RichardW's Velocette rebuild

[RichardW]

Thanks, they certainly imply they can do it!

I measured the bore as best I can. Right at the bottom it's pretty close to 64mm, which is right for a +40 re-bore. Where the rings come at the bottom of the stroke side to side is still 64mm, but front to back has opened out to 64.2mm. At the top of the ring stroke it has opened out to 64.1mm side to side and 64.3mm front to back. So there is some wear - but it might be catchable with rings with smaller gaps - certainly the rings appear to be pressing on the bore all the way up.

[xantia_v6]

What is the ring gap at the tightest part of the bore?

[RichardW]

Ring gap is about 0.8mm at the base, but increases significantly towards the top of the bore (although it's very difficult to measure!) - up to about 1.3mm, although the ring is still holding the wall.

I was thinking if I could close up the gap to 0.2mm at the base, then it would only be 0.7mm at the top. Nothing to lose except the cost of a couple of rings

[moizeau]

That should be close enough to get it running. It will allow you to finish the rest to have a ride.

[myglaren]

Needs sound on!

[RichardW]

That's funny Steve!!

Been getting on with some jobs on the bike that I need the bike for so that I can then take it down and get the exhausts made, whilst I finish off those items. And decorate the kitchen....

I rigged up the brakes and clutch. Brakes seem OK, clutch cable is too short really, there is no adjustment in it. So I will need to get a new inner and re-make it (I bought it as a complete unit, but I suspect it is for later machines). The throttle cable is too long, so that will need to be shortened. Going to need gorilla fingers to operate the clutch Then I moved on to the saddle front mount. Dug out a few bits, and lashed this up. I'll cut down the supports, and then the 8mm bar, will need to get some nuts to spread out the supports. Then I need to decide which way up to fit the springs (you will note they are opposite ways up!).

Next moved on to the gear change gate. Found a piece of old shelf bracket which was close to the right size. Mocked it up with some cardboard - pretty easy to feel where the gears are, and then I marked the positions on the blue tape on the tank.

Moved it onto the steel and roughed it out with the pillar drill

Then after some effort with the files...

Wasn't really in the right place first time, and I couldn't get top - then realised I had done it with the adjuster on the gearchange (the bottom of the vertical link is threaded into the clevis pin) right at end. So I slotted the holes on the back for tank mounts, then adjusted the link to the centre, and it seems to be not far off now. I need to sort out the pivot, but I can do this when it comes back.

Tomorrow I need to silver solder the bridge onto the exhaust nut, measure up the clutch cable, have a look at the throttle, put the engine back together enough so that the exhausts can be fitted, then I should be ready to take it down the road.

[myglaren]

I thought of you earlier.
I was reading an account of a lad who had bought a small engined motorbike to putter around on. After using it for a while it would leave clouds of smoke behind.
They did the usual investigative things and were stumped so split the engine and discovered that someone had replaced the piston with a wooden one with a stainless steel foil on the crown.
The smoke was the piston burning.

Can't remember where it was now.

[RichardW]

No wooden pistons here...!!

Tried to solder up the exhaust ring yesterday, but even with 2 blowlamps on it, I can't get (or at least keep) enough heat in it to melt the solder. Need to swaddle it in my soldering mat I think the keep the heat loss from the rest of the ring down.

[Zelandeth]

What type of blow lamp are you using?

I was astonished by the difference between MAPP and the conventional propane ones...if you're still persevering with propane, time for an upgrade. Toolstation do a kit with a torch, several nozzles and a canister for about £60 as I recall.

It has become an alarmingly regularly used tool in the garage.

[RichardW]

I've only got a butane one - I have been thinking about a MAPP one - saw the plumber using one and he basically just waved it in the direction of the joint and it was soldered! Maybe a good time for an excuse

[Zelandeth]

This is the pack I bought: Toolstation link

Just be careful and experiment a bit first...the sheer magnitude more heat this produces than a propane torch takes a bit of getting used to. It's way easier to set fire to things accidentally with this!

[RichardW]

A long day out on Saturday saw the Velocette going on holiday to Whitworth, north of Manchester:

It's away to get the exhausts made. We took some friends with it in the van , and went for a ride near my parents in Kendal, then dropped into theirs for a curry before heading home. Having left home before 8 to pick the van up 20 miles away, came back and loaded the bikes set off about 10, didn't get back home till 11 having covered 420 miles (+ 10 miles on the bike!). Mercedes Vito - WTF is that foot operated parking brake all about???

I need to get on with painting the tank and other bits so I can assemble it all when I get it back (another 400 mile round trip to pick it up...!)

[RichardW]

Progress on the exhausts

[moizeau]

They look really good, how's the engine going? PS Love the Norton plaque, I worked there as a kid in Shenstone

[RichardW]

I've had new longer rings made, but as the bike has been away, not done anything with them. I'm hoping to go and get it this weekend / early next week to allow time for final assembly before we have its Birthday / renovation party on the 23rd. If the rings work, it might be a runner!