Underwhelmed..

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FastFred

FastFred

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My 850 has been in a vacuum bag for 5 years as I have been racing classic bikes. As most I have run out of garage space and could do with more room so have debated selling the Commando. It's a real cracker but I rode it this year and found it so underwhelming, not so much the power but the slack/backlash in the drive system in top gear. I can't remember now exactly but it had a spoke or two of slack/rotation measured next to the chain guard. I mate checked his and similar. Mine has new cush rubbers. Any ideas as it just makes such a clunk going into top? I would like to keep it but it just didnt spark any excitement like when I swopped my Suzuki GS750 for my first Commando. Thanks.
 
After riding racing bikes for 5 years can you really expect an OEM Commando to stand up to a comparison?
But first you might disassemble, clean and adjust your clutch. Then adjust primary and drive chains to spec.
Then if it still just doesn't bring back the excitement of your youth, pass it on to it's next caretaker.
I've had a number of modern bikes which vastly outperform my Commando, yet the Commando still brings
a big smile onto my face.
 
Part of that "clunk" is sticky clutch plates. When you shift into gear, your box engages half of your clutch plates to spin and your clutch disengages the other half. If your plates are oily, they stick together and throw some force at the back wheel through the chain momentarily as they break free of the other half of the plates... There's your "click". Clean your clutch plates...

The Japanese classics all have the next stage of evolution in their rear wheel cush rubbers, so they don't have that loud click when you load up the drive chain. Don Pender who posts here makes a modern cush drive hub for the commando and one piece axle to go with it. Of course, for someone thinking of selling their commando, I can't imagine you want to put money into it.

Alternatively, you could adapt japanese wheels and get the same result, but that's neither cheap, nor easy to do. My commando has yamaha wheels with a modern cush drive, so the "click" is gone. My wheels are lighter and stiffer, but it's still a commando with somewhere less than 50hp, so I don't expect it to pass any modern superbikes on the straight aways...

Underwhelmed..
 
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Not trying to offend the experts here but it's worse than Velo Venom and Interceptors. I'm not comparing it to the race bikes and the clutch primary are all fine. Thanks anyway for your constructive advice gents.
 
While going from Duc to Griso it takes a few runs through the gears to adjust my actions , same with going from either Italian to Commando I have all adjustments up to snuff on the Norton after a couple runs through the gears all is good and would say the Norton compares favourably to either one of my modern bikes ... sounds like you need to dig in a bit and get it shifting the way you like , the Norton gearbox should shift smoothly once setup ,as you know from being long time owner ...
 
I think your right Craig. Probably like it takes a few miles to adjust to clutch bite height on a hire car.
 
Are the cush rubbers in the rear wheel worn out?
I can't say I've ever noticed much slack in the driveline of the Commando, not underway at least.

It's MK3 with the sturdy cush, so that might be the difference.
The early cush is said to be prone to wear, guess that's why it was upgraded.


Glen
 
I fitted a Suzuki rear disc hub from an early spoked wheel GS 550/750 which has a superb cush drive. The pre MK3 Norton effort is pathetic.

Martyn.
 
Hi Fred
Just in top gear as you let the clutch out?
That seems unusual & I can't think of a reason why?
What have you been racing? Lol
Chris
 
Just measured the slack amount in top Gear, mk3.
It is 2.5" at the rim in 4 the gear.
I can't say I've ever noticed the slack or any clunkiness while riding. It's smooth on and off the throttle.
I did notice the slack /clunky problem when riding a BMW rt1200 r.
That one was like a buckboard going thru a parking lot. Clunk clunk clunk as things went back at forth at low speed. Even the owner couldn't ride it smoothly at low speed. At highway speeds it was OK.

Glen
 
Yes that's when. I will have a good look at it later this year.
I raced a TZ350G early 90s for two years and was going to do the Manx but the wife got herself pregnant so racing stopped as we were skint.
Put racing out of my mind for 23 years but decided to have a go 2015 and bought a Honda k4 350 to try to do the Classic TT. Took me four years to get there but I competed this year and got Classic TT newcomer award 25th place. Will go back this year on k4 again and a Maxton TZ350G once I get it going.
 
Two and half inch sounds about what I found, will wash clutch and check over with this advice .
 
1.) Primary and secondary chain adjustments.
2.) Rear wheel drive rubbers
3.) Clutch plate teeth are getting worn and pointy
4.) Clutch center hub is worn with notches
5.) Badly worn swing arm bushing(s)
 
For it to be doing it only in top gear has to be something in your gear box, everyone keeps saying crush rubbers but you said they are new and tight as worn CRs would be doing it in every gear and if in the clutch would be the same in every gear so next step would be to look inside your gearbox, maybe a worn 4th gear, I have owned my Norton for over 43 years now and its never done what you describe with only top gear, so something is not right somewhere, so rubbers OK, clutch is OK and primary and rear chain is OK then I be looking in your gearbox, maybe time for a rebuild, its not a hard job to do and if you do the gear box best to pull it off the bike then you will get to go through the clutch as well, anyway hope you sort it out as something is wrong and should be smooth as.

Ashley
 
The gear box is a torque multiplier as well as a movement multiplier so yes, difference in every gear.

Been working with Norton’s for nearly half a century now and can say that to my standards I have seen gross slop in all the gears on most all Norton big twins. To the OP, take a systematic approach and make the observations of where the movement is being transferred to.
 
You wouldn't race a Commando anymore in the Classic TT as the only class would be the Super bike that has Suzuki XR69's and Michael Dunlop lapping at 126mph. It's all about getting the professional TT riders there to boost visitor numbers and you can't argue with that really like it or not.
I'll go through the Norton systematically when I've time thanks.
 
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