Suggest frame mods

[coomo]

This is the sort of front cross tube piece mentioned above by rvich. The rear shock mounts on this frame are also modified for a little more support for the rear loop, but mostly to move the mounts a but further apart for this particular build.

View attachment 4244

Ken

 

[coomo]

I intend to do this frame "upgrade" ie the crosspiece welded in between downtubes.In Europe (HNW) its referred to as a "Thruxton" modification.Any idea on how far down
its welded in guys?

 

[kommando]

No set place but 1/2 way between the bottom of headstock and the front iso tabs would be both effective and easy on the eye.

 

[Fast Eddie]

It's just a tube I cut to fit and welded in. It was a pretty common mod for racing Commandos back in the '70s and '80s. I did it on both my Commando framed race bikes back then.

Ken

Ken do you know what that little extra cross tube is supposed to do? What forces it’s acting against or failures it protecting against?

 

[gortnipper]

Flex and splaying of the front down tubes, especially under hard braking. Look at pics of the Dreer 880s and he did this mod as well. When I did my recent resto I made this mod.

 

[lcrken]

Ken do you know what that little extra cross tube is supposed to do? What forces it’s acting against or failures it protecting against?

Sorry for the delay in answering. I've been without internet access for a few days because of the local fires. Anyhow, the answer is pretty much what gortnipper said. It was a fairly common mod for race Commandos back in the '70s, and I copied the idea from someone else back then.

Ken

 

[Fast Eddie]

Thanks Ken.

Hope you and yours are all safe ?

 

[cjandme]

I like the idea of the front down tube cross brace and the valve spring underneath to help out the isolastic rubber mounts in keeping everything lined up where it is supposed to be, while still allowing for freedom of movement..... P. S. Are the California wild fires headed your way Ken? I sure hope not, take care though, Cj

 

[lcrken]

One of the fires started 2 miles from my house, and I had a good view of the flames from my front porch. We were on evacuation watch for a while, but fortunately the wind blew the fire almost directly away from us toward the coast. The fires are still growing, but not in our direction. I think we will be fine, but we have the motor home ready to leave, just in case. It is a bit distracting, though

Ken

 

[Fast Eddie]

It is a bit distracting, though

Master of understatement Ken...!

 

[gortnipper]

Yeah, my cousin's house had their yard burn, and their windows explode and the side of the house charred. But it was saved. Not great, but could be a lot worse.