Norvil Head steady...worn out...fix?

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Hi Plj,
Is the Hmm a bit disaproving about my comments 'the original design being rubbish'.
All it was is 2 exhaust mounting rubbers attached with a couple of flat plates which gave movement in all directions.
Even when new the bike handled like a camel with arthritus when going round tight bends, not like my good old featherbed Atlas.
The latter Mk 3 & Norvil ones were better but I think still with room for improvement.
I had better not mention that I have a Mikuni Carb, Japanese Master cylinder & chinese wing mirrors.
The wing mirrors are brilliant, £10 a pair second hand from Startwright Roptary Specialists in Leeds.
Now i'm in real trouble. Wish I had a fake name.
 
Hi plj,
Yes ive got the spring on mine.
I tried it without the spring & with it.
It does seem a little better with the spring as it gives the whole thing a bit of taughtness & flexibility.
I had the spring too tight at first & it seemed to let the vibration through but when I slackened the spring a bit I came to a nice balance between better handling & smoothing out the vibes.
I'm very pleased with the Dave Taylor head steady overall.
The isolastic vernier adjusters are also very easy to adjust compared to the old shimming method.
Cheers Don
 
Don Tovey said:
Hi Plj,
Is the Hmm a bit disaproving about my comments 'the original design being rubbish'.
All it was is 2 exhaust mounting rubbers attached with a couple of flat plates which gave movement in all directions.
Even when new the bike handled like a camel with arthritus when going round tight bends, not like my good old featherbed Atlas.
The latter Mk 3 & Norvil ones were better but I think still with room for improvement.
I had better not mention that I have a Mikuni Carb, Japanese Master cylinder & chinese wing mirrors.
The wing mirrors are brilliant, £10 a pair second hand from Startwright Roptary Specialists in Leeds.
Now i'm in real trouble. Wish I had a fake name.
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Hi Don certainly not!! sorry for the confusion its just this thread was re-started from a previous thread that became a bit acrimonious, the original head steady as you say was rubbish actually laughable :) except when you had to ride the damn thing at speed around corners i referred to it as handling like a "pig on rollerskates". I had an 88 Dommie now that handled could scrape the pegs easy on that (wideline). I have a 38 Mikuni the Norvil head steady i used for ages but had design faults which meant it needed loads of work or the side plates bent!! As you can see from my pic I am no purist my 74 Commando is used all year round and has been for 28 years so whatever works I will use, sorry for the misunderstanding if you go to the start of the thread and work through you will see redrider something or other bringing up his 'improved' DT style head steady then search the forums and find another long thread with the same arguments....

Have to agree about the vibes not dropping off till 3000 or so I spent ages adjusting the spring thing riding a bit for everything to settle down then re-adjust finally got it down to 2750 or thereabouts. The Norvil type didn't give me a tingling vibe in the pegs though...
 
Don Tovey said:
Ive got the Dave Taylor head steady on my 72 interstate now instead of the original rubbish effort designed by Norton (sorry Norton designers)
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The original design AFAIK was three isos of which the top one was dropped due to cost. There is a lot of wrong stuff written about the Commando story but this would actually make sense. From an engineering POV the idea behind the sliding guides is only correct with three nicely space mounts.

ps, ive just noticed this is actually an old thread but has been replied to again recently.
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Yes, my fault - Swooshdave had a link to this thread in his recent HS related question and I didn't notice the date until after I posted -sorry for that.

Anyway if you don't mind I'd like to explain what I don't like on the DT head steady and why I was slightly anoyed by the Redrider version and how he presents this.

First of all I actually am an engineer and since about five years I'm working in motorsports mainly, I'm doing automotive stuff for about 12 years by now. I've been involved in the design and calculation of structural parts for vehicles the average lap speed of which is substantially higher than top speed of a good race-ready Commando. So thanks, Redrider, for proving the point of "arrogantly accusing critics of nescience".

So, what did I mean with "bullshit" regarding these head steadies: It's the way the HS forces are fed into the frame. A clamp is a good design for a satelite dish holder on a balcony but has absolutely no justification on chassis parts. None whatsoever, zero, nada, niente.... In itself it is an unnecessary stress raiser on the tube but in this special case it is also mounted at a bad position. To feed forces into a tubular structure a mount should be as close to a node as possible and certainly not in the middle of the tube. This is a well know basic in space frame design. The calculation Redrider asked for this is pretty simple - it's just the comparison of the bending moment in the reinforcement tube which is a function of the leverage around the next nodes (with all other parameters sufficiently equal). Here the original (reinforced!) Norton design is not perfect but way better than the TTC-HS.

The claimed "function of one's interest in properly measuring and adjusting the vertical alignment of the motor/swingarm assembly." doesn't really impress me as well. First the male-female arrangement of the Taglieri-derivatives is adjustable within roughly half the pitch of the rod ends which is already pretty good and most likely sufficient. Secondly: I'd strongly assume that the "vertical alignment" of the Commando drivetrain is NOT constant enough to gain very much from this advantage simply because of the hysteresis of the Iso-shims setup. And just from a practical POV: A male-female setup can't unscrew itself, a LH-RH setup can. Been there, done that, no shirt. And the fact that a design has worked for whatever mileage proves actually one point only - that it basically works. Not that it is good....

Third and final point: Isos vs. Rods in general. The isos are planar sliding guides, rods are spherical. Rubbers support the weight, rod's don't (well, not at that angle). From an engineering POV I'd prefer three isos with detail improvements on the guides over these mixed designs. Or as I said before a setup with three rubbers and four (!) parallel rod-ends of equal length. However when I last mentioned this somebody answered that this is nice in theory but the Commando frame flexes quite a bit - and I have to admit that I agree..... :wink:

That's it for me regarding this so if this thread RIP - fine by me.... :roll:


T
 
Tintin said:
The original design AFAIK was three isos of which the top one was dropped due to cost. There is a lot of wrong stuff written about the Commando story but this would actually make sense. From an engineering POV the idea behind the sliding guides is only correct with three nicely space mounts.





Anyway if you don't mind I'd like to explain what I don't like on the DT head steady and why I was slightly anoyed by the Redrider version and how he presents this.

First of all I actually am an engineer and since about five years I'm working in motorsports mainly, I'm doing automotive stuff for about 12 years by now. I've been involved in the design and calculation of structural parts for vehicles the average lap speed of which is substantially higher than top speed of a good race-ready Commando. So thanks, Redrider, for proving the point of "arrogantly accusing critics of nescience".

So, what did I mean with "bullshit" regarding these head steadies: It's the way the HS forces are fed into the frame. A clamp is a good design for a satelite dish holder on a balcony but has absolutely no justification on chassis parts. None whatsoever, zero, nada, niente.... In itself it is an unnecessary stress raiser on the tube but in this special case it is also mounted at a bad position. To feed forces into a tubular structure a mount should be as close to a node as possible and certainly not in the middle of the tube. This is a well know basic in space frame design. The calculation Redrider asked for this is pretty simple - it's just the comparison of the bending moment in the reinforcement tube which is a function of the leverage around the next nodes (with all other parameters sufficiently equal). Here the original (reinforced!) Norton design is not perfect but way better than the TTC-HS.

The claimed "function of one's interest in properly measuring and adjusting the vertical alignment of the motor/swingarm assembly." doesn't really impress me as well. First the male-female arrangement of the Taglieri-derivatives is adjustable within roughly half the pitch of the rod ends which is already pretty good and most likely sufficient. Secondly: I'd strongly assume that the "vertical alignment" of the Commando drivetrain is NOT constant enough to gain very much from this advantage simply because of the hysteresis of the Iso-shims setup. And just from a practical POV: A male-female setup can't unscrew itself, a LH-RH setup can. Been there, done that, no shirt. And the fact that a design has worked for whatever mileage proves actually one point only - that it basically works. Not that it is good....

Third and final point: Isos vs. Rods in general. The isos are planar sliding guides, rods are spherical. Rubbers support the weight, rod's don't (well, not at that angle). From an engineering POV I'd prefer three isos with detail improvements on the guides over these mixed designs. Or as I said before a setup with three rubbers and four (!) parallel rod-ends of equal length. However when I last mentioned this somebody answered that this is nice in theory but the Commando frame flexes quite a bit - and I have to admit that I agree..... :wink:

That's it for me regarding this so if this thread RIP - fine by me.... :roll:


T
Click to expand...

tin
you have pointed out the same reasons that I went round and round with redrider on his BS claims. I have NEVER liked the clamp on the top tube nor the TALL stand off on the cyl head bracket. he also wants to put a twisting load on the other iso's to try to correct a misalignment issue that WILL change the clearance top to bottom on the abutments to ptfe washers IMHO not the thing to be doing. I was the one that brought up the spaghetti swingarm and frame and it is a FLEXIE FLYER frame by any standards. if he thinks he can sell an improved CNC front rod kit compared to my COBBY work more power to him but I NEVER claimed ANY handling improvements from my parts, just less maintenance on the front mount ass. and a stronger headsteady than stock or the DT unit.

windy
 
Tintin said:
Yes, my fault - Swooshdave had a link to this thread in his recent HS related question and I didn't notice the date until after I posted -sorry for that.
T
Click to expand...

I'll be glad to take the blame for a good rant. :mrgreen:
 
I say we all gather at a club racetrack, pay for the day's track rent, and duke it out with the best bikes taking bragging rights and the losers going home with thier mouths shut!
 
grandpaul said:
I say we all gather at a club racetrack, pay for the day's track rent, and duke it out with the best bikes taking bragging rights and the losers going home with thier mouths shut!
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Can we discuss something else now I am getting a headache....... :roll: :roll:
 
How are we ever going to bury this thread if people keep contributing to it?

Sorry...couldn't resist :oops:
 
B+Bogus said:
How are we ever going to bury this thread if people keep contributing to it?

Sorry...couldn't resist :oops:
Click to expand...

Please,Please STOP.......................................................... :oops:
 
grandpaul said:
plj850 said:
Can we discuss something else now I am getting a headache.
Click to expand...

Sure, start another thread.
Click to expand...

I did but nobody answered it was about the P10 being fitted with a Reed Valve Main Breather...thought it was interesting considering that this was a design from 1965.
 
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