Hope somebody may help,have noticed a clatter from the front end recently.Mudguard and stays okay,may be clatter on the rebound or broken springs,headstock bearings okay no play ,use 20/50 oil in forks.When you push forks up and down all okay?
Regards Barrie.
The 3 main possibilities would normally be head stock bearings, fork bushes or front brake anchor fixings. Head stock bearing play is easy enough to detect with wheel off the ground and then try to detect movement at bottom of fork legs. However, fork bush wear may be more difficult to detect in the same way and it might be better to check it with the wheel removed to allow each fork leg to be checked separately. I believe the front brake plate has a steady strap fitted and, if not tight, might cause clatter in principle.
If the clatter persists and the above checks don't reveal a problem, it might be necessary to take the forks off in order to check their internals for a problem. I think a clattering front end may well be a big safety issue and it is probably not worth the risk of riding the bike until the problem has been sorted.
A clanking noise heard when the forks fully extend is usually caused by the top and bottom bush hitting each other.
This is quite common with the heavyweight BSA forks pre 1966 type and is sometimes mentioned in period road tests and experienced by many owners over the years. There is not much damping when the forks extend.
The US service sheet below gives some information.
Thankyou for the help so far, had new fork bushes head bearings,chunks mainly on big bumps or lots of little bumps
If noise from the brake plate and head bearings is ruled out, the next step is probably to remove the fork legs and, without the spring getting in the way, to exercise the fork legs to see whether you can re-produce the noise. If it's coming from a fork leg, you are probably then going to have to take it apart to check the fit of the top and bottom bushes and whether they are moving on the stanchion for the bottom bush and inside the fork slider for the top bush.
Hi,
As you have fitted new bushes I assume they were a nice sliding fit with no known wear on the stanchions so , although there may still be a wear problem try something else first. As has been mentioned, the damping on the return is very poor on these forks so perhaps this a can be improved by using a different oil. You say that this is a recent thing so it was OK before. Was this before fitting the new bushes and were you using 20/50 oil?
A slightly heavier mono grade may help and an SAE30 can be found in small quantities in lawn mower suppliers.
Dave.
new top bushes may have play in that they move up and down in the slider. There are shims available to take up this play betwen the bush and retaining clip.
Although it is annoying the clanking has no effect on the fork performance.
see here https://draganfly.co.uk/product-category/bsa/sparesparts-for-bsa-a710-b3133-c101112-m202133/forks-abcm/telescopic/
number 20
Thank's for all your useful reply,s.All fork parts are new after restored bike,read about fork rebound on early forks.
Will try thicker oil like Dave,s suggestion sae30,may be 20/50 a little to thin?. Think thicker oil will do no harm,give it a go
easy first option, will let you know how i get on.Did the bush shims on rebuild ok. Is a broken spring be possible ? Regards Barrie.
Going to a thicker oil will do no harm but expect a harder ride. I use 15 grade in the forks of my B33 and Shooting Star.
Changed oil in forks to Morris golden film 50 grade i have all ready, seems a lot better than 20/50 on these early forks.Clanking noise has gone or reduced a lot,may the oil be little thicker than should be,but seems to work okay.Might try 30 grade next time.
When looking for front end clanking,did notice fuel tank rocking on the front through bolt making a noise.As bolt does not clamp tank to frame as such,elongated holes in ears.Will try plastic sleeve on bolt to reduce rattle. Barrie
Hi Barrie,
Interesting that you noticed the tank making a noise. This reminds me of a similar occurrence on my wife's '51 Flash. The tank on the early plungers was bolted tight to the frame. Unless really tight it would make a noise whist riding. The later ones had a rubber bush so that the tank was then isolated from the frame. If yours has a gap you either need to clamp it tight to the frame or if the gap is quite large fit some large washers to take up the gap and then tighten it really well.
Dave.
Hi Dave
Thanks for the advice,yes there are small gaps between the tank bolt ears and frame.
This partly the clunking i here over bumps,will pack out tighten more.The thicker oil is
better in the forks now,better cushion on the early type forks .Regards Barrie
Tap washers work well between the frame and tank.