Good evening everyone,
Me again. I found a bit of metal (cast) in the bottom of the primary chaincase (1965 B40F) so thought I'd better have a look at the chainwheel teeth. Sure enough, one was broken off. Two questions please:
1. The bike's not done many miles since I was last in the pc, so I'm thinking this might be recent. What would have caused it? Me trying to get the rotor nut off? Me using my clutch locking tool eg when tightening the kickstart ratchet nut? (The locking tool is a bit like the one in Rupert Ratio.) Something else?
2. Do I need to buy a new chainwheel?
Thanks in advance.
Phil
Hi Phil,
Unless you jammed something against it then from your list I would go for something else. Can you post picture of the piece and the damage on the chain wheel?
Dave.
No I didn't jam anything against the tooth. Here are some photos: two of the bit of metal I found in the bottom of the pc (it's the one piece from two different angles); one of the chainwheel with its broken tooth; and one of my clutch locking tool (in case it's relevant.) The little bit of metal doesn't fit exactly on the wheel to make up the missing tooth, so maybe more than one piece broke off and maybe I lost the other bit(s) when mopping oil from the bottom of the pc. I think there's just the one broken tooth.
Any ideas how it might have happened, and do I need to buy a new chainwheel?
Phil.
Hi Phil,
The locking tool look fine and would not have caused this. Id the broken surface still shiny and fresh looking or is it a bit dull? Bright and fresh looking could mean it is recent otherwise it has been like that for a while. As you have the chain off examine it closely to see if there are any marks on the rollers or if any rollers are missing. Also look for any marks on other teeth ad on the drive sprocket. Check the chain for wear as this damage could have been caused by a slightly slack worn chai. If everything looks good then you could get away with the broken tooth as a good part of the drive side is still there but gently smooth the rough bit to avoid damage to the chain.
Dave.
How do I check the chain for wear? I seem to remember last time I adjusted it there was not much, if any, adjustment left.
Hi Phil,
I think that 'no more adjustment' means worn out. I have just fitted a new primary chain to my A65 for this reason. No need for any further inspection as I would say this is definitive and unlike a rear chain they cannot be shortened. Make sure the replacement is a continuous one IE not joining/spring link.
Dave.
Okay thanks Dave, I guess I'll get a new chain. While I'm at it, maybe I should get a new chainwheel as well. Phil