Sunday, September 8, 2024

Brompton DIY hub cleaners

I have never been a workshop kind of guy. I would say I am more of a MacGyver kind of kind of guy.

My office is 95% devoted to reading and writing of one variety or another and that's what it looks like. That said, the other 5% is devoted to puttering and MacGyvering.

For almost as long as I have owned my Brompton bike, I have wanted hub cleaners. So far I haven't bought any. That's because the Brompton's small wheels won't accommodate the usual leather strap hub cleaners. The spokes will prevent them from working properly.

That means it's a challenge for MacGyver-me.

My first attempt used a leather lace looped around the hub with a bolt sewn to the lace loop to provide a target for the forces of gravity. It was not by any means attractive, and it kind-of worked. It worked really well on the front hub, but the one on the rear hub would occasionally get caught in the spokes, and I would have to stop when I heard the clicking, release the bolt from the spokes, and carry on. It was annoying. Ultimately I sliced it off. That was some time last year.

I happened to be at our mechanic's workshop picking up our car. On the window sill there was a leather strap that looked like it might do the trick. I asked if I could have it.

When I got home it turned out that the strap was too short. I tossed it into a plastic bag in my office cabinet where I store odds and ends. I have an impressive collection of odds and ends. I collect all kinds of stuff that might eventually be useful. Like when I discard a torn shopping bag, I cut off and keep the straps. Same goes for plastic buckles from backpacks, strapping, plastic cinch-things, and the list goes on, and on. Same goes for screws, nuts, bolts, washers... you get the idea. My collection is such that I know from experience that I have the right hardware for almost any little fix-it.

That leather strap I got from our mechanic was held together by a gold-coloured stub-thingy, like the fastener on some purses. It was a screw-on type. I picked up a set of 15 on Amazon for $10, and as soon as they were delivered, I went to the odds and ends collection.

I found some black straps. They were too light for the project but they had a channel on each side. I thought "... if I had some little ball-bearings I could fill the channels...". As soon as I thought of ball-bearings, I remembered that among the odds and ends were the curtain ball-bearing-esque chains that I rescued from curtains we discarded. Wonderful, they fit the channels perfectly and provided the weight that was needed.

The rest was scribbling out a plan in my notebook...


...measuring the Brompton hub diameters with my Vernier caliber, doing the math to get to the circumference, cutting some paper strips based on my guess for the straps, taping the strips on the hubs as a test, deducting some length to get to the right length...

Hub cleaner math

Front hub radius 27/32”

Front hub diameter 1  21/32” 1.65625”

Front hub circumference 5.21”

Front hub cleaner test length 7”

Front hub post test length 6”

Front hub total length including 1 inch for double clasps 7”

Rear hub radius 1 6/32”

Rear hub diameter 2 6/16” 2.375

Rear hub circumference 7.47”

Rear hub cleaner test length 10”

Rear hub post test length 9 1/2”

Rear hub total length including 1 inch for double clasps 101/2”

... cutting the straps and the ball-bearing chains to the right lengths, threading the chains into the channels in the straps, burning holes for the studs with my little battery-powered soldering iron, putting it all together, sewing the channels on each end of the straps to prevent the chains from escaping, fitting the straps to the Brompton, and there you have it... TADAH!!    





It was fun in a weird way. We'll see how they perform in actual use.

Oh... and by-the-way... despite appearances, I'm a lawyer, not a doctor. It just so happens that over time I have collected things like a clamp, a scalpel, a dentist's pick... I love those tools.

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ed.: The rear one is too small, and the weight is too well distributed so it doesn't stay put, but rotates with the hub so it doesn't actually do the job. That one is for sure a do over. What I really need at more traditional leather straps. 

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The copyright in all text and photographs, except as noted, belongs to David Masse.