Re sprag clutch

[rick]

Hi,

I have a cush drive on the end of the drive side crank shaft. My question is how do you adjust it, it has a main adjusting nut which fits onto a large spring
My Bike is the BSA L29 350 sloper engine

Rick

[chaterlea25]

HI Rick,
I think you are referring to the cush drive assembly ?
The early BSA ones have a nut and locknut, It must be tightened enough to prevent the cams physically riding over each other,
ie, the spring must be coil bound before the cams can reach the peaks.
If the cams are allowed to ride over it will result in a damaged crankshaft (imagine a jackhammer attacking the crank  !!!!!)
On later types with the splined crankshaft the nut must be fully tightened, A,B and M models 65ft lbs
HTH
John

[rick]

Sorry John  meant to say Cush Drive, got sprag clutch on my mind at the moment Ive now modified the original posting. How do you set it up? do you just tighten the nut down as far as you can tighten it or is there a set procedure to follow

[chaterlea25]

Hi Rick,
As I described, the cams must be able to move relative to each other but not "hop" over
I cannot remember if the inner nut is fully tight or not, the outer is then locked to the inner to prevent it coming undone.
On My L25 theres about 1/8th of an inch of threads showing outside the locknut.

It wouuld be well worth your while to try and get hold of one of the "Pitman" BSA books that deal with the 30's models, something like this ??
http://www.ebay.co.uk/itm/1937-VINTAGE-MOTORCYCLE-HANDBOOK-THE-BOOK-OF-THE-BSA-PITMANS-LIBRARY-/331494842758?pt=LH_DefaultDomain_3&hash=item4d2ea1e186

HTH
John

[33d6]

Hi Rick,
Back in the 1950's the old magazine 'Motor Cycling' used to run regular 'Service Series' articles on various obsolete models. They contained useful information enabling owners to keep their bike in good condition.
Service Series No 23 published in two parts a week apart covers the 1928-32 493cc Sloper model BSA. First part covers the engine, the second the gearbox and frame. The writer also comments they cover all Sloper models in general.
The first part was published in 'Motor Cycling', May 19, 1955 on pages 78 & 79. The second part in next weeks issue on May 26, 1955 on pages 120 & 121. I suggest you get copies. Your best bet is probably the VMCC Library or you can buy the original magazines from someone like Pooks.
Another good source of info is Newnes 'Motorcycle Repair and Upkeep'. Printed in two volumes in the early 30's this covers the broad spectrum of all makes from the late 20's to about 1932 or so when it was printed. There is a special chapter on BSA. Someone in Germany reprinted these volumes and they regularly appear on UK eBay. Well worth the money as they cover the original electrics fitted, the original carburettor, etc, etc.
Frankly, if you have got yourself a nice vintage bike as you have you need to collect as much period information as you can and then study it. The bike will be all the better for it and you will learn a lot.
Cheers,

[cardan]

Speaking of old things, how's your latest repair 33d6? Hope all went well.

Leon

[33d6]

Hi Leon,
Yes, surprisingly easy. A week in hospital followed by a week in rehab. Now walking unaided without crutches or stick but not far.  I did have hopes of joining the mates on our annual run to Beechworth but SWMBO was not amused.
It's a lovely run. The bike requirement is anything old and asthmatic so all sorts of stuff has been dragged out of the back of the shed over the years. I've done it on my 1926 250 Matchless, my 147cc 1929 Excelsior and '51 James Captain when the hip was really grumpy. Other bikes range from a 250 New Imperial, the Barr & Stroud sleeve valve engine 'Ever Onward' to a 1939 Panther outfit and a Big 4 Notrun. The original 633cc Big 4, not your namby pamby post war revised 600cc version. As a change from his usual 197cc Ambassador Popular one mate did it on a minute Bultaco Lobito with his knees up round his ears. Watching him climb off after an hour in the saddle was pure Oscar material.
We do a careful inspection and sample the goods of every winery, pub, bakery, caff, cheese factory, etc, etc en route and cover about 500 miles of eating and drinking there and back over the four day weekend.
You can see why I was keen to go.
Cheers,