Motorcycle project special gear change linkage

Junkyard Dog Part 9 – More Exhausts and Other Stuff

Custom motorcycle downpipesSome days are great and everything goes just how you want it to. Other days are like today and nothing goes as planned. I woke up full of enthusiasm to get on with the exhausts, the first side went quite well but I knew the second side would be a bit harder as it had to match the first half. I had a dozen stainless steel welding rods and all the other consumables I needed so I set about it. What a nightmare, I really struggled to get the angles right, made a right mess of the first pipe – so bad I had to scrap it. That gave me a challenge as now instead of just making one cut I had to make several so I could replicate the first pipe from the other downpipes that I hadn’t intended to use.. It took a good few hours and much trial and error before I got it right. There are now bits of pipe all over the place and I am concerned as to whether they will polish up well enough or not. I won’t know for a while because some dunderhead forgot to order the Abranet!!

So, while I wait for that I got on with the gear linkage. The standard arrangement would be no good as the footpegs are much further apart than on the donor bike. I scratched my head for a while and had a rummage around the jumble pile – with there not being any bike jumbles on thus far this year the pile is huge and pickings are rich. Sure enough I found just what I was looking for – a gear shift linkage that had the right size splined arm to go on the Suzi’s gear shaft and it was steel so I could weld to it. I cut off the arm part and then used a length of steel rod to extend it. The rod came courtesy of a 125 front wheel spindle that was hollow – the bore being exactly the right size to slip over the end of the gear shift shaft. I slit it so that I could do it up nice and tightly once it was fitted, it worked out really well and was done at zero cost – just my time.

Custom motorcycle linkageNext job was a minor one, the bit of the stand that you put your foot on to push it down was in the way of where the exhausts will run. I cut it off and will weld on a new one that is longer and at an angle that will clear the exhausts.

I still have a couple of engine brackets to weld on to the frame and a few that need cutting off but things are rapidly getting to the point where the whole thing can be stripped down so that everything can be cleaned and painted and then be re-assembled.

Scottie and Ian have found a couple of pairs of handlebars that look like they would do the job nicely, I will grab them next time I am over there and see which ones look best. I can then start to look at the wiring and a few other bits. I’m still not totally sure how I am going to connect up the rear brake but I don’t think it will be too difficult. I may have to blow some of the meagre budget on a custom cable. Don’t think I can bring myself to do it though so the jumble stuff may have to be raided again.

The gear shift thing didn’t work out as I had planned it – there was far too much movement in the long extension and the lever felt horrible. It was clear that the extension needed to be supported at some point along it’s length. The support would have to be removable otherwise I wouldn’t be able to get the sprocket cover off  and service anything behind it eg sprocket, neutral switch, clutch release assembly. In the end I came up with a short bracket welded to the frame with an M6 tapped hole. A second bracket holds a plain bearing that sits between the two exhaust pipes (not yet fitted) to add the required strength.

Custom motorcycle gear linkage supportWhile I was at it I added extra weld to the arm at the end to make sure it can’t break off – there is a surprising amount of pressure on it from the boot activated shift lever. It is a lot better now but it’s still not perfect. While it feels ok you can still see the extension moving a bit if you press hard on the lever, I am concerned that could result in fracturing further down the line. The pivot that used to be used for the gear shift mechanism is now vacant, I am going to add to the bracket another bit that slips over that pivot – it can’t move at all then.

The linkage looks ok and works well enough as it is so it’s about reliability at the end of the day, I want the bike to be usable, all the parts used to build the shift linkage etc is scrap. The long rod is part of a small outboard engine drive shaft. Bit heavy for the job but it’s all I could find that was free and long enough.

Article provided by David Powell of Boston Bike Bits.

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