1939 ES2 wheel rim offset

They're next to impossible to measure in-situ and if your new rims don't have the same bead form / size as mine then any measurements are likely to be misleading.

The front rim sits centrally in the forks and bearing in mind the width of the brake drum, it looks as if there is an offset on the rim. However, the dimples and piercing in the OE Dunlop rim don't look asymetrical and I've never heard of the rims being 'handed' on these hubs with identical flanges. Could it be that there is sufficient play to allow the rim to be pulled over ?

Anyone doing much old bike stuff ought to be seeing quite a lot of Norton hubs as they were used for quite a while.

Devon Rim seem to know the offset as they sell kits.

Are the flanges on the plunger hub the same as on the front ?

Previously tony_baxter wrote:

Hi all,

sorry not been on here a while, put the ES2 on hold, as I have too many projects and needed to get some others out of the way. Not actually managed that yet, but, I paid for new rims last year, and was about to send the details when I discovered that the frame was bent, and the wheel rims were non original. That is WM3 not 2. I decided I would wait until the frame had been sorted, then line up engine /gearbox sprockets correctly, then hubs, and finally I would be able to tell (using an old rim), what the offset would be. The supplier needs to know in order to correctly dimple and punch the new rims. However, the supplier is now asking if I can supply the info soon, I think they want to finish these before the end of the tax year !

I have searched the forum, and from what I understand, the hub flanges should be central to the rim ? I have the equal sided cotton reel hubs front as well as rear.

Does anyone know definitive answer ?

Pic attached of the front hub and the rear and bare front together.

And no, after finding lots of 'cowboy' type modifications on this bike, I am not trusting to measure the old rim to get the offset !

cheers, Tony.

Hi Tony,

In my original Norton maintenance and instruction manual for my WD16H, the following data is listed for these cotton reel hubs under wheel building:

Long spokes: 8-5/32" long with 90 degree heads 8/10 i.w.g. butted spokes.

Short spokes: 8-1/32" long with 90 degree heads 8/10 i.w.g. butted spokes.

Under para 93 for wheel building it states that " .. the wheels are laced 1 over 3 pattern with a right hand offset (a straight edge of the hub in which the single row bearing is fitted should give a measurement of 1-3/8" from the straight edge to the edge of the rim).

Operation 1: Fit the 20 long spokes to the single bearing side of the hub; the heads of the spokes alterating inside and outside the hub.

Operation 2: Fit 10 short spokes to the opposite side of the hub to alternative holes with the heads fitted inside the hub flange

Operation 3: Fit the rim

Operation 4: Fit the remaining spokes to the hub and rim (heads outside hub)

Operation 5: True wheel and tighten spokes.

I use this data on all of my Nortons fitted with cotton wheel hubs and haven't had a problem. Note this is for a standard WM-2 rim. For other sized rims just adjust the offset accordingly.

hope this helps.

Previously tony_baxter wrote:

Ian, that's great, I will take a closer look tomorrow. I did spend half an hour this afternoon with rule, vernier and dividers measuring the front end. The flanges seem to be exactly the same diameter, so I guess the slightly longer spokes are to account for the offset. This gives me extra info that will help, I suddenly realised that I meant to order the rims last week !

Sorry for late reply, this forum doesn't send topic notifications !

Cheers, Tony.

Hi Tony,

Yes this is why the spoke lengths are different. Longer spokes go on the single bearing side (which is the timing side of the bike.)

regards, Ian

Hi

I have a 1945 M18, which has the same hubs as the late 1930s ES2, and just had those wheels rebuilt. Yes, the rim is offset with respect to the hub lacing points, as Ian has elegantly explained, but it is easier to think of the rim being central to the outer edges of the hub (ignoring grease seals sitting proud). My measurements and wheelbuilder confirmed this. He said he always worked from the hub edge and never the lacing points, so in his words the Norton rigid rims were 'central' and not 'offset'. The front and back are the same and can be swapped.

Norm

Hi Tony (and anyone else who can help),

Did you ever find out what the correct offset was for your bike wheels?

I have a 1936 ES2 and I'm trying to find out what the offset needs to be. I have one old wheel, which I thought was an original for the bike (which I bought in bits), but there doesn't seem to be any offset on it, and when I fit the wheel in place on the back it seems slightly too far to the right (non break side) maybe 1/2". When I fit the wheel on the front, it seems even further out to the right Maybe even a full inch. (see image of front attached)

I wonder if the offset measurements given by Ian above are for the front, rear or both?

I've seen here that the Devon Rim Company sell a spoke kit for the 19" cotton reel wheel specifically for the rear, which leads me to belive that there may be a different offset on the front (even though they deon't seem to sell a kit for the front).

But in the parts list manual I have covering my bike year it shows that the ES2 has the same spokes on both sides.

Any suggestions would be welcome as I hope to buy the bits and build my own wheels ASAP.

Thanks,

Aled

Hi Tony. My 36 Inter came as a box of disassembled and miss matched parts. The wheels were eventually laced by Anglia Wheels, who I would recommend, but whose figures for the offset I doubted. I assembled the hubs complete with brakes etc. The rear hub required new spacers in order to get the chain line to my satisfaction. With carefull measurements I marked the exact centerline of both hubsin relation to the Frame / Forks, which were alreadyin perfect alignment.The hubs and replated rims were then supplied to Anglia who commented that this was not as per his figures but would do as I requested. The result is,both wheels are nowin perfect alignment and so is the rear chain. I would also add, that when rebuilding the hubs I replaced the open bearings with2XRS type. This required some modification to the inner sleeve as the double row bearing is a couple of mm wider in 2XRS I have used this modification in the past with excellent results.

Thanks David.

I've had another go and fitted the spare wheel I have to the back properly and it now looks to be perfectly in the middle. However the same wheel fitted on the front is still 3/8 of an inch out. I'm can;t see how that could be if the wheels are interchangable.

I'm now as stumped as ever. (Please see images of the same wheel fitted front and back)

The parts books show the same hub and rim, front and rear and there is no change mentioned in the 1939 supplement (at which time the brake swapped from left to right) so this suggests that the wheel is not the problem.

I photographed my front spindle components when mine was apart. Does this help ?

[IMG]http://i248.photobucket.com/albums/gg164/commando16h/NOC/PC160608_zpslbybj1zm.jpg[/IMG]

After reading many different conflicting manuals and accounts I've decided that whether or not there should be an off-set on these wheels, I do need an offset on mine.

I beleive I need an offset of 3/8". Can anyone tell me how I work out the the difference I need in spoke lengths to get that offset? i.e. will the 1/8" of an inch differenc in spoke length used by Tony above give me the actual 3/8" offset I need?

thanks

Hi all

This thread is getting realy boring pre war rigid norton wheels are the same front and rear on all models exept the inters I have allready put the offset measurements on this site look back through the earlier pages

Regards Roger

Aled, building wheels out of line to correct another fault is really not the ideal course of action. If your spacers are correct then your forks must be bent or twisted. I assume that there are no Indian-made components in there ?

Have you tried turning the front wheel round (brake on the right) and checking if the error swaps over ?

Previously aled_corps wrote:

Hi Tony (and anyone else who can help),

Did you ever find out what the correct offset was for your bike wheels?

I have a 1936 ES2 and I'm trying to find out what the offset needs to be. I have one old wheel, which I thought was an original for the bike (which I bought in bits), but there doesn't seem to be any offset on it, and when I fit the wheel in place on the back it seems slightly too far to the right (non break side) maybe 1/2". When I fit the wheel on the front, it seems even further out to the right Maybe even a full inch. (see image of front attached)

I wonder if the offset measurements given by Ian above are for the front, rear or both?

I've seen here that the Devon Rim Company sell a spoke kit for the 19" cotton reel wheel specifically for the rear, which leads me to belive that there may be a different offset on the front (even though they deon't seem to sell a kit for the front).

But in the parts list manual I have covering my bike year it shows that the ES2 has the same spokes on both sides.

Any suggestions would be welcome as I hope to buy the bits and build my own wheels ASAP.

Thanks,

Aled

Aled, the offset applies to both as the wheels are interchangable. All cotton reel hubs are the same for all models except the WD Big 4 side car drive model which has the wheel bearing in the brake drum instead of the hub.

regards

Hi Roger, Sorry if you find this boring, it's quite an important part of the bike, and a costly mistake if I don't get it right.

Thank you for your measurements above, thats the best information I've found about this query and have finally ordered rims and spokes today using these.

The only thing I was hoping to get before I ordered was confirmation of what the actual offset will be with these spoke measurements. I am hopeful that it will be the 3/8" offset I'm looking for, but I can't seem to find anyone either here, or at Hagons or Central Wheels who can confirm that for me. So I've gone ahead with the order and am hoping that they fit.

Aled