Shimano Alfine 11 - Longer term reliability

For discussions about bikes and equipment.
Brucey
Posts: 39899
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 11 Feb 2020, 7:27pm

the 'squashy feeling', especially in the lower gears is 'normal' for this type of hub, and is (mostly, I think) caused by the presence of roller clutches.

In a post above , Meandros seems to claim that the direct driving pawls inside Rohloff hubs are less efficient when climbing. I beg to differ! On the same hills, I find myself using lower gear ratios when using hubs with roller clutches (Nexus8, Alfine8, Alfine 11 etc) and I also find myself going very much more slowly. I agree you are best off pedalling swiftly at low torque with these hubs, but this is making the best of a bad job; I think the roller clutches have a strong negative effect on pedalling efficiency.

I suspect (but cannot prove) two further things

1) that the flexing is worse if the roller clutch is in poor condition, i.e. there are not very many rollers engaged and sharing the load. This would be expected to cause the drive rings to flex more, into various odd-sided polygonal shapes, under load. Brand-new hubs, badly lubricated hubs and hubs where the bearings are not correctly adjusted are all likely to be worse in this respect.

2) that the measured efficiencies that you read of are measured under constant torque conditions, where the flex (which normally occurs with every pedal stroke) doesn't affect the efficiency readings.

So overall I have concluded that, for my riding, anytime where efficiency is important, hubs without roller clutches suit me better that those with.

Hubs with pawl drives include

Most SA 2s, 3s 5s, 7s, 8s (*) hubs,
most Sachs/SRAM 2s,3s,5s,7s (**) hubs
Shimano Nexus 7 (***)
Rohloff 14.

But note the following

(*) SA 5s 7s and 8s hubs have a patchy reliability record
(**) SRAM hubs are no longer made and the 5s/7s hubs seem internally reliable, but have pretty lousy shifting arrangements.
(***) No roller clutches in Nexus 7 hubs but no roller bearings either. It is not a super-efficient hub, partly because there is no direct drive gear ratio.

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

jb
Posts: 946
Joined: 6 Jan 2007, 12:17pm
Location: Clitheroe

Re: Shimano Alfine 11 - Longer term reliability

Postby jb » 11 Feb 2020, 8:13pm

Brucey
Did you not think that in the vidio it seemed a little excessive, he did say it was present in all gears which I certainly never noticed, only in tenth & seventh I think.
Cheers
J Bro

Brucey
Posts: 39899
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 11 Feb 2020, 9:03pm

It might be, but I'm not entirely sure which gears he is in when he is doing the demonstration.

FWIW on a MTB the tyre often makes any transmission feel a bit squodgy, but on a more road-oriented machine I'd say that -to an aggressive rider especially- the A11 hub especially feels very squodgy in many of the lower gears.

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

meandros
Posts: 59
Joined: 1 Jan 2018, 7:34pm

Re: Shimano Alfine 11 - Longer term reliability

Postby meandros » 12 Feb 2020, 12:49pm

It felt to me, whenever I was using a regular pawl clutch IGH that _when shifting gears_ it seems especially less efficient than a roller clutch IGH as I can better maintain cadence (put more pressure on pedal stroke at precise moment of shifting) on account of the roller clutch mechanism aiding with shifting; that is to say, no need to stop pedalling or slow down which, to me, seems an issue especially in lower gears when going steep slopes: in that scenario, I know for a fact, pawl clutch IGHs don't cut the mustard.
Btw, isn't it that, by design, the Alfine 11 is more efficient in higher gears than lower ones and the roughloff is the exact opposite? I'm sure I saw a graph once somewhere. Overall, the roughloff is more efficient on paper by about 5-6%, but my claim is that in real world use, the roller clutch is just a more evolved design, as far away from a "bad job" as you can be, actually making shifting easier. Even acclaimed hub makers like CK and I9 state the only reason they didn't use roller clutches is the public being in favor of clicks in their rear hubs and preferring loud hubs over silent ones. It can be argued as to how tight the roller clutch spring in the A11 actually is or needs to be however precise and silent engagement was never an issue with roller clutch freewheel hubs.

Brucey
Posts: 39899
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 12 Feb 2020, 1:38pm

Both Rohloff and Alfine hubs are less efficient in the lower gears because both use one additional gear train in the lower half of the gear range; in essence the Rohloff is a 2x7 gear, the Alfine 8 is a 2x4 gear and the Alfine 11 is a 2x6 gear (with one unused ratio). The alfine 11 (like the Nexus 7) has an additional handicap in that the one ratio they have chosen not to use is the direct drive ratio, which means that the average efficiency of the hub is worse than it could be.

It is a bad idea to always shift under load with any IGH because there are always some shifts where there is a sliding clutch which may object. In N8/A8 hubs this is shift 4-5 , N7 hubs 5-6 and A11 hubs it is 6-7. In the shimano hubs the other shifts can usually be made under some load rather than none and this is nothing to do with the roller clutches, rather more to do with the unidirectional loading in each gear train and the way the sun pinions are locked. Indeed the N7 hub has no roller clutches and can be shifted under load as well as a N8 more or less. The N8 hub originally had just one roller clutch, but the current N8/A8 hubs have no less than three, with either one or two in use in any one gear, always two in the lower half of the gear range. In the A11 hub it is worse than that, IIRC you can have three roller clutches in some gears, each contributing its bit of sponge.

In any event the amount of time you spend not pedalling hard during shifting is a tiny fraction of the whole with any hub (or any gearing system cone to that). You need to be travelling extremely slowly for this to genuinely impede your progress in any real way.

If you attach an electric motor drive through the hubs you may measure a certain difference in the efficiency of various hubs but this is pretty much completely bogus; real pedalling is variable torque, not constant, and anything which feels spongy when you pedal (which can include fat tyres, belt drives, certain IGHs, Nu Vinci drives, some framesets etc) is almost certainly soaking up your effort in a bad way. My butt-dyno is pretty sensitive to these things and when climbing or into a strong headwind it feels horribly slow on some hubs and not on others. I think Andrew S may have first raised the issue with me some years ago re roller clutches and since then I have done a lot more miles on various hubs and I have pretty well come round to his way of thinking. [NB I never liked shimano 'silent clutch' freehubs because they also use a similar type of clutch which also feels spongy under high torque. ]

FWIW the Rohloff ain't perfect either; there are signs of sponginess in some (mostly lower) gears. However this arises (I think) mainly through the various parts inside the hub flexing slightly under load, and is nowhere near the sponginess often felt in A11 hubs.

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

CXRAndy
Posts: 50
Joined: 18 Aug 2019, 1:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby CXRAndy » 4 Apr 2020, 11:58am

Ive just modified my Alfine drain plug to a magnetic version

I acquired a batch of 3 mm Neodymium magnets 0.29 kg pull

I set the drain plug in a piece of alloy to hold it whilst I drilled the required hole. By the way the thread for the drain plug is 6mm by 1mm pitch

I drilled a couple of millimetres into the plug applied Araldite steel epoxy adhesive. Its oil, chemical resistant.

Set magnet in hole left to cure for a couple of hours
Image Attachments
20200404_112623.jpg
20200404_112810.jpg
20200404_113302.jpg

Brucey
Posts: 39899
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 4 Apr 2020, 2:06pm

nice work! Do let us know how much crud you 'harvest'. If there is much oil sloshing around in the hub, and there is swarf in it, you should start finding particles on the magnet after the bike has been ridden a few tens of miles.

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

CXRAndy
Posts: 50
Joined: 18 Aug 2019, 1:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby CXRAndy » 4 Apr 2020, 6:22pm

Will do, its on my brand new Alfine, zero miles

. I wanted to collect any material from the outset. it will help me decide when i need to strip and clean the hub

There doesn't seem loads of oil inside. enough to coat the drive as I spin it by hand but not swimming in oil. Should I add more?

CXRAndy
Posts: 50
Joined: 18 Aug 2019, 1:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby CXRAndy » 25 Apr 2020, 8:29pm

My first ride with a the Alfine 11 Di2 was very disappointing. I have gone with unusual gearing because it's what I wanted the bike to do.

I have a 32t crank, 23t cog. This gives me just over 20 mph and a nice low climbing gear.

The problem, is loads of slipped, crunching gears in 1 to 4 mostly. I was spinning the crank not grinding.

Gears 5 through to 11are perfect. The bike runs beautifully quiet, shifts well when pedalling. It just these slipping gears. Hub has only 15 miles !

I was going to strip it down to look inside.

Any pointers, I feel like ditching the whole Alfine and going back to single speed.

Brucey
Posts: 39899
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 11 - Longer term reliability

Postby Brucey » 25 Apr 2020, 9:02pm

do check that the shift servo isn't free to flap about (twist) in use. Also check that the shifting performance isn't susceptible to adjustment (*). Otherwise I'd suggest that this is the exact situation where the shimano two-year warranty should be brought into play.

(*) On cable operated alfine (yes, yours is Di2, bear with me) you need to check that

a) the marks line up in the cassette joint in gear 6 and
b) because the hubs and cassette joints are not made perfectly, that the hub doesn't work better if it is (nominally) 'slightly out of adjustment'.

On point b) very many A11 hubs have been shown to have been impossible to use if a) only is used to set the hub. I purchased a used A11 hub from a forum member who had basically given up with it; 'it never worked properly' he said. When set as per a) it slipped, and it slipped worst in the low gears, much as you describe. However once I'd applied b) the hub worked perfectly. The difference between 'useless' and 'perfect' was a little over 1mm of cable adjustment.

On Di2 Alfine hubs there is an 'R' mode (see dealer manual) in which there are 8 settings. These settings effectively adjust the hub as per b) above, although you don't have marks to look at per se. If you have not done so already then I'd suggest that you experiment with these settings. With a cable operated hub I can tell you which direction is likely to most likely to offer an improvement, and you can see how far the marks move in gear 6 and verify the movement is as desired. With a Di2 hub neither thing is true; pot luck I'm afraid. At least you can see which of the 8 settings you are in on the display.

hth

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

CXRAndy
Posts: 50
Joined: 18 Aug 2019, 1:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby CXRAndy » 26 Apr 2020, 11:33am

Brucey. Thanks for the prompt reply

I did go into trim function (same as derailleur trim). It did make a bit of difference to how the shifting behaved and increased the incidence of slipping and missed gears. I will recheck the shift motor and dot alignment. Thanks

I maybe back with further questions :D

CXRAndy
Posts: 50
Joined: 18 Aug 2019, 1:45pm

Re: Shimano Alfine 11 - Longer term reliability

Postby CXRAndy » 26 Apr 2020, 2:36pm

Success I think. I disassembled the setup and checked the alignment. I went through the steps and aligned the timing mark on the hub and then put the motor in the position indicated by the photo. It seems to fit together better. That didn't cure the slipping. What it was in the end, was loosening chain under tension of acceleration. I decided to rejig the manual tensioner and its perfect now. I can pull wheelies now with no slippage. :D

Update to the magnetic drain plug. The oil is black now after 15 miles from new. Also a small bump of fine metal particles was collected on the magnet.

So its doing its job drawing the swarf from the new hub,. I will keep a close eye every 100miles. Another little benefit is with a magnet in the plug, it sticks to the allen key so now worries of dropping whilst removal/refitting

zeluzel
Posts: 10
Joined: 27 Jan 2020, 11:38am

Re: Shimano Alfine 11 - Longer term reliability

Postby zeluzel » 28 Apr 2020, 5:04pm

vanGoose wrote:My book grew to 52 pages, ...


Hi! None of those links work any more, could you please PM me a copy?

vanGoose
Posts: 14
Joined: 15 Mar 2018, 8:47pm

Re: Shimano Alfine 11 - Longer term reliability

Postby vanGoose » 15 May 2020, 8:57pm

Hi zeluzel,

i always release the documents for one month, so the link is meant to expire...

Never mind, i renewed the link, it will do until 2020-06-15.

https://c.gmx.net/@329602864890517692/P ... EjXCnpZyCw

There are a few things to add, though:

- My article is free for everybody to use, share, whatever - no limits. And it comes without any warranty. You act at your own risk.
- I wrote about the SG-S700, which was replaced by the 7000's since some years. There were significant changes/improvements, so one must expect that my stuff is partially outdated.
- While many of my pictures and "findings" might be of some importance for people wanting to strip down (and put back together...) the hub internals, my original intention seems to be less interesting to most readers.
- I still love my "modding" i.e. changing from "assisted down-shifting" to "preselectable down-shifting. For me it is simply great.

While i am around just now, here are a few updates to my story:

The "second" hub i worked on is now operating for some years i.e. some 8000km and i am basically happy with it. Every once in a while she gets mad at me and slips a pawl. Lets say it does it about once in two weeks.
Once in those two years i had to re-tighten the shifting cable by "two clicks" at the shifting lever adjusting barrel thing. Not any other trouble.
Recently, the pawl for gear 2 stopped to reliably extend. Reason: i never did any maintenance over 8000km. Oil changed, back to normal.
I can confirm that the roller clutch, mainly in the higher gears, slips a bit at maximum pedal force when i have to be faster than that guy in the car approaching... I do, however, rate this little against that nice and silent operation which the rollers provide.

I have one more thing to do. The reason that i had to re-tension the shift cable is a little defect in the shifting lever. That one has a mechanism which lets the lever act, upon shifting down from gear 2, only in the second half of its move i.e you cannot accidently try to shift down "two gears" then, which you could from any higher gear. This mechanism is a very good way to avoid that you pull the cable against the end position and possibly stretch it. Unfortunately, that protection stopped working and i sometimes DO now force the cable beyond "gear 1". That's made it stretch or otherwise change its seat, so i had to re-tension.

I will go and try to find that little nose in the shifting lever assembly which must be the reason for the problem. But if anybody here knows it already then i'd be happy to be told.
Best regards
vanGoose
everyday cyclist, sram-3, spectro-s7, a-8, a-11, r-14

zeluzel
Posts: 10
Joined: 27 Jan 2020, 11:38am

Re: Shimano Alfine 11 - Longer term reliability

Postby zeluzel » 22 May 2020, 8:49pm

@vanGoose Thanks a lot! I'm sort of IGH geek (though I never owned one yet :p), so I'm pretty sure I'll find it interesting ;).

edit: Just by looking at it I can tell, I'll like it. Wish I had one of these to actually look at, as I go through your writing.
edit 2: But all in all, how would you rate this hub?
The "second" hub i worked on is now operating for some years i.e. some 8000km and i am basically happy with it. Every once in a while she gets mad at me and slips a pawl. Lets say it does it about once in two weeks.

For me sounds absolutely unacceptable, especially for an equipment that claims to be totally maintenance free and "just-working".