picked up my new '70 cmdo the other day

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goo

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comments/ questions,

clutch force is WAY high

brakes...what brakes?...anybody here fit a disc w/ master cylinder in front?

starting (neutral/clutch out) some times the foot crank just wont move. it may be slipping into gear. somebody said if it does that , clutch in and depress the crank then clutch out and retry.

what do the two switches below the horn do?

if i want to lube the clutch cable does the botton part need to be removed from the xmisson?

what's the little screw on the throttle screw for, throttle friction?

thanks for the help, gents

goo
 
I don't see no 70 Cmdo! Just cuz you say so don't make it so.

Put one of those clamp on lube thingies and it will push the stuff threw. But along with other things, what you really need is to adjust the clutch pack height.

I got a nice mastercylinder from MikeXS for $70 bucks. Worth checking out. Go through the caliper. Ya-hoo.

Switch assignments seem to change from owner to owner, check your manual to see what they are suppose to do. You do have a manual, don't you?

The little screw on the throttle is to hold the Universal Vista motorcycle cruise control in place.
 
goo said:
comments/ questions,

clutch force is WAY high
No reason for this. Go through the adjustment proceedure in the Riders Handbook, it's about as good as anything I've read. You may have to screw in the adjuster until contact and turn it out about 1/8-1/4 turn, not 1 like the book says. When you get it right the clutch lever will break over like a compound bow at about 3/4 the way to the handle.

brakes...what brakes?...anybody here fit a disc w/ master cylinder in front?
Arc your front brakes, it will make a world of difference. I have some high friction RGM on the front that have been arced but have not tried yet, waiting for carb parts.

starting (neutral/clutch out) some times the foot crank just wont move. it may be slipping into gear. somebody said if it does that , clutch in and depress the crank then clutch out and retry.
Don't know, shouldn't do this.

what do the two switches below the horn do?
If it has a button at the front, sliding switch in middle and button at rear, they should be headlamp flasher, dip switch (hi, lo beam) and horn.

if i want to lube the clutch cable does the botton part need to be removed from the xmisson?
Up to you, or get a Venhill cable.

what's the little screw on the throttle screw for, throttle friction?
Yes, if you can get your meaty claws on it, you may be able to tighten it enough to keep you going at 65 all day.

thanks for the help, gents
Good luck,
Dave
69S

goo
Click to expand...
 
brakes...what brakes?...anybody here fit a disc w/ master cylinder in front?

Funny thing about front TLS brakes on Commandos. 30 years ago you couldn't give them away and everyone wanted to convert to the '72 and later disc brake. Today the drum brake front ends are selling for outrageous amounts...a nostalgia thing. It might be less of a hassle to sell what you have for big bucks and buy a new disc front end from Norvil Motorcycles, Andover Norton or the like. Functionally this is a better choice.
 
pic

picked up my new '70 cmdo the other day
 
Nice! You bought it! I remember the photo from when you were 1st looking at it.

To swap to a stock Norton disc (72 and on) you need the lower fork leg with the calliper mounts cast into it, hub, rotor, spokes, rim, calliper and RH switch cluster along with the master cylinder. You should be able to buy a complete front wheel on ebay fairly reasonably as a lot of people upgrade the stock front brakes with more modern ones. Your twin leading shoe brake you have now will fetch just about enough on ebay to buy the parts too. You should have the master cylinder bore resized to 13mm for maximum efficiency if you go that route. You can also have your drum brake turned and re-lined pretty cheap (if necessary) and set up to work properly.
 
Believe me, less than 2 hours work and maybe $5 in parts and the TLS can be made to work as good or better than the first Norton disk. Ask.

Vintage brakes will do it for about $500. If you don't want to do it, send the TLS complete to me and I'll do it for you.

No more food dragging.

Dave
69S
 
Personally I'm a little surprised at the seemingly bum wrap the early Norton disc brake has gotten on some of these threads. My memories of drum brakes on the brit bikes of that era aren't good. By today's standards yes the Norton disc brake has been surpassed but in it's day it was a contender. I had a new 750 combat with disc brake in 72 . My room-mate who was an excellent British Bike mechanic had a 70/71 production style cafe racer with the 2LS drum brake and he would have traded me front brakes in the blink of an eye. Our other room-mate who raced for Honda and Kawasaki had great respect for the new Norton-Lougheed brake as did others around the track in 72. As I recall in 72 the metric bikes emerging on the market all ran dual disc brakes like the earlier Dunstall and Lyster disc brakes and they suffered from the same shortcomings, only one active piston in each calliper. The inside pistons were fixed. By my recollection the Norton-Lougheed brake was the 1st MC disc brake to have both pistons hydraulically activated in one calliper and the single disc was considerably larger diameter than most others of the day. The Norton Lougheed brake performed better because the hydraulic fluid absorbed the shocks and vibrations and kept equal pressure on each side of the disc. These shocks and vibrations weren't equalized with a calliper that only applied force to one side of a disc and had no pressure response on the fixed side. All modern disc brakes today have as many as 6 hydraulically activated pistons placed on both sides of each disc.

Apparently by simply doing the 13mm master cylinder conversion the Norton Lougheed disc brake preforms quite well even by today's standards.
 
RennieK said:
As I recall in 72 the metric bikes emerging on the market all ran dual disc brakes like the earlier Dunstall and Lyster disc brakes and they suffered from the same shortcomings, only one active piston in each calliper. The inside pistons were fixed. By my recollection the Norton-Lougheed brake was the 1st MC disc brake to have both pistons hydraulically activated in one calliper and the single disc was considerably larger diameter than most others of the day.
Click to expand...

As I understand it, at that time, Girling owned the patent rights for motorcycle twin piston calipers (and may still do so?) therefore any manufacturer who fitted twin piston calipers would have had to pay Girling royalties. Various single piston, swinging or sliding caliper designs were used by the Japanese because it was a way of getting around the Girling patent.

http://www.girlingauto.com/en/About-Us/ ... ing-Story/
 
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