Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Why Couldn't They Just Use The Same Axle?

In putting my 68 T120R back together, I discovered (fortunately in time) that the lower legs were from a 1969 (unified threads). But, I had a heck of a time getting the axle to align with the axle cap bolts. That should have been my first tip and I should have gone the the parts catalogue and checked if there was a difference in axles. I think the "restorer" who did this bike before me mixed a 68 axle with 69 lowers. This all occurred to me when I stumbled on a video that I'd forgotten was out there. Mike Raber did a few nice tech videos and they are still up and available. Here is the one on the different axles: https://www.youtube.com/watch?v=70WwEzAgvCU

At the end there is a picture of the different axles and their years and part numbers. A great video by Mike! Sure miss that shop.

I'm sure Mike won't mind me posting a screen grab of the axle comparison. It's interesting how difficult it is to tell them apart.

Hello Mike,

Probably the main difference around 68/69 year is the need for a longer axle for the new TLS front brake. This change follows through into different fork yokes (top and triple tree) to allow for the fork legs to be spaced correctly for the longer axle. Your "restorer" hopefully changed all the bits together, if you have the TLS brake fitted?

Thanks, Stanier8F. Seems like I need to do a comparison of all the parts in the catalog and then do some measurements of the front end. I just put the front end back together and aligned the rear and front, so this is annoying. I bought this bike "fully restored" quite awhile ago when I didn't really know enough and now I am finding nothing but things that were done wrong. And, it is a mix of parts, so, ever step is checking and double checking. I guess that's what makes this all so fun! Thanks again for your insight.

It's "character building"

I thought in 69, they made the stanchion centres 1/4" wider to give more tyre clearance and that was the reason for the different axle. The Trophy bible has this.

Yes, it was connected to the tyre width not the TLS brakeplate which was first fitted in 68 with the narrower axle, then they fitted the longer axle, then realised the fork lower stub did not engage as well with the brakeplate so introduced a fork lower with longer stub. 68 to 70 front ends look deceptively similar but lots of small details to catch the unwary.

J.R. Nelson book too.

What I've found is that I have what appears to be 69 triple tree and lower legs (unified threads). It's unclear whether I have the 69 or 70 axle as it is in the assembled wheel. But, it is one of these two as it measures 7-1/4" in length. The distance center to center at the triple tree is 6-3/4". But, the distance center to center of the lower legs at the brake plate/hub cap is 6-5/8." And, that is about how much the space is off at the bottom where the bolts need to align with the channels in the axle. So, it appears that the forks taper in toward the wheel. I'm thinking that one or both of the stanchion tubes might be bent, even though the bike rides well. Any thoughts or suggestions? Obviously, I've got to tear this down and figure out where the problem is.

The Trophy bible gives the 69 as 6 3/4" and the 68 as 6 1/2". The other change made at same time was doing away with steering damper and fitting a solid nut.
One possibility for the taper is the bottom of the triple tree is from an earlier bike, but if that was the case, I would have thought it too hard to get the stauchions to mate with the top. The other is a staunchion bent right at the base of the triple tree so the fork would still function

Lay the stanchions next to each other on a flat surface and rotate one and then the other 360 degrees. If they are straight, the stanchions will remain in full contact along their length. I’ve been told that stanchions can be slightly bent from front to back and, if properly aligned, may allow the forks to function properly. This was the case with my forks but I chose to replace the stanchions. And that’s another story...

I started another thread not realizing I could use the "Full Editor" and attach a link here. I dove into this and came up with a three page summary that I think helps to identify the key things about the fork changes in 1968 and 1969. You can access this PDF summary from my Google Drive and feel free to distribute it to anyone that would benefit.

https://drive.google.com/file/d/1WvIZ6UUlqvO7IE7-Z-fNMHI6ngeonGL4/view?usp=sharing

I updated my document to include an explanation for why the fork lower members (sliders) part numbers were superseded in 1970.

https://drive.google.com/file/d/1WvIZ6UUlqvO7IE7-Z-fNMHI6ngeonGL4/view?usp=sharing