calikid2006

I built a wheel with a Sturmey Archer rx-rf5 internally geared hub with a kick brake for my girlfriend's bike.

The problem is that sometimes the kick brake just doesn't work. This was particularly concerning when she was going down a hill and could not brake!

The issue is solved when you shift to a different gear, and then shift back. But we are talking about safety, so this is not an adequate solution.

Is this a setup issue? I followed installation instructions correctly I believe. Do these hubs just need to wear in? Is this just how they are? Is this one defective?

Any thoughts would be much appreciated.

JohnDThompson 

Sounds like a defective hub to me. I'd return it to wherever you purchased it and ask for a replacement.

Moe Zhoost

Coaster brakes work best with the right crank leverage angle. Could it be that she tried to apply the brake at an awkward crank angle? Backward motion is limited by the drive pawls so if your angle is not right the thing to do is pedal around again to get to the sweet spot. Shifting could release things a bit to allow further backward movement. You probably investigated this already, but I figured I'd throw out a simple fix first.

Also, I am sure that you realize that rear brakes (especially coasters) are, used alone, not all that efficient for stopping. I have a drum brake SA 5sp hub and if I apply only the rear when descending a hill, deceleration is not obvious.

I could not find an exploded drawing for this hub. Do you have one?

Good luck - let us know what you find when you figure it out.

Mr IGH

Sturmey lacks proper design and quality manufacturing, as a result, robustness and longevity are non-existent. As you've discovered, Sturmey can even be deadly. Since the hub needs to be replaced, swap in a Nexus SG-C6000-8C Coaster Brake Hub, Shimano IGHs won't let you down.
https://www.universalcycles.com/shop...&category=2713

If that's too pricey, there's a 3 speed version:
https://www.universalcycles.com/shop...&category=2713

There's no excuse for that kind of failure mode but it's pretty typical for Sturmey all through its history....

Homebrew01

Is there a front caliper brake ??

GamblerGORD53

Well, coaster brakes aren't the best invention for sure. Pretty weird situation.

My previous model SA 5w with drum brake has 10,000 miles and still needs a microscope to see what has worn. It does have problems with the shift springs design. One is very weak and won't hold shape.

Front caliper brake ?? LOL
Shi&mano hubs last any better ?? LOL

Put a Sturmey Archer DRUM brake on the front. Problem solved. Mine has 20,000 miles, 4,200 on tour at 120 lbs. Works 100% of the time with absolutely NO need for adjustment. New bearing at 17,000 miles, $8. Already outlasted a pocket full of POS rim scratch pads.

corrado33

Is this really true or are you biased? (I honestly don't know.) I always though SA had a good reputation? Perhaps only the old hubs and not the newer ones?

Mr IGH

I've been servicing various SA products since 1975, they were junk back then but so were low cost derailleurs and shifters. As other bike products have improved, SA keeps shipping the same old problems. First time I saw an SA coaster fail was in 1970, my buddy's Colt had an SA 3 speed coaster, a 70lb 3rd grader killed it.

The SA 5-speed hub is on it's 3rd or 4th version since 2000, all with different shifters, indicators, etc. Still a flaming pile of caca....

Moe Zhoost

So 15,000 miles on my SA 5 speed (drum brakes) is an indication that it is not robust and won't last? Interesting view of the world you have.

Perhaps I am biased - so I googled "shimano IGH problems" 34,200 hits then "sturmey IGH problems" 9,800 hits.

I think if you explain the specific issues instead of throwing out generalized opinions you would come across as more helpful.

corrado33

I don't know, I tend to trust the people who actually service the items in question for their opinions. Generally their opinions are slanted downward a bit, as they only see the hubs with problems (or cars with problems in the case of mechanics) but still. They generally make good points. (For example, my brother was a german car mechanic, worked at a mercedes dealership for a while. He thinks all modern german cars are crap, impossible to work on, etc. Is that true? Probably not, but if you ask him about a specific part he will let you know how it can fail and when you can expect it to fail.)

Mr IGH

The fact that SA is absent from the OEM market speaks volumes about SA's issues. Shimano sells 100x SA so a Google stat is meaningless. OP's experience is frightening and nothing new....

Moe Zhoost

The point is that the OP asked for help and all you said was "you got junk, throw it out and buy something else".

This is the universal answer, right?

"My Ford driver side window goes up slowly" - "Junk, buy a Chevy"
"My knees hurt after long rides" - "You need a knee replacement"
"My wife doesn't like to ride" - "You need to ditch her and find someone else"
"Rough week at work" - "Quit and find a different job"

The universal answer is just not helpful. Assuming that you have the experience to understand and diagnose the OP's issue, perhaps you could offer the benefit of this experience by actually trying to be helpful.

Yes, you are correct google stats are about as worthless as most user product reviews. My point was that Shimano hubs were not problem free as you implied.