Tuesday 30 May 2017

Look at me!

This is some heavily compressed video of me driving my kit car around castle combe. It's interesting for me to watch, because at the time I thought I was making a pretty good job of it. The turn ins and clipping points are good, all the exits are wimpy and don't use anything like the whole track. The problem might be incorrect entry speed, putting the power back at the wrong time, or most likely a failure of courage.

If you look at how much the horizon rolls and pitches you can see that we're actually on luxuriously soft suspension.

If you're interested in the speed, we're doing almost 110mph around the bend after the start-line. You're not allowed to time your laps at a track day, but looking at the timestamps on the video I get an average speed of about 75mph.

Richard "grow a pair" B

Tuesday 23 May 2017


I can't even flirt with the idea of pretending I'm normal, but I'm sure that this isn't what normal people do with an afternoon off work:

That's an old oscilloscope, two speedometers and a multimeter on a workmate connected to a kit car which is on axle stands running at 120mph. Between the seat and the wheel arch you can just see the bamboo which operates the throttle.

This is the temporary connection onto the speed sensor.

My speedo had gone wrong in a very odd way and I found it hard to find the fault. My brother (when he's not drinking rum, stealing treasure and hitting people with belaying pins) is an aircraft engineer and he's much better at fault-finding than me. I told him about the ridiculous amount of time and effort I spent on the speedo fault. "There's an inductive sensor pointing at a toothed wheel on the driveshaft, there's the wiring up to the speedo, and there's the instrument itself. I've got a spare speedo and that showed the same fault. I tested the sensor and that's OK so there must be a fault with the loom"... My brother interjected "Or the driveshaft" and in a matter of moments had understood a fault that it took me a week to find. It seems that the magnetic reluctance is off-centre and the speed signal shifts phase with every turn of the wheel.

Richard "aconcentric reluctance" B

Wednesday 17 May 2017

Stop the Car!

This weekend I went to Castle Combe in my kit car with my brother. It was raining heavily, there was standing water on the track, and the car was wearing semi-slick tyres. The morning was like the most ludicrously extreme and dangerous trust-building exercise. On two occasions my brother seemed to be driving us earnestly and fast towards a bale of tyres (at Bobbies chicane).

I lost control of the Vehicle so severely (at Tower) that by brother was bracing himself for the crash. He hurriedly grabbed the sill and the dashboard and in the process he turned the indicators on and the wipers off. I just about rescued the car and didn't quite hit anything.

He was even more frightened when we went to the motorsport shop and bought a complete set of brake pads.


Richard "Mintex M1144" B

Tuesday 9 May 2017

Dirty Weekend

My weekend was dirty, I didn't get a lot of sleep, and I achieved almost nothing useful. Stop reading now if you don't want to hear about me taking the clutch out of my motorbike.

I ride a high-powered moped called a Yamaha TMax. It has chewed through its clutch in only 25000 miles and since I've had new friction material put in, there's a nasty clunk somewhere in the drive train. In some ways the TMax is like an old British bike, it's a parallel twin with a 360 degree crankshaft, the crankcase splits into left and right halves and you can't apply the brake with your right foot.

The bike has too many gearboxes. It's got a V-belt variomatic transmission, a centrifugal clutch, a vestigial single speed gearbox in the back of the crankcase and a wildly complicated final drive chain running in an oil-batch. As the nursery rhyme goes:
The crankshaft's connected to the variator.
The variator's connected to the V-belt.
The V-belt's connected to the main sheave.
The main sheave's connected to the clutch basket.
The clutch basket's connected to friction plates.
The friction plates're connected to the plain plates.
The plain plates're connected to the clutch boss.
The clutch boss's connected to the first motion shaft.
The first motion shaft's connected to the output shaft.
The output shaft's connected to the chain wheel.
The chain wheel's connected to the drive chain.
The drive chain's connected to the intermediate sprocket.
The sprocket's connected to the other chain.
The other chain's connected to the splined hub.
And that's what turns the wheel.

If the fault was in the vestigial gearbox or the final drive it would have to be engine out, cylinder block off and split the crankcase. I think the bike would be written off. It took me all weekend to take the clutch out and put it back in again, amongst hundreds of other ridiculous things you have to take the coolant out and the water pump off. Now that I've done it once, and I've built the tool to hold the clutch basket I think I could do it again in about 8 hours.

The good news is that I've found the fault and the bike isn't written off. The bad news is that I've no idea if or how it could possibly be fixed. The gear that takes power from the clutch boss to the first motion shaft is helical and it generates an axial thrust. The clutch boss slides up the shaft until it hits the basket. The end-float is highly critical, wrong, and seemingly can't be adjusted.

Richard "And my speedo's broken" B

Thursday 4 May 2017


I spilled a trail of chicken fat across my lounge carpet, so this weekend I hired a carpet cleaner. Cleaning the carpet meant moving most of the furniture upstairs and that meant tidying up the drinks cabinet.

One of my friends used to go out with a girl who drank Southern Comfort. I've had a half bottle of it left over since my housewarming party. As nobody has drunk it since and as he's been married to someone else for over a decade I decided it was time to throw the bottle away.

Even more out of date and surplus to requirements is the dregs of a bottle of Jamesons Irish Whisky. My longest serving friend and I shared a truly catastrophic hangover in 1992 and this bottle (amongst other drinks) is what did the damage. For me it was certainly in the top 3 all time worst hangovers, but not the winner – I can remember one when I genuinely prayed for the sweet embrace of death rather than endure it any longer. I think this particular hangover might be my friends all time number one. He has barely drunk a drop of spirit since and he wasn't himself for a week.

Neither of us wanted the bottle so I tried to throw it away. Grasping the bottle cap ready to pour it away and the idea that I was just about to smell the whisky made me so nauseous that I couldn't even open it. I've still got the bottle, and our best idea to get rid of it is to bury it in the garden and then move house.

Richard "Rug Doctor Who" B