The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Dean on 14.04. 2014 21:03

Title: Primary problem finally sorted?
Post by: Dean on 14.04. 2014 21:03

I was browsing on here last night and came across the tip to use a ratchet strap over the seat and round the swingarm to simulate the weight of the rider when adjusting the rear chain.
So this morning I taped a tall  piece of cardboard to the chainguard, climbed onto the rear ot the seat and used the mudguard stay as a reference to mark the height of the seat with me on the bike. Strapped a big ratchet trap round the seat and swing arm and compressed to the marker.
Blimey, the rear chain was tight!
No wonder it felt like the suspension was bottoming when I hot a bump at speed, but more significantly I may have solved a problem I've had ever since I built the bike. I have had to keep re-adjusting the primary (belt) drive as it keeps tightening up. Well, now I have and explanation for it. The tight rear chain must have been pulling the gearbox back slightly *roll*
I will take for a hard run in the next few days to test this out.

Even if this is not the issue I must express my thanks for the tip on loading the suspension with a ratchet strap. Sorry I cannot recall who posted it but I owe you one. Its tips like this that make this forum invaluable to me.

Title: Re: Primary problem finally sorted?
Post by: muskrat on 14.04. 2014 21:32

That was BSA54_A10
Cheers

Title: Re: Primary problem finally sorted?
Post by: duTch on 14.04. 2014 23:35

 I thought you had an idea like that Musky...??

 I think a lot of people don't realise the chain is tightest when the sprockets are in the same line as the S/a spindle.
 I reckon ideally the spindle should be on the same centre as the drive sprocket...??