10

I bought a nice belt-drive bike with an Alfine 8 hub. While I love everything about the belt, the Alfine hub gives me grief: under high(er) torque - think fast acceleration from a stop at a light - it skips/slips for about half a rotation and makes a lound cracking/crunching/slipping noise.

This happening in gear (i.e. not connected to gear changing).

I brought the bike back to the dealer and he replaced the back wheel incl. the hub. The new back wheel is behaving better but it still slips/skips under load.

My dealer thinks this is normal. I never experienced that on any bike and not on my old Nexus 8 either.

Questions:

  • Is this normal?
  • If not, what can I do to stop it?

Thanks so much!

  • That sounds like the chain slipping over the rear sprocket ... oh wait you have a belt drive. It's probably worth making sure the belt is tensioned properly though. – Argenti Apparatus Nov 13 '17 at 23:22
  • Is this always in one of the lower gears? I.e., it happens when you are accelerating from a stop or low speed? – Argenti Apparatus Nov 13 '17 at 23:24
  • 1
    No, skipping under load is absolutely not normal. Keep taking it back to the dealer until he fixes it. – Mike Baranczak Nov 14 '17 at 17:49
  • 1
    I wonder if the Alfine has some sort of clutch to prevent damage from excessive torque. How tall/heavy/strong are you ? – Argenti Apparatus Nov 14 '17 at 21:53
  • 2
    You can check the tension in the belt using this Gates app for your phone: play.google.com/store/apps/…. I'm not sure if there's an iOS version. There will be two bolts holding your bottom bracket in place. If you loosen these you will be able to spin the bracket both ways using an allen key. montaguebikes.com/folding-bikes-blog/2016/03/… Whilst app is open, pluck the belt to determine the frequency. For internal hub gears, Gates recommend max 50Hz. – forgetso Nov 16 '17 at 15:06
5

Alfine owner here whose hub is slipping after having changed gear. The Alfine is extremely susceptible to misalignment in the setup. There are two sets of yellow markers that need to be aligned. One can be adjusted using the gear barrel adjuster.

https://aseasyasridingabike.wordpress.com/2013/02/01/a-simple-guide-to-adjusting-a-shimano-nexus-hub-gear/

The other needs to be adjusted when the hub is set up. Sheldon Brown's extremely helpful web site indicates how you can achieve this.

https://www.sheldonbrown.com/nexus-mech.html

You will also need to tension the belt to the appropriate tension as mentioned in my comment and here:

https://www.montaguebikes.com/folding-bikes-blog/2016/03/adjusting-belt-tension-with-eccentric-bb/

Finally, the gear cable must be well greased as any stickiness will cause the gears not to drop in properly and skip/crunch etc. Unfortunately, I'm now of the opinion that the gear cable needs greased every 3-6 months, which is not the level of servicing I'd envisaged when purchasing! That said, it's still easier than replacing entire chain sets.

| improve this answer | |
  • I never greased the gear cable on my hub, that was never a problem for me. Don't think the people in the bike shop ever regreased it either. – Nobody Aug 21 '18 at 10:23
3

I have an Alfine 11 (so very similar) and I had the hub replaced 2 times on warranty because of this skipping problem. The third one is fine so far (~15000km on it).

So based on my experience: Have it replaced a second time.

It also does skip when misaligned as mentioned in the other answer and yes it's tricky to get right and tends to misalign over time. Also it can freeze in the winter (still works, but need to change gears by hand on the lever on the hub) and this could also cause skipping because it would stick between gears. But your bike dealer should be able to fix/diagnose this within seconds.

So my suggestion:

  1. Go to your dealer.
  2. Ask them to verify it's aligned properly and works in general.
  3. Test whether it still skips.
  4. If yes, demonstrate it in front of the dealer.
  5. Insist you need a replacement.
| improve this answer | |
  • 1
    And, well, this isn't really part of the answer: But ever since I got a second bike with a Rohloff hub I would never get an Alfine one anymore. The Rohloff is really much better if you can afford it. The Alfine one works ok. The Rohloff one works perfectly, smooth, changes fast, changes under load (although there is a disclaimer in the manual that it could skip if you do. Never happened to me so far and it explicitly doesn't damage the hub), silent, change any number of gears at a time. – Nobody Nov 17 '17 at 19:16
2

I also have a belt drive bike with a Alfine 8 hub (Cube Hyde Race). I have experienced exactly the same problem ie popping/skipping under load.

I have sent it back twice, and still no good.

The first time Tredz sent it back to Cube they replaced the hub internals. This was no good at all and clearly had not been test ridden at all. I sent it straight back.

The second time Cube replaced the whole hub. It was ok for a couple of rides and then started popping again.

I have asked Tredz for a refund or replacement bike but so far they have refused. I think with all the reports out there I stand a good chance in the small claims court.

The problem has nothing to do with yellow marker alignment or belt tension, otherwise cube would not have replaced the hub and internals twice!

Speaking to a local bike mechanic it probably has more to do with production tolerances of the mechanical parts. The whole system relies or very precise tolerances.

| improve this answer | |
  • Welcome to the site! It seems everyone's having the same problem! – David Richerby Feb 25 '18 at 0:38
  • I would go and do one last attempt of tightening the belt if I was you: I had to tell my mechanic to tighten the belt and he almost refused and insisted it was "tight enough". Ever since he did it even more, the problem has vanished entirely for me. I'm a very happy camper with both the Alfine and the belt drive now! – SebastianR Mar 3 '18 at 10:44
1

Be mindful that despite their branding, these hubs are not meant for heavy loads; rather, it is their intention that, when stopped, the rider shifts to a low enough gear that they are spinning the bike up to speed, rather than mashing up to speed in a high gear (which is how the majority of novice cyclists destroy their knees and ruin their commutes).

Here's what I think happened: you got your new bike, but the work of bedding in the cables wasn't done to completion. As a result, during your rides, your cable was "stretching" into the inside of the housing, leading to a misalignment of the gear cable. When your LBS replaced the wheel, they had to reset the cassette joint and cable, which would have improved the performance, however, if you still had break-in left on that cable, shifting problems would have returned.

At any rate, there are really only three likely possibilities:

1) The cable is not aligned properly.

2) The hub internals are damaged.

3) You are using it incorrectly.

The first possibility is easy to rule out. Familiarize yourself with the indicator markings on the hub cassette joint - the part of the hub that swivels around to change gears. There are two yellow marks on the underside of the hub that must align perfectly in 4th gear (for 7 and 8 speed Shimano IGHs). The markings on the bottom are easier to see than the window at the top, but require a work stand or flipping the bike upside down. If, after every episode of skipping, you check the cable and the indicator markings are lining up perfectly, then you have successfully ruled out the cable as being misaligned, which is the most common problem with these hubs.

The second possibility requires no explanation. There is practically no way to positively determine that a hub is defective: you merely have to rule out the other possibilities.

The third possibility is exceedingly common. Perhaps your bike shop didn't prime you for what the hub is actually capable of. Perhaps you're shifting under load (do you stop pedaling immediately before shifting, then resume your cadence only after you've shifted and confirmed the shift by feel?) Perhaps you're simply trying to put too much torque into the hub. Are you a heavy rider who likes to stay in a high gear? If so, you can expect the worst performance from your parts: learn to love low gears and learn when to coddle your parts and when it's ok to put down the watts.

A few other notes:

The tension of your belt is almost certainly irrelevant. However, a loose belt may correlate to skipping/grinding issues because if your wheel has slipped forward in the dropouts (or, as the case may be, your dropouts have shifted forward in the frame), that could affect the tension on the cable (it depends on how the housing is routed; if the housing stops at the cassette joint like it should, it won't have any affect; if, on the other hand, the housing stops at a frame braze-on then your wheel must be exactly in the position that lines up the indicator markings in the appropriate gear. I can clarify this if you think it may be the problem).

Frames, especially steel frames, can have considerable flex in them. You can sometimes see the bike flexing down at the bottom bracket when mashing up a hill, especially on older bikes with thin tubing like Reynolds 531. We see a lot of "ghost shifting" on vintage bikes with friction shifters because the flex of the frame under heavy load physically yanks the cable. You could be simply mashing too hard and pulling the cable - even a millimeter would throw the planetary gears out of alignment and cause problems. The solution to this is to alter your riding style: shift yourself into a nice low gear when at a stop light or beginning an ascent. Gradually increase your gearing until you hit your desired speed.

| improve this answer | |
  • 1
    Thanks for your help. My problem is solved now and it was solved after I instructed my mechanic to tighten the belt more (the Gates app showed me it was at the lower end of the spec). Despite your assertions and my mechanics insistence I have no problems any longer. It sounds crazy - I know. But that's my case :) – SebastianR Mar 3 '18 at 10:48
  • i'm glad it worked out, and i'll remember that if i run into this problem in the future! – Nathaniel Hoyt Mar 4 '18 at 16:46
1

The SG-S7000-8 on my wife's commuter was slipping on first and fifth gear. After a month of banging my head against this it turned out to be not the oil or the grease or the bearings or the cable (all which I replaced). it was the stupid return spring on the small clutch.

https://backwardincompatible.com/post/186916671580/shimano-alfine-sg-s7000-8-loose-spring-on-the

credit to Andrew Kashutin for identifying it

| improve this answer | |
  • Welcome to SE - I'd normally suggest new users read the tour and bicycles.stackexchange.com/help/how-to-answer but this answer is an excellent summary, and leaves the URLs as supporting information. +1 and do have a go at answering any other questions that catch your eye. – Criggie Aug 25 '19 at 0:49
1

I had the classic 8-speed backpedal clutch-slip blues, but instead of taking it apart, I took the wheel off the frame. Then I squirted a mixture of WD40 and spray cooking oil (olive oil) into the space behind the belt drive ‘gear’. I also used the same mixture of water dispersant and light lubrication to make the cable slide easy. Now my Marin cycles cross trainer is running like new.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.