Atlas Clutch

Have to agree that the Atlas clutch is a bit borderline, however if we had some linings that were designed for oil it could work fine. We went to the moon yonks ago and now in the 21st century ,why not a bit of progress?.

Careful assembly and the use of correct weight clutch springs should help. I upgraded my 99 to an Atlas engine and clutch and the clutch, though heavy, is perfectly acceptable. Some clutch springs on offer are pretty much impossible to compress.

When all else fails, go to the book and read the instructions! Glad to hear you got it sorted.

Apparently there are 2 or3 different make clutch springs on sale, some of which are too heavy gauge, lighter ones made a big difference on my 99 ,along with a new nylon lined cable and thin silicon lube. Don't know if they would cope with the Atlas power, but I will be trying a set. Re -profile mod also done on the box internal lever.

Previously robert_tuck wrote:

Apparently there are 2 or3 different make clutch springs on sale, some of which are too heavy gauge, lighter ones made a big difference on my 99 ,along with a new nylon lined cable and thin silicon lube. Don't know if they would cope with the Atlas power, but I will be trying a set. Re -profile mod also done on the box internal lever.

The clutch on my 99 is seriously heavy. I replaced the springs with new ones from RGM but no change. Where did you get the lighter ones you mention? I've checked the cable and routeing. Thanks. Barry.

Hi Barry, I did some research and found that the right springs are a thinner gauge and slightly longer than I bought from a Norton stockist before. RGM Do sell the right ones so if you are still having problems then you need to go right thro the system. 7/8th lever pivot centers?nipples free to turn in levers, levers set to keep hands in line with arms , new nylon lined cable ,lubed with liquid silicon (not oil) ,handle bars with a rise to avoid fork tops, not Norton straights!,loose run round headstock,not trapped by tank,loose cableties over engine, smooth run round batterybox/oil tank if needed drill cable hole thro engine plate to get best run. Gearbox internal lever aligned correctly and set to start close to inspection cover, lever reprofiled to remove bump,no flats on ball bearing or roller, pushrod oiled over its length. springs only tightened enough to not slip ,file off ridges formed on spring boxes, I think you get the picture.

Hi Andrew - the Atlas nor any featherbed twins had a diaphragm clutch nor belt drive. Sounds like a Commando or some such modification. Cheers Howard

Previously robert_tuck wrote:

Hi Barry, I did some research and found that the right springs are a thinner gauge and slightly longer than I bought from a Norton stockist before. RGM Do sell the right ones so if you are still having problems then you need to go right thro the system. 7/8th lever pivot centers?nipples free to turn in levers, levers set to keep hands in line with arms , new nylon lined cable ,lubed with liquid silicon (not oil) ,handle bars with a rise to avoid fork tops, not Norton straights!,loose run round headstock,not trapped by tank,loose cableties over engine, smooth run round batterybox/oil tank if needed drill cable hole thro engine plate to get best run. Gearbox internal lever aligned correctly and set to start close to inspection cover, lever reprofiled to remove bump,no flats on ball bearing or roller, pushrod oiled over its length. springs only tightened enough to not slip ,file off ridges formed on spring boxes, I think you get the picture.

Thanks Robert for the check list.

Most of the usual ones I have already addressed and will now work through the rest but there's only one thing; I love my straight bars!

I'm glad you said the springs should tightened just enough not to slip, I tried following the book advice to have the top of studs level with the adjusters but it was impossibly stiff felt almost coil bound.

Thanks again

Barry

I have been looking for some bar risers to use with the straight bars on the Atlas, about 20mm would do,no luck so far. The new cable made a big difference ,once lubed.

If you have a Commando clutch on an AMC box then I'm fairly sure that you need a Commando operating arm in the gearbox. The Commando type spring needs more lift to spring the diaphragm over-centre (where effort reduces) than an AMC clutch needs in order to simply separate.

...but this is a hazy memory so check before changing anything.

NA is the AMC code on the Norton boxes. Commando boxes were normally stamped with the six-digit engine / frame number.

The shell will not be the problem but I believe that the Commado had a different cranked arm / cam thing that attaches to the cable. It can be changed with the outer cover removed...The angle that it goes back at is also critical...It must be in line with the cable entrance.

Previously richard_payne wrote:

â?I believe that the Commado had a different cranked arm / cam thing that attaches to the cableâ?

Here you can find something about this matter: http://atlanticgreen.com/ndnsclutch.htm

Fritz