Author Topic: A10 front fork slider repair  (Read 4664 times)

Offline MikeN

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Re: A10 front fork slider repair
« Reply #15 on: 09.07. 2009 20:00 »
Lannis,

I know that Alex knows of what he speaks from experience, and I respect that, but I do not understand why one would choose UNF when Whitworth coils and bolts are available. I would see it as an excuse to have the Whitworth kit around for other purposes where it is not convenient or you would not want to casually change to UNF.

Richard L.

Its probably because 5/16-24 UNF is nearer to the correct tpi of 5/16-26  BSCy than 5/16-18 Whitworth (or 5/16-18UNC for that matter).
Which means it (Whitworth) also has a considerably smaller core diameter and is not ideal in this application.
Mike

Online RichardL

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Re: A10 front fork slider repair
« Reply #16 on: 09.07. 2009 20:13 »
I used "Whitworth" generically. Perhaps the original is 5/16-22 BSF, for which there is also insert sets. Unfortunately, that type leg is not in my parts book so I can't cross-reference the BSA part number to a parts list on stainlessbits.com, or the like, to know the exact original thread.

A bit of self analysis: Why is it I am politicking for British threads when other threads might do? I think, because I regret replacing 3 of 4 sump-plate threads with 6mm inserts instead of getting the appropriate British inserts.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline beezalex

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Re: A10 front fork slider repair
« Reply #17 on: 09.07. 2009 20:35 »
Well, I go for the more commonly available threads because 1. I can get everything for it in less than 24 hours and 2. particularly for safety-critical applications, I like to get high-strength fasteners and those ARE in fact available at my local hardware store in SAE threadform.  By all means, though, if originality to that level is important to you and you're not in a hurry, spend the extra time and money.
Alex

Too many BSA's


Offline LJ.

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Re: A10 front fork slider repair
« Reply #18 on: 09.07. 2009 21:06 »
I expect poor ole Lannis's head is spinning by now!  *lol*

Note: Is that correct? Lannis's or Lannisses? I give up!
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline Lannis

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Re: A10 front fork slider repair
« Reply #19 on: 10.07. 2009 00:06 »
I think "Lannis's" would be right although I've never really thought about it.  Since it's my name, I suppose I can make up the rules if I like.

I had not thought about the possibility that there might originally have been studs in these holes, and nuts went on them to hold the axle caps on?  Were they originally studs or bolts .... ?

I'm suspecting bolts, since my A65s all had them, but studs would make sense too.

Lannis
1961 A10 Golden Flash
1969 A65 Firebird Scrambler
1955 M21 Commodore
1935 Matchless Model X Project
1990 Moto Guzzi California III
1983 Moto Guzzi 1000SP
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1966 Morgan 4/4

Offline coater87

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Re: A10 front fork slider repair
« Reply #20 on: 10.07. 2009 03:13 »
 I have found the proper thread inserts from re-coil.

 The problem I see is the lack of insert length, maybe I am missing something in their offerings, but it does not appear they offer longer length inserts. Just what we would call "stubs", which are great for most uses, but certainly dont cover them all.

 Take my barrels for instance, the threads are shot completely. I would feel much more comfortable using a coil for the head bolts if they were deep enough to almost bottom out. But the short ones they offer have me worried to the point I may just have to go with SAE from Heli-coil for piece of mind.

 Anyone know of a place that offers the correct thread inserts in longer lengths?

 Lee
Central Wisconsin in the U.S.

Online RichardL

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Re: A10 front fork slider repair
« Reply #21 on: 10.07. 2009 04:25 »
Lee,

Recoil is an Alcoa product. Here is a link to their catalog. I think the British thread listings start around page 46 (or thereabouts)> The trick will be finding a distributor for the size you want. It may take a call direct to Recoil/Alcoa.

 http://www.alcoa.com/fastening_systems/commercial/catalog/productcatalog/Alcoa_Recoil_Catalog.pdf

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

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Re: A10 front fork slider repair
« Reply #22 on: 10.07. 2009 06:32 »
Studs and nuts, or set screws/bolts? Both my BSAs have studs and nuts on the fork bottoms - already there, not mine.

I always use studs washers and nuts where I can as the fewer times things come out of critical 'oles the better.
I'll happily make things in metric if that means stealing less metal at the receiving end! But I'm also a big fan of 5/16th 24 and 3/8th 24 UNF - a very useful pair of fine threads and easily obtainable everywhere your side Lannis, in good quality as you say. Just means carrying one extra, AF, spanner from time to time. Per MikeN's comment, I use WW very rarely except into alloy as the minor diameter is so small - which is why BS'Fine' came about.
Bill

Offline beezalex

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Re: A10 front fork slider repair
« Reply #23 on: 10.07. 2009 14:33 »


In steel, fine thread bolts are fine and the threads should be able to endure many, many assembly/disassembly cycles under ideal conditions.  Unfortunately, dirt and misaligned threads tend to limit this.  With helicoil (or recoil, for that matter) the threads become much stronger since they are now rolled, just like the threads on the bolt, so it should be as good as a stud.  AFAIK, BSA never used studs until the OIF forks.
Alex

Too many BSA's


Offline cus

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Re: A10 front fork slider repair
« Reply #24 on: 11.07. 2009 00:12 »
G'day All,
I might as well throw my hat in the ring as well. I just re-built my front end, & this is
my opinion only, but I would be replacing those sliders rather than mucking around with
the threads on such a critical part of the bike, it sounds like they are pretty old
& are probably flogged out inside as well. Over here I can get new for about $120 ea.,
then you need bushes etc. but could be worthwhile (Peace of Mind) doing 100kmh down a bumpy road.
Then you are right for another 30 years!

regards, Cus
56 G/Flash project

Offline Lannis

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Re: A10 front fork slider repair
« Reply #25 on: 19.07. 2010 21:52 »
Here's another thread I never responded to with the solution, despite tons of excellent input.  My apologies.

I made it home fine from the trip I made with the old bolts barely holding the axle on, with a good check-over whenever I stopped.

I ended up taking the sliders to a good machine shop, with directions to remove a minimum of metal from the existing holes, and tap them for high-tensile studs of the appropriate length.  They did, and it works great.   It's nice to be able to tighten down properly on those axle clamps!

Lannis
1961 A10 Golden Flash
1969 A65 Firebird Scrambler
1955 M21 Commodore
1935 Matchless Model X Project
1990 Moto Guzzi California III
1983 Moto Guzzi 1000SP
1986 Yamaha TT225 trail bike
1966 Morgan 4/4

Offline brackenfel

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Re: A10 front fork slider repair
« Reply #26 on: 20.07. 2010 18:23 »
Hi Lannis,
I think that bolts are the standard fitment rather than studs..
My '61 Flash had a similar problem when I took the front wheel out to look at the brake shoes.. In my case the bolts were worn as well & there was (I hope!) enough thread left in the legs for new bolts. I didn't overtighten them though, just in case... Check the bolts in there are the correct ones - I've found all sorts of strange bolts on my bike that are "almost" right thanks to previous owners...

I suspect this may be a fairly common problem - good luck with sorting it...

Adrian
1961 A10 650 Golden Flash - Blue
1954 BSA B33
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Online groily

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Re: A10 front fork slider repair
« Reply #27 on: 20.07. 2010 20:50 »
Well done Lannis. Whatever might have been there to start with, there's nothing better than studs and nuts. I keep on wondering why the heck bolts or setscrews were used when studs would've been better if there's clearance. Whenever I can I replace anything that screws into something sensitive (and which has to come off often) with a stud . . . and make it a stepped one if the original hole is doubtful. Might surprise the next owner, but I'll be dead by then, so no problem.
Bill