When I built Hornsby, I was happy to find the Equal cable-operated disc brakes in purple. At the time they were only available from the US, even though they’re manufactured in Japan. (They’ve subsequently become available locally, and yes, they’re cheaper here.) Installation was straightforward, and they’ve mostly worked well with little adjustment needed.

Well, that was true for the back brake. The front was a little grabby from the start, causing the fork to shake a bit when the brake was applied. I spent some time making sure the headset wasn’t loose, which is the usual cause of this problem in front braking.

Time is not healing this wound

The issue has not improved with time — it’s only got worse. On my most recent commute it was quite bad, to the point I didn’t want to use the front brake. It was also squealing a bit in a way that made it sound like the pads had worn through and the caliper was rubbing on the disc.

With rain in the offing today, it was the perfect opportunity to give the bike a going-over in the Workshop in the Sky. The first step was to get the bike in the stand, remove the front wheel, and make sure there was absolutely no play in the headset bearing. Quickly done: the headset is perfect.

Next I had a go with the hex wrench at testing all the bolts securing the caliper to the fork. Because the fork has an IS mount, there’s an adapter and that means four bolts instead of two. They were all good — I might have got one-eighth of a turn out of one of them. (I’m a bit worried now of getting them out next time the need arises.)

The last check was that the disc was secure on the hub. I had to remove quite a lot of the contents of the toolbox before I located the right one — still attached to the breaker bar. And once again, I might have got one-eighth of a turn out of it. I had a look at the surface of the disc and there was no obvious scoring.

At this point I was stumped. Just to be sure, I checked the bolts on the caliper itself: nice and tight. I removed the brake pads, inspected and cleaned them. Plenty of material left, and no sign of uneven wear. I replaced the pads and mounted the wheel in the fork again. At this point I was wondering if the hub itself was to blame — did I not adjust the bearings properly during the last cleaning? There was no evidence of play.

As I spun the wheel, I finally noticed that the disc was very slightly warped. If you called it half a millimeter you wouldn’t be wrong. It was little enough that I had to close one eye to notice it. It was easy enough to spot then while spinning the wheel with some speed, but harder to narrow down to a specific location when turning the wheel a bit at a time. I gave a few firm nudges with the disc alignment tool, and thought I finally detected a bit of improvement.

Before returning Hornsby to the bicycle parking garage (where these photos were taken), I finally remembered to attach the omamori that I’d ridden up to Aso Jinja specifically to get. Finally I had Nana call the security center to unlock the door for the freight elevator, and took Hornsby back to ground level. On the ramp down to the bicycle parking, I used only the front brake, and I didn’t detect any grabbing — only smooth braking power. That will be all the testing until the next commute.

Good Samaritan pump

Unrelated to Hornsby’s grabby front brake, I’d been thinking during the Edogawa ride about my new bike pump, which is specifically made for the Clik valve system. What will I do if the tubeless tire fails and I need to swap in a spare inner tube? Well, swap the Clik valve to the inner tube of course. But what if I need to lend the pump to José, or help out another rider?

I have a similar pump from the same maker with an attachment for both Presta and Schrader valves. Would that attachment fit this pump? Very simply: yes. So into the tool bag it goes.