Tech talk
All is never lost… there will be something out there to help when things wear out and replacements can’t be found… like gear change shafts for instance.
Reaching the bottom of Callart Pass in the Pre-65 Scottish 2017 – it’s a good old slog up from Callart Cottage to the viewpoint at the top where I’m not the only one to stop and er… take in the view shall we say before attempting the drop down to Loch Leven – I was fishing for the gear lever when it eventually dawned the thing was missing. Luckily for me I was in third and able to ride along to Kinlochleven, buy another lever (thanks Albert) and head back to finish the sections.
What happened to the lever? I know it was tight enough on the bolt – a quick check is part of the pre-event prep. But it had still dropped off, a closer inspection post-trial showed the reason to be the splines the lever sits on were almost worn off.
It’s likely to be expected after at least 50 years of abuse by big boots and the scenario goes along these lines: the lever possibly comes slack just a little, enough so it can move on the splines which wears both those on the lever and the shaft. The knock-on effect is this wears the splines even more.
The old trick of clamping the lever in a vice and running a hacksaw through the slot will cure things for a trial or two but is little more than an emergency bodge. The only real answer is to replace the shaft but it is all part and parcel of the gear change quadrant too and with BSA being long gone, there’s less and less chance to find the whole thing. Luckily, Burton Bike Bits do a replacement shaft which can be fitted to the old one, bringing everything up to scratch again.
The idea behind the replacement is simple, measure where the shaft needs to be cut and how long the replacement needs to be, make sure the ends are square, line everything up correctly and weld in place.
Such engineering is beyond me but I know a lad who can and he suggested a slight tweak to the method. This involved boring out the new shaft and turning the old shaft down so it is an interference fit, applying Loctite engineering adhesive and pressing the whole lot together. Job sorted.
Though this repair was for BSA’S B40 model, we understand from the spec on the website it will work for a number of other BSAS too and the feedback on the shaft is good.