
I know we all like to get our bikes in tip top condition but sometimes we have to think how many miles we actually do on the bikes and how much money we can spend on them.
Haha, yes, fair point Pete. I remember a bike mechanic telling me once that when you start doing something on an old bike you usually find another thing needs renewing, oh and then another, and then ah I ought to get a new...and so on. Meanwhile, as you say, the wallet is emptying. But I enjoy it. I guess it's pretty well established that old bikes are money pits. I imagine classic cars are the same, although I've never had one so don't speak from you experience (I enjoy Bangers and Cash on the telly though.) Of course when I've put it all back together the oil leak will probably still be there - and maybe worse! But, as I say, I enjoy it, and I'm learning. Phil
Hello everyone, Nothing is simple. Got my new engine sprocket in the post today. Whereas the old one would push on easily by hand, this one is a tight fit. Started to tap it on - tricky without a piece of tube to keep it square - in order to check alignment with the clutch basket, then remembered I would need to get it off again to put the chain on, or to sort out the spacer thickness if alignment is out. So I went to get it off, and ... you've guessed it, it's now on a bit, and stuck. I see there are two threaded holes in the sprocket, so guess I need to make an extractor to get it off, and then get a bit of tube from somewhere to get it on again. In a normal domestic garage like mine, of course, bits of suitable tube, and bits of stuff for making extractors, aren't just lying around waiting to come in useful. So, as I say, nothing is simple. (Or cheap, as Pete A10 pointed out.) Sigh. Phil
Further to my previous message, I guess a good way to remove the sprocket is with a couple of bolts and a two-legged puller. Can anybody recommend a two-legged puller? Also, as always, all advice is much appreciated. Phil
Hi Phil,
Something like this may do the job. You could also use bolts that fit the threaded holes in the sprocket.
On Amazon for £19.99. I might buy one of these myself. Google sprocket pullers and you will quite a selection.
Dave.
Looks good, I like the fixable width of the jaws, and the revolving tip. But 1.5 mm wide leg ends - is that enough? Phil
Hi,
If you get something like this you could replace the legs with bolts that thread in to the holes on the sprocket. This would be very secure whilst operating the puller.
Dave.
Ah yes, as long as the bolts fit through the slots in the puller.
Or I guess I could just get a piece of 1" x 1/4" flat bar, drill two clearance holes for the 1/4" BSF bolts, and a threaded hole in the middle for another bolt. That might work okay? Might need some kind of Alli pad to prevent the middle bolt damaging the end of the shaft. What do you reckon? Phil
Ordered the puller.
Regarding tapping the sprocket onto the splined shaft, I must say it feels very tight. I need to get something like a bit of tube to go over the shaft to keep the sprocket square when tapping it on. Ideally the tube would have a closed end to tap on. So in other words a bit of alli bar with a blind hole in it. Which means I need someone with a lathe. I know a local bloke who does things like that, but of course we're on lockdown for a few more weeks. Frustrating! I'm surprised putting the sprocket on is this complicated! Still, must keep smiling. Things could be much worse. And might be before I've finished this! Phil