Friday, March 18

Doughnuts Bedevil a Cyclist

Four Sets of Doughnuts Have Slipped in Two Years
I'm sure I'm only one of many that has the problem outlined today. I don't recall the subject being treated at bicycle school. SLIPPERY DOUGHNUTS. The symptom is illustrated in the photo above. No, these aren't the kind of doughnuts you eat, but the kind that are SUPPOSED to keep your exposed brake cable from messing up the paint on your frame. After a ridiculously short period, instead of remaining in place on the cable, they work their way back to the rear end of whatever cable they are sitting on. After only a brief time more, they work their way back within a block of being set where they belong. Before too much longer, they simply disappear from the cable altogether, one at a time.

Buddy originally came with some classy white doughnuts. They slipped pretty much within a month. When I had to change out the rear brake cable, I put the first set of black rubber ones on. THOSE lasted nearly six months. Now, my third set of black rubber doughnuts routinely vibrate to the back of the cable run, even without any brake application.

The question is: does anyone have a practical solution for this other than increasing the cable housing run or simply doing without? If the cable were BELOW the top tube, I'd be inclined to simply give up rubber doughnuts for Lent, but it's easy to damage the paint with a cable running ABOVE the tube. I've considered a drop of super glue on each doughnut, but somehow that seems like it might not be a brilliant solution, particularly if I accidentally glued a doughnut to the frame. A small dab of tire patch glue? I am NOT going to try WD-40.

14 comments:

limom said...

How about using some heat shrink on the cable to prevent the donuts from skittling around.
Preferably white.
the heat shrink tubing I mean.

Anonymous said...

could you wrap a narrow piece of tape around the wire below the donuts, and loop it around the wire once or twice to make it thicker than the donut-hole? Could this be yet another use for duct-tape?

limom said...

Oh, and not ON the donuts, before and after I was thinking.

Big Oak said...

I hate those stupid little things. They just kept sliding back and finally I pulled them off. I couldn't take it any more.

Oldfool said...

Full length cable housing. I've never even seen one of those donuts. Sounds like a solution for a problem that does not exist.

Pondero said...

I forgot the donuts on my AHH build. Being too lazy to unassemble and reassemble, I wrapped hemp twine around the top tube a few times and tied a knot. I figured it would be a temporary stop-gap, but it is still there...in place. I understand that not everyone can pull-off that look, but I can. I'm tacky all over.

Jon said...

You can slip some small heat-shrink or other tubing over the entire length of exposed cable. The cable will slip through the tubng, and the cable stops on either end will hold it in place.

John Romeo Alpha said...

I thought the rule was "If it sticks and it shouldn't, WD-40. If it should stick and it doesn't, duct tape." If duct taping the little donuts doesn't appeal, maybe try those little plastic coffee stirring straws in place of the donuts. Although they might whistle in the wind.

Chuck Davis said...

There are donuts and there are donut holes

The donuts under discussion here are available holed for brake cables, and shift cables

Anonymous said...

I've given up and done without the donuts.

Although the Friday morning Krispy Kremes at work always beckon.

Ed W said...

I'd recommend shrink wrap too, Steve. Just don't shrink it onto the cable so you can replace it easily. I did that on the Bianchi when it was new and it still doesn't have any scratches from the cable. Lot's of scratches and dings from other stuff, but not the cable.

Velouria said...

Interesting. I don't like "donuts" but on the 1 bike where I have them, they have stayed perfectly put since last August.

Steve A said...

I last replaced the doughnuts on December 12 and have put less than a thousand miles on the bike since then. I think an exposed cable ABOVE the top tube takes more abuse than one BELOW the top tube. My road bike doughnuts last much longer, though even they are good for not much more than a year.

Shrink wrap seems to be less common than people think. Duct tape on the cable is simple, quick, and easy to reverse.

Khal said...

Yeah, those are exasperating.

How about narrow, color-coordinated zip ties on the top tube to limit donut travel?

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