Babies and gearboxes

The fact I’ve managed to do anything on the bikes in the last few weeks is a minor miracle. My wife is expecting our second child and with D-day approaching fast, I’ve had to focus on preparatory DIY.

I have managed to move forward with my projects though, if not at startling speed.

The Super Squirrel racer is sitting patiently, waiting for a trip to be organised to Alan Jeffries dynamometer in Plymouth. After that I’ll be trying to get the new fuel system completed for the final Cadwell park race meeting for the BHRC (British Historic Racing Club) at the end of September.

The Moss/Silk Scott racer is just about to enter a new stage, as I’ve found someone locally who will soda blast the frame. It’s about double the cost of normal media blast cleaning, but I wont have to plug every aperture in the vain attempt to stop the abrasive media ingress. I also don’t really want it in my workshop if I don’t have to. It gets everywhere. In terms of my own time, I think it’s worth the extra. I’m intending to take it up there this week along with the oil and water tanks.
Roger (my dad) has also given me the engine (in bits) to make a start on and I need to do a dummy build to look at timings. A couple of months ago contacted a guy who lives fairly locally to me who has done some very impressive expansion chambers for more modern machines and told him about this project. He’s interested in looking at what would be necessary (or possible) in terms of pipes and he needs provisional timing information to run through his calculation programme. I’ll write more about it all in a separate post.

The main subject of my attention at the moment is the Norton Model 18 which we’ve had in the family for over thirty years now. The last time the Norton was used was I think 2001, when I actually used it for daily transport through the winter. I’d come back from five years of travelling and working abroad and simply didn’t have anything else. It jumped out of third gear a lot and pulling the chair only managed 47mph top speed but I really liked riding it, once I’d got used to riding an outfit.
I brought it down to Devon sometime last year with the plan of returning it to the road. Unfortunately as I wrote in one of my first posts on this site, their was a problem with the engine and I’ve temporarily replaced it with a later one. This requires a conversion to run using coil ignition and alternator.

Only last week I also removed the gearbox to have a look at the jumping third gear issue and unfortunately the news wasn’t great.

Damage to dogs on Norton four speed gearbox
Damage to dogs on Norton four speed gearbox
Five gears had reasonable damage to the dogs and I’ve ordered some (also secondhand) replacements from the Norton Owners club. Also the gearbox casting is cracked at the lower gearbox mounting pivot on the drive side. Apparently this is a common problem and I will have to get it welded. It’s a design weakness here I think so I’ll have a look at some possible improvements to the arrangement. I need to order a bunch of other things for it, but it’s a really nice bike and is too good to sit around for another 10 years. My grand plan is to get it recommissioned and use it my everyday road bike. It’s much more of a sensible option than in many other counties too. The route between here and work is about 50% tiny lanes where you often can’t do much more than 25mph anyway. The roads through Dartmoor are more open than the ‘lanes’ in the South Hams but the presence of sheep, cattle and ponies create an element of surprise. The undulating nature of the land favours a engine rich in low down torque and flexibility. This terrain is the ideal stamping ground for a big single more than anywhere else I know!

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