Internal hub gears - rear wheel slipping

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songsforpolarbears
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Re: Internal hub gears - rear wheel slipping

Postby songsforpolarbears » 24 Jun 2012, 7:02pm

thanks for replying.

hubgearfreak wrote:
7_lives_left wrote:Do you have left and right mixed up?


that's my guess too. i've not had nor do i have any shimano hubs, but it occurs to me that the more positively serrated washer should be on the driveside.


On the left hand side (non drive side) I have been putting the yellow washers followed by the 'tall' nut.

The the right hand side (drive side) I have been putting washer followed by nut&washer in one.

IMG_0569.jpg


jb wrote:You have got the sprocket side internal nut out by 45 degrees by the look of the photo this is stopping it slotting into the slot thus making it have little contact area even when tight and causing it to slip

I suggest you take the wheel right out and start again.


Hmm, this is news to me. Can you tell from this photo?

download/file.php?id=16276&mode=view

Thank you

Brucey
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Re: Internal hub gears - rear wheel slipping

Postby Brucey » 24 Jun 2012, 8:23pm

-you need big, toothy washers on the drive side rather than the other side.

-try to have a large washer both sides of the dropout if possible

- IIRC the bellcrank unit is held in position by a bolt, part #28 on the EV.

-if the wheel slips persistently, put the ATW on the left side and fit a chain tug to the right side.

cheers
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hubgearfreak
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Re: Internal hub gears - rear wheel slipping

Postby hubgearfreak » 24 Jun 2012, 8:27pm

songsforpolarbears wrote:On the left hand side (non drive side) I have been putting the yellow washers followed by the 'tall' nut.


from the photos it looks to me like the yellow one is the one with the most positive teeth, i'd have fitteed that to the drive side.

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RickH
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Re: Internal hub gears - rear wheel slipping

Postby RickH » 24 Jun 2012, 9:21pm

According to my reading of this Sheldon Brown page (nearly half way down) the Yellow non turn washer (5R) should be on the right (drive side) & there should be a brown mirror-image one (5L) on the left.

Edited to add - looking at some of the Shimano tech specs list on this page they DO seem to use the yellow washer on the left, at least on the coaster & roller brake models, but they also appear to use different nut washer combinations depending on axle length. Knowing exactly which model would probably help narrow things down.
Rick.

songsforpolarbears
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Re: Internal hub gears - rear wheel slipping

Postby songsforpolarbears » 24 Jun 2012, 10:53pm

RickH wrote:Edited to add - looking at some of the Shimano tech specs list on this page they DO seem to use the yellow washer on the left, at least on the coaster & roller brake models, but they also appear to use different nut washer combinations depending on axle length. Knowing exactly which model would probably help narrow things down.
Rick.


The hub reads SG-3C41

songsforpolarbears wrote:NEXUS 3-SPEED HUB w/Coaster Brake SG-3C41 Inter-3 Hub - http://www.shimano.com/media/techdocs/c ... 704663.pdf



Thanks for all the replies. I am determined to get the most out of this bike. It is far too comfy a ride to have to working poorly.

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mjr
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Re: Internal hub gears - rear wheel slipping

Postby mjr » 1 Oct 2015, 11:46am

thirdcrank wrote:I'm not sure your problem is connected with the gear cable fitting / adjustment but I'd still preserve / commit to memory / bookmark billynibbles reply for when it is. I think you have reassembled it with the nuts and washers in the wrong order. Have a look at this:

http://techdocs.shimano.com/media/techd ... 655189.pdf

Shimano appear to have rearranged their website into an annoying mess. What did it say? What is the correct order?

I currently have Nexus box - holey nut - axle-mounted accessories (rack etc) - washer - chain tug - dropout - chain case support - serrated washer - hub (including locknuts inwards) - dropout - chain tug - yellow non-turn washer - washer - accessories - cap nut and I'm wondering if that's correct.

The chain case seems too far in and is very gently rubbing on some spokes and I'm surprised that the chain tugs are between the serrated washers and the dropouts, so I'm wondering if someone has reassembled this in the wrong order and the chain tugs should be inside the dropouts... but that wouldn't necessarily move the chain case support any further out anyway and it has to be inside the dropouts else it'll hit the seat stays. So unless the slight change in stay flex from having two chain tugs inside somehow changes the alignment of it, am I best off bending the support? But then I'm taking the wheel out and everything off the axle anyway so I might as well put it back in the right order...

Any advice would be welcome. I think I'm using my third-choice bike until first and second are back on the road! :lol:
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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Brucey
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Re: Internal hub gears - rear wheel slipping

Postby Brucey » 1 Oct 2015, 12:36pm

wayback machine, yay!

https://web.archive.org/web/20140211220115/http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Nexus/InternalHub/SG-3C41/SI-35U0C-001_ENG_v1_m56577569830655189.pdf

But this makes no allowance for chain tugs etc. The important stuff is what bears against the dropouts, and how well it fits.

FWIW you will find that the locknuts are often not serrated on Nexus hubs, only the NTWs are serrated. If so you will need the NTW to bear directly against the dropout in most cases. Thus if you have a single-sided chain tug, it may be best to fit that (or the NTW) on the inside of the dropout, even if it is rather fiddly to do so.

If you have a double-sided chain tug (and there are special ones made specifically for Nexus hubs, in stainless steel) then you have no serrations that bear directly against the dropout. Any metal chain tug should help to keep the wheel in place without slippage, so that can offer a solution. If you use a nyloc nut on the chain tug, it'll stay put for longer.

Note that if your dropout is wider than the tab on the NTW then you are in trouble; the NTW may squirm and twist (in low gears especially) and this will let the wheel move around. Some shimano hubs only allow NTWs to be fitted on one side of the hub but even then If you can fit one NTW each side of the dropout this can help; there is just more grip there.

If you do that, you may find that the chain tug cannot be fitted easily, if at all. Sometimes you can put a kink in it so that it still works. If push comes to shove with a N3 hub I think it may be possible to

- fit a slimmer locknut (3/8" x 26tpi) on each side of the hub, to make more room on the axle for NTWs etc (you may need to grind the flats a bit longer on the axle)
- grind flats onto the end of the axle and use a NTW there even if it never had one before
- weld a chain tug fitting to a NTW, so that there are just fewer parts to deal with.

hth

cheers
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mjr
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Re: Internal hub gears - rear wheel slipping

Postby mjr » 1 Oct 2015, 1:26pm

Thanks Brucey. I didn't realise Wayback Machine captured PDFs.

So that mentions only the non-turn washer and some of the nuts which makes me think pretty much all the rest is a free-for-all and I should reorder things to get the serrated parts against the dropouts/forks and the chain case away from the spokes. I'll look carefully at the NTW and get a second one if it seems like a good idea.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.