Atlas Clutch Wobble and chain adjustment frustrations

Johnnymac · Aug 1, 2015

Hi guys, I'm just going through and trying to fine tune everything on my 66 Atlas. Now that I've got it running and rideable I've noticed a pretty good clutch basket wobble. I've looked online and the general consensus is that it could be the clutch rollers?

Also, I have another issue that is driving me nuts. When I go to adjust the primary chain... as soon as I get it to the correct tension, then slowly turn the engine over the chain either gets tighter or looser. I'm thinking that also has to do with the rollers? It makes getting the primary tension really impossible. I've also had a heck of a time getting the drive chain correct. As soon as I loosen the rear axle and adjust the chain tensioners to get the correct drive chain tension, when I go to tighten the axle back up, the chain gets TIGHT. No, it doesn't appear that the axle is moving any as the axle is snug up against the adjusters. Why would tightening the axle up tighten the chain? In order for me to get it right, I had to adjust the chain to where it was very loose so when I tightened the axle, it snugged up the drive chain. I have not had this problem on any of my other bikes.

Any thoughts?

Rohan · Aug 1, 2015

If you tighten the axle and the chain goes tight, it has to be pulling the wheel back.

Tightening the axle is not binding up the wheelbearings or brakes is it, so the wheel feels tough to turn ?

Its really common for part worn chains to have tight spots and loose spots, since the chain can wear differently in different parts.
Its ALWAYS recommended to set the chain tension for the tightest feeling part of the chain.
If the difference between the tightest and loosest is excessive though, the chain should be discarded and replaced with new.

You may need to explore if the clutch hub sits squarely and solidly on the splines.
If it can rock or move, it won't ever run true.
Opethiselps.

texasSlick · Aug 1, 2015

I think you need to pull the clutch. Check the rollers, and check Item 12 in the link below. The center shock absorber body is prone to break the "wings" and the clutch will have a lot of wobble if one or more wings or tabs are broken.

http://www.andover-norton.co.uk/SI%20Clutch.htm

Re: rear chain

As you are certain the wheel is not moving rearward when tightening the axle, the only other situation that comes to my mind to explain the chain becoming tight as you tighten the axle, is that a twist or cocking Is occurring in the brake drum and sprocket. Keep a critical eye on the rear sprocket as you tighten. Should a cocking be the case, then disassembly of the rear axle and brake drum is in order to determine why.

Slick

Bernhard · Aug 3, 2015

texasSlick said:
I think you need to pull the clutch. Check the rollers, and check Item 12 in the link below. The center shock absorber body is prone to break the "wings" and the clutch will have a lot of wobble if one or more wings or tabs are broken.

http://www.andover-norton.co.uk/SI%20Clutch.htm

Slick

The Norton Clutch Shock Absorber Rubber (8 & 9 in picture) can also send you mad because only very rarely will the clutch sprocket run true :!:

I used to mount a gearbox shaft on a lathe put the clutch on it and carefully push the toolpost into the high spots to try and get the sprocket to run true.

norton bob · Mar 9, 2018

Johnnymac said:
Hi guys, I'm just going through and trying to fine tune everything on my 66 Atlas. Now that I've got it running and rideable I've noticed a pretty good clutch basket wobble. I've looked online and the general consensus is that it could be the clutch rollers?

Also, I have another issue that is driving me nuts. When I go to adjust the primary chain... as soon as I get it to the correct tension, then slowly turn the engine over the chain either gets tighter or looser. I'm thinking that also has to do with the rollers? It makes getting the primary tension really impossible. I've also had a heck of a time getting the drive chain correct. As soon as I loosen the rear axle and adjust the chain tensioners to get the correct drive chain tension, when I go to tighten the axle back up, the chain gets TIGHT. No, it doesn't appear that the axle is moving any as the axle is snug up against the adjusters. Why would tightening the axle up tighten the chain? In order for me to get it right, I had to adjust the chain to where it was very loose so when I tightened the axle, it snugged up the drive chain. I have not had this problem on any of my other bikes.

Any thoughts?

norton bob · Mar 9, 2018

You have mentioned the rollers, wear can occur to the running surfaces in the drum and roller plate and the rollers themselves, Some new parts can make the problem worse as manufacturing is now in the hands of outside contractors and in the absence of new bikes the quality control testing is now done exclusively by us, the customer. I measured the clearance in my set up and concluded there was 3/4 thou clearance at the rollers allowing the drum to rock and the clutch plates to rub inside the drum causing drag.I cured this problem with a set of one thou oversize rollers , this left a one or two thou clearance. a cheap fix. Another invisible problem that makes reliable chain adjustment impossible can be the ability of the gearbox top fixing bolt to either grip the frame plates or slide back and forth ,This is caused by the bolt corroding into the gearbox tunnel and not working as it should. Adjusting the drawbolt just twists the whole box giving the appearance of adjustment but not the effect. Not easy to fix as box may need to come out to drive out the bolt and clean off 50 years corrosion. Wheels out of line can also produce funny effects on chains as you tighten up. Oh dear, just noticed the date on this thread!!, thats a bit sad, must get out more.

Bernhard · Mar 10, 2018

Rollers can start a small amount of clutch basket wobble, However it is the rubber shock absorbers that are the biggest offenders, I have replaced the rubbers in 2 of these clutches, and in both cases I was tearing my hair out trying to get the basket to run true.

texasSlick · Mar 10, 2018

Wish the PO had informed us how this was resolved! The feedback is informative to the contributors, as the contributions are informative to the PO.

Slick

norton bob · Mar 10, 2018

There are pattern rubbers around that have the wrong shape . Carefull to buy from a reputable source.

Atlas Clutch Wobble and chain adjustment frustrations

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