Saturday, July 17, 2010

A10 Fork Springs on S7 Deluxe

The recent subject matter of discussion in the Sunbeam Owners Fellowship got me thinking about how to cure the bouncing front end of my S7D.  The suggestion was to swap out the stock fork springs for slightly longer ones used on the S8, or from a BSA model A10 Rocket Goldstar.  It seemed an easy enough task after reading the Bedside Book.  I easily obtained NOS springs from the UK and went to work.

The top cap nuts and steering head bearing tensioner came out easily.

I then backed off the pinch bolts on the top triple tree.  It easily came off with a few bumps from a rubber hammer underneath.  I laid it carefully back against the tank with a towel.  (A good man always knows where his towel is.  I like to think of myself as a really hoopy frood.)

After jacking up the front end, the screws from the spring shrouds came off and I protected the mudguard with some towels as well.

This was too easy.  The next part involved some clever improvisation.  I didn't have the right spanner to remove the nuts from the top of the triple tree.  So I had to make something.  I took the next largest size socket that I had, which happened to be 1-5/8"... then taped two 10-32 screws to the inside of it.  This way the screws would grasp the notches in the nuts, and turn them off easily.

The nuts easily came off and I had access to remove the headlamp and brackets.  I left them as one piece and set them atop the handlebars and top triple tree.

The ease of dismantling was interrupted by a trip to Harbor Freight to get a bigger adjustable wrench, since I didn't have one quite big enough to take the bottom nuts off the forks.

Reversing the order of disassembly, puts it all back together.  The forks are rather stiff now.  I hope this improves the handling as much as everyone says.  Tomorrow I shall find out.  No sense in going out to try out the handling in the dark... especially when there's a new Doctor Who episode on.

5 comments:

  1. graeme laird scotlandJuly 18, 2010 at 2:34 AM

    Well done, nice job you did with replacement repairs,mine is std 1950 picked up in Jan stood still since 1978 100% all there S7 Deluxe,just had the first MOT done at the weekend after restoring her so did 5 miles that day with out any licence plates have cover insurance now for her 30 days..here in |Scotland Uk now have to apply for an age related no to 1950 from DVLA,was toying on the idea of new springs from a beeza but the handling seemed ok to me a bit heavy..think maybe have to grease the ball races a bit more on the steering head or the friction damper to tight.
    Let me know if the improvement is like night or day? or hardly any difference?
    Was the cost worth it?
    regards: Graeme Laird. Angus in Scotland

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  2. 100% improved. The low speed handing is good now, and the bounce at 45 mph is eliminated. Yes, its like DAY and NIGHT.
    Well spent £21 GBP.

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  3. Nice work! That should make another trip to Jefferson more enjoyable behind or ahead of the Panhead.
    Carl

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  4. Had to do something on my S7 after changing the fork bushes as then the headlamp got too close to the front mudguard using standard length springs. I cut some scaffold pole 20mm long and stuck them above the springs below the yoke and this fix works just fine.
    The handing on mine is very good. I have a modern round section front tyre and adjust everything. You need to clean up the fork sliders to stop them ripping the seals to bits. The front end used to judder badly at speed but solved this by balancing the wheel properly.
    Some people run on 20 year old square section tyres with oval wheels, knackered steering bearings and worn-out fork bushes and no oil...... and then they will tell you that S7's dont handle!!

    all the best

    Andy from London

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  5. That early S7 is a old dublin ireland registered bike. ZJ was from January 1949-July 1950. Wonder how ended up in Ohio!

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