orientation of non rotating washers (Nexus 8-Speed Internal Hub)

[phca...@gmail.com]

The anti-rotating washers on my Nexus 8-speed internal hub axle are opposite to what every service manual I've seen suggest they should be. In particular, the yellow washer is on the left side and the brown is on the right! As well, the tab on these washers is on the down side of the dropouts whereas the photos I've seen all appear to have the tabs on the up side! I should add that I have a Shimano Rollerbrake on my bike.

Can anyone explain why my setup is different than what the manuals show?

Thanks

[David Scheidt]

phca...@gmail.com wrote:
:The anti-rotating washers on my Nexus 8-speed internal hub axle are opposite to what every service manual I've seen suggest they should be. In particular, the yellow washer is on the left side and the brown is on the right! As well, the tab on these washers is on the down side of the dropouts whereas the photos I've seen all appear to have the tabs on the up side! I should add that I have a Shimano Rollerbrake on my bike.

:Can anyone explain why my setup is different than what the manuals show?

The anti-rotation washers come in different angles, to match different
angles of dropouts, so that the cassette joint cable stop points in
the right direction (along the chainstay, typically, some times the
seat stay.) They're not inherently for the right side or the left
side, but they come in pairs that are mirror images of each other. If
you have vertical droputs (or nearly vertical), the tabs go down, if not,
they should be on the closed side of the drop out. (that's what the
docs say, I'm not really sure if that matters a whole lot.)

--
sig 74

[AMuzi]

Usually in matched pairs. At least one is required for that
or any other planetary geared system.

The various angles help to get the cable lined up with the
hub's cable fitting so if it works and you can get your
fingers in to disconnect for a wheel change, leave it as is.

I don't have a brown one to compare but if the two tab
washers have significantly different angles, either replace
one or leave one out. It matters not whether the tab faces
up or down.

p.s. in answer to the question not asked, your Shimano
roller brake needs grease through the grease port regularly.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[avag...@gmail.com]

http://goo.gl/iNlEkD

[Paul Calamai]

Thanks all for responding but I'm still searching for an answer. The washers I have are a matching pair however the yellow is marked 5R (for right) and the brown is marked 5L (for left) but they are installed opposite to the marked sides! I've sent a message to Brodie (my ride is a Brodie Section 8) to see if they can offer an explaination.

[Andre Jute]

I don't know why the arrangement is different on you bike but, assuming it isn't just a hungover Monday assembly problem which fortunately hasn't killed you yet, we can all speculate. The document you want if you don't have it already is http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Nexus/InternalHub/SG-8R20/34R0D-SG-8R20-EN_v1_m56577569830600211.pdf

Speculation: Those anti-rotation washers are handed and oriented the way they are to account for the orientation and angle of the frame end, what the crude and ignorant call "dropouts". A pair of washers if swapped from side to side and/or turned upside down so that the "tongue" is at 180 degrees to its previous orientation, will give the designer more possibilities for aligning his frame ends. Is there something odd in the alignment of your frame ends, not covered by the table on the document cited above, but covered by a bit of vector thinking as described in the paragraph?

Still speculating: Alternatively, it may just have been a supply problem: the recommended washers may not have been available, so a lateral thinker ordered the ones that by turning them around would do the same job. I remember having to wait for the precise washers I wanted, while others were freely available, and wondering if I could swap make the available ones do in a different orientation, but it wasn't urgent as at the time I also had a new Rohloff to play with, so I just got the right ones.

Andre Jute
Lateral thinker

[avag...@gmail.com]

try an exorcism with

Ecclesiastes 3:1