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Atlas clutch lever pressure

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I am currently rebuilding a late 1966 Atlas, the clutch lever takes considerable amount of pressure to use, considerably more than my other bikes which include a 1967 650SS, 1957 ES2 [both of which have a similar clutch] or my 1969 Fastback. The Atlas has a brand new drum [RGM] 7/8 lever pivot, I have purchased new springs [no difference], my cable is new and routed the same as my 650SS, I am now looking at the gearbox end and note the activating arm is different between Dommy 04-0029 and Commando 06-0715, has anybody tried a Commando arm or haver any other suggestions?

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Not tried the Commando type as I'm told that the Commando clutch need more travel and less force. Hence the different different lever. So the 06-0715 will make the Atlas clutch even harder to operate. If you have a lever with what RGM calls a fulcrum distance of 7/8 you can skip the rest of my post. Handlebar levers come with different pivot centre to cable nipple centre distance. A longer distance makes the clutch harder to operate. I suggest that you measure it on your on your bikes. As discussed in a recent thread, the laydown gearbox has less travel than the AMC box making it problematic to use a Commando clutch. I've also noticed that there is a number of different clutch springs. I have a similar problem with the Manx, which has the original handlebar with welded on levers. Probably made for the laydown box. With a TTI gearbox which has quite long clutch travel, the clutch is hard to operate. Very tiring after a couple of laps.

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Reprofiling the gearbox lever helps. there is a detail showing the area to be eased. There are some rogue clutch springs being sold (too thick/stiff) and it takes a micrometer to identify the bad ones . I have cheated a little and drilled a hole thro the oil tank support and gearbox plates  to give a better run for the cable, This being on a deluxe so I can perpitrate such horrors under the panels!!. Just one of many. Dare not let anyone see the spaghetti wiring and breather plumbing.

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Hi Robert,

In your post you mention that; “Reprofiling the gearbox lever helps. there is a detail showing the area to be eased”. Do you have any info on exactly what needs to be done to the gearbox lever to ‘reprofile’ it?

Thanks

Regards

Tony

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Has been a bit of a bug bear for me on a 650ss.  Bike had been restored and everything renewed.  All fine except for clutch feel.  Taking the plunge and opening the oil bath again...

What I discovered was the spring cups were slightly distorted.  Witness marks on the side of the spring suggested they were dragging down the side of the cup. I had some spare from another machine, replaced them and now.....  easy.

The comment regarding rouge spring diameter may also play a part in this as the clearance to cup wasn’t huge.   

jon

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The sides of the spring cups also wear into ridges as they work against the clutch center face plate.There is no big secret to getting a good clutch. Lots of small  measures add up to a serviceable job. get them all right and you will feel the benefit.

Thanks guys for your assistance, I have reprofiled the activating arm and tidied up the rollers, I will re assemble check the cable and hope for the best otherwise it will be remove the primary cover and recheck springs & cups [again]. Thanks Al

I have to say that after many years of trying to lighten the pull on the clutch lever of my Atlas including most of the mods mentioned I resorted to a belt drive with Commando clutch. This resulted in a blissfully light clutch action, longer lasting left hand glove and no primary chain case leak

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The standard Norton straights bars are another issue as they normally don't allow the brake/clutch levers to follow a straight line from the shoulder down(the bent wrist action is inefficient and can easily give you tennis elbow).and drag the cables over the fork top nuts. All fixable with a set of bar raisers .About 25mm lift is needed.  Painted black they are invisible. 

 


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