I have a B33 allegedly 58' and it has the SLS brake drum, I also have TLS front hub assembly of the Triumph/BSA later models. It has been suggested (here) that the most expedient method of grafting the TLS hub onto my bike is to swap the existing lower shrouds for the later A10 model type which possess the later type of brake steady, the one which is integral to the lower fork slider. This would also solve the problem of the differing front wheel spindles, the existing spindle being QD and the TLS unit has the retaining brackets with two bolts to either side. My question, however, relates to the information contained within the instruction manual for these machines (B31/33). The 2 copies I have, both seemingly identical and nominated as 00-4079 and they are the reprinted March 1965 editions. I am unsure as to whether these publications relate to my machine! The foreward to the information provided within the booklet advises the owner to switch on the ignition prior to attempting to start the engine (amongst other things) my bike does not possess such an item, and the diagram denoting the various controls does not feature an advance/retard lever. The reason I have been poring over these printed pages is because it would appear that I need special tools 61-3350, 61-3005 & possibly 61-3063 in order to carry out the transplant and I am unsure of the facts. I would appreciate any advice as to these problems.
If your bike is 1958 then the frame number would commence FB31 and the engine number GB33. This would be coil ignition and 7 inch full width hubs back and front.
What do you actually have?
If you have the 8 inch half width hub then it is one of the best single leading shoe BSA brakes, given decent linings and mechanical condition.
You don't give the true picture. You say your B33 is 58 does it have the 8 inch half width hub which is the one fitted up to 56 when they went over to the Ariel type. Then about 58 they went to the Triumph type with the clamp on the bottom of the fork leg. If that type you can build up the brake anchor with weld to engage properly with the TLS brake plate. If you have one of the earlier forks then you will need new fork legs. You will need the tool for unscrewing the oil seal holders. Also you need the means to pull the stanchions back up. Either the proper tool or a ground down top nut with a length of studding welded to it.
In theory you can remove and replace the forks in the yokes without special tools.
The service sheet from 1948 explains. Sounds easy but expect to try it a few times before you succeed.
Removing the oil seal holders is not so easy and you need the correct tool or a home made one.
On fitting the TLS - photo shows 1968 fork (designed for TLS) at the top and up to 1965 type designed for SLS at bottom.
You will see the difference in length of the lug for 1968.
Hello Julian & Idie, The Frame No is indeed FB31 1555, which I believe is 1958 - however it has a magdyno and does not have a ignition switch. All I want to do (He said simply) is convert the bottom part of the forks to accept the TLS hub and spindle. Thank you very much for the diagram & service sheets. The difference in the length of the square protuberances which secure the drum look quite small. I am unaware of the date of the TLS, but the depth of the lug is about 3/8"
My 350 has the Aeriel drum, full width, not very effective - The 500 has has the half width unit, which is more effective.
The 500 motor is way older...47!
The lug on the later fork stands out approx 4 mm further from the fork tube than the early fork.
Thank you Julian, could I really impose on your good nature and enquire whether you might be able to provide the factory part number for the right lower fork slider with the square locating peg as suitable for a B series 1958 frame?
42 5076 for off side and 42 5078 for nearside.
Last photo iis an 8 inch TLS with the slot built up with ali weld. A bit blurred unfortunately.
Hi Julian, could I impose and ask for a description of what identifies the fork sliders suitable for 8" half width brakes (M21)? I really need a set but have never seen them so son't know what I'm looking for.
Sorry for hijackng the thread! Glenn
Hello Julian - so grateful for the info - many thanks!
The M21 for 8 inch brake like the Gold Star ones - lots of images on google.
basically like the ones above but with different lower part to take screw in spindle, off side threaded for 9/16 x 20tpi left cycle thread and nearside to clamp the spindle.
Like the ones on the A7 below except the brake anchor should be flat plate. Not the best quality photos, they were taked around 20 years ago.
Thanks Julian!
Glenn
Things are progressing... I have located the off side shroud with the retaining square peg & I understand there is another off side unit available as well (NOS Goldie apparently) but identical part No. 42 5076. My question now would be, could I purchase two off side units and simple rotate one of them to fit onto the nearside? I am thinking there may be some discrepancy between them threadwise, other than that it looks fairly routine - if the square widget gets in the way I will tremove it...simples?
I may be wrong reading what you are saying. The fork leg with the square lug is for the full width hub. Gold Stars as far as I know never had full width hubs. A fork leg offside for a Gold Star has a left hand thread in it. The fork legs for the full width hubs have the clamp section on the bottom cut away on one side. If I get into the garage tomorrow I will take pictures of the differences.
The Gold Star part does not take a full width hub.
The fork bottoms you need are as in the photo below. They came from a 1958 A10, same parts as the 1958 B31/33.
Rotating a fork bottom would present some problems.
The mudguard stay mount would be in front of the leg rather than behind.
You can see other problems from the cross section below.
There is a used pair on ebay at the moment.
https://www.ebay.co.uk/itm/BSA-A7-A10-FORK-LEGS/164165870901?hash=item26390c6535:g:xhEAAOSwxOlemv7Z
Does this mean that (a) the Gold Star has the same part number as the units designed for the full width hub, or (b) the guy who responded to my request(accompanied by the correct part number) has made a mistake?
As it happens my front mudguard locates in the two holes below the pinch bolts so I think I could rotate the slider as the brackets half way up it are not used. However, obviously if there are left & right handed threads in the equation allied to the fact that the NOS slider I purchased should have a slot and will not mate to a full width hub whichever way it is orientated makes the whole problem insurmountable!
What heading should I search under to locate the ebay pair please?
The Gold Star Clubman parts are 65 5420 for offside and 67 5057 for near side. Gold Str scramblers use different parts. The 42 5076 part number is unique to the 1958/59 A7/10 and B31/33 bikes with full width iron hubs. No part numbers on these parts so you have to identfy visually.
Click on the link in my earlier post to bring up the ebay items.
The point about reversing the slider is that the bottom lug for the spindle is not symetric to the slider but offset so you would struggle to get it to fit.
There are no left hand threads on the full width hub fork sliders.
Julian...A massive thank you for your assistance with the TLS project! I am increasingly impressed with your knowledge and experience in matters BSA. The bad news (from your perspective) is that I haven't even unscrewed a nut yet. I successfully bid for the pair of sliders you identified as the required units on fleabay and, hopefully, I will be able to return the previously purchased slider to its place of origin. Currently I am pondering as to whether it is necessary to remove all the top yokes etc as per the instruction manual, or whether it is possible to start at the other end and remove the sliders only - do you have any thoughts on this
Gratitude where due to the other members of the club who have also contributed to this discussion.
Sydney Carlton comes to mind!
You will need to remove the fork leg complete to be able to change the slider. Which means removing the front mudguard. The oil seal holder can be tight especially if it has not been removed for a while.
I have now received the pair of fork sliders and they are in better condition than the NOS item I already purchased. Strangely both the first slider and the same one of the pair (O/S with square projection) are identical as far as I can tell, obviously the original is not for a Goldie as I was informed by the vendor. The recent acquisition has the letter S stamped on the face of the square projection, does this mean anything significant I wonder?
If I can add a few thoughts..
My 1954 B33 has the 8" half width hub,, This uses fork bottoms that are different again, the wheel spindle fits through the LHS and screws into the RHS leg. The hole in the LHS leg is larger than the RHS.. the bottom of each leg looks different, only one has a pinch bolt. Hard to explain but I don't have a photo handy... Not sure exactly which brake you are trying to fit..
Removing the oil seal holders can be an issue. On my bike I was lucky, I could undo them by hand ! On a previously owned Ariel I had to use an oil filter strap wrench used carefully over the threaded part .. Some are on so hard even the special tool may be difficult to operate..
Removing the legs.. As mentioned, the mudguard has to come off - you may need to raise the bike a fair way to allow it to drop, depending upon the type fitted.. Then just undo the two bolts in the lower fork holders. The legs may need a little persuasion to come down. On the other hand, when I was waggling the LHS one on my bike the RHS one fell out.......
Hope this helps..
Adrian
Bristol UK