Fork Considerations for Drum Brake

[CWinters]

Wondering whether any of you have built bikes with front drum brakes, and if so what was your choice as far as fork blades? Any problems down the road?

Having been taught the basics of brazing (with frame #00 as the result), I am now going to try for a simpler single speed frame. This is going to be a city bike, and I would like to use a front wheel with a drum brake. The frame itself will be either straight gauge, or something like Columbus Chromor, so I am not looking to make a lightweight fork. My main goal is that it's safe. Would appreciate if others could share their experience.

[Eric Estlund]

Don't shoot for light in the fork blades- build them on the stouter end (of road blades, that is). Remember that the brake arm is leveraging against the middle (thin wall/ smallish cross section) part of the blade regardless of the clamp (custom, provided band, etc). I try to minimize the for/ aft slop on the lever attachment as well.

I've built many hundred of these, and haven't had any issues, but again, I've never chased weight. The fork isn't the best place to under gun regardless, and the mid-mount lever is even better reason to build conservatively.

[CWinters]

Thanks as always Eric. Yes, definitely not going for lightweight here. Do you have specific recommendations for blades? I am planning to rake the fork out quite a bit (say 70mm, continuous/banana-style curve). I am thinking this for the crown.

[Eric Estlund]

Sorry- I try to avoid specific spec recommendations (I've been quoted out of context before and have seen some stuff I would not have recommended).

I would suggest mapping things out on paper before committing- that sort of bend may or may not line up well with the brake lever.

From that degree of rake I am assuming you will be weighting the front of the bike- even more reason to go for a substantial blade on the fork.

[CWinters]

Got it, thanks Eric.

This ought to be fun...

[Jim N]

R side rack and light by jimn, on Flickr

These are TT FB4s, so 1.3 at the bottom, .9 at the top. They haven't unraked yet after a year and a half of almost daily use.

[CWinters]

These are TT FB4s, so 1.3 at the bottom, .9 at the top. They haven't unraked yet after a year and a half of almost daily use.

Thanks. I did not even know drum brakes could unrake a fork; thought it was only a concern with disc brakes.

That build looks real nice. I plan to use the same wheel & tire size.