Rumbling in pedals when coasting / problem when backpedaling
 

I am having an issue with my bicycle. Over the last week or so, when coasting I can intermittently feel a rumbling/strong vibration in the pedals. Also, when I try to backpedal, I get a weird noise and there is some resistance.

As I say, the issue is intermittent - it happens frequently when I'm coasting but is not constant.

I recently had my internal gear hub (Sturmey Archer 3-speed) serviced and I'm wondering if something has gone awry following the servicing...

I am wondering if anyone might have any ideas or suggestions about what the issue could be and what can be done to rectify it.

It would help if we knew the model number of the hub, it should stamped on the shell of older hubs and possibly painted on the newer ones.

Also, how does it feel when riding while pedaling? Does it shift properly? If you lift the rear of the bike and spin the rear wheel, does it slow quickly? If you grab the rim and move the rear wheel from side-to-side, is there any play?

Thanks - the hub is the SA S-RF3.

When I'm pedaling I don't experience any issues. I can shift easily between all three gears and there are no issues when riding in any of the three gears.

If I lift the back tire and spin it backwards it spins normally and quietly. If I lift it up and engage the wheel via the pedals (spinning pedals by hand) I get the same noise/vibration problem when I let go of the pedals (i.e. same as when coasting). I also get the same intermittent noise and resistance (as when pedaling backwards) if I manually turn the pedals backwards by hand.

I will check again for side-to-side play but I don't recall noticing that.

I should add as well that the hub is relatively new. The service I had done on it was the first service after a year of daily commuting spring/summer/fall in Toronto.

My SA AW hub rumbles when coasting sometimes. I traced it down to debris caught under the dust shield behind the cog. Clean it off, and the rumbling goes away. For a while.

This is a reach since I haven't seen the bike.
Is the chain too tight? Since you just had it serviced, the LBS may have set the rear wheel back a bit too far. It would probably still shift OK if that was the issue. There should be a bit of slack in the chain (not much).

I previously tried moving the chain position - the problem I am having persists whether the chain is tight or loose. It definitely seems to be an issue with the hub/wheel. I just want to figure out whether it's internal to the hub and something the LBS is at fault for from when they serviced it, or something else. As JohnDThompson mentions, perhaps it's some grit or debris under the dust shield. I'll try to get at that this weekend.

So, I took my bike back to the LBS to examine the issue I am having with my Sturmey Archer S-RF3 3-speed internal hub. He took it apart and said there is no evidence of grit, debris, misalignment or malfunctioning of the hub. After test riding it, he suggested it is normal for Sturmey Archer internal hub to exhibit intermittent vibration/rumble when coasting and for some resistance/noise when backpedaling. (He indicated he has a SA hub and it does the same thing.)

I suppose my follow-up question here (to other SA hub users) is, is this consistent with your experiences? This is my first SA hub, and as I said initially this wasn't an issue I noticed in the first six months of use (i.e. prior to servicing).