Originally Posted by
JaccoW
@
scarlson Just curious how this ended. Did this fix your problems with the hub?
It smoothed things out quite a bit, but it's not perfect. That tandem also hasn't gotten much action because I had knee problems and the cranks are suddenly too long for me. I'm changing the cranks very soon, so we'll see how it goes!
If anything the intermittent braking also sounds like this hub was used with a fork that was not stiff enough for a hub brake. Because in that case it bends, releases tension from the cable, springs back and then start braking again.
I don't think that's what's going on here, for three reasons.
1) The results have been similar for many forks, as I mentioned above (three were tested: old Stumpjumper, Salsa Fargo, and Fuji Touring fork on the tandem)
2) The judder is in sync with the wheel rotation. It slows as the bike slows, and speeds up as the bike speeds up.
3) The cable is in housing all the way to the adjusting barrel on the reaction arm, so unlike a cantilever where this can occur, it's running independent of fork flex. Unless you're suggesting the reaction arm can bend in relation to the cover plate and actuator cam, and that this is dependent on fork flex, which seems far-fetched. Or that my cable housing is too short, and getting pulled under fork flex, which I know is not the case.
Another option is the wrong brake levers. These really work best with Sturmey's 4-finger brake levers. I used a similar brake with drop bars for example and it just doesn't really brake all that well. Not with normal pull levers and definitely not with straight-pull (V-brake) levers.
I have tried it with at least two brake levers: four finger Shimano BR-AT50 brake levers, which are standard-pull and huge, and Cane Creek/Tektro SCR-5 road levers, which are for cantilever or side-pull or centerpull (standard pull in any case). All levers were pretty similar, and I have really strong hands. The Sturmey Archer documentation indicates that any normal pull lever can be used, although I've heard others say the Sturmey Archer lever is some special lever that works better somehow, but nobody ever says anything specific. It's all speculation and anecdotes as far as I've seen. I'd like to know how much cable this lever pulls for an inch of lever travel at the spot where the middle finger naturally grips the lever. Maybe that would shed some light on things.
As I said, I used it a lot in the winter. It was exposed to salty road spray, which could have made its way in between the aluminum and the steel (cast iron?) drum and corroded things, creating an expanded spot (because corrosion products take up more space than the base metals). That's my guess as to why it got to be so bad, and in a progressive nature. My Honda Insight has aluminum drums with pressed-in cast iron liners, and I've had no problem with those in spite of the winter weather and road salt. But like I said, the Sturmey Archer was actually getting road spray inside it, and my Honda's brakes are probably not.