Atlas front end on a 1970 TR6

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seattle##gs

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somebody dropped off a 1970 TR6 - spring gold - for a small electrical bug and I have been looking at it for a few days. It is absolutely gorgeous viewed from any direction. I really like my Atlas but this Triumph makes it look ordinary. I took a short test ride and it performed well but the front end is wiggly at best. I roll it in and out of my garage along with a 78 Triumph and my Atlas. The forks are uninspiring. I know they are just a tube with a spring. So my question is...Has anyone here put on the front end from an Atlas onto a pre-OIF Triumph? It seems like an excellent idea and would look similar to the Triumph...at least they are from the same era. The hardest part would be the steering stem. If the Triumph handled as good as it looks it would be a terrific bike.
 
There is nothing wrong with Triumph forks... especially from 1970... Doug Hele et al had them fully sorted by then.

In fact, they are probably technically superior to the Road holders.

You‘d be doing a LOT of work for naught IMHO.

Stripping them and rebuilding them to stock is all you need do.

And... you’re totally right about the looks...!
 
There is not much to sort out in pre-OIF forks. You can change the weight of oil or use a different spring but that's just about it. I know these were raced hard for years and perhaps there were some small tricks the individual owners came up with ( I would think a bullet proof fork brace would be essential) but really, there is nothing to work with.
I like the frame, it handles well and that has been developed by famous people over the years, a lot through trial and error. I had a 69 Bonnie that I rode hard on mountain roads in my 20's...I loved the handling. I made the mistake of selling it to my brother who promptly crashed it while drinking. So keep the frame and do something about the forks. My atlas seems so much more solid than the Triumph.
Ideally I would stuff an Atlas motor and trans into the Triumph frame but that is an impossibility.
 
There‘s a lot you can do to Triumph forks if you want to. You can gut them and fit modern cartridge internals, or send them to a pro outfit like Maxton to do so, they’ll set them up for your precise weight and riding style, etc.

But you‘d have to be a very hard road rider, and / or have way more power on tap then standard, to class that as a worthwhile job on a road bike.

Seriously, considering the performance on offer, the standard forks, in good condition, are perfectly fine.
 
The 69/70 Triumph forks are shuttle valve, better than the previous versions including the Triumph comp forks which used Matchless/Norton/BSA type rod dampers. Until you have checked the internals then anything could be going on from simple wear or wrong viscosity oil to the shuttle valve itself not even being there (a lot more common that you think).

The one issue I picked up, from having a set on a rig allowing me to push and pull on the stanchion to check the damping effect, is that as the shuttle valve moves from compression to rebound positions there is no damping, but this also is inbuilt into the rod dampers too.

Th effect of this non damping 1/4" is that on smooth roads where the forks have little movement then damping is at its lowest when it should be at its highest.
 
It could be that the forks are very worn out. I know nothing of its history other than the guy bought it new in England 50 years ago and has owned it all this time. It is a faded spring gold with the large tank. Some of the striping is worn away but otherwise very nice condition.
I remember my 69 Bonneville having the same type of flexi forks but still sure footed on mountain roads, especially after I chucked the K70s and put on modern tires of the day. It felt like I couldn't fall off. I lived in Reno in the 70s and the road up to Virginia city was perfect and only lightly traveled. There were many times when I encountered no cars at all.
 
seattle##gs said:
It could be that the forks are very worn out. I know nothing of its history other than the guy bought it new in England 50 years ago and has owned it all this time. It is a faded spring gold with the large tank. Some of the striping is worn away but otherwise very nice condition.
I remember my 69 Bonneville having the same type of flexi forks but still sure footed on mountain roads, especially after I chucked the K70s and put on modern tires of the day. It felt like I couldn't fall off. I lived in Reno in the 70s and the road up to Virginia city was perfect and only lightly traveled. There were many times when I encountered no cars at all.
Click to expand...

I have a feeling the fondest memories are usually the oldest ones.
 
Seattle... so we are talking about a one owner from new, unrestored, original ‘70 Triumph here...?

If you start sticking Atlas forks in a bike like that you want flogging mate !!
 
I wouldn't dream of altering this bike. The most I would do is rebuild the forks with stock parts. He just put in a new alternator and podtronics and there is a charging problem. I suspect a faulty podtronics. No charging at the battery terminals.
If I had a TR6 of my own that had been through years of mix and matching I would consider the Atlas front end. Appearance wise it would resemble the stock Triumph front end complete with rubber gaiters and I believe it would be a better front end.
 
seattle##gs said:
I wouldn't dream of altering this bike. The most I would do is rebuild the forks with stock parts. He just put in a new alternator and podtronics and there is a charging problem. I suspect a faulty podtronics. No charging at the battery terminals.
If I had a TR6 of my own that had been through years of mix and matching I would consider the Atlas front end. Appearance wise it would resemble the stock Triumph front end complete with rubber gaiters and I believe it would be a better front end.
Click to expand...

Phew, that’s a relief !

On the hypothetical point of the Atlas front end, I still disagree. Overall strength and resistance to flex is the same on both. The Triumph however has superior damping internals, and is therefore a better fork I believe.

But unless either of us gets both sets on a bench, or shock dyno, or tarmac, and do a back to back test, we‘ll not know for sure!
 
You might consider install of an OIF 1973 on disc brake front end. (could install 1971-72 conical also, but I prefer a disc brake.) Simple "bolt-on" conversion on my 1968 --- with the correct bearing adapters. Still Triumph ... Atlas front end on a 1970 TR6Atlas front end on a 1970 TR6
 
seattle##gs said:
There is not much to sort out in pre-OIF forks. You can change the weight of oil or use a different spring but that's just about it. I know these were raced hard for years and perhaps there were some small tricks the individual owners came up with ( I would think a bullet proof fork brace would be essential) but really, there is nothing to work with.
I like the frame, it handles well and that has been developed by famous people over the years, a lot through trial and error. I had a 69 Bonnie that I rode hard on mountain roads in my 20's...I loved the handling. I made the mistake of selling it to my brother who promptly crashed it while drinking. So keep the frame and do something about the forks. My atlas seems so much more solid than the Triumph.
Ideally I would stuff an Atlas motor and trans into the Triumph frame but that is an impossibility.
Click to expand...


If you put the Atlas motor and trans in a Triumph frame then add the Atlas front end, you would have an Atlas missing its Featherbed frame!
That was the famous joke about the Norton Atlas and the Commando. Norton had , in the Atlas, an aging and extremely vibratory engine in a great frame, so they threw away the frame and kept the motor to create the Commando.

I suspect the joke came from someone who wasn't a Commando or Atlas owner. I'm really glad Norton did keep the engine!
That Featherbed frame on your Atlas is a pretty special item though.





Glen
 
Last edited:
worntorn said:
If you put the Atlas motor and trans in a Triumph frame then add the Atlas front end, you would have an Atlas missing its Featherbed frame!
That was the famous joke about the Norton Atlas and the Commando. Norton had , in the Atlas, an aging and extremely vibratory engine in a great frame, so they threw away the frame and kept the motor to create the Commando.

I suspect the joke came from someone who wasn't a Commando or Atlas owner. I'm really glad Norton did keep the engine!
That Featherbed frame on your Atlas is a pretty special item though. Glen
Click to expand...

Most of this is true to some extent, but the Atlas was only going to be reasonably smooth with the original 7.5:1 pistons, anything higher was going to vibrate to such an extent that it became uncomfortable for the rider, that it would vibrate your teeth filling out- dont ask me how i know.
 
My Atlas with Commando pistons was almost unbearable to ride and certainly no more than 100 miles. I could feel pain and numbness creeping up from my hands to my shoulders. So I had it balanced, put in a distributor with a Boyer, and a single Mikuni. The custom made air box fits between the oil tank and tool box. All that made for a very nice motorcycle and I still have it.
I really like the looks of the 1970 Triumph, The Brits really got it right. Appearance wise it is the XKE of the motorcycle world. If it had the Norton motor in it it would have been outstanding.
One time, in my gathering of motorcycle parts, I got a featherbed frame where someone had chopped out the two top rails and put in a single backbone. No explanation.
 

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