Dunlop and Jones rim combination - stay with default front and rear?

I have reviewed on this site most all of the postings on Dunlop and Jones rims on the late '73 and '74 Commandos and note that in all of them the Jones was used on the rear of the bike and featured the internal tire grip device and heavier spokes to handle the newer 850 engine's torque. This is exactly what I found on my own '74.

Fast forward to now, and I want to be sure I am correct in re-spoking the wheels to place the Dunlop up front, and the Jones on the rear, discarding the internal grip device. I am using K-81 vintage tires for this bike. This begs the question was the Jones considered a stronger rim overall and was it introduced in lieu of a Dunlop to handle the increased torque? Or, was this just as is mentioned as a "grab whatever rim was available" assembly line coincidence?

Topical posts:
= https://www.accessnorton.com/Norton...orrect-tires-wheels-spokes.16649/#post-242870
= https://www.accessnorton.com/NortonCommando/type-rims-and-tires.24034/

Jdub said:

Fast forward to now, and I want to be sure I am correct in re-spoking the wheels to place the Dunlop up front, and the Jones on the rear,

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The spoke angles are specific to the particular hub width, diameter and offset, so a rim with holes punched/drilled for the Norton front disc hub must be used for that purpose and also correctly oriented due to the considerable disc hub offset.

The rim punched/drilled for the drum hub therefore must be fitted at the rear.

The exception would be if the front hub/brake was also a Norton drum as both front and rear drum rims were the same (Dunlop MB41).



Edit:
The front disc rim has larger (0.30") nipple holes than the standard MB41 drum rim (0.25") holes apparently fitted to the majority of 850s except for those Mk2/2A rear rims that had the 0.30" holes.

Additionally the Disc side spokes are a heavier gauge than the plain side with correspondingly bigger nipples, although I don't think this affects the rim drillings.
As LAB has already mentioned, the offset is very noticeable, plus the smaller diameter of the cotton reel hub changes the exit angle.

B+Bogus said:

Additionally the Disc side spokes are a heavier gauge than the plain side with correspondingly bigger nipples, although I don't think this affects the rim drillings.

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Yes, as mentioned, although different spoke gauge (8 & 9 SWG) the two sets of disc wheel nipples are the same diameter (0.30").


https://andover-norton.co.uk/en/shop-details/15900/spoke-nipple-8g-x-300-02-1694-
https://andover-norton.co.uk/en/shop-details/16031/spoke-nipple-9g-x-300

Is there Dunlop rim documentation that specs out Dunlop rim numbers as they apply to Nortons?
I am interested in MkIII Interstate, but would like a Norton specific document for all models.

I see MC27 on a front
and MC287 on rear

p400 said:

Is there Dunlop rim documentation that specs out Dunlop rim numbers as they apply to Nortons?

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Not any actual Dunlop documentation that I know of.

p400 said:

I am interested in MkIII Interstate, but would like a Norton specific document for all models.

Click to expand...

p400 said:

I see MC27 on a front
and MC287 on rear

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Front should be MC275

Dunlop Commando rims. All are 19 x WM2 (1.85"):
MB41 drum rim front & rear
MC275 disc, front, 1972-1975
MC286 850 Mk2/2A rear
MC287 Early 850 Mk3 rear
MC288 Late 850 Mk3 front
MC289 Late 850 Mk3 rear

The Jones rear rim marking (thanks to gortnipper from a previous discussion) is:
W.M.2.19 JONES 91 0033
https://www.accessnorton.com/NortonCommando/type-rims-and-tires.24034/#post-353223

Once again just amazed with the knowledge on this site. Will start my search for an MC275 to match my Jones 91 0033.

(EDIT - Just found an eBay front disc wheel using the MB 41 rim - note spoke extension past nipple into the rim: https://www.ebay.com/itm/Vintage-19...481566?hash=item54613a931e:g:TmwAAOSwTOtbadWE)

Jdub said:

(EDIT - Just found an eBay front disc wheel using the MB 41 rim - note spoke extension past nipple into the rim: https://www.ebay.com/itm/Vintage-19...481566?hash=item54613a931e:g:TmwAAOSwTOtbadWE)

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Yes, a drum rim laced to a disc hub!
The spokes are clearly bending where they enter the nipples which are also being forced out of correct alignment!

If you get a new one from a dealer make sure they have pierced it to the correct angles for the correct Norton hub, I have seen two in the last two weeks that have not been correct. Most wheel builders will supply any 40 hole rim and lace it to the hub, resulting in bent spokes at the nipples. One was Devon rim supplied but laced by someone else, the other one I saw on the forum, but can't remember who posted the photo.

yes I see the stamp now, needed glasses.

Rear is 287