Anyone had a similar problem with the GB shifter

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ukdodger
Posts: 2992
Joined: 18 Aug 2007, 5:32pm
Location: Sunny Surrey

Anyone had a similar problem with the GB shifter

Post by ukdodger »

My tour to Berlin and back was ruined yet again by hubgear problems. I got to Berlin but leaving the GB shifter seized up in third. It was almost immovable. As the Rohloff hub had started leaking oil about halfway I assumed the hub had seized up and got a plane back home. Dismantling the shifter I discovered that a small piece of metal had got between the moving surfaces of the shifter. The result as anyone who has ever put copper fittings onto copper pipe will know is that if a small piece of the wire wool used to clean the fitting somehow gets between the pipe and fitting the two are almost impossible to get apart. That's what happened with the shifter.

I also discovered that the Rohloff is hard to change by pulling directly on the concertinas (the wires entering the hub itself). It wasnt like that when I left.

So is it possible that having to exert more effort at the shifter (I noticed it getting stiffer approaching Berlin) to change that my extra effort ground some metal off of the shifter and which found it's way between the moving surfaces of the shifter. The surfaces are metal to metal. No bearings are involved.

You can see the damage in the pic

Image
Brucey
Posts: 44513
Joined: 4 Jan 2012, 6:25pm

Re: Anyone had a similar problem with the GB shifter

Post by Brucey »

were the shifter parts greased? If not, or the grease was contaminated or had washed out, I'd expect two aluminium surfaces like that to 'pick up' on one another without much provocation. A tiny piece of grit or swarf could easily start the process. Once started, it'll carry on without doubt, until the parts will no longer turn freely.

I don't know what the usual cable tension would be to make shift in your hub but it is usual that this will vary with the particular shift (there is different stuff moving inside the hub on each shift) and also whether the hub is turning forwards (without load) at the time or not.

With many IGHs the cable tension can become very high indeed before the shift will 'go' if the transmission is under load or the wheel is not moving at the time the shifter is used. Any binding in the cables (and/or the shifter) will make the shift seem stiff at the hub if the cables are still connected.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
tatanab
Posts: 5033
Joined: 8 Feb 2007, 12:37pm

Re: Anyone had a similar problem with the GB shifter

Post by tatanab »

Contact GB, they may have suggestions, replacement parts or warranty parts. Admittedly it was for saddle parts but I found them helpful and of course their English is impeccable. I tried to identify the small part spares from their website and ordered the wrong part (note they have a high minimum handling/postage rate) so I contacted them. They send me the correct parts by the next post free of charge.
ukdodger
Posts: 2992
Joined: 18 Aug 2007, 5:32pm
Location: Sunny Surrey

Re: Anyone had a similar problem with the GB shifter

Post by ukdodger »

Brucey wrote:were the shifter parts greased? If not, or the grease was contaminated or had washed out, I'd expect two aluminium surfaces like that to 'pick up' on one another without much provocation. A tiny piece of grit or swarf could easily start the process. Once started, it'll carry on without doubt, until the parts will no longer turn freely.

I don't know what the usual cable tension would be to make shift in your hub but it is usual that this will vary with the particular shift (there is different stuff moving inside the hub on each shift) and also whether the hub is turning forwards (without load) at the time or not.

With many IGHs the cable tension can become very high indeed before the shift will 'go' if the transmission is under load or the wheel is not moving at the time the shifter is used. Any binding in the cables (and/or the shifter) will make the shift seem stiff at the hub if the cables are still connected.

cheers


That's interesting Brucey and sounds right. The shifter didnt come with any grease and I never greased it thinking that any grease would itself pick up dirt or grit and start the same process. This happened the day after the only rain of the trip. Maybe the two are connected. In 2013 though I did 2800m with this shifter and hub with no problems. I mothballed it after that tour until this one.

I really think though that I've had enough of touring with a hubgear. This is the second tour ruined by the failure of one. What are your suggestions for a friction shift deraillier. The simpler the better!
rualexander
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Joined: 2 Jul 2007, 9:47pm
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Re: Anyone had a similar problem with the GB shifter

Post by rualexander »

Could just use Rohloff's own shifter which is very reliable and long lasting.
An oil leak from a Rohloff is not really anything to worry about in the short term.
If your hub cables are stiff, it is probably worn or frayed cables, easily enough changed with the quick change cable kit.
You were in Germany, shouldn't have been too hard to find a Rohloff dealer to take a look at it.
Brucey
Posts: 44513
Joined: 4 Jan 2012, 6:25pm

Re: Anyone had a similar problem with the GB shifter

Post by Brucey »

it does all sound rather frustrating, but in all fairness did the hub itself fail?

You mention an oil leak but IME this is most likely to happen on a rohloff if the skewer is too well greased; this blocks the breather hole in the axle and then ambient temperature changes can force oil out of the hub. You need to lose quite a lot of oil before it is a real threat to the hub.

Shifters of any kind can give trouble, even friction ones. But having said that, my own favourite touring bike still has friction shifting 3 x 7 gears on it and the only major change in the last 30 years has been to use a cassette hub in the back instead of a freewheel. It does need a bit of tlc but if it ever does break on tour I will very likely be able to fix it with a trip to the LBS and there is much to commend that....

It is rotten luck that your shifter packed up like that; I looked at the GB 'instructions' and they don't indicate any grease, but I'd instinctively look to grease a part like that; I just can't see it lasting otherwise.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
ukdodger
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Location: Sunny Surrey

Re: Anyone had a similar problem with the GB shifter

Post by ukdodger »

Brucey wrote:it does all sound rather frustrating, but in all fairness did the hub itself fail?

You mention an oil leak but IME this is most likely to happen on a rohloff if the skewer is too well greased; this blocks the breather hole in the axle and then ambient temperature changes can force oil out of the hub. You need to lose quite a lot of oil before it is a real threat to the hub.

Shifters of any kind can give trouble, even friction ones. But having said that, my own favourite touring bike still has friction shifting 3 x 7 gears on it and the only major change in the last 30 years has been to use a cassette hub in the back instead of a freewheel. It does need a bit of tlc but if it ever does break on tour I will very likely be able to fix it with a trip to the LBS and there is much to commend that....

It is rotten luck that your shifter packed up like that; I looked at the GB 'instructions' and they don't indicate any grease, but I'd instinctively look to grease a part like that; I just can't see it lasting otherwise.

cheers


It was very hot for most of my eighteen day tour. That could be a candidate. If it is blocked I'll do an oil change and see how much comes out. If that's the problem it will save me sending the hub away to be checked.

Where about's is the breather hole? Skewer??

I wont use the GB shifter again. I only bought it in the first place because it went over my 25.2mm handlebars which I prefer. I'll go back to the Rohloff shifter and 21mm bars much as I dislike them.

I've been using a friction shifter on my six speed shopping bike for fifteen years. Zero problems.

Thanks
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Anyone had a similar problem with the GB shifter

Post by Brucey »

the breather exits into the inside of the hollow axle. More info here;
http://forum.ctc.org.uk/viewtopic.php?f=5&t=87555

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
ukdodger
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Re: Anyone had a similar problem with the GB shifter

Post by ukdodger »

I returned my GB shifter to GB and they sent it back with some sort of blue grease between the moving surfaces. To touch it feels more sticky than greasy. Any idea what it might be.

I have asked GB but they have yet to reply.

Also there was none on it when I bought it.
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Anyone had a similar problem with the GB shifter

Post by Brucey »

blue grease is often (but not always) a waterproof grease. This is very often stickier than other greases.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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iow
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Re: Anyone had a similar problem with the GB shifter

Post by iow »

maybe something like evinrude triple guard grease? it fits the description (blue, sticky, intended for sliding surfaces, french firm etc..).
mark
Des49
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Joined: 2 Dec 2014, 11:45am

Re: Anyone had a similar problem with the GB shifter

Post by Des49 »

iow wrote:maybe something like evinrude triple guard grease? it fits the description (blue, sticky, intended for sliding surfaces, french firm etc..).


That's exactly the grease I thought of too. I have 2 tubes of this from my outboard engineer and use it for my mtb headset and greasing threads on some bikes.

If it's cold it can take a bit of effort to squeeze from the tube. So the gear changer may be stiffer to use in those conditions, but it won't wash out easily.
Samuel D
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Re: Anyone had a similar problem with the GB shifter

Post by Samuel D »

What does Gilles Berthoud being French have to do with the Evinrude grease, though?
ukdodger
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Joined: 18 Aug 2007, 5:32pm
Location: Sunny Surrey

Re: Anyone had a similar problem with the GB shifter

Post by ukdodger »

Thanks for the replies chaps. I think iow nailed it. Waterproof grease. Strange that a) there was none in it when I bought it and b) there's no mention of changing it. Cant believe it's there for life.

Just a moan but this thing cost over £100.
Des49
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Joined: 2 Dec 2014, 11:45am

Re: Anyone had a similar problem with the GB shifter

Post by Des49 »

ukdodger wrote:Thanks for the replies chaps. I think iow nailed it. Waterproof grease. Strange that a) there was none in it when I bought it and b) there's no mention of changing it. Cant believe it's there for life.

Just a moan but this thing cost over £100.


A justifable moan, especially with a ruined tour.

In my experience one of the main downsides to the usability of the Rohloff is the gear changer. I have the Rohloff grip and when very sweaty, especially when muddy, or cold, the grip can be almost impossible to operate. But I have never tried alternatives, too pricey to just try out.
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