The heavy subject of weight...

I weighed my alloy project and it came in around 330pounds dry. For a 73 850 lump.

I can't find my 850 riders handbook, but my 750 one quotes 385-395, but does not state fluid condition.

I did some searching on this here, and found Ludwig stating his bike is 291 pounds with fluids and battery.

I call BS on this. I need proof of this. I know how much weight I have been removing, I just don't see this as a realistic number.

What are the base numbers on stock machines both wet and dry?

For the '72 750 Roadster it was 395 lbs dry and 420 lbs wet. (from old brochure and roadtests of the era) 850s heavier.

Have you done the really expensive stuff like alloy barrels and stepped cranks.

330 lb is pretty good. My 500 Domme featherbed race bike is 304 lb with oil. No battery (magneto)

johnm said:

Have you done the really expensive stuff like alloy barrels and stepped cranks.

330 lb is pretty good. My 500 Domme featherbed race bike is 304 lb with oil. No battery (magneto)

Click to expand...

Where I come from a Domme is one of those masterful ladies you meet in fetish clubs......now I don't particularly go for slim women, but I don't fancy meeting a 304lb one with a whip in her hand either.... :shock:

bwolfie said:

I weighed my alloy project and it came in around 330pounds dry. For a 73 850 lump.

I can't find my 850 riders handbook, but my 750 one quotes 385-395, but does not state fluid condition.

I did some searching on this here, and found Ludwig stating his bike is 291 pounds with fluids and battery.

I call BS on this. I need proof of this. I know how much weight I have been removing, I just don't see this as a realistic number.

What are the base numbers on stock machines both wet and dry?

Click to expand...

Aren't you suppose to send a private email now if you disagree, or something like that? (actually i bet you'll be in about 350 or so, not bad by any means but not particularly impressive either :shock: :mrgreen: )

I hope my skepticism nets some good results. It's always better to question. I mean no disrespect, and have started a private dialog. I havent gone completly into alloy barrels and crankshaft lightening. I am trying to do the affordable bits first. And maintain reliability. I am just having a hard time wrapping my head around another 40 or 50 pounds missing. And still retain street legal bits. I know it is possible, but it seems extreme.

Steve Maney crank ~8lbs savings
Alloy Barrels ~10lbs savings (SWAG)

Take all the metal washers you absolutely do not need, put them on a scale and weigh.
Back cut the heads of bolts
Drill out centers of the gear box through bolts
Drill out centers of axles
If stock hubs, then you are carrying a lot of weight, especially the rear. Try a rear QC spool hub (A&A Racing) and alloy sprocket.
Race alloy fuel and oil (or oil in frame)
Light weight race alloy triple clamps instead of the steel lumps

The list goes on and on ($$$)

Herb Becker is a master of weight reduction. The 750 Seeley is around 280lbs wet. The 500 Ultra short stroke Seeley is 265lbs wet.
A Commando frame is pretty damn good and light and I seem to recall Herb sayiing one of his 750's is at or under 300lbs.

You need to have an eye for it and not over do it at the expense of safety & reliability

Lightness is Rightness, but costs more to add its subtracting. I want a 300 lb dirt bike Commando someday, though not the full tilt boggey set up which may come in ~330 lb wet, minus full fairing and luggage rack and bags.

Remove center stand for ~8+ lb of mass off. Drill out big or cluster of holes in rear drum side and even more through the friction surfaces. There's a lot of un-needed mass in the battery tray and battery size only needs to give voltage enough to supply 1st sparks. 1.2 ah worked a treat on Peel but to idle slow over 1 min. Foot stalks are bad positions and rear sets weight less but about 1/3 of factory mass can be removed by somewhat expensive wasting of drill bits. I've not yet rifle drilled Peels
gear box bolts and forgot about them til this post alerted me 3 oz more can go.

Steel cradle is over build but for the front holes so at least a lb could be wisely drilled out of it. But still will be like 3-4 lb heavier than alloy cradle. Iso's parts can be made out of 7075 or 6061 too.

Muffler plates don't need all their flat solid faces either. Peashooters are like 6lb and each header ~3 lb.

I found I could just detect each 7-8 lb removed in stages on last Peel, in ease to fling, throttle response and lifting back up. IIRC each 7 lb = 1 hp in get go.

holey-artifacts-t6942.html?hilit=holey%20artifacts

bwolfie said:

I weighed my alloy project and it came in around 330pounds dry. For a 73 850 lump.

I can't find my 850 riders handbook, but my 750 one quotes 385-395, but does not state fluid condition.

I did some searching on this here, and found Ludwig stating his bike is 291 pounds with fluids and battery.

I call BS on this. I need proof of this. I know how much weight I have been removing, I just don't see this as a realistic number.

What are the base numbers on stock machines both wet and dry?

Click to expand...

You have to look closely at Ludwig's bike to spot the differences as it has been built rather well, if you correlate the various posts around here you will find a lot of the changes, a big hint would be to count the spokes! I think there is also mention of his brake disc somewhere as well, now when you extrapolate this sort of attention to detail to every single component on the bike.......

Dances with Shrapnel said:

Steve Maney crank ~8lbs savings
Alloy Barrels ~10lbs savings (SWAG)

Take all the metal washers you absolutely do not need, put them on a scale and weigh.
Back cut the heads of bolts
Drill out centers of the gear box through bolts
Drill out centers of axles
If stock hubs, then you are carrying a lot of weight, especially the rear. Try a rear QC spool hub (A&A Racing) and alloy sprocket.
Race alloy fuel and oil (or oil in frame)
Light weight race alloy triple clamps instead of the steel lumps

The list goes on and on ($$$)

Herb Becker is a master of weight reduction. The 750 Seeley is around 280lbs wet. The 500 Ultra short stroke Seeley is 265lbs wet.
A Commando frame is pretty damn good and light and I seem to recall Herb sayiing one of his 750's is at or under 300lbs.

You need to have an eye for it and not over do it at the expense of safety & reliability

Click to expand...

do some exercise, eat a salad............

mikegray660 said:

do some exercise, eat a salad............

Click to expand...

No kidding - different subject but across the same lines. After all, we are talking about the goal here (bike weight), not the journey.

There's also lighter tires.
Smaller wheel diameters.
Titanium axles and and trans bolts.
Substitue with Aluminum fasteners where appropriate/possible.

Although probably inappropriate for a big twin I have a laced up rear spool that came off of someone's boy racer which had much smaller gauge spokes and aluminum spoke nipples - real light!

After market light weight disk rotors.
Lockheed Magnesium race calipers.
I've seen custom made aluminum brake caliper pistons to replace the steel ones.
Trimming unnecessary frame tabs and gusset plates off of the Commando frame.
Light weight (teflon puck) head steady.
Titanium valves with smaller stem diameters.
Rationalizing how much braking capacity you really need (and can use) on the rear wheel; it does not need much.
TTIndustries Magnesium cased race transmission.
Alloy shift levers and linkage
Throw out the handle bars and replace with racing clip ons and light weight forward controls.
Replace the fork top nuts with aluminum top nuts.
Replace Roadholder internals with aluminum replacement stuff.
Replace road holders with a Triumph disk front end.
Bore out the intake ports to huge in order to remove all that extra metal - NOT.
Jim Schmidtt light weight rods and pistons.
Convert to belt drive with an alloy clutch basket.
Change to Barnett alloy clutch plates
Change to an alluminum clutch pressure plate.
Change to a 520 chain
Change to a high power density race battery.
Change to lighter weight rear chain slack adjusters
Change to light weight gear box slack adjusters.

Oh yeah, and don't forget to lighten the rocker arms :lol:

Rocker arms: DONE

And I splurged on Ti spring retainers

Dances, minus some extra expensive small minimal exotic stuff your list about covers it for Ms Peel, but note there's over 6 lbs in steel oil tank to be rid of too. Also can run one quart short of oil if extra cooling capacity don't nullify.

Going tubeless I hear pays back over same amounts in the other areas.
Alloy nipples and very thin or few spokes is asking for trouble in the long run in a heavy twin pressing its envelope. Spend $6000 for some one off narrow carbon fiber wheels and hubs with ceramic bearings and stay on smooth paths. ugh.

One half an exhaust system removed from heavy DS of bike is way worth while.
Alloy exhaust nuts plus Milk of Magnesia can be felt as less heft.

Some spinning oz's are lurking to remove in many cogs and gears and sprockets.
One could cut holes out of belt drive w/o issue as long as outer edges ok.
Don't need a primary case for dry belt but there are plastic covers that match factory looker. Don't need gaskets for any major seam in a Commando.

LED aftermarket lights are worth a few more oz out away from center of gravity. Digital mini meters instead of clunky clocks and cables and drives.

No oil filer, mount/hoses either as useless any way but catching stuff that could clog a passage in uncared for bike over long periods topping off w/o just renewing oil.

Rear loop is needless just to hang a tag and light vs under seat or off to side.

Somethings got to be done about a dang light stand to hold it up by itself.

I remember reading in Norton, The RACING STORY, that they got the Manx 500 featherbed race bikes well
under 300 pounds.

interesting

SteveA said:

johnm said:

Have you done the really expensive stuff like alloy barrels and stepped cranks.

330 lb is pretty good. My 500 Domme featherbed race bike is 304 lb with oil. No battery (magneto)

Click to expand...

Where I come from a Domme is one of those masterful ladies you meet in fetish clubs......now I don't particularly go for slim women, but I don't fancy meeting a 304lb one with a whip in her hand either.... :shock:

Click to expand...

We're a pretty tough lot down here in the Southern colonies :roll:

Another one is to run tubeless tyres and seal the spokes.

But earlier comments are correct too. You dont want something that breaks all the time.

ludwig said:

Hollow wheel spindles are lighter than titanium ones .

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Hollow titanium wheel spindles are lighter than hollow steel wheel spindles but I am not going there; it would likely flex like a piece of spaghetti as Ti has 1/3 the modulus of steel if I recall correctly. Dry spaghetti.

But I have no reason to doubt you.

bwolfie said:

Rocker arms: DONE

And I splurged on Ti spring retainers

Click to expand...

:x I forgot Ti spring retainers.

Also:

Allen head valve adjusters with aluminum lock nuts.
Run without a head gasket (must be a few grams there) ala Jim Schmidtt recommendations.
Thin wall (larger diameter) steering stem.
Lighten cam followers or run BSA style per Norvil or per Dunstall
Do away with the battery and up the capacitor capacity or go to an ARD under cover Magneto if you can get your hands on one.
Aluminum engine/trans cradle and front iso mount.
Aluminum swingarm (never saw one for a Commando)
Light weight rear shocks.
Light weight tire tubes (not recommended)
Light weight seat pan and padding
Replace all nuts with lighter weight self locking aircraft nuts.
Drill and lighten the countershaft sprocket (judiciously).

There, now I feel better.

I hope this was of some use.

Cheesy said:

You have to look closely at Ludwig's bike to spot the differences

Click to expand...

I would not mind having a peak if Ludwig would oblige to post a few pictures. Sounds like Ludwig has done his homework.

Oh yeah replace the stem and axle bearing spacers with drilled and notched Al tubes.
End notches make it easier to knock out bearings too w/o having to shove spacer aside barely enough to snag edge of race. Same for the Z plate and bunch of other spacers if any left with all the pairing off going on. Its a bit of a task to seal spokes w/o adding back as much as a tube, but at least the mass would be closer to the hub.

With my Dunstall 2 into 1 into 2 exhaust I replaced the last Y with an S making it just a 2 into 1 and eliminated one whole exhaust muffler. It didn't alter the performance at all.