couple questions - rearhub, WM2 rim, offset

rebuilding my 74's rear hub - question, it appears there was a white material used on the inner bore of the hub and the OD of the bearing spacer. best I can describe it as something to keep the spacer from rotating within the hub - a mild glue like substance. when you folks rebuild the rear hub, are you just assembling with any such material. almost seems like a thread locker type of material used on two mating smooth surfaces. question 2 - I vaguely recall reading that the dunlop WM2 rims have a RH/LH side. mine was noted as being "Dunlop" on the LH side, or are these things symmetrical?

any setup tips - initial hub to rim setup for offset. since I've never done this, i'm thinking some sort of spacer blocks to shim the rim in relation to the hub on a flat surface. I know there is an offset, just not sure how to initiate the build. any help would be appreciated. TIA....

yes hub offset?

When I did my first ever wheel build, the Norton mk2 rear hub, I was using an 18" rim as recommended by several folks here as this gives you more rear tire sizing options. Studied many a lot of youtube video's on how to rim build. I made a truing stand out of my pedal bike work stand, a vice, and some clamps to hold rim vertical on original axle & bearings. A dial indicator used for determining where to apply slack & tension in hte spokes for both radial and axial runout. Worked pretty well. Got it under 50 thou all round which is better than my OEM rim spec on my modern bonne. did spoke tension by tuning twang method, so all spokes played same higher note when whacked with a metal spanner or screwdriver.

As for offset, yes there was a post on here from way back that stated what to aim for but I can't recall exact figure. I'll be rechecking everything on the jig again when I come to do my first tire change over this winter.

Found this referenced posting on NOC:

"
Commando wheel offset - the definitive answer
I have the definitive answer as to what is offset, how much, and which way!

I set up a 1973 850 on the frame table and verified it was straight. I then put together a dummy engine and installed it with new isolastics, new washers, Hemmings adjusters, and a Norvil head steady. I put both adjusters on the left side, checked the swinging arm in my fixture and then installed it in the frame. I took all the play out of the adjusters and started measuring:-

• The frame is symmetrical
• The engine/gearbox cradle is offset 1/8" to the left.
• The swinging arm is offset 1/8" to the right so the axle pads end up centred in the frame

I then installed the rear wheel:-

• The spoke flanges are offset 1/8" to the left as mounted in the arm, so the rim is laced off 1/8" to the right to put the tyre in the centre
• The centre of the rim is 3.3/8" from a straight edge laid across the brake drum (not the backing plate

With the stock Dunlop rim, if you sight across the rim on the brake drum side you will see about 1/16" of hub when it's in the right place. In my opinion, front and rear adjusters should be on the same side. Otherwise as things wear and you take up the slop you angle the engine and gearbox in the frame. Since the swinging arm mounts to the cradle, a little one way in the front and a bit the other way in the back and the rear wheel is out of line considerably. The chain will still line up but the wheels will not.


"

xbacksideslider said:

yes hub offset?

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sorry, confused. "yes," what are you saying yes to? "hub offset?" - don't understand

Try this, as you say that NOC one just confuses


Following A request from A good customer of ours regarding Commando MK3 wheel offsets I searched for my notes but (typically) could not find them so I have measured a number of loose wheels lying around, I may add more and measure the ones on Bikes but for the moment this is what I have found. Please note these measurements are simply what I have found here, I make no comments about there accuracy and any further information anyone may have would be welcome. All the measurements are taken from the outer face of the hub to the nearest part of the rim.

COMMANDO CUSH REAR

NIL measuring from offside WM2 unflanged alloy rim -
.200” measuring from offside WM2 chrome rim not original
-.250” measuring from offside WM2 chrome looks original

Offside refers to the speedo drive side.

Call Buchanan’s, tell them what year bike and type of brake. They will give you the proper offset. I bought a cheap balance, truing stand and got the rim close to their number. I then put the wheels back on the bike and checked them. I centered the front between the forks and the rear between the rear hoop using plumb bobs. I had already checked the frame and hoops with a laser so I knew everything was straight. Final numbers were within a couple of mm’s of Buchanan’s recommendation. I used a dial indicator for final trueing.

joe czech said:

it appears there was a white material used on the inner bore of the hub and the OD of the bearing spacer. best I can describe it as something to keep the spacer from rotating within the hub

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There's nothing that could cause the spacer to rotate and with the spindle/axle tightened then it obviously can't rotate.

joe czech said:

I vaguely recall reading that the dunlop WM2 rims have a RH/LH side.

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Not sure about the rear drum brake rim but the front disc brake rim is definitely handed.

joe czech said:

mine was noted as being "Dunlop" on the LH side, or are these things symmetrical?

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Then I suggest you refit the rim as you found it.

thanks for the replies. i'm going to set my offset same as my original readings, since my rear wheel/tire assembly looked pretty much centered and did not have any riding/handling issues. my question is how do you folks stage your hub and rim to start the lacing process. i'm thinking of using several wood blocks (3 or 4), of the correct thickness, around the rim to get a starting point. would that be a viable method, or is there some better method? hub's ready to go back together today, along with the lacing process.

BTW (LAB), my offset readings were close to GME's. "Dunlop" rim will be reconfigured as original, as well as the hub to rim orientation. I marked the hub to it's relationship to the rim (valve stem hole). probably doesn't matter though.

BTW2 (Greg M.E), super write-up.

All the standard drum rear wheels I've seen (WM2x19) have the drive side of the rim flush with the machined outer face of the hub.
As for lacing up, feed the inside facing spokes in first, follow the witness marks from the original spokes and you'll find the rim will only line up one way.
I tend to keep the stampings on the RHS. It doesn't matter on the drum brake hub bikes as they're centred on the hub.

one other thing - can't find any specs, but what's the factory specs on runout, if there are any. dropped the ball, and did not check my "before" readings

joe czech said:

my question is how do you folks stage your hub and rim to start the lacing process.

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I use a 5 gallon pail once the first 10 spokes are laced up.
After all 40 are in, then it all goes in the trueing jig: http://atlanticgreen.com/images/whljiglg.jpg

Not shown is the 2 magnetic basee dial indicators up/down and left/right

joe czech said:

one other thing - can't find any specs, but what's the factory specs on runout, if there are any. dropped the ball, and did not check my "before" readings

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Again, check with Buchanan’s, they are very helpful. My thinking is axially it should be as good as you can possibly get it. IIRC Buchanan’s says 10 thousandths is what they look for in lateral run out, it’s been over 5 years since I did mine so it’s a little fuzzy. Bottom line is depending on how much time you want to invest will determine how straight and true it will be.

What I have been quoted as industry tolerance like 1/16" (.060" +/- .030") seems quite sloppy to me.
I try for +/- .005". of course you have to ignore the splice seam which can be a big whoop de doo on both steel and flanged aluminum rims. Flangeless aluminum for me going forward...

joe czech said:

thanks for the replies. i'm going to set my offset same as my original readings, since my rear wheel/tire assembly looked pretty much centered and did not have any riding/handling issues. my question is how do you folks stage your hub and rim to start the lacing process. i'm thinking of using several wood blocks (3 or 4), of the correct thickness, around the rim to get a starting point. would that be a viable method, or is there some better method? hub's ready to go back together today, along with the lacing process.

BTW (LAB), my offset readings were close to GME's. "Dunlop" rim will be reconfigured as original, as well as the hub to rim orientation. I marked the hub to it's relationship to the rim (valve stem hole). probably doesn't matter though.

BTW2 (Greg M.E), super write-up.

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When I did mine, I followed an online video on lacing spokes. No pre staging of hub or rim. Just had it on a bench and began with one of the two spoke types in use. Cant recall which I started with. If a mistake is made, youlll know before you finish them all and need to backtrack or start over. No biggie, just time.
Oh, there was recommendation to use copper slip or silver anti seize on all spoke nipples to prevent galling while tensioning.