Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board TLS hub questions/fact check

Trying to sort out a front end for my 58 TR6, it does have preunit trees which are 6.5” width. From what I gather, 69/70 unit trees are 6.75” with appropriately wider axle and the earlier unit forks are 6.5” width.

My question is, are the hubs all the same where I can just use an earlier axle with a 69/70 TLS hub and plate on my 6.5” wide forks, or do I need to source a 69/70 hub as well?

Hi Oscar,




Hth.

Regards,

So all I need is to ensure I get the shorter axle respectively? And what does “Hth” mean, lol sorry some abbreviations still escape me.

Hi Oscar,

I know the 1968 TLS axle is for 6.5" width forks. Maybe Stuart means the others from preceding years will all work also.

As I understand it the hub introduced in '67 carried through to 1970 (ie both SLS and TLS brakes). Just the axle changed in '69. I believe the part number does change around because of the screw holes for the 1968 nave plate.

I have no experience with the bearing/axle layout for '67 and earlier and whether these will combine to work in a TLS hub and pre-unit forks. But sounds like you are on top of that.

HTH = hope that helps.

Cheers
Ray

Oh, yeah, it works just fine. It's the only way to fly if you want to actually ride these things.

626T06

Cheers,
Bill

Bill is that a 69/70 hub/plate on earlier model forks?


Otherwise, thanks all for the help!

I have little knowledge of earlier forks, but isn't the length of the brake plate anchor post of the timing side fork leg longer on the wider spaced forks?

The picture shows a '69-70 plate (650cc) which was also used '69-74 on the T100R 500cc bikes as well.

You are correct that the anchor post is longer on the 1969 and later forks.
This is further evidence that the forks are spaced wider apart.

Although the combination flanged wheel hub / brake drum is the same from 1966 to 1974, and the 1968 version of this brake will interchange with the 1966-67 forks, I assume the need for the wider forks must be to fit the 1969-type brake plate?

I have a 1969 TLS front brake on my 1967 T120R. It is a significant improvement over the standard brake. I did not use the later axle. I just swapped brake plates on the 1967 wheel. Whether or not I had to use a spacer somewhere, I do not recall. Anyway it has worked well for a number of years.

Bill, does it look like the one on the picture, or is it the 1968 version with the loooong brake cable?

No, it is 1969 TLS with the shorter cable, that runs up the forks, not the earlier one that bows backward. It is identical to the one on my 1969.

Hm ok, so the newer brake plate works with earlier hubs. It would make sense that you didn’t use the newer axle as I assum you have the 6 1/2” width forks.

I think I’ll dive in and report back with results. Now to find some
Unit forks and hub...

Hi Oscar,

Apologies for the delay replying ...

To clarify confusion introduced in later posts:-

Axles
Not "TLS" or "SLS", they depend only on the distance between fork-leg centres and the sliders/axle caps.

The axle used on '68 6-1/2" forks irrespective of hub/drum or brake is W1641, it was introduced in '65 with changed sliders and axle caps. The preceding W1239 axle is also for 6-1/2" forks and also fits the hubs. Whether you use W1239 or W1641 depends on the sliders and axle caps, not the hub/drum or brake.

Digressing slightly but to illustrate interchangeability:-

. early triples (built May, June, July 1968) have the notionally-'68 hub/drum and TLS brake plate between fork legs 6-3/4" apart, so on the notionally-'69 W2057 axle, brake plate engaging with the the notionally-'69 H2295 right-hand slider;

. '69 T100C's built well into 1969 still had notionally-pre-'69 7" hub/drum and SLS brake plate between fork legs 6-3/4" apart, so on the '69 W2057 axle, brake plate engaging with the the '69 H2295 right-hand slider.

Hubs/drums and brake plates
The 'double flanged' (external 'flanges' for the spokes on both sides) hub/drum in "Hawaiian Tiger" Bill's picture was introduced in '68 with the '68-only 8" TLS brake plate (brake cable entry from the rear of the plate, "Irish Swede's loooong brake cable") and left-hand screw-attached hub/drum "Cover plate". Essentially the same hub/drum, with the '69-on version of the TLS brake plate and clip-on "Cover plate", was used on the '69/'70 triples, 650's, T100R and T100T, '71-'74 T100R, '73 "BSA" T65 and some TR6P's supplied to Oz.

'66/'67 hub/drum has an external 'spokes flange' on the brake plate side only. This hub/drum was also used on early '68 T100R's (and T100T's?) that used up the remaining 8" SLS brake plates.

Pre-'66 doesn't have any external 'spokes flanges'.

All the axles are interchangeable in all the hubs/drums and all the brake plates will fit over the axles, The only differences to watch out for are:-

. axles for 6-3/4" forks have a 20 tpi UNEF (Extra Fine) brake plate nut thread, axles for 6-1/2" forks have a 20 tpi Cycle thread, the nuts aren't interchangeable (I think a UNEF nut might fit both but a Cycle nut doesn't fit a UNEF axle thread?);

. right-hand sliders for 6-3/4" and 6-1/2" forks, because of the width of the brake anchor lug;

. 7" and 8" hubs/drums and brake plates;

. shoe width - later are wider because the spoke heads are in the external 'flanges', not inside the edges of the drum.


Length (up and down the slider) is only relevant to 7"- or 8"-diameter brakes. The width of the "brake plate anchor" on a '69-on slider is greater because of the increased distance between fork legs, nothing to do with the actual brake plates.


I assumed "length" to be "up and down the slider" and "how far it sticks out from the slider" to be "width". The same sliders were used certainly on the C-range, some of which had 7"-dia. hubs/drums. Right-hand slider with a wider brake anchor lug is used on '69-on 6-3/4" forks.



Precisely.

Hth.

Regards,

Wow that helps IMMENSELY! Thank you!!

wait, stuart, typo, which was which?

Hi Kevin,




Fixed in the original post but ...

"axles for 6-3/4" forks have a 20 tpi UNEF (Extra Fine) brake plate nut thread, axles for 6-1/2" forks have a 20 tpi Cycle thread,"

Hth.

Regards,

cool

this information is hard to get into one place, but swapping earlier forks is something lots of people do, including me. your advice got my disc brake front end on my dry frame T120.

i have no idea how you catalog all this stuff in your head. even if you look it up, you still have to know it's there.

Stuart, or anyone really, I just have one more question. If I’m not mistaken it sounds like I can use the 69-70 TLS hub and brake plate with even a 64 fork as long as I have the respective axle for that year? There are no issues with regards to tLS hub widths on any of the 6-1/2” spaced forks from years 64-68? I guess my only confusion is with the “right hand sliders” or difference in sliders in general as they apply to TLS hubs

Hi Oscar,



Afaict, that's what's in Bill's picture:-

. the brake plate is '69-on but it's had the normally-polished outer ring machined off and then the centre - that's normally left sandcast - has been polished;

. the slider and axle clamp are pre-'65,

. so I assume the axle is also the pre-'65 W1239;

. the hub is specifically '68-on TLS, with the external 'spoke flanges' on both sides.


Use the slider applicable to the forks. The anchor lug is wider on sliders for 6-3/4" forks so, if you use one on 6-1/2" forks, the wider lug squeezes the brake plate against the hub, which stops the hub/wheel rotating.

Hth.

Regards,

With the conversion above, you have the option to use either the cable stop on the backing plate or the one near the end of the fork leg. I chose to cut off the cable stop on the backing plate instead of the fork leg, that way the bike could be returned to original spec if ever it was desired to do so.

55T-Bird63


Also, with my other pre unit there is significant interference with the rear fender stay, so it has to be bent out a tad and a new longer bolt and spacer used to clear the linkage. Not sure if that will be needed on your bike. The first bike has a front stand that doubles as a stay and that one has nice bends that make it clear without modification.

Cheers,
Bill

Ahh I think I’ve got a grasp on things now. I’ll report back with my own mosh mash of parts when it gets put together!

Ok so I know I need axle part number W1239 or W1641, but as previously mentioned by stuart it would depend on my axle caps and sliders. Can someone explain or post pictures of what the difference is between sliders and axle caps on 64 vs 65 and later forks? I'm looking through parts catalogs and can't seem to tell the differences between the sliders, axle caps, or axles for that matter.

As background info I ended up with 69 TLS hub and its axle, and what I'm told is a 64 fork, which seems correct as they measure out to be 6 1/2" wide. Supposedly the axle that came with the fork is a 64 axle however I don't see how it can be, as its too wide for the fork and measures out to be the same length as the axle on the 69 hub. It seems as though the previous owner either sent me the wrong axle, was using the wrong axle, or mislabelled the fork and the axle.