Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Forks rebuild

Hey all, I’m rebuilding a pair of 1971 A65 forks. The parts book shows a sealing washer (rubber inside) on the down tube Allen bolt 97-4004
The recess isn’t big enough for this washer. Have I got the wrong part?

No, wrong position. It goes on the inside. Just put the bolt through and drop it over it. The less adventurous type stick it to the damper tube with grease.

ah, that makes sense. Thank you!

Or you could cheat like I did and put a spot of super glue on the bottom of the damper rod where it meets the Alu washer, holds it for long enough to get it all assembled. 2 drops was enough.

I had to use some fire to remove the aluminum stanchion plug on one of the forks. Now it doesn’t fit back on the dampener tube. There’s a some what loose spacer inside the plug that is made of nonmetal? Apparently it got smaller ??

There is a loose non metallic " seal " in the bottom plug, sounds like you toasted it, get another plug seal unit.

If I recall, that plastic seal (not really a seal) is held in with a few swages. I removed the swages to remove the old plastic piece and made a new one out of Delrin or some other unknown plastic, and re-swaged it in place. I think it is sort of a flow restrictor rather than a seal.


Tom

The plug is a seal between the lower slider/damper tube chamber and the upper inner stanchion/damper tube chamber. Because of the clearance of the stanchion in the slider and the flex of the stanchion a traditional seal would probably not seal very well and cause too much stiction. The plug seals on the ends which is why it is loose radially.
If you already have the stanchion nut mounted, are you sure the damper tube is not just hitting the top edge of the plastic sleeve? Thread a long 5/16" bolt into the damper and drop it through, use the bolt to push the damper tube around until it aligns with the sleeve. Otherwise slip it on the damper tube then tighten in the stanchion.

I found a NOS replacement online, thanks for all the tips.

I have hit another snag in my fork upgrade. To recap, I want to change out my 1970 A50 single leading shoe with a 1971 A65 twin leading shoe brake setup. I found a complete hub and having it laced on my rim. I found the appropriate fork stantions and axle to accept the different hub, and got new fork tubes, but these forks tubes are too thick for the A50 triple clamp. Assuming I can locate a 1971 A65 triple clamp, will it work on my 1970 A50? I always thought the A50 was basically the same bike as the A65 (smaller barrels)...

also, will 1971 A65 steering head bearings fit into a 1970 frame?

The 1971 and 1972 models were all 650's and oil in frame with totally different parts than the 1970 and earlier A50's and A65's. You will need a bearing adapter to run the OIF triple trees on your 1970 and earlier frame.

Last time I checked, BCS and I believe Lowbrow Customs had the bearing conversion kit/parts.

thanks for responding. Is this the kit you are referring to?
http://www.britcycle.com/Products/99/99_3733a.htm

What about this SRM set-up? Will this work do you think?

http://www.shop.srmclassicbikes.com/product/t140-disc-or-conical-hub-conversion-steering-bearings

No, that Triumph kit in the first link is not what I was referring to.

Yes, the second link of the T140 or Conical hub conversion is what you want.

I received my SRM tapered roller bearing conversion kit today (in record time no less) the bearing outers fit my A50 frame perfectly and the inners fit on the new A65 steering stem as well. The bottom part of the steering stem has a shoulder, is it intended to fit inside the lower bearing? Because it does not. This triple clamp assembly came with no bearings so I’m not sure how it’s supposed to go...

** actually I think this is a 1971 OIF Triumph triple clamp **

Nope your image is correct, the bearing doesn’t go past that shoulder. On the OIF the bearing sits seeping into the headstock than it does on the pre oif so the spacer gives the clearance needed for the bottom yoke to work.

HTH

All these conversions cannot get around the fact that the taper roller bearings are thicker than the original cup and cone, so your yokes will be further apart. So if you use the normal headlamp ears there will be a gap at the top, black paint or tape on the stanchions will cover it up.

I probably will not use the chrome headlight ears as they don’t fit over the triple clamp. The SRM bearings are spot on, I’m very impressed!

Another issue I’m seeing is the steering lock section of the Triumph triple clamp is interfering with the A50 steering lock on the frame. Hopefully I can shim that out, or something will need grinding. Not planning on using it anyways. It took a thief 30 seconds to break the lock in my Commando.

20 secs with a file will fix that, it only stops casual theft;.