WTD: Sturmey Archer hubbed wheels

garethrl wrote:

Can someone tell me about the forces that the reaction arms tend to load onto fork blades and stays? The frame is 531 (c, I think) so it's light enough without being a featherweight. Can I simply bolt these wheels in place safe in the knowledge that the tubeset can take the stresses? It's a Raleigh Team frame from about '74, designed around caliper brakes but with guard/rack eyes, and tyre clearance, wheelbase and rake suggesting it's built for solidity rather than speed.

Graham - I'm interested in your comment on the longevity of the Highpath shoes. Were these shoes compatible with Sturmey hubs? And is there any chance of finding a set these days??

Click to expand...

Hi Gareth,
the reaction forces are at least twice those you would get from rim brakes because they are concentrated on one side of the fork or frame not both. The shorter the reaction arm the more the reaction force. This could cause a problem on an aluminium frame where the repeated flexing could eventually lead to metal fatigue. It should be fine on a steel frame as long as the drop-out' brazing quality is adequate. There is a type of reaction arm where the forces pass through a right angled pivot and then upwards towards the fork crown. This takes out the twisting forces and tries to stretch the fork blade or frame-stay instead.

The Highpath shoes would not fit as they are for 80mm diameter drums. However the longevity is mainly due to the way that the Highpath' hub brakes allow for large amounts of adjustment to compensate for brake shoe wear. This allows the angle of the activating levers to be adjusted where it joins the activating cam. You may also be able to adjust this with the Sturmeys?

Graham.

P.S.
I forgot to mention a major feature of drum brakes is that they are tough, and won't be damaged by impacts that could buckle unprotected brake disks.

chris667":3ts43wsd said:

When I built my Cleland-inspired mountainbike with drum brakes, I found a lot of people saying "Drum brakes? Are you mad?". No-one I knew had ever actually used them for offroading.

And the truth about drum brakes, and brakes on steel rims is this: yes, they don't stop you as well as discs, but actually, not half as badly as most people would have you believe. It's all about anticipation.

I think these braking and gearing systems that work, sometimes for decades, with almost no attention at all have been sadly ignored by an industry who tried to make every cyclist emulate the racer.

Click to expand...

You make some interesting points there, Chris.
There are several factors that people overlook with hub brakes. First is the naming of the different kinds.
Drum, disc, roller, band and coaster are all hub brakes.
The Leleu drum brakes I used to fit to the early Clelands were the only kind of drum brake that proved at all reliable, but even then, they had rare occasions when they would work less than at their best. Nevertheless, their performance was far better than any rim brake on the market.
I now use roller brakes. The pair on my current bike work perfectly; that is to say, they give me the braking feedback that I demand, totally reliable feathering. They are three years old and have had no maintenance, apart from greasing a couple of times.
The principle drawbacks for hub braking systems generally is weight and cost. But when one considers the cost of renewing the blocks on rim brakes, and after a while, replacing your rims, along with wheelbuilding, the cost element becomes far less of an issue.
When I consider the maintenance aspect ~ after all, my bike is for riding, not fixing, I am very happy indeed to carry that little extra weight!

Chris ~ any pictures of your Cleland-inspired mountain bike????