differences between Commando and S type

rivera · Jun 21, 2019

Dave, you´re right it is some kind of a nightmare.

My left exhaust header also cracked. I already used up two by 3000 miles!
The current one is from Andover and I hope it lasts longer!
I did not thighten the silencer clamp fully so the system has some play

The dogleg bends inwards and the upper silencer touches the side panel riunig the paint job. And yes, I fitted a new exhaust nut without broken teeth afterwards.

I changed to a Roadster exhaust sytem as I was waiting for a new header .

and with S type exhaust:

Lorenzo · Jun 22, 2019

here I am posting some details of the bike in the hope it may help to spot if it is an 'S' or a normal 'Roadster' type.. (btw originally it had the headlamp halo, but I am not sure this was added by the former owners)

NPeteN · Jun 22, 2019

The only real difference between early roadster and S is the exhaust, which is easy enough to change out. Its difficult to tell, my own bike is a 1410 which has all the above S identifiers but an engine number after the "last" S. I wouldn't doubt the dealer in 1970 decided he would have an easier time selling a "cool" S model to some groovy American and swapped the exhaust and panels.

If you want an S, get some pipes, slap a decal on the side cover and call it an S. Sounds like everything else is there already.

L.A.B. · Jun 22, 2019

Lorenzo said:
here I am posting some details of the bike in the hope it may help to spot if it is an 'S' or a normal 'Roadster' type.. (btw originally it had the headlamp halo, but I am not sure this was added by the former owners)

As previously mentioned, the only actual difference between an 'S' and a '70 Roadster is the exhaust system.

However, that bike has the later 71-on yokes, which, may not be original? If they are the originals it's almost certainly not an 'S'.

Edit: The speedo would normally be fitted on the left-hand side.

Lorenzo · Jun 22, 2019

can you tell if the Tommaselli throttle was original at that time?
if not, what should I get to make it original?

Danno · Jun 22, 2019

Tomaselli equipment was hot aftermarket stuff back in the day, but definitely not original. If you'd care to trade it for an original 1971 Commando throttle, let me know.

rivera · Jun 22, 2019

You have the later 1971 fork yokes.
You cannot mount the "halo" on those .
There are no thread bosses under the top yoke for the upper fixing screws.

NPeteN · Jun 22, 2019

rivera said:
Dave, you´re right it is some kind of a nightmare.

My left exhaust header also cracked. I already used up two by 3000 miles!
The current one is from Andover and I hope it lasts longer!
I did not thighten the silencer clamp fully so the system has some play

The dogleg bends inwards and the upper silencer touches the side panel riunig the paint job. And yes, I fitted a new exhaust nut without broken teeth afterwards.

I changed to a Roadster exhaust sytem as I was waiting for a new header .

and with S type exhaust:

Uli,
Did you ditch your prop stand? I'm considering removing mine for various reasons. How is life without it?

rivera · Jun 22, 2019

No, it is there under the brake pedal, barely visible. But I mounted the later style main stand for the gearbox cradle.
The cradle already had the holes for it.
My frame is bent slightly upwards where the original one was fixed. On even ground both wheels touched ground

Lorenzo · Jun 22, 2019

Danno said:
Tomaselli equipment was hot aftermarket stuff back in the day, but definitely not original. If you'd care to trade it for an original 1971 Commando throttle, let me know.

thank you: can you tell if the original throttle for the 1970 Commando is the same as the one on the fastback and the later '72-'73 Commando?

Danno · Jun 22, 2019

Lorenzo said:
thank you: can you tell if the original throttle for the 1970 Commando is the same as the one on the fastback and the later '72-'73 Commando?

Most likely, but it's hard to say exactly. Changes were never made wholesale on a model-year basis. Some things on early examples were stock AMC items that were used on different machines and changed at random at later dates. There may have been 3 different throttles used from '68-75.

Danno · Jun 22, 2019

I was just comparing the throttles in my garage. The one on the '71 appears just like the one on Jimbo's original '68 Fastback in the F/S section, but the one on the '73 has a different shape that I would have attributed to something older than '71 rather than newer. The one on the '73 looks more generic, with an extra boss on the casting that looks like it could also have been used for a push-pull twin cable.

Danno · Jun 22, 2019

Looks like the 1975 (Mk III) throttle was integral with the switch pod and not a separate assembly.

Old Britts exploded diagram shows the same throttle from '71-'74. Older throttles Not Available. Leads me to believe the '73 has had it's throttle swapped for a posssibly older (pre '71) example or even something more common. I believe Amal made throttles at one time.

acadian · Jun 22, 2019

rivera said:
Dave, you´re right it is some kind of a nightmare.

My left exhaust header also cracked. I already used up two by 3000 miles!
The current one is from Andover and I hope it lasts longer!
I did not thighten the silencer clamp fully so the system has some play

The dogleg bends inwards and the upper silencer touches the side panel riunig the paint job. And yes, I fitted a new exhaust nut without broken teeth afterwards.

I changed to a Roadster exhaust sytem as I was waiting for a new header .

and with S type exhaust:

One of my SS headers (from RGM) fractured in the same spot, while waiting for a replacement I decided to have a go at TIG'ing it up and the welded header is still on the bike while the replacement collects dust. Unlike yours, the flange on my headers appears to be a separate piece slipped over the curved pipe then welded from the outside. Because of this double wall arrangement I was able to lay down a hefty bead of weld on the inside which seems to have done the trick

jbruney · Jun 22, 2019

I'll have to look tomorrow, but I believe my throttle is Amal. Worn pretty bad and had to take a bit off to get it to even tighten down on the bars. Need to replace it soon....well it still works good, so that'll be put off until it doesn't I guess.

Danno · Jun 22, 2019

The '73's throttle is identical to this one-owner '74.

The '71's is the more common one, I think. Like this:

rivera · Jun 23, 2019

The 1970 Commando did not have the control clusters. There is a WIPAC Triconsul switch on the left hand side
with a black knob for horn, a green one for high beam flasher and a high beam/low beam switch.

Lorenzo · Jun 23, 2019

rivera said:
The 1970 Commando did not have the control clusters. There is a WIPAC Triconsul switch on the left hand side
with a black knob for horn, a green one for high beam flasher and a high beam/low beam switch.

This is what I have on the left.. can you show your 1970 throttle?
Also, I am wondering where I can get the right handlebars: the semi-western sold at Andover seem to me shorter than the originals I can see on your bike..

L.A.B. · Jun 23, 2019

Same 'Doherty' twistgrip from '68 to early '73 (in Danno's 2nd photo) then the Amal 'quick action' twist grip (Danno's 1st photo).
The 850 Mk3 twistgrip is built into the switch cluster.
Note that a different upper cable is required for each type.

rivera · Jun 23, 2019

Lorenzo said:
This is what I have on the left.. can you show your 1970 throttle?
Also, I am wondering where I can get the right handlebars: the semi-western sold at Andover seem to me shorter than the originals I can see on your bike..

This is the semi western handlebar from Andover Norton. Bike came in parts with a Roadster handlebar.
This is the best pic showing the throttle.

It is a Amal replica as far as I remember. Used on many british bikes.
I had to add indicators at the handlebar ends for German TÜV. I switched to some almost invisible LED blinkers meanwhile. Seat is now an original 1970 one.

differences between Commando and S type

rivera

Lorenzo

NPeteN

L.A.B.

Moderator

Lorenzo

Danno

rivera

NPeteN

rivera

Lorenzo

Danno

Danno

Danno

acadian

jbruney

Danno

rivera

Lorenzo

L.A.B.

Moderator

rivera

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