Friday, 20 March 2015

Clamping Down

One of the many problems that have arisen so far during my shakedown period has been the inability to get my levers and twist grip to clamp onto the handlebars. The bars are polished stainless, and I guess that 19 mm OD stainless is of sufficiently less OD than chrome plated 3/4" tube, enough to allow the parts to move. They are not that loose, just enough to worry you. 

So, a few minutes with shears, a fine file and some 0.5 mm brass sheet produces a neat & tidy solution.

All is now rigidly clamped in place.

Monday, 16 March 2015


Well, I got out on my test drive, and it feels much happier - smoother, more torque at the bottom end...

Unfortunately, about 5 miles in, a misfire appeared and the engine stopped. Having experienced this many times during the fuel filter saga, I was quick to look for fuel supply problems and cracked the fuel supply banjo to find all was well. The bike started again, only to stop again after about 100 yards - this happened once more, and then I was close enough to push it home...

Charging had looked good on the ammeter from the first day. All the lights worked perfectly, apart from one indicator which persistently rotated around to face the floor, but in general everything had been fine. However today, when I had the bike running again, switching on the lights would kill the engine.

The Lucas C35SD gives 70 W at about 1700 rpm which equates to 32 mph in top gear, but when you are running around town the ignition, brake light and frequently used indicator loads soon drain the battery, which appears as a fuel-starvation-like misfire. I cursed that fuel line again until I realised what was going on, and a CTEK battery charger came to my rescue. Actually you need about 20 W for the ignition alone, or about 3 Amps; in top gear, you get 3 Amps from the generator at an average of 23 mph – these bikes are really not for town use.

My 1951 Mk1 has a 20 Ah battery bank hidden in the Lucas GU11E style fibreglass box. I'd be surprised if you could even get to the shops with the earlier small battery...

Sunday, 15 March 2015

Valve Timing

So, we had another nice little run out yesterday, on a shopping errand this time. No dramas, Amelia running nicely with her new brake shoes. She attracted some attention from a cyclist who came over exclaiming: "Oh, a Squariel! I haven't seen one of those in years!" He proceeded to tell me about his Triumph TSS and T120R, which apparently was fitted with a Morgo pump as well.

You meet the nicest people on an Ariel.

I'd heard mention of the effect valve timing has on overheating, and it occurred to me that in the joyous response to the problems I had had setting up the valve timing initially I had possibly not been too careful to get it spot on, being happy to go with the factory timing marks. Ariel folk lore tells us this is not wise.

So, when I arrived back form shopping I whipped off the offside rocker cover, the #1 plug and the front crankshaft cap and had a look - and it looked like number one inlet valve was opening near TDC - it is supposed to be 3/16" before TDC.

So, late in the night, and with the head torch on I took off the timing cover. I discovered that if you remove the dynamo sprocket you can reset the valve timing without removing the camshaft sprocket (and hence you can leave the oil pump in place too) After 4 or five attempts I finally got the timing as close as I could - which I think is spot-on. The cam chain tension makes a big difference, and you have to test it with tension on the cam chain.

I may need to change the cam chain at some point - a worn chain affects the valve timing.

So that done, I reset the ignition timing, a job which is very easy in the dark, because you can see when the points open if you turn the ignition on, since there is always a little spark when the points open. However, testing it all again the next day revealed the valve timing was indeed spot-on, but the ignition timing was way to far advanced, as evidenced by several kick-backs and spitting at the carburettor. Realising what these symptoms meant, I reset the points gap and the ignition timing again.

And after all that, as usual, she starts easily; but probably more easily than ever; she runs eagerly (though I could only manage a couple of miles) and she idles very much more smoothly.

We have some errands tomorrow; we will see what happens on a longer run

Sunday, 8 March 2015

17 mile test run; fun with brakes

Lovely test run out to Bawburgh today, about 17 miles around the countryside. Bike is definitely running less hot, since after 8 miles I still had maybe 25 psi oil pressure at 30 mph, but that was dropping to 10 psi on the gauge at the end of the trip. I measured the oil temperature - 95 degrees C in the tank (about 200 F), which is much higher than I have seen after, say, a 5 mile trip.

As you can see the bike is on the sidestand - what I noticed later was that the carburettor drips fuel onto the dynamo in this position. I had left the fuel on though. 

The engine sounds happy enough; I'm not too sure about this gauge - I keep wondering how I would feel if it had never been fitted. I'm tempted to buy one of the club reproduction gauges, or to get this one calibrated.

Out on the road though, the Ariel was handling fine for the first few miles until I became aware of a juddering from the front end, which I initially put down to the road surface. On braking however I found no movement in the front brake lever, and realised the brake was seizing on. Near home, I stopped for traffic lights and saw smoke coming from the front brake (I've been here before, with the Bantam)...

Arriving back I was greeted with grease everywhere. As we all know, hot brakes cause the grease in your hubs to melt...

Stripping the brake down revealed some serious damage to the linings, and bits of lining (2-3 mm bits) all over the drum. The linings you see in the pictures are greasy, but those matt grooves in the middle are way below the wearing surface:


Cratered Lining
Now, I don't know if this is a result of heat, or the heat is a result of this breaking down. I'll take it back to the supplier tomorrow and see what they say.

Odd, since it had been bedding in nicely and getting quite effective.

Thursday, 5 March 2015


Hurrah for QD rear wheels:

It makes changing tubes so easy. A lot has appeared in the press lately about the quality of unbranded inner tubes, usually relating to poor vulcanising around the valve. The tube I took out was not unbranded, but wasn't one of the big names. It had a small split along one of the mould lines:

Its under that blob of Tyreweld. All fixed now, with a nice new Michelin tube from Vintage Tyres.

Oh, and it started first kick (well, first enthusiastic kick)!