Author Topic: Sounded like a bucket full of bolts  (Read 253 times)

Online Slymo

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Sounded like a bucket full of bolts
« on: 16.12. 2019 22:53 »
Went for a 400 mile ride to Wellington on the 58 SR the other day. First big test of the machine which I have comprehensively rebuilt and I was extremely pleased with the overall performance.

Auckland to Wellington is a fairly fast ride and if you pick the right roads quite pleasant. After a stop in the Waikato for a large fried breakfast we made it, with a couple of stops for fuel, to Taihape where there is an excellent cafe. At this point I thought I'd check the primary chain tension and indeed found that I could make it touch the top of the case. A quick application of the spanners and it was once again in proper adjustment. From there with full tanks the Velocette Venom my travelling partner and I made it to Foxton for another re-fuel where in typically howling plains winds I lost my ear plugs.

All went well until we arrived at a slow bit in Levin which required a low gear trawl up the main street. It was at this point I noticed that my gearbox sounded like a K series Bedford truck box in a tired state. Visions of flaking hardening and missing teeth where top of mind but we were close to the destination and I thought that I would grin and bare it and see what was going on when I got into Welly. Apart from the woeful siren in first, second and third all was good and I garaged the bike that night thinking of the ignominy of trucking the SR back to Auckland.

Next morning bright and early I was ripping the box apart. Oil was slightly golden in colour but no signs of any real distress. The clutch which had been prone to slip under hard acceleration looked fine and the sleeve pinion bush which was my chief suspect (I had replaced it with off the shelf bronze bushes from the local supplier) was also fine.

Three assemblies later (I for some reason kept putting the spacer on the main shaft inside the inner cover) the bike was back together and still making the noise. However my time was up and in the absence of any obvious sign of problems I decided to ride the 400 miles home. It was a great ride again. The A10 has lovely long legs and was an absolute pleasure to ride. The West Taupo Road was empty and buzzing up that was about as much fun as you can have in a seated position.

The morning I left Wellington I'd had a thought that in adjusting the primary chain I hadn't re-positioned the baffle plate at the back of the timing chest. The gearbox in the SR is definitely not mint. The bearings in it when I got it were more shagged than any I've seen before and worse there was a bit of pitting and water damage to a couple of pinions but it went together well with new bearings throughout and whilst it did howl a bit in third it was well within my tolerance levels.  The sliding plate was obviously bearing up against the clutch and making the primary case into a sound box amplifying all the normally concealed racket.
I've sorted it now and once again the SR is turning heads for the right reasons not because people think there is aproaching a fire truck or Police pursuit. All of you with more BSA experience than me are probably nodding sagely but for those like me new to pre unit construction this may save you a sleepless night.


Online morris

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Re: Sounded like a bucket full of bolts
« Reply #1 on: 18.12. 2019 19:45 »
Makes me think of the time when a rattling noise coming from around the primary scared the hell out of me.
It was the kind of noise you got when we were kids and pinched playing cards to the front forks of our bicycles to have them rattled by the spokes, only louder.
Turned out it was the primary chain hitting the "slab" on the upper part of the gasket...  *eek*
 BTW, never understood the need for this "slab" though all SA primary gaskets seem to have them?
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Offline Bsareg

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Re: Sounded like a bucket full of bolts
« Reply #2 on: 18.12. 2019 22:20 »
The "slab in the gasket is for the inner primary case fitted to the singles. Basically the same case except the inner "dips" there to allow clearance for the mag points cap to be removed.
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