Sunday, 23 February 2020

QR50 - Stanchions & Yokes

I might have mentioned a few times that the stanchions, which in this design have integral bottom bushes, were absolutely trashed through rust - so much so that I needed a new pair.

These are pretty hard to come by, and expensive. I decided to make a pair.

The originals are chromed steel tube, finished diameter 21.5 mm. After much deliberation I decided to use 22 mm OD 304 stainless tube, which meant the holes in the yokes needed to be eased open. I did this using 60 grit emery tape and a hone, which I made from a scrap bit of tube with a slot to carry the tape; the tube OD was reduced to allow for the thickness of the tape. I ran this slowly in the lathe:

Here's the hone. It took a couple of hours and a metre of tape to open those holes out to 22 mm.

Since I don't have a M10 x 1.25 mm tap set, I elected to rescue the old top nuts from the original yokes. I cut these out using a parting tool and a corner turning tool. I removed all traces of chrome in the process, to avoid contaminating the weld.

I used the TIG set at 50 A to put an autogenous peripheral weld down:

Two new fork legs!

The yokes come up nicely. They have been stripped and cleaned using various wire wheels; the paint is UPol Satin Matt Black over UPol etching primer:

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