Author Topic: Blue Star Single Spring Clutch  (Read 338 times)

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Steve.S

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Blue Star Single Spring Clutch
« on: 30 September, 2023, 01:57:50 »
Can anyone explain the design of the Clutch Hub Bearing?
 1932 models had 2 identical brass? rings (15-307 Clutch Ball Retainer) to hold the balls, but in 1933 BSA changed one of them to a thicker ring (15-306 Clutch Ballrace Ring).
I assume the thinner ring goes on first? Can anyone confirm?
Regarding fit, it seems clear neither of the rings should rotate on the hub, so an interference fit would be needed on the hub. The inner one could probably be a light interference fit (to allow for removal), but what about the outer ring? If this were an interference fit, it would be necessary to adjust it's position carefully, to give the necessary clearance to allow the balls to rotate. Maybe just push it hard on and then back it off tad? It probably wouldn't back off squarely.
Neither of my rings are an interference fit, but the outer ring has never moved outwards allowing the balls to drop out, in thousands of miles, even though- if loose- there is nothing to stop the ring moving.
Does anyone have any thoughts on this?
 

Phil Hartshorn

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Re: Blue Star Single Spring Clutch
« Reply #1 on: 04 December, 2023, 18:44:42 »
Hi Steve
I don't know whether you sorted your clutch queries or not. It looks like the bearing guides are retained by the clutch plates. It's a long time since I had my clutch in bits, so my memories are a bit vague. Maybe the picture below will help.

Phil Hartshorn

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Re: Blue Star Single Spring Clutch
« Reply #2 on: 04 December, 2023, 18:51:14 »
Sorry Steve I can't make the attachment work. Email ED and hopefully he'll send me your email address.

Steve.S

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Re: Blue Star Single Spring Clutch
« Reply #3 on: 29 December, 2023, 18:47:14 »
Phil,
Sorry, I've only just seen your reply. Very rude of me.
I should have mentioned it's the single spring clutch I'm referring to.
If the picture you mention is the one in the Instruction book, I already have that.
In fact there is a gap between the outer brass ring and the 1st steel plate, so although it would stop the ring coming off, it wouldn't stop it from moving outwards.
I wonder why BSA changed the thickness of one of the rings?
Thanks anyhow for your reply.