500/550 Rear Hub D ring 79mm x 2.6mm (91261-323-000)

[Erny]

Just have (finally!) my rear hub apart to replace dumper rubbers.
Will also replace bearings (left one has damaged seal), but windering where to get specific D ring that goes between hub body and flange. My old one has 1.85mm instead of 2.6.

Original seems it is nowhere available, just found some aftermarket but it is O ring, not D ring.

How do you manage that on your builds? Not sure if O ring instead of D ring will seal (groove for D ring seems to be wider than for O ring)

D ring is item #50

[sye]

May be worth sending these an email?

https://www.barnwell.co.uk/products/d-ring-seals/

[deltarider]

Are you sure it is supposed to be a D ring? CMSNL, DS and the Japanese CB500 Parts List suggest it is. All other sources say it's an O-ring.
The pic in the parts lists is not very clear, I'm afraid and you're not the first one that has trouble interpreting it. There could be an error.
I've worked on my drive flange some years ago and IIRC, the large (thin) O-ring goes around the boss and the smaller thicker one is supposed to be on (rather in) the back side of the PLATE, SPROCKET SIDE. I remember mine was a bit squared, but I have no idea if it originally had been so so, or deformed by the groove. Mine sat quite loosely.

[K2-K6]

I was wondering the same D or O ring.

Ordinarily the groove form controls the "in use" shape.

The rocker gasket for example might have two square form grooves for the O-ring to deform into and allow the two metal faces to meet completely. If it doesn't have those two unused corners for the ring to expand towards you can't close the joint completely.

Compared to a groove with a semi circular form that Forces the O-ring to hold it's shape and give extension to it's uncontained side such that it seals lightly with the other metal component and helps prevent the two touching while giving a dust seal.

It's all in the detail 

[deltarider]

IIRC, back then I've concluded that the pic was wrong and that #50 should have been named #51 and vice versa.

[Bryanj]

Its definitely a D ring, I had some of that part number in a job lot years ago but non left

[Oddjob]

Yeah, it's shaped like a D when new.

[Erny]

It is definitely D shape, groove is unusually wide (to accomodate flat part of ring). I assume it is to better seal as per my googling: "The flat geometry on the base of the D-ring stops the seal from twisting and rolling, preventing spiral failure often seen when O-rings are used in reciprocating applications"

I sent email to banrwell, let's see if they answer something

[Bryanj]

If you cant get the D ring i would measure the depth of the groove add a very small amount and call that the x section of the one you want and fit with lots of rubber lube

[Erny]

Or (just thinking) place a band of thin rubber for example from old thin bicycle tube) under the old D ring, like that make groove shallow and hopefully original D ring will still seal. Will try it if it fits

[K2-K6]

Or (just thinking) place a band of thin rubber for example from old thin bicycle tube) under the old D ring, like that make groove shallow and hopefully original D ring will still seal. Will try it if it fits

You can make a band like that by sanding the two ends to a taper (in thickness) and glueing with puncture repair solution to give a uniform band.

Easiest to do it in a wider band as it's more stable to work with, then cut off a single strip to give the final width you need.

[Erny]

Update on this topic - I found company which will manufacture D rings up to specification (79x2.6), from NBR material.

Tomorrow I'm going to place order - is there somebody else interested too?
Expected cost is 5-6 euro/pc depending final qty.

Let me know asap if interested

Shipping from Slovakia to UK is normally quite cheap in bubble envelope

[Oddjob]

How many do you need to order to get them done Erny?

Put me down for 5 please.

[Sesman]

I’ll take a couple please.

[mickwinf]

I would take 2 please