The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Alex kettle on 23.03. 2021 16:51
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So this was a working setup before I stripped the forks down for refurb. On hindsight I should of paid more attention when taking things apart. It would of saved me this post here. The problem I have is that the brake plate is a country mile of locating into the fork leg. It was locating before how much I couldn’t tell you. One question I have is should there be a washer or washers that sit on the front wheel bearing face and against the back of the brake plate to space it off? I think there was one in there at least but was unsure if one was behind the hub nut. My father had these wheels rebuilt in the late 70s and the bikes had use since then. Could it be the hub offset incorrect or am I cocking things up putting the forks back together? The front spindle is self aligning is it not with relief for the bolts. Everything is lose currently and when pushing down on the forks there solid. I’ve fitted progressive springs and internal dampers. So many questions I can’t see the wood for the trees.
Enlighten me
Thanks in advance
Alex
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If that is the original full width 8" drum, 42 5853 is the casting number for the backplate used on the standard single cam 8" brake on Shooting Star , A10 and Rocket.
That TLS backplate could be the problem, A65 parts list should give the assembly sequence. Other possible is that it is the wrong fork leg for the backplate.
Swarfy.
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Thanks for the reply swarfy. Just to avoid confusion it’s a triumph twin leading back plate. Seen a few running this setup. Not sure what I’m doing wrong. Possibly a number of things
Cheers
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The A65 forks which were designed for the TLS plate have a longer peg than the A10 so either the plate needs moving over, the A10 fork peg needs extending or the brakeplate slot needs building up.
The photo shows 1968 A65 fork fork bottom above the A10 version. You can see the difference in the pegs.
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Thanks Julian . I’ll have another look at it. The A65 peg is clearly a lot further out
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assuming a10 forks... Interesting you say it previously fitted – I’m surprised. That looks like a later (69?) triumph TLS with the more agreeable cable angle. I fitted one last year. The usual routine is to build out the slot on the brake plate to meet the lug on the a10 forks because the fork spacing and hubs varied across years and models – a10, a65s and later 69 triumphs had 6 ¾” fork spacing but earlier triumphs had 6 ½” spacing. 68 a65 forks are particularly weird.
there should be no washer/spacer between the inside of the brake plate and the bearing housing/retainer. if building up the lug was not done then maybe someone packed out the plate with a spacer? That would be concerning as reduce the linings' contact area. Or maybe they just hoped the minimal contact between slot and log held… yikes.
The a10 spindle fits the triumph tls brake plate and hub (not the conical). Also your comment:
The front spindle is self aligning is it not with relief for the bolts
Is strange as, while no expert, the spindles I’ve encountered have slots to locate the end-cap bolts. Is it the right spindle?
Have a look here and see if my previous confusion and summary is relevant.
https://www.a7a10.net/forum/index.php?topic=15533.msg132080#msg132080 (https://www.a7a10.net/forum/index.php?topic=15533.msg132080#msg132080)
EDIT: OK I’ve just noticed that looks like a full width a10 hub… is it? The triumph tls plate has wider brake shoes. Maybe someone put in a spacer between the hub bearing retainer and the tls brake plate to hold the plate out so the linings don’t grind themselves to death on the spokes, while also ensuing the lug and slot mate better. That sounds a bit scary.
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Can't put anything in there becaus you could not replace the axle without it dropping off.
The axle should have a step in it to sit against the bearing inner and all spacers have to be on the outside of th backing plate unless they have some sort of retainer.
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Right I’ve come to the conclusion that this is the wrong hub to have this tls shoe fitted to. I am still unsure of the correct hub and spindle that I need to make this work. Is it a a65 hub or a triumph hub I need or are they one and the same?
Photos below are of the current set up
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Right I’ve come to the conclusion that this is the wrong hub to have this tls shoe fitted to.
If it was a working setup before you pulled it apart then it is a problem with the way it has been reassembled
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Looks like a PO has spaced the backplate away from the hub to try to alleviate the fact the hub and backplate do not mix. As you have measured, the shoes are too wide and therefore overlap the spokes.
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Your right RDfella that’s exactly what I think the PO has done. That PO would be my dad. When I quizzed him he said it was so long ago he can’t remember what he did i.e 1975.
Currently looking for a suitable 8” think flanged hub now to build into the wheel. Might as well get it right. I’ll get the brake plate lugs welded up too so it’s making more contact with the fork lug.
Post coming up in the wanted section 👍🏻