Racing again (at last)

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I struggled with that for a couple of seasons once. Turned out I’d got the relationship between the rear wheel spindle-swinging arm spindle-final drive sprocket centre lines wrong.
 
storm42 said:
Hi Mke, I was with a mate of mine at Cadwell and he was on a Spondon TZ, suffering from off throttle chatter though. horrible smelly thing it is.
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Whats "off throttle chatter" ? I started off being facitous but then thinking about it i wondered how you get "off Throttle chatter " on a TZ when the idea is to keep it on the boil 6K and above using the gearbox and clutch! It did take me a long time to crack TZ riding coming from Nortons but when I did the lap times started to fall and so did I ! there isnt a corner a cadwell ( club circuit and the mountain[twice] ) I havent crashed at. If I havent understood this chatter phenomenom please feel free to put me right !
As far as smelly things go ,In the pre synthetic days , i used to run mine on Castrol R30, nowt wrong with that smell, who doesnt like the smell of "R".
Racing again (at last)
 
Moto55UK said:
Whats "off throttle chatter" ? I started off being facitous but then thinking about it i wondered how you get "off Throttle chatter " on a TZ when the idea is to keep it on the boil 6K and above using the gearbox and clutch! It did take me a long time to crack TZ riding coming from Nortons but when I did the lap times started to fall and so did I ! there isnt a corner a cadwell ( club circuit and the mountain[twice] ) I havent crashed at. If I havent understood this chatter phenomenom please feel free to put me right !
As far as smelly things go ,In the pre synthetic days , i used to run mine on Castrol R30, nowt wrong with that smell, who doesnt like the smell of "R".View attachment 17733
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That's funny Mike. I used to get front chatter around Charlie's at the last bend and dip onto the straight. Fork damping I guess on the TZ. You can run compression and rebound damping now at the CRMC and GPOriginals clubs.
 
Castrol R can turn a good four-stroke into an instant shit-heap. I tune and ride my Seeley like a two-stroke.
 
Al you've been shielding longed than me!
If your not? Get out there & follow Ralph with a video & a write up.
On my wish list lol one go pro & a pass to come out & play.
 
Fast Eddie said:
I struggled with that for a couple of seasons once. Turned out I’d got the relationship between the rear wheel spindle-swinging arm spindle-final drive sprocket centre lines wrong.
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How far out was it Nigel?
 
I can’t recall figures Ralph, but essentially I had the swinging arm pivot too low. My hypothesis being that this allowed, under certain circumstances, the chain to be trying to pull the wheel upwards whilst the rear shocks were trying to push it down and one ended up working against the other. But thats what you get when you trying dabbling in chassis design when you don’t know what you’re bloody doing !!
 
Moto55UK said:
Whats "off throttle chatter" ? I started off being facitous but then thinking about it i wondered how you get "off Throttle chatter " on a TZ when the idea is to keep it on the boil 6K and above using the gearbox and clutch! It did take me a long time to crack TZ riding coming from Nortons but when I did the lap times started to fall and so did I ! there isnt a corner a cadwell ( club circuit and the mountain[twice] ) I havent crashed at. If I havent understood this chatter phenomenom please feel free to put me right !
As far as smelly things go ,In the pre synthetic days , i used to run mine on Castrol R30, nowt wrong with that smell, who doesnt like the smell of "R".View attachment 17733
Click to expand...

He was getting chatter off the throttle whilst tipping into corners, it didn't seem to be brake related but he fitted a new front disc anyway. The chatter was bad enough to make the bike move sideways but as soon as he touched the throttle the chatter disappeared.

He is back racing from a long time out of it but he used to ride TZs back in the day, he has been on the phone today because someone on one of the forums he frequents, has posted an old program from Scarborough and Steve Parrish was on pole, Joey Dunlop was 6th the list of names is impressive and in 26th on the grid was my mate (Steve Denman) he got back into racing last year on his RG500 but it broke and the spares are rare and slow to arrive so we talked him into buying a TZ, He found this Spondon one in the picture.

Racing again (at last)


But it has this chatter problem,
 
Fast Eddie said:
I can’t recall figures Ralph, but essentially I had the swinging arm pivot too low. My hypothesis being that this allowed, under certain circumstances, the chain to be trying to pull the wheel upwards whilst the rear shocks were trying to push it down and one ended up working against the other. But thats what you get when you trying dabbling in chassis design when you don’t know what you’re bloody doing !!
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Ah, I remember Martin at Minnovation giving me a quite specific figure for the gearbox shaft relationship to the swingarm pivot and wheel spindle centre at half suspension movement commenting that it would cause all sorts of problems if I didn't get it right. I didn't argue.
 
storm42 said:
He is back racing from a long time out of it but he used to ride TZs back in the day, he has been on the phone today because someone on one of the forums he frequents, has posted an old program from Scarborough and Steve Parrish was on pole, Joey Dunlop was 6th the list of names is impressive and in 26th on the grid was my mate (Steve Denman) he got back into racing last year on his RG500 but it broke and the spares are rare and slow to arrive so we talked him into buying a TZ, He found this Spondon one in the picture.
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Nice looking 350G/H with campagnolo wheels, definately on my lust list! Mine was a 350E with a G spec engine carbs and exhaust. The RG your friend has , what spec is it ? in the past i was very intermate with the workings of the Mk6,7&9 lovely engines . That program from scarborough dependant on the year has it got a D. Griffith listed?

All this talk of 2 strokes is getting me over excited , can someone steer this thread back to Nortons , or at least offer a cure for " 2 stroke Chatter".
 
storm42 said:
The CRMC ran its first meeting of the year last weekend and after Steves posted he was going I decided to enter. I haven't raced with this club before but as I had registered the bike with the club, game on. Bit of a culture shock though, there are some very fast riders and bikes in this club, mostly Jap multis with a few Ducatis, not really the place for a Norton but a welcome escape from the current problems.

Enjoyable weekend but not without problems. First and second practices went ok and the changes I made to the head, pistons and deck height all seem to have worked, but I managed to go out in the first session with no damping on the forks (six P's), and I was suffering from pronounced chatter in a couple of corners. The second session had the recommended settings and cured the chatter in the Gooseneck but it was still there for the first corner after the start finish straight, which is a bit quick, 3 more clicks on the rebound and wait for the timed practice.

Timed practice provided me with my best racing excuse for not being at the front. I got held up by a Jap multi for a couple of laps and when I got past, I was on my second free lap when braking downhill into Mansfield, a left hander, my left handlebar snapped off, I reckon if it wasn't for my clutch cable I would have punched the floor, most inconvenient. I was lucky to stay on and managed to stop just before I ran back onto the back straight. Anyway my one clear lap put me 28th on the grid.

A 60 mile round trip to rob a mates bike of its clip ons got me in the first race the next day, thanks Pete. First race I made up 11 places and finished 17 but first in class, although there were only 2 others in my class, but I don't care I accepted the cup and cap anyway. :)

Second race and I got a much better start from 20th on the grid but the clutch started slipping almost immediately and I think I ended up 19th just behind a GSXR 750 that I managed to pass in the first race.

I am just not in the same class as a lot of the rider in the CRMC though, so it will be back to the BHR when they start again. not that the riders in the BHR are bad, but there aren't so many Jap bikes. To put it in perspective My best lap was 1:59 and Richard Molnar did 1:42 an a Manx, still, he isn't over 60 and his dad makes the best Manx Nortons money can buy so all in all, I'm happy.

Now, can any of the racers on the board recommend some strong clip ons please?.
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Is Richard Molnar related to Andy Molnar? Andy was here in California in 1984 and joined our Pinecrest Rally in the Sierras. That’s my black ‘73 750 MkV Next to him.
Racing again (at last)
 
Moto55UK said:
Nice looking 350G/H with campagnolo wheels, definately on my lust list! Mine was a 350E with a G spec engine carbs and exhaust. The RG your friend has , what spec is it ? in the past i was very intermate with the workings of the Mk6,7&9 lovely engines . That program from scarborough dependant on the year has it got a D. Griffith listed?

All this talk of 2 strokes is getting me over excited , can someone steer this thread back to Nortons , or at least offer a cure for " 2 stroke Chatter".
Click to expand...
Don't be dull Mike, you know you want a TZ ;)
 
storm42 said:
So you have noticed that too, very diplomatic. :D
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Having read some of Andy's missives a few years ago, I would say that Andy thinks he is charge of a lot of things that he isn't!

My experience with sons is that you are never as much in charge as you think you are!

But, between them they are getting some good engineering done!
 
Moto55UK said:
Nice looking 350G/H with campagnolo wheels, definately on my lust list! Mine was a 350E with a G spec engine carbs and exhaust. The RG your friend has , what spec is it ? in the past i was very intermate with the workings of the Mk6,7&9 lovely engines . That program from scarborough dependant on the year has it got a D. Griffith listed?

All this talk of 2 strokes is getting me over excited , can someone steer this thread back to Nortons , or at least offer a cure for " 2 stroke Chatter".
Click to expand...

It may be for sale soon :)

D. Griffith was listed.

His current RG is a converted road bike, he used to have a Mk4 but says his current one is better in all areas.
 
storm42 said:
He was getting chatter off the throttle whilst tipping into corners, it didn't seem to be brake related but he fitted a new front disc anyway. The chatter was bad enough to make the bike move sideways but as soon as he touched the throttle the chatter disappeared.

He is back racing from a long time out of it but he used to ride TZs back in the day, he has been on the phone today because someone on one of the forums he frequents, has posted an old program from Scarborough and Steve Parrish was on pole, Joey Dunlop was 6th the list of names is impressive and in 26th on the grid was my mate (Steve Denman) he got back into racing last year on his RG500 but it broke and the spares are rare and slow to arrive so we talked him into buying a TZ, He found this Spondon one in the picture.

View attachment 17736

But it has this chatter problem,
Click to expand...

Can of worms here we go....chatter to me is something that happens when fully leant over, going on or off throttle may induce it.

Here you guys are talking something else, which occurs goung from upright to leant over. The picture is taken in a straight line, and I have to say that man does not look comfortable! He might consider the riding position, adjusting seat, footpegs and handlebars to accomodate him rather than the previous rider.

The issue may be related to weight transfer under braking and how smoothly he is able to apply and let off the brakes. He may also need to consider how he is using the rear brake, and if he should!

Once he has sorted that......spring rates suitable for his weight?....tyre pressures

Lots of argument going on about suitable rear shocks for genuine TZ frames, based on shock length and mounting. Spondon probably used a genuine shock at first!, but I doubt it has one on today.

All of the issues apply to Commandos or any bike.

Mystery issue on a Commando! When I raced my Fastback in the mid '70s, I could induce a hopping of the rear wheel particularly going downhill into Cadwell Park's Mansfield Corner, it went away if I tightened the chain (see Eddie's comments).
 
SteveA said:
Having read some of Andy's missives a few years ago, I would say that Andy thinks he is charge of a lot of things that he isn't!

My experience with sons is that you are never as much in charge as you think you are!

But, between them they are getting some good engineering done!
Click to expand...

Very good engineering, they seem to be buying any businesses going just now, I asked them if they had any clip ons and they sent me to TGA which they now own.
 
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