Question

Status
Not open for further replies.
Joined
Sep 26, 2009
Messages
2,210
Question, what would be the life of a rear chain ,if the swing arm is fixed to the frame.. guessing when the chain is tight under load and the transmission is vibrating this is chain HELL :evil: But would a Extra rubberr cush rear hub help? I am prepared to change the chain every 2000 miles . or less :!:
 
Tony Smith built a Commando Featherbed, iso mounted motor, swinging arm solidly mounted to gusset plates as standard.

I can't say what the chain life was, but he said the bike worked well, handled well, and was smooth.
 
john robert bould said:
Eddie
Is Tony Smith the Guy who now lives in France , Builds race bikes and his wife race's a Seeley?

The Tony Smith I'm referring to is the ex Norton racing Tony, raced for Gus Kuhn a lot, Thruxton motorcycles, and the factory a little in the latter stages I think.

He still lives in Oxfordshire, as I think he always has.

He still plays with Nortons, he has what must be the cleanest mk3 in existence, and is currently building a mk3 / fastback.
 
I'm thinking you could run the chain loose, and if you could mount a spring loaded idler sprocket on the slack side, you might get away with it and have normal chain life.

Slick
 
Tex, Dont think a loose chain helps...the top run is under tension [Pulling] and the lower is tight decending banks .[throttle off] .


texasSlick said:
I'm thinking you could run the chain loose, and if you could mount a spring loaded idler sprocket on the slack side, you might get away with it and have normal chain life.

Slick
 
On my Commando/Featherbed frame I get very long life out of my rear chains, the chain I am running now has been on my Norton for 5 years now when the Norton was rebuilt but it had been on the Norton for a few years before the rebuild, since the rebuild it has done 25,000 miles and probly has done 5,000 mile before the rebuild, so 30,000 miles so far, its not a brand name chain, its just a heavy duty chain that I brought from a chain supplier in Brisbane and cost about $40 at the time.
A lot of poeple might disbleive me that I get this sort of milage out of my chains, but I do, I run enough slack in the chain for the up and down movement of the swingarm as well I keep the maintenance up on the chain, I pull the chain off every service and give the chain a good degrease and a good soak over night in oil before putting it back on, I have only adjusted the chain 2x in that 5 years now, look after your chain and it will look after you.
I am just about to replace my chain with one of Andy's chains as I lost a joining link from my chain a few months ago while giving the Norton a good rev out in second gear, it got caught up on my sliding seal in the primary case (the new inner case was short of a shim), I just shake my head when poeple say they only get 2,000/3,000 miles out of their rear chains, in 39 years of owning my Norton I have only replaced the rear chain 5 times, the rear sprocket and front sprocket 2 times and my Norton has well over 140,000 miles on it.

Ashley
 
Tex, Dont think a loose chain helps...the top run is under tension [Pulling] and the lower is tight decending banks .[throttle off] .

Yes, you are right. I did not think about throttle off condition. I do think the loose chain will allow some movement of the drive sprocket due to iso flex even when the top side is under tension...not the perfect solution, but perhaps chain snapping solution. As you point out, the decel condition does not work...the backlash will be horrible.

Like you said....it will be hell on chains....and mainshaft bushes too.

It comes back to - Norton did it with the cage for a reason.

Slick

PS: It would seem to me that you could set up a "chugging" vibration with the engine/gearbox iso mounted and the swing arm rigid on the frame. Fast Eddie reports someone has done it with good results....sure would like to know the details.
 
john robert bould said:
Tex, Dont think a loose chain helps...the top run is under tension [Pulling] and the lower is tight decending banks .[throttle off] .

Thats how every chain in motorcycling operates though !!
So chain life for this bit of it is going to be the same as about every motorcycle ever made ??

That idea of running the chain loose with a tensioner is how a lot of motorcycles operate too,
and they get reasonable chain life.

ashman said:
On my Commando/Featherbed frame I get very long life out of my rear chains, the chain I am running now has been on my Norton for 5 years now when the Norton was rebuilt but it had been on the Norton for a few years before the rebuild, since the rebuild it has done 25,000 miles and probly has done 5,000 mile before the rebuild, so 30,000 miles so far, its not a brand name chain, its just a heavy duty chain that I brought from a chain supplier in Brisbane and cost about $40 at the time.

Your bike doesn't have iso mounts though, so the loose-tight cycle from the iso joggling doesn't happen.
It gets normal featherbed chain life - whatever that might be.

A lot of chain life is how good the quality is of the chain,
and how religious the owner is at keeping it oiled/lubed/greased - and clean..
 
Status
Not open for further replies.
Back
Top