The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: bsa-bill on 03.05. 2009 09:50

Title: TLS cam nut thread
Post by: bsa-bill on 03.05. 2009 09:50

HI guys, I'm looking for a bit of info -
Started to biuld my front brake up ( TLS replacement for standard one ) and it would seem the nuts on the cams are not cycle thread, a cycle nut will go about half way on then gets tight, the original nut will screw onto a cycle bolt though.
I know there is a thread ( is it BSF ) that is close to a cycle thread but thought I'd ask and save a bit of time.

Thanks - Bill

Title: Re: TLS cam nut thread
Post by: flashblack on 03.05. 2009 09:59

Hi Bill, i used to have one of those brakes on mine and when i built it up i seem to remember those threads being unf, which they seemed to use in the late sixties for some reason.
    regards Richie

Title: Re: TLS cam nut thread
Post by: bsa-bill on 03.05. 2009 10:09

Thanks a lot Richie, I know where I can lay my hands on a couple of those.
(Forum to the rescue once again)

All the best - Bill

Title: Re: TLS cam nut thread
Post by: BSA_54A10 on 03.05. 2009 12:29

3/8 UNF to be precise and it was a special shake proof nut there being no spring washer behind it

Title: Re: TLS cam nut thread
Post by: bsa-bill on 03.05. 2009 17:25

Thanks Trevor - been upto our worshop but all our nuts are unc so I need to order some and as you've informed re shakeproof I'll get stainless self locking from Custom fasteners - quite a good firm to deal with.

All the best - Bill

Title: Re: TLS cam nut thread
Post by: BSA_54A10 on 04.05. 2009 08:25

I think that it was one of those oval holed jobs you know they go tight then slack then tight then slack and you always worry that when they went slack it was because you stripped the threads. Can never remember the correct name for them.