Commando weight

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Fast Eddie

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In the 'preferred Commando' thread, Glen and biscuit came up with some good info on weight.

As a recap, Glen weighed his 650ss at 404lbs dry, but has saved approx 7lbs with the belt drive, so it 'should' have weighed 411lbs.

Glen estimated that early Commandos came in around 15lbs heavier than the Featherbeds, which would therefore be 411+15=426lbs (anyone able to verify this?).

Glen weighed his MK3 Interstate at 448lbs, but has saved approx 6lbs, so it 'should' have weighed 454lbs.

Biscuit then weighed his MK3 Roadster at 462lbs, but this was on 'proper' NASCAR scales so I assume this to be more accurate.

I don't have access to NASCA scales, so I used Glens method to weigh mine.

Mine has got quite a lot of weight saving ideas built into it, belt drive with Barnet clutch, alloy rims, Shoria battery, rear sets, Maney style pipe, and lots of other small stuff. It is a MK2A, so not electric start etc.

Anyway, using 'the Glen method' mine comes in at:
Front: 178.2.
Rear: 208.78
Total: 386.98lbs

I don't know what a box stock MK2A Roadster weighs, if anyone can verify, please do, but it must be more than Glens 'early Commando' estimate of 426lbs. If so, my fiddling around has saved over 40lbs, which is what I had optimistically estimated it at.

Maney claims his crank is 7lbs lighter and his barrels 10lbs lighter, so when I fit my 'new' 920 motor I should be more like 370lbs.

This is all well and good, but it puts Ludwigs 300lbs Commando into perspective, or more pertinently, it puts the work into perspective that he put into it. Respect to you Ludwig!
 
I'm gathering bits together for a lightweight 920 Commando but for weight reduction it will fall short of Ludwig's creation.
My goal is 350 lbs without fuel but with CNW e-start, so maybe 325 without e-start? I'm thinking that last 25 lbs is very difficult to remove and also means some loss of aesthetic appeal.

For example, Ludwig made a lightweight primary cover out of epoxy. I would sacrifice a few pounds here for the stock item. A polished Commando primary cover is an attractive thing, just can't do without it.

It will be interesting to see what the various stock bikes weigh in at. I don't have one here to weigh or I would be all over it.
A friend has a 750 basket case all apart, I might do some comparitive weighing of items (MK3 crankcases vs 71 750 crankcases, etc) and report that here if that is OK.

Glen
 
worntorn said:
I'm gathering bits together for a lightweight 920 Commando but for weight reduction it will fall short of Ludwig's creation.
My goal is 350 lbs without fuel but with CNW e-start, so maybe 325 without e-start? I'm thinking that last 25 lbs is very difficult to remove and also means some loss of aesthetic appeal.

For example, Ludwig made a lightweight primary cover out of epoxy. I would sacrifice a few pounds here for the stock item. A polished Commando primary cover is an attractive thing, just can't do without it.

It will be interesting to see what the various stock bikes weigh in at. I don't have one here to weigh or I would be all over it.
A friend has a 750 basket case all apart, I might do some comparitive weighing of items (MK3 crankcases vs 71 750 crankcases, etc) and report that here if that is OK.

Glen

You're gonna have to get radical with stuff to get down to 325lbs Glen !
 
True, and it might be a bit unrealistic, especially starting with slightly heavier MK 3 cases, crank, frame and swing arm.
The MK3 swing arm, which looks as though it could be dropped from a tall building onto concrete without changing shape, is surprisingly light at 8.5 lbs, including spindle. I was contemplating building an alloy swing arm but I don't think the weight savings would be much there.
A Showa Big Piston fork and Brembo brakes grafted onto the front end will drop considerable lbs, might be lighter than Ludwig's modified roadholders. This setup will also stop and suspend very well.

Glen
 
Next time I take my Mk 3 Roadster for it's mot I will get it weighed for interest and post the result.
It has alloy rims and AP caliper, but not much else from stock.
Will do the same with my Interstate at a later date, as it's only just been tested.
sam
 
When riding the #2 prototype, I stopped at an in-road scale. The bike and I weighed 425 lb. At the time, I was somewhere around 130lb., suggesting the bike was about 295. It didn't have center or side stands at the time, and none of the fiberglass bodywork was fitted. The gas tank wasn't the production version either and had maybe 2 gallons of fuel in it.

I'd expect the early production Commandos were around 330 lb. I'd anticipate the Atlas, with its heavier frame, would be around 420 in road-going trim.
 
frankdamp said:
I'd expect the early production Commandos were around 330 lb.


The published (dry) weight of the early Commando was 415 lb.
 
Having built sub 300lbs Brit racers myself, and having seen the efforts Ludwig had to go to, in order to achieve his '300lbs Commando' I'm afraid I have to question your memory on this one Frank...
 
The weight of the roadgoing featherbed frame with swing arm is not much different than the Commando frame with swing arm. It's deceiving because one generally hefts the Commando frame without swing arm and Featherbed frame with swingarm attached.
There might be 5 pounds difference there. I would be surprised if it's any more than that.
Add in the Commando engine plates and isos and I believe the Featherbed ( mild steel Road version) is a little lighter than the Commando.



Glen
 
A bit of searching turned up this post from Lance. I was surprised how light the Featherbed is when everything is added in.
The Manx version would be approximately half the weight of Lance's road goer. ( wall thickness is one half)

by LanceH » Sat Nov 08, 2014 7:46 pmSomebody asked the question so (as best as I can respond):

Commando – Some sort of 750, I think. No IDBare Frame: 28.5lbsFrame and Swingarm: 36.5lbsFrame, Swingarm and Isolastic Plates: 49.0lbs

Featherbed – 1955Bare Frame: 32.5lbsFrame and Swingarm: 40.0lbsFrame, Swingarm and Engine Plates: 43.0 lbs.

The featherbed is missing the rear frame loop and it could be argued that I haven’t included all the commando isolastic rubbers, etc but enough for a simple comparison, I believe. You could close the gap with lightening, but the featherbed is 13% lighter to start with.Cheers,Lance
 
worntorn said:
A bit of searching turned up this post from Lance. I was surprised how light the Featherbed is when everything is added in.
The Manx version would be approximately half the weight of Lance's road goer. ( wall thickness is one half)

by LanceH » Sat Nov 08, 2014 7:46 pmSomebody asked the question so (as best as I can respond):

Commando – Some sort of 750, I think. No IDBare Frame: 28.5lbsFrame and Swingarm: 36.5lbsFrame, Swingarm and Isolastic Plates: 49.0lbs

Featherbed – 1955Bare Frame: 32.5lbsFrame and Swingarm: 40.0lbsFrame, Swingarm and Engine Plates: 43.0 lbs.

The featherbed is missing the rear frame loop and it could be argued that I haven’t included all the commando isolastic rubbers, etc but enough for a simple comparison, I believe. You could close the gap with lightening, but the featherbed is 13% lighter to start with.Cheers,Lance

IF (intentional use of caps there) I recall correctly, a Manx type wideline in T45 is 16-17lbs... It's not half the total weight as things like steering head, gusset plates, brazing thickness, various brackets and mounts are constant irrespective of the tubing wall thickness.
 
There are featherbeds and then there are featherbeds, right?
Wideline vs Slimline? "Water pipe" vs "501" or some other Reynolds alloy?

Part of the pitch for the Commando frame was that it was thinwall 501, right? or am I misrecollecting?

No doubt, though, when you add in the isolastics and the swing arm aspect of the cradle plates, it's going to be heavier.
 
Lance's is a 55 so it's wide line. At 32.5 lbs it will be the road going mild steel or "waterpipe" frame. As far as I know, all road going frames were made of this stuff.
Can't see wide line vs slimline making any appreciable difference, just added bends in the tubing for slimline, maybe a few ounces.

Given Lance's info, 415 dry book weight for a 750 agrees with 404 for my slightly lightened Featherbed bike.



Glen
 
xbacksideslider said:
Part of the pitch for the Commando frame was that it was thinwall 501, right?

No, it's a fairly ordinary grade of mild steel.
 
Light weight is important in a race bike, however the law of diminishing returns applies. It might be much more important to get the handling right and the isolastics work against that as well as weight reduction. Braking safely right down into corners and getting on the gas earlier is very important on short tight circuits. On big circuits, a heavier bike with slower steering might be more stable and if it loses a bit coming out of and going into corners, it might not matter so much ?
 
I suggest that some people might have a misconception about what is ideal in a race bike. It is easy to build a fast bike which cannot be ridden fast. The best ever four stroke racer was the Aermacchi Ala D'oro of the late 60s. I suggest some of you might benefit from evaluating it.

https://www.youtube.com/watch?v=8TvJTipY8ao
 
Ok folks,

The checks and balances are in...

Previously, I wrote that my modified Commando weighed:

Front: 178.2.
Rear: 208.78
Total: 386.98lbs

I’ve just finished the current rebuild, which included alloy barrels and 7lbs lighter crank. Plus some other pluses (thicker cases, TTI box) and minuses (footrests and a few other bits).

Net result:

Front: 165
Rear: 204.6
Total: 369.6

That’s wet, almost full Roadster tank, full oil.

I’m happy with that, 370lbs wet for a road going Commando is pretty much what I’d been aiming for.

For reference though guys, this is with alloy barrels, light crank, alloy belt drive, alloy clutch pack, lightweight 2:1 pipe, minimal footrests, alloy yokes and clip ons, Shorai battery.

What am I getting at? All those blokes with stock cranks, barrels, clutches, etc that think they’ve got 300-350lbs bikes... think again.

This weight reduction lark is hard work!
 
By way of comparison and reference, my T140, which is stock apart from lighter battery and exhausts, removed mirrors and indicators, weighs in at 410lbs.
 
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