TW wrecks a perfectly good Commando etc.

[kommando]

Looks like you have a nice collection !! Are those extended studs?

I've just found a picture of the lower rubber mounts on the T140AV. Apparently Bernard Hooper was also involved. It's pretty simple if you compare it to a Commando.


View attachment 84051

I think this mount is from a Triumph 2000, not a Metro, have some more pics and will add later.

 

[Chris]

Nige
My friend Nick (Rip) had an av. He said you needed to keep up the maintenance as they wallowed, a very Commando type weave! He wondered how they would be with heavy panniers, top box & radio. Nice ride when new.

 

[cliffa]

The swinging arm area is not simple on the Triumph AV frames though as Triumph wanted to allow the swinging arm to move but not mount it to the moving engine like Norton did.

I think the biggest potential problem with such AV frames, and I think the same happened back in the day with Commandos, is that the smoothness makes the rider think that 8,000rpm is ok !

Good point about over revving !!

I saved this picture years ago after a visit to the NMC and looking at the AV there. I could not fathom the rear mounting by looking at the bike, but this helps..

 

[mdt-son]

The bracket is done besides some filing on the sides, the fillets on the side welded up (ER70 wire) nicely but I hit the corners with a 5mm radius cutter anyway (set up took longer than the cuts which is often the case)
It could have been more basic (less time) but since I am copying a JC idea I thought it better (an excuse to) flash it up a bit.
It is reasonably light weight.

Interesting project, Time Warp. I am working on a similar idea.

-Knut

 

[Time Warp]

Interesting project, Time Warp. I am working on a similar idea.

-Knut

Thanks Knut.
I will record the measurements and weld the lower cup to the frame today.

Because the Isolatics are in place the spring pressure needed might be quite low, we will see.
It is in this case primarily to suit the floating spindle head steady.

This should have the spring vertical with around 5mm clearance to the frame lower cross tube. (The 13.5mm measurement could be reduced to reduce that clearance)
The 15mm vertical measurement gave around 1.5mm top of the spring plate to the engine case at its lowest point.

 

[74ok]

I think it said in that original thread JC had no Isolastics in the housing just a spacer tube (iirc) and that panhard bar.
It occurred to me (The bracket is done and will do some final work on it tomorrow) having the Isolastics in place will reduce the needed spring pressure.
Maybe in my case all it will do is maintain things centrally which I need for the head steady but not do anything for vibration.
I think I allowed around 6mm of movement to contact (3mm any direction) spindle to bore in the frame hanger bracket , it might be like a jack hammer if not enough, hopefully the spring will stop that.

View attachment 84040

Sep 28, 2013
JC said & mentions 'isolastic washers' only, but the KW spring is not installed yet

comnoz said:
"a linkage I made using one of my headsteady tie rods. I have removed the isolastic washers from the front mount and use the tie rod to eliminate the sideways play. That has been on there for several years."



then cliffa found this post
Aug 6, 2021

comnoz said:
"There is no rubbers or iso shims in the front mount. Just a spacer and a couple plastic caps to keep the dirt out.
The spring is easily removed by removing the long front mount bolt, this allows the motor to be raised just far enough to remove the spring.
The tie rod link keeps the front of the engine from moving side to side [like the original iso shims did -except the rod ends don't wear out quickly"

 

[mdt-son]

Thanks Knut.
I will record the measurements and weld the lower cup to the frame today.

Because the Isolatics are in place the spring pressure needed might be quite low, we will see.
It is in this case primarily to suit the floating spindle head steady.

View attachment 84075

Hi Time Warp,
I have a difficulty understanding your sketch - please explain.
Do you have measurements of the two crankcase / front mounting bolts (06.3213) vs. the frame downtubes? C/C measurements paralell to the lower rails would be really helpful. The tech manual shows dimensions of the frame but details at the finer level are not shown. What is the lean of the engine's top end vs. the bottom rails? My bike is still disassembled with engine out, otherwise I would have taken the measurements myself.

Regards,
Knut

 

[Time Warp]

I edited the drawing to hopefully clarify.
The measurements are for a JC type bracket (that you could see in his photo assuming the upper part attaches at the lower case/isolastic housing 3/8" bolt location)
I tacked the lower cup on today (night)

I had considered having the spring forward under the Isolatic tube but it would take invasive modification to the frame down tubes and not sure it would be better.
I could get those measurements but it would take some time and set up to be accurate.

When the lower rails are level the upper small brace tube is the same, the top tube + 10° and the cylinder - 18° .
Make a basic picture of the needed measurement locations and I will look into it .

I will need to support the bike off the main stand to see what actual load is on the spring, the poundage needed will be a lot lower having the Isolastic outer rubbers in place.

 

[mdt-son]

I had considered having the spring forward under the Isolatic tube but it would take invasive modification to the frame down tubes and not sure it would be better.
I could get those measurements but it would take some time and set up to be accurate.

When the lower rails are level the upper small brace tube is the same, the top tube + 10° and the cylinder - 18° .
Make a basic picture of the needed measurement locations and I will look into it .

Thank you, Time Warp. Your sketch is much clearer now. I will provide a simple 2D drawing for you, incorporating the angles you kindly provided.

- Knut

 

[Time Warp]

That is done now primed and painted, ready to fit and forget.
To old to be on the ground welding (T.I.G) so simply grabbed the bike at the top frame tube and up it went with the engine crane.
0000 steel wool got the frame portion matching the original frame paint later on.

Thanks to JC for the idea.

 

[Time Warp]

I forget what pictures / gibberish has been posted in the past.

 

[cliffa]

That looks superb !!

 

[mdt-son]

I forget what pictures / gibberish has been posted in the past.



View attachment 84132

Nice engineering work, Time Warp. The only feature I miss is cylinder head drain return being plugged and the oil drain routed to the sump where the oil belongs. I am convinced there is enough oil spill from the pump and the timing cover to lubricate the gears and spindles. if not, a small oil jet off the oiling gallery would do the trick.

- Knut

 

[cliffa]

Nice engineering work, Time Warp. The only feature I miss is cylinder head drain return being plugged and the oil drain routed to the sump where the oil belongs. I am convinced there is enough oil spill from the pump and the timing cover to lubricate the gears and spindles. if not, a small oil jet off the oiling gallery would do the trick.

- Knut

There was a video posted somewhere on here a few months ago of a Norton restorer / modifier who blocks the normal head drain then creates a new one which routes externally down to a T or Y joint and then around the front to spigots inserted over the followers. Seemed like a good use of the returning oil.

 

[Time Warp]

I will call it done unless I put proper weld fillets on the two inside corners on the top bracket which would fill that small divot being a fuse only.

A maybe might be a short length of small rubber inner tube over the outer spring with grease on both springs.

The black paint hides it for the most part.

The springs are a new stock AN inner and outer ( part-no: 06.7823 / part-no: 06.7822)

The final compressed dual springs length came out at 31.5mm, (42+mm free length) that was bouncing the engine on the spring a few times with the 1/2" bolt removed, letting it settle and the main 1/2" bolt would slide through the frame lugs and Isolastic inner tube with no resistance at all.
Oddly enough the workshop manual gives the installed valve spring height at 31.98mm which might suggest the poundage is in the zone, neither under or over compressed.

It might have been interesting to know how many pounds pressure it would take to compress the springs to that 31.5mm compressed length.

 

[Time Warp]

The local bicycle shop gave me an inner tube to make a cover for the spring and also ordered some more Tri-Flow dry cable lubricant which I have found to be the best overall.



I had time to measure up for a spring system for the rear Isolastic / cradle tube but given the limited interest in these sort of projects and I do appreciate the people who are interested but it would not be worth documenting (time consuming) or taking up server space.

 

[Time Warp]

 

[Fast Eddie]

View attachment 84305

That’s NICE !

 

[cliffa]

There was a video posted somewhere on here a few months ago of a Norton restorer / modifier who blocks the normal head drain then creates a new one which routes externally down to a T or Y joint and then around the front to spigots inserted over the followers. Seemed like a good use of the returning oil.

Replying to my own post here, but the guy in question is Dave Sundquist. You can see his idea @ 16:45



(thanks 74ok)

 

[Time Warp]

That’s NICE !

Thanks, for the DR650 (new caliper, new take off Showa forks)
At the time I could not find an off the shelf bracket.

I have a new Brembo rear caliper and master cylinder to fit but at this stage it is not doable with spoke clash at the rear side of the caliper.