What could repeatedly cause a free-hub to malfunction?

kategg

Evening everyone,

I'm new to the Forum and don't know much about the technical side of biking, so apologies if I should have posted this in the beginners section. But I use my bike every day to commute so this area seemed good too!

II started using my bike again in September after having been out of the country for a year. I got it serviced and mentioned a problem I had found where the pedals were jumping occasionally. They tightened everything up, put some new brake pads in etc and said it was fine.

Then I noticed the problem was still there. It didn't seem to affect the gears - I wasn't changing gears. Just like the chain was slipping or something but it was pretty violent and I felt quite concerned about it - if it happened at the wrong time on the road it could definitely throw me off and make me lose my footing with horrible consequences.

So I went back to the shop, they decided the chain had stretched and would have to replace this and the back casette. The bike felt ok for a day or two but then the problem was there again, getting more and more frequent.

So I went back again (to be fair, they never charged me for labour after my initial service) and described it and focussed on it and they put in a new free-hub. Perfect - I had fully stable and secure pedals once more. Felt great to be able to put my trust in them again.

The problem is, over the past week or two (about a month after they replaced the part, although due to Christmas and the storms I haven't really used the bike that much over that time) the problem is starting to appear again. I really think that the problem was fixed rather than the jumping just didn't happen for a while - the pedals felt completely fine. I can only assume that something external to the free hub is causing it to malfunction. Which surprises me as the way the bike shop guys described it it sounds like a completely self contained part that would be quite difficult to interfere with.

So before I go back to the shop and end up spending more money, I thought I would ask and see if anyone out here had any ideas of what could be happening so that I can be a bit better informed. I would really appreciate your help if you have any thoughts.

Thanks!

kategg

PS in case it is important, I am riding a Specialized Women's Globe Sport Hybrid, bought during Summer 2008.

The Rookie

The symptoms you describe can be caused either by the gears (selecting a lower gear breifly will feel like a short loss of drive) or the freehub.

It is possible that when riding with a defective freehub you damaged the wheel where the pawls engage, that could give you the same situation a bit later on - that may be repariable without a new wheel/hub it may not (what hubs?), it may also be the front is dropping breifly to a smaller chainring and needs the indexing tweaking slightly to stop it happening.

Simon

Simon

MichaelW

According to the Specialized archive, the 2008 Globe Sport used Shimano Altus RM-30 hub. The freewheel action is held within the replaceable freehub part so there is no wear on the actual hub. This is a low-end piece of kit which means plenty of metal compared to the high-end lightweight ones and the design is well proven, very reliable and durable.
With a new cassette, chain and freewheel fitted your drivetrain should be fine. Check the indexing and limit screws on your rear deraileur. Check you gear cables are not fouling and are properly seated at the ends.
Does the slippage happen in a particular gear? Do you avoid cross chaining (small-small or large-large combinations)?

davis

Are you sure it's the freehub again? It can be quite tricky to diagnose a sudden violent slipping sensation. Which bike shop, and where are you?

kategg

Hi everyone,

Thanks for all taking the time to write back to me. I took the bike back to the shop (Woodrup's in Leeds) and as the guy had a look over it, even I could see that the chain was in a bit of a bad way. Don't know how it got so bad so quickly - I don't keep the bike outside. They cleaned it all up for me, a couple of the links had stiffened completely so they were probably the cause of the problem. It's seemed fine since they did that.

So I came away feeling stupid and a little guilty - should have checked that before I bothered them with it! I was just so gutted the problem had returned again I just assumed the worst. Bless the bike shop though, they did their best not to patronise me and still refused to take any money for the service.

davis

Ok, so you need to add some chain cleaning into your bike maintenance routine. There are many, many guides and opinions. The distallation of most of this advice is to give the chain a wipe with a rag to wipe most of the gunk off and lubricate with some sort of oil. A "proper" chain cleaner and meths, then bike chain oil is probably best but I tend to use a rag with some GT85 on it and then some chainsaw chain oil to lubricate, but mostly because it annoys the purists. "Best" bike gets "proper" oil, and it probably makes not a jot of difference.

(hopefully this isn't patronizing)