The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Sealandroader on 20.07. 2014 22:27

Title: type of bolts
Post by: Sealandroader on 20.07. 2014 22:27
excuse my  ignorance,  can anyone tell me the type of  bolts i require to fit   stays   (42-6510 )   TO MY FRONT MUDGUARDS, i think  they are  unc  but only a guess, and i would prefer to get it correct  1st time
Title: Re: type of bolts
Post by: Derby Rob on 20.07. 2014 23:29
well if i had to guess i would go with british standard cycle,i thought that only the engine had unf/unc or whitworth .
Title: Re: type of bolts
Post by: morris on 20.07. 2014 23:34
I find these look nice;
http://www.degroot-bsa.nl/index.php?route=product/product&path=45_130&product_id=1159
Title: Re: type of bolts
Post by: chaterlea25 on 20.07. 2014 23:35
HI,
The bolts will not be UNC or UNF,
They will be 26 tpi cycle thread (most likely)
It would help if you also added the year and model and which location the bolts are located
Are standard guards fitted?
comprehensive list here, http://stainlessbits.com/link12.html
but I cannot see the part number you quote

HTH
John
Title: Re: type of bolts
Post by: Sealandroader on 21.07. 2014 16:41
thanks for your replies  , now sorted, it was UNF  that i required, now ordered and  dispatched.
Title: Re: type of bolts
Post by: Garry Point Lonsdale on 16.08. 2014 12:45
Can anyone advise me where I might be able to buy lend borrow or steal a 26 tpi thread file.  The threads on my fork legs of my basket case A10 have been damaged and I am unable to screw the new chrome throuds down.   There are also quiet a few other bolts that will need repair.   

Gaz
Title: Re: type of bolts
Post by: bsa-bill on 16.08. 2014 14:21
I've never had much luck with threads files on smaller sizes, I'd say get cycle thread dies, you only need three sizes to cover about everything on the bike.
I've just tidied up the threads on my forks with a split die, I use a screwdriver in the split to turn them in places where you can't get the handle/holder, the screwdriver opens the die a little so as long as you watch to keep on the thread it cleans them up, a time or two like that then you can dispense with the screwdriver and get full depth on the thread.
Title: Re: type of bolts
Post by: unclerob on 16.08. 2014 18:03
Hi, Cromwell Industrial Tools sell BSW/BSF thread files
https://www.cromwell.co.uk/index.php?search_all=thread+restoring+file&p=advancedsearch&q=0&search.x=41&search.y=6
 I had the same problem and bought one but in the end found that an old seal holder with some slots cut in it did a better job....
Title: Re: type of bolts
Post by: muskrat on 16.08. 2014 21:01
G'day Gaz. I'm with Unclerob for fixing that thread. Cut a few slots in one of your old seal holders, open it up a tad, screw on then put a hose clamp over it and tighten it. A little at a time, might take a few goes.
Cheers
ps. I got a tap & die set 1/4"-5/8" from Tracy Tools 30 odd years ago, only broke one so far.
http://www.tracytools.com/taps-and-dies/loose-sets/26-tpi-cycle-1-4-1-2
Title: Re: type of bolts
Post by: bsa-bill on 16.08. 2014 21:21
 whoa there - I got thrown by the throuds and was still thinking about   Sealandroader stays so my post probably don't make a lot of sense - yep might have a long search looking for a die that size.
Agree with the use of an old sealholder.
And on the subject of such, I've just had mine off the Flash, it can be a bit of a struggle, I found a good tool is one of those rubber straps that you wind around and through the handle which has teeth that grips the belt, normally pretty useless I've found BUT think maybe I was using it wrong, wrapping the belt around the threaded bit of the seal holder merely tightens the threaded bit to the thread on the fork, if you grip the very top of the seal holder it seems to get a better grip and puts no pressure on the threads - result mine came off no problem and had been on for around thirteen years at least
Title: Re: type of bolts
Post by: duTch on 16.08. 2014 23:25

 Made sense to me Bill, for what it's worth- even after I got to the throuds (thinking the top shrouds yoke pinch bolts), I was wondering how Sealander got on with those UNF's
Title: Re: type of bolts
Post by: RichardL on 17.08. 2014 15:29
thanks for your replies  , now sorted, it was UNF  that i required, now ordered and  dispatched.

I'm confused (What, again?)

42-6510 is a mudguard listed for a Goldstar, but, I think, used on later models as well. Draganfly uses the same mudguard picture for the Goldstar and for your '62 A7, but they don't reference "42-6510" on that page. From that picture and the parts list, it seems the screws you're looking for are part number 2-204 (or 02-0204). Burton Bike Bits lists that part as 1/4" CEI. In my opinion, unless you are going for absolute concourse or museum condition, screws and nuts such as these can be whatever is available and fits the look you are going for.

From burton:

Triumph, BSA, Norton Price List
File Format: PDF/Adobe Acrobat
Jan 7, 2014 ... 02-0204. BOLT - 1/4" CEI X 1/2" UH (GKN. £0.35. R). 02-0220. BOLT - 1/4" CEI X 3/8". (EX-. £0.35. TIEBAR TO EXHAUST). 02-0250. STD BIG ...
www.burtonbikebits.net/TRIStock.pdf

Link to Draganfly mudguard page:

http://draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/943-a-group-1954-62

Richard L.
Title: Re: type of bolts
Post by: muskrat on 17.08. 2014 20:45
I'm sure your right Richard. 1/4" cycle thread bolts were used. The only problem with using UNF is having to carry another spanner of the AF variety. BSA didn't use UNF/UNC threads until the later A50/65's.
Cheers