Shimano Alfine 11 - Longer term reliability

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jb
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Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 25 Jan 2014, 12:50am

Part 2

13. The tabbed guide ring (item 9) can now be weedled out, it has to be turned as well to allow the tab to follow the grooves so it can come off.
NOTE: easily left off when rebuilding.
P1070125.jpg
Tabbed guide ring item 9 (marked three!) needs to be pulled forwards turned for tab to line with groove and then removed

14. Gear carrier 2 (item 10) can now be slid off turning as before to flatten the pawls, also as before the sun gear should remain in the cluster to prevent the planet gears losing their timing. It cannot escape without removing the small planet gears.
Note the lugs that engage the carrier unit 1 (item 12) make sure they go back the same way (the shiny marks will give a clue). Check for damage & free movement.
15. Slide off the last sun gear (item 11) turning it anti-clockwise to flatten the pawls. Note which way round it goes. (gear teeth out plain side in)
P1070128.jpg
last removable sun gear, press down pawls to allow it to slide over. Small hair springs that operate the pawls just visible in their grooves

16. Slide off the remaining gear cluster (item 12) and the ball bearing cage (item 13) also note the roller clutches on items 12 & 17 which engage with their respective gear carrier cages 7 & 12. These have to be turned against each other on assembly to help them go in.
P1070132.jpg
strip down complete for most purposes, pawl hair spring ends visible, also the fixed sun gear and behind that the gear clutch & roller clutch on the sprocket unit.

We have now gone as far as is practical, the only reason for going further would be if the sprocket side wheel bearing had gone (item 18 & 20) or one of the oil seals (item 19 & 23 or the splined washer 21) is leaking – unlikely the bearing will have gone since it runs in oil and I don’t know what the spares situation is with it, the seals are obtainable. You will also need special tool (item 47), I made one on my lathe; it needs to be a fairly good fit.

Next is to examine the axle assembly and check it is all ok.
1. There are three selector pawls, check that they spring in and out easily, check that none of the fine springs are broken. (no item numbers; these all come as part of the axle assembly)
2. Check that the pawl faces are not chipped or worn and that their mating ratchets inside the floating sun gears are not worn. (they are not razor sharp when new)
3. To check all is operating correctly it is easiest to re fit the cassette joint and now place the axle back into the upside down bike frame. Connect the gear cable and run through each gear – watch the pawls flick out and retract.

4. For correct operation they should follow the following sequence –
11th pawl 1 (furthest from fixed sun gear) out, pawl 2 out, pawl 3 in
10th pawl 1 out, pawl 2 in, pawl 3 out
9th pawl 1 in, pawl 2 out, pawl 3 in
8th pawl 1 in, pawl 2 in, pawl 3 out
7th pawl 1 out pawl 2 in, pawl 3 in
6th clutch disengages, pawl 1 out, pawl 2 out, pawl 3 in
5th pawl 1 out, pawl 2 in, pawl 3 out
4th pawl 1 in, pawl 2 out, pawl 3 in
3rd pawl 1 in, pawl 2 in, pawl 3 out
2nd pawl 1 out, pawl 2 in, pawl 3 in
1st pawl 1 in, pawl 2 in, pawl 3 in

5. As the cable pulley is turned by hand the selector should turn smoothly against the spring, if it doesn’t turn easily and /or the pulley will turn but the selectors don’t there may be some grit or piece from a damaged part that is snagging it, try flushing the whole mechanism with plus gas or similar.

The most likely cause of wrong gears being selected is broken pawl springs or stuck pawls any other damage to the selector will likely cause it to not work at all or jam up.

Check all gear teeth for breakages although being press formed they don’t look as good as machine cut gears.
The gear carriage assemblies can be flushed out but don’t leave fluffy rag bits inside them . There are thin circlip springs holding the planet axles in DO NOT REMOVE THEM.
Check the thrust shim in item 7 that item 10 presses against if it is wearing it could be the cause of the ‘glitter’ in the oil. I had one that wore for no apparent reason – it could have not been properly hardened? Sideways thrust is generated by the helical gears in the first set of gears (item 12)
P1070176 (800x600) (640x480).jpg
thrust washer held in item 7 by a fine circlip spring - also keeps the planet gear axle shafts from coming out - so watch it.

P1080009(1).JPG
The thrust shim shown inside the ring gear item 7. the planet assembly that runs against the shim is shown next to it. The sun gear cannot escape without removing the planet gears.

For any replacement parts go to a Shimano dealer and give them the part number shown next to the item in the chart (on the full chart available on the Shimano web site) you might be surprised at what you can get or you may have to buy a part assembly.
Or alternatively if you can pick up a broken second hand one; it might have spare undamaged springs in it.

Assembly of the inner unit is a reversal of above – don’t forget to fit the ball cage first (item 13), squirt some oil round the planet gears as it might take a while for oil to reach inside to their needle rollers.
Rotate the sun gears whilst sliding onto the axle in order to push the pawls down, likewise the roller clutches and to mesh the gears as they mate up.
Fit item 9 before sliding on the last ring gear assembly (item 7).
Finally the two anti-spin springs need to have their bent ends engage the hole in the back plate before the circlip is clipped in place – Note there seem to be two different designs, one has two holes opposite the other just one.
If it is desired to fit a new oil seal in the hub at this time, push the old one out, there is a tool for fitting these in but it can easily be pushed in place with a thumb (and cause less damage) it clips into a shallow groove.

1. Now secure the unit by the axle in the vice, sprocket side down, lower the wheel and hub carefully into it twisting it as the roller clutches come into contact. Be careful not to damage the oil seal in the hub by rubbing the axle screw thread on it.
2. Squirt some oil onto the cone ‘o’ ring, run the cone down the axle until it stops against the bearings, slacken a tad and spin the wheel to bed it down and make sure nothing is scraping.
3. Fit the lock nut and run it up to the cone
4. Lightly turn the cone until pressure is felt, back off half a turn & nip up the lock nut
5. Place finger and thumb over the lock nut so that they are touching the hub, move the wheel rim up and down and feel for a slight bit of play through your thumb. If none is detected back of the cone until it is. Then by small increments turn back the cone and nip the lock nut until the play is almost undetectable then tighten the lock nut. Note: an over-tight cone can cause creaking when cycling, excessive play will strain the mechanism.
Take it out the vice and spin the cluster via the sprocket spline, there should be no lumpiness.
6. Re-fit the plastic cover and nip up making sure the mating surfaces are clean
7. Fill with 25ml of oil & leave on its side for a while. Then check for any leaks from the axle or plastic cover before fitting the dust cover & sprocket.
Cheers
J Bro

Brucey
Posts: 39514
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 25 Jan 2014, 1:48am

good work fella!

Your oil looks pretty murky there... how far had that gone?

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

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barrym
Posts: 633
Joined: 22 Jun 2012, 10:05am
Location: Corsham - North Wilts

Re: Shimano Alfine 11 - Longer term reliability

Postby barrym » 25 Jan 2014, 7:07am

Wow! Great post. Don't have one of these hubs currently but it is likely and this will prove extremely valuable. Thank you.
--
Cheers
Barry

Blackredgold1964
Posts: 83
Joined: 21 Dec 2007, 11:03pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Blackredgold1964 » 25 Jan 2014, 9:48am

Fascinating, thanks, my 11-speed hub is only 2 months old and what you describe is too complicated for me but I'll keep this for future reference anyway.

jb
Posts: 943
Joined: 6 Jan 2007, 12:17pm
Location: Clitheroe

Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 25 Jan 2014, 12:00pm

Brucey wrote:
Your oil looks pretty murky there... how far had that gone?

cheers

That was the original Shimano magic oil after a 1000 miles (the pictures are from different times by the way I just picked them to illustrate the point).
It was full of filings (glitter) from the wearing thrust ring.

I think this hub will be far easier to strip down to this stage than the Nexus/Alfine 8 by the way. Everything comes off in modules & holds together. I've taken a Nexus partly in bits and it looked a bit more involved.
Cheers

J Bro

rfryer
Posts: 740
Joined: 7 Feb 2013, 3:58pm

Re: Shimano Alfine 11 - Longer term reliability

Postby rfryer » 25 Jan 2014, 12:19pm

Thanks, JB, that's an excellent resource. I can now look forward to having an excuse to take mine apart!

bobc
Posts: 495
Joined: 5 Apr 2012, 11:59am

Re: Shimano Alfine 11 - Longer term reliability

Postby bobc » 25 Jan 2014, 7:51pm

Thanks JB, top job

MikeF
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Re: Shimano Alfine 11 - Longer term reliability

Postby MikeF » 25 Jan 2014, 10:19pm

Surely JB's post should be on too good to lose?
"It takes a genius to spot the obvious" - my old physics master

bobc
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Joined: 5 Apr 2012, 11:59am

Re: Shimano Alfine 11 - Longer term reliability

Postby bobc » 27 Jan 2014, 10:55am

Interesting reading and comparing the alfine11 with the sturmey archer 8 speed: the alfine uses the same "sun locking -> gear up" system as the SA8 withthe addition of a "high ratio/low ratio" clutch.
If you analyse the SA8 gearing system it is possible to arrange for even gearing steps and preferential single or dual stage gear-ups with the exception of double jumps between the lowest (000 to 001) and highest (110 - 111) ratios. If we assume shimano have eschewed the 111 ratios because of the inefficiency of 3 gearing stages and tried to miss out the lowest jump in the higher ratio; this opens the question why did they not offer a 13 speed with wider range instead of 11;- any thoughts jb?

jb
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Location: Clitheroe

Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 27 Jan 2014, 12:19pm

Well firstly I would suggest they are struggling for space as it is on the selector arms, without making the axel significantly fatter and the hub correspondingly bigger I cannot see how they would get more selections onto it. Rohloff have had to go the way of having two clutches to avoid making the pawl area too busy. Which means for Shimano, a radical design change away from their own pet system which is orientated more towards an effortless change in all peddling conditions using one cable – which Rohloff isn’t.
Secondly as far as I can see the only other possible gear not being used is direct drive. I’m not familiar with the SA system.
Cheers

J Bro

bobc
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Joined: 5 Apr 2012, 11:59am

Re: Shimano Alfine 11 - Longer term reliability

Postby bobc » 27 Jan 2014, 3:06pm

I can readily believe that they felt their single cable selection system would start to be flakey with more ratios to select from - plenty folk already have trouble with just(?) 11 speeds (see many of the pages above). But the cogs are already in there to do 13, they've made a choice not to..... (OK the cogs are in there to do 16 but at the price of poor efficiency and/or non-linear jumps in 3 of 'em).
Put simply, there's a clutch & 3 pawls all of which can be in or out - that's 16 combinations!
There's loads of data on the web about the SA 8speed, I'm actually using one so I looked it up, and it is an instructive simple introduction to how the upper and lower halfs of the alfine11 work.
It's worth calculating the 3 stage gear-up ratios and how they are combined to get the 8 speeds - maybe I'll bung it on its own thread :)

jb
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Location: Clitheroe

Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 27 Jan 2014, 4:00pm

Ah, I see what you mean, but 2 of the gears are part of the same shaft so cannot be used independently making a maximum of 12 possible combinations
Cheers

J Bro

jb
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Joined: 6 Jan 2007, 12:17pm
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Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 27 Jan 2014, 4:46pm

Here are the Alfine 11 gear combinations in diagram form. (photos! unfortunatley can't load pdf)
P1080621.jpg
Alfine 11 gear diagram

P1080617a.jpg
Alfine 11 gear combinations

P1080618a.jpg
Alfine 11 gear combinations
Cheers

J Bro

bobc
Posts: 495
Joined: 5 Apr 2012, 11:59am

Re: Shimano Alfine 11 - Longer term reliability

Postby bobc » 27 Jan 2014, 5:06pm

Gotcha - the 2 suns that share "stepped" planets obviously can't both be locked at the same time, so that waves byebye to 2 more ratios bringing us down to 11 :)
great info jb thanks again.

frankz
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Joined: 21 Jan 2014, 12:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby frankz » 28 Jan 2014, 2:13pm

Hi JB
Thanks for that. I was away. Will gird my loins for this job!