The pedals go round

[slowmotion]

I've got 30 month old Shimano 105 gears with a triple chainring. If I walk the bike, the pedals go round. If I'm stationary waiting for a traffic light and I back-pedal to get the cranks to a suitable position for moving off, sometimes the cage on the rear derailler rotates forwards and puts tension on the lower section of chain. Is something wrong with the freehub? Can sombody advise me what to do? It isn't really a problem, just annoying.
Thank you.

 

[Saluki]

All the bikes that I have ever had have had the pedals going round as I walk with it. I just thought that it was a thing that happened.

 

[numbnuts]

I have no idea <goes out to have a look>, when I reverse the bike the pedals go round, but in forwards they don't.

 

[Dave Davenport]

Sticky freehub.

 

[fossyant]

What he said !!

Give it a service.

 

[benb]

Or bunged up jockey wheels on the rear mech.
Or very mucky chain.

 

[slowmotion]

Or bunged up jockey wheels on the rear mech.
Or very mucky chain.

The jockey wheels are OK. The chain is surgically clean.

 

[ianrauk]

Chain Line, being a triple and all...

 

[slowmotion]

Chain Line, being a triple and all...

I wondered about that. It still does it when I'm on the middle ring though. Would the inner and outermost cogs on the cassette cause it behave the way it does?

 

[lpretro1]

Defo freehub body

 

[Davidc]

It's got to be the freehub sticking.

Had the same thing with a Shimano freehub about 6 years ago - 3 years on the bike at the time. The blurb I've seen says they aren't serviceable, and the freehub had come with the wheel. My response was to flush it out with a degreaser. At the risk of being publicly flogged by other members I'll admit that the degreaser was about 1/4 can of WD40. That brought out a load of dirty muck with small sandy grit particles as well. I then left it for a day for the WD40 to evaporate and dribbled Finish Line wet in over the course of 3 days. I didn't take it apart for fear of never getting it back together again.

The freehub then worked fine until I sold the bike it was on, prior to which I had done about 1000 miles on the bike with it working fine.

I've only done this once so can give no confidence in it working again but the experience may be of use to you. My thought was that riding a lot in wet weather and on muddy roads may have been the cause, not just wear and tear, but again no proof just a suspicion.

 

[andrew_s]

Shimano freehubs are officially not serviceable.
It's not actually any more difficult than a standard screw-on freewheel, apart from the minor fact that you need a special tool that Shimano stopped selling 7 or 8 years ago. If you take out the wheel bearings, you'll see a couple of little notches on the outside edge of the RH bearing cup. You need some tool that will use these to unscrew the bearing cup.
Short of making your own tool, the best thing to do is what Davidc did.

 

[slowmotion]

Thank you all very much for your advice. I'm grateful. I looked at Youtube for clips. There is one by a Vietnamese-sounding guy who seems to have done what Davidc did, flush it with WD40 and dribble in the grease/oil. I like the look of that, not least because it could be a bit of challenge. I'll probably use Jizer, loads of washing-up liquid, endless hot water rinses, and an oven at 50C for twelve hours.
I looked at Shimano techdocs. The disassembly looked a bit fierce...loads of washers etc. and I still have to work out whether I have a FH5600 or FH5700. As a fallback, I think I may buy a new freehub ( about £30 ) in case my servicing of the old one proves to be less than satisfactory. I could use it if the DIY method fails.

Anyway, once again, thanks for your advice.

 

[Davidc]

Thank you all very much for your advice. I'm grateful. I looked at Youtube for clips. There is one by a Vietnamese-sounding guy who seems to have done what Davidc did, flush it with WD40 and dribble in the grease/oil. I like the look of that, not least because it could be a bit of challenge. I'll probably use Jizer, loads of washing-up liquid, endless hot water rinses, and an oven at 50C for twelve hours.
I looked at Shimano techdocs. The disassembly looked a bit fierce...loads of washers etc. and I still have to work out whether I have a FH5600 or FH5700. As a fallback, I think I may buy a new freehub ( about £30 ) in case my servicing of the old one proves to be less than satisfactory. I could use it if the DIY method fails.

Anyway, once again, thanks for your advice.

The last bit is very much the view I took - if all else fails replace. It's not too expensive to take a risk with.

I'd dodge the washing up liquid, it has salt in it which longer term might corrode the thing.

 

[slowmotion]

I use washing up liquid when rinsing Jizer off my chain. I figure that that if there are absolutely no traces of bubbles in the fresh rinsing water, there are probably no traces of de-greaser. Once I'm convinced that the water is entirely uncontaminated, I suppose I could sip it for saline traces. Taste buds are a pretty sensitive detector.