The outer plate of my fathers “blueScott” clutch has 3adjusting screws with locknuts is this standard or something my father thought up?Also it appears to be dished?
Hi , This appears to be the standard clutch in later years. It replaced the earlier solid pins of the
narrow clutch basket in the late 1920 s. Regards
Only the ‘works’ TT clutches had a plain “machined from the solid” pressure plate. Production road bikes have the pressed and dished plate. I’m not sure when the three adjustable thrust pins replaced the earlier, non-adjustable 3/8″ diameter solid thrust pins, probably early to mid 1930s. The nuts are 5/16″ Cycle thread, but 1/4″ spanner size, which is 0.445″ across the flats.
It sounds as if production bike clutch is the one we need . Ours is quite wobbly,it has 3 1/4 by 26 TPI threaded bushes,but the clutch is not working very well,so we think we need one of these if any one has one? new or old!
Hi Sheelagh. Where is it “wobbly” ? The whole clutch ? Just the pressure plate ? The slots for the ‘tongues’ of the plates are in both the clutch centre and the outside of the basket/chainwheel, and if those slots develop corrugations due to wear, it is a tedious job to sort out, and I do it by hand using diamond coated slips or files, because the steel is too hard for a metal file. The old Ferodo (ASBESTOS !) button friction inserts are of course long obsolete, and best replaced with continuous rings of modern friction material, bonded on. I use Saftek in Cleckheaton (formerly Mintex), and they do a very speedy and good value service, virtually by return of post. It’s probably worth replacing the six spring studs as they may be bent, and the Spares Scheme supply new ones in stainless steel. Also check that all the rollers are still in place. They are 3/16″ by 3/16″.
Second endorsement for Saftek, very fast turn round, keen pricing and good work.
Send the brake shoes off at the same time (soft woven linings) and save on postage.
You can even stipulate the radius of the finished shoe —
Have made up new cork plates, also have Ian Pearce plates,thestuds appear to be straight,but the end plate “wobbles”when you run it in the lathe although the centre runs true and it appears to be dished.One roller missing ,does this matter,sorry to be a bit of an idiot over this I nEED MY dAD BACK!
Alan Noakes, (I was with him this morning) does replacement pressure plates in a substantial thickness of alloy to get over this problem. I miss my dad too, even though he died 33 years ago. (1908 to 1985). 😥
Hi Sheelagh, sorry that I could not help with a replacement pressure plate, as I said I do make a heavy duty Dural pressure plate but none in stock at the moment, a quick fix might be to modify a spare steel inner plate by turning out the inner dogs and then opening up the centre diameter by a quarter of an inch, this plate could then be brazed on to the dished original obviously there would be a gap on the outer edge that would have to be filled with the brazing material but you would end up with a much stiffer outer plate that is not dished, it is most important that the pins are all exactly the same distance away from the rubbing face of the pressure plate, I find the only way to do this properly is to take the plate off the clutch after getting the free play correct and finely adjusting the pin height with a vernier or height guage. Alan Noakes. firstname.lastname@example.org
Thank you all of you for your help,we will try the clutch as it is with cork plates at Santa Pod in a couple of weeks,and then have a think over the winter if it still isn`t good,to see what we do next?
There are ways round everything, if man made it (sorry, if a person made it), it can be re-made, no matter what.
Run it the way it is and if it its lacking then look for a solution.
If you need a beefed up pressure plate then fine, it can be done, alloy is pig easy to machine and will do the job, times have changed, as has materials.
😀 😀 Roger Moss has the answer Sheelagh..He has run the gamut of fixes on his racer.. I’m sure that now he has a bit of spare time he would love to advise you on his solution.. Regards Ted 😀 😀
Ihave spoken to him and Richard before,but will wait until he is feeling a bit better!