Dave Taylor Headsteady

grandpaul said:

... With those three means, an acceptable alignment can be obtained.

Again, this isn't for all-out racing, and my butt is nowhere near that fine-tuned.

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Well, the question then is, what are you aligning? The only value of adjusting the link length is to either achieve zero preloading, or to achieve proper vertical alignment of the motor, thus the rear wheel. The only way to get the later on the DT unit is to fully shorten the link length provided (by screwing the male end fully into the female end), which results in a remaining vertical misalignment of approx. .25" (measured at the top center of the motor head to the frame mounting point) on any given stock Commando frame. The head steady "alignment" is a measure of the verticality of the rear wheel - not the motor. If this misalignment is not noticable, then the much studied variations in isolastic gap settings ranging from .010" to .0015" is surely not noticable, nor a factor in affecting improved or diminished handling. At the same time, it is impossible to measure the misalignment, then determine the adjustment needed, then undo the DT unit, then reset the clamp or link length to a "guess" position, and then reinstall it to its former position from which the measurements were taken. At best, this is a Sisyphean task designed to frustrate any reasonably motivated mechanic. What's really interesting, is that with just a bit of study and effort, a remarkable improvement in handling and vibration is so easily achieved with the application of the appropriate equipment; and one need not be a racer to appreciate the absence of vibration and a truly predictable ride through the twisties.

Jeandr said:

What does this say about a micro alignment of the head steady :?: Sometimes good enough is just that, good enough....which BTW is the way HD does it)

Jean

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Interesting points. I guess if that mechanic & rider's experience is good enough, then everybody in racing, manufacturing, and maintenance should be following that satisfying scientific method!

As to the Commando in particular, the same concept really does hold some sway. This is why its a precarious path to add new technology to this old machine, or to partially alter the original geometries of frame, wheel, suspension, etc. as the range of tolerances among the designed whole do tend to balance each other out and result in a well balanced machine. That said, I'm sure that rider you reference would agree that the proof is in the pudding. I didn't set out to perfect an alignment because my ride was acceptable, nor because I'm a perfectionist bench racer. I am a rider. And, as such, I recognized the imprecision in the ride, the handling, the tracking, and the resulting "accepted" level of vibration on my, and others, bikes; and then set about to find a way to EASILY improve all of these less than acceptable characteristics. Surely, this is an unimportant discussion and trivial process for those who are satisfied with their current bike's handling. But, for those who are interested in improving it, it is a rewarding process to engage.

Regarding the application of the heim link to the lower mounting points. That's a fine solution for controlling vibration, and reducing lateral movement, but they are the wrong locations for controlling vertical alignment, and it cannot fix the inherent flaw of the Commando frame. Last week, I met a gent who owns one of the original Dreer modified Commandos. He looked at the TT Head Steady, and said, Yes, that's how Kenny addressed the problem on his original bikes! I think Keith's, or Dave Winship's, or Mike Taglieri's setups are similarly effective. I just happen to like the clean, simple results, both visual and technical, of the TT Head Steady. Surely, others seem to disagree.

I am not saying misalignment is what is desired, but It would have been nice if you had done some tests (did you???) instead of relying on seat of the pants impressions. Like taking a slalom course and seeing the speed of the bike measured with a data logger, both with a stock setup and with your head steady dialed in correctly, then your customers or future customers could justify the expense. Right now the only argument (to me) is that it looks good and has some means of adjustment to accomodate different frames. The adjustment argument falls flat if I build my own because it will be made for MY frame.

It is good of you to promote your product, I wouldn't have known about it any other way.

Jean

Jeandr said:

I am not saying misalignment is what is desired, but It would have been nice if you had done some tests (did you???) instead of relying on seat of the pants impressions. Like taking a slalom course and seeing the speed of the bike measured with a data logger, both with a stock setup and with your head steady dialed in correctly, then your customers or future customers could justify the expense. Right now the only argument (to me) is that it looks good and has some means of adjustment to accomodate different frames. The adjustment argument falls flat if I build my own because it will be made for MY frame.

It is good of you to promote your product, I wouldn't have known about it any other way.

Jean

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I guess I'm a student of the Gus Grissom school of seat of the pants testing. Those I ride with have seen the results. Sorry, I don't have the facilities to test to the standards you seem to demand; must be a function of the data-over-experience times we live in. With several thousand miles logged on each of the five principle types of steadies out there, I'm rather comfortable with my findings. If I may, your understanding of the alignment issue may be incomplete. The fact is that ALL Commando frames are inherently misaligned. That's not my discovery; that is a known fact among those who've studied the subject, and many frames, ever since they were in original production. It's not a matter of you building your own steady and thus removing the misalignment; it is a matter of correcting for the misalignment that occurs in the assembly of subframe to frame. If you can construct your own steady and accommodate the particular misalignment on your particular frame, then you will have performed the entire frame reengineering process; more power to you. As I stated, the purpose of the adjustable steady is to provide a less intensive method for solving the problem; and one that can accommodate wear and future readjustment.

It's interesting how the concept of sharing an idea, or questioning an established assumption, provokes such hostility. Don't believe me, just study the subject yourself and come to your own conclusions. I frankly couldn't care less if someone prefers to stick to their own beliefs. For those with an open, analytical mind, let's see what they have to offer on the subject.

RedRider1971 said:

grandpaul said:

... With those three means, an acceptable alignment can be obtained.

....The only way to get the later on the DT unit is to fully shorten the link length provided (by screwing the male end fully into the female end), which results in a remaining vertical misalignment of approx. .25" (measured at the top center of the motor head to the frame mounting point) on any given stock Commando frame.

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Is this to say the link on the DT head steady cannot be made short enough to be aligned properly? Wonder why they would do that, wouldn't it just be a matter of moving the attachment point and making the link a little longer? Now I'm curious to see how mine fits.

littlefield said:

Is this to say the link on the DT head steady cannot be made short enough to be aligned properly? Wonder why they would do that, wouldn't it just be a matter of moving the attachment point and making the link a little longer? Now I'm curious to see how mine fits.

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That is the case. Of course, then you will find the tower is too tall to fit within the tight confines of the tank tunnel. If you look into the unit's history, you will see that the original design included an adjustable tower on the head base. I can only assume, from my work, that a decision was made to fix the tower location on the innermost position; perhaps due to fit issues confronted among the various tank tunnel configurations, as well as cost of production concerns. At the same time, the link was reduced to a male into female arrangement, versus a turnbuckle interlink, further reducing the cost of production. As a result, the shortest possible attainable length on the rod remains too long to achieve proper vertical alignment. Given the method and cost of production, it will require a remodeling of that unit to resolve this issue. That is precisely what led me to do it myself.

I must be one of the lucky ones because I don't detect any problems with the fit and alignment of the Taylor steady on my Andover replica frame. I bought it with an open mind and because I fancied trying it. If it had not been a substantial improvement, one or other of the spare steadies that I have lying around would have gone back on, possibly the even more expensive Norvil type that I had been using. I don't have a problem with owning up to my mistakes, expensive or otherwise, but this wasn't one of them.

There was absolutely no high pressure selling from RGM, just friendly service which I find far preferable to the encyclopedia or religion door to door selling methods.

I think that it is useful to discuss strong and weak points of components on an open forum but I find it rather extreme to suggest that the Taylor steady should be thrown in the scrap bin. I shall certainly not be doing that.

I have absolutely no connection with the suppliers of any of these parts.

79x100 said:

I must be one of the lucky ones because I don't detect any problems with the fit and alignment of the Taylor steady on my Andover replica frame.

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Your situation then is a good one to ask about. When you refer to alignment, what are you aligning?

Mark - What criteria do you use for vertical alignment? How do you determine that the rear wheel is "vertical"?

This is coming back around to another thread where I eventually added my two cents: I have seen VERY FEW instances where a Norton Commando rear wheel/tire was framed exactly in the centerline of the frame. As it happens, my 880 is perfectly centered. I'll attribute that entirely to the fact that I am running Kenny Dreer's VR880 tranny cradle which was designed to minmise the offset, and zero it out with the adjustable isolastics.

I would think that a few critical measurements and some minor machinework on the isolastic root tubes should easily negate that entire situation on ANY stock Commando chassis setup.

Just a bit further on, I hope none of my replies on this thread have been construed as hostile; anyone who knows me knows that I am anything but that.

ludwig said:

Ok , I said that I would not react , but I guess I just can’t resist .
1.why a clamp , while you already have a perfect fixing point in the threaded cross tube of the original head steady ?
( I find RR's expanation about adjustability not convincing )
2.the max amplitude of the vibration is less than 2 mm .Using rose joints to control this is technological overkill .

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What are the other options?

[quote
5.The job of a headsteady is essentially to allow free movement in a vertical plane , and limit lateral movement to a preset value .
Damping , friction reduction or a compensating spring are optional .
This goal can easily be achieved by a simple strap of steel bolted to the head ; held in check by a U- shaped clamp on the frame , or something similar , using the existing fixing points .
Ok , maybe slightly more complicated , but anybody who can drill and weld , can make it in an afternoon for less than 5 dollars material cost .[/quote]

Ok, with the "simple strap of steel" how are you allowing for movement in the vertical plane?

Like Ludwig, I wonder about using the head steady to correct mis-alignment of the rear wheel. When I got my Commando, one of the legs of the swinging arm was higher than the other, which resulted in a cocked wheel. I straightened the arm and checked it with a bar through the rear wheel spindle slots and the swinging arm spindle mounted on vee blocks. I had to rebuild the wheel to the correct offset, which was 1/8" to the left. It is now vertical and the centre line of the rim is on the centre line of the frame. The ends of the rear isolastic tube are now flat. The old rear iso mount had deformed, which resulted in the engine/gearbox being canted in the horizontal plane. The new iso mount has corrected this. Correct me if I'm wrong, but is this not a better way to solve alignment problems than using a DT-type head steady to align the rear wheel? I have used some of Dave Taylor's basic design for my own head steady, which mounts to the frame via the threaded cross tube and it works. That said, Redrider's head steady looks like a fine piece of machine work.

Jean — what do you mean when you say '"... Jim's idea for the lower isolastic"? And how exactly does HD do this? I've never looked at a modern HD close up.

Since this thread is about Dave Taylor Head steady I'll take the opportunity to add my 2 cents.

I installed it about a month ago. I have a metric frame and use a stock shim to take up the clearance for the clamping device on the lower frame tube. Works fine an feels very solid.
At present the vibration signature is very much as the original head steady, vibrations up just above 2000 rpm and "nothing" above 2500 rpm, without doing much tuning at all.
The BIG difference is in handling, the bike is significantly better with (what I've noticed so far) no negative side effects. Much more stability and cornering feeling.

For me this is a one of the best upgrades I have incorporated on my bike.

Cheers,
Per

RedRider1971 said:

79x100 said:

I must be one of the lucky ones because I don't detect any problems with the fit and alignment of the Taylor steady on my Andover replica frame.

Click to expand...

Your situation then is a good one to ask about. When you refer to alignment, what are you aligning?

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A good squint with the old Mk1 eyeball, a straight edge and a length of string.

With the Taylor clamp set in a neutral position, my motor seems to be upright and in line.

I am happier with the idea that the isos are not pre-loaded in one direction. Had that been so, I think that I would have tried to solve that rather than pushing or pulling with an adjustable cross-rod. It may well be that the quality control on these 1990s small batch Andover frames is better than when they were being thrown together in their thousands.

The proof for me is that I can now ride hands-off for the first time with this frame and can relax on Belgian rain-grooves (Ludwig will know the stretch between Brussel and Leuven).

ludwig has now inspired me to copy his design in a manner that I am able to; I have no machining skills, but I DO have welding skills! My Interstate will benefit from the simplest (and cheapest) of designs I have seen to-date. I suppose the biggest hurdle for me will be measuting my chassis as precisely as possible with limited means, and building my steady to best compensate for the typical misalignement in Commando frames. Certainly I could re-work the lacing on the rear wheel to help correct the fractional offset.

maylar said:

Mark - What criteria do you use for vertical alignment? How do you determine that the rear wheel is "vertical"?

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I came across this article some years back;http://www.motorcycle.com/how-to/chassis-alignment-basics-3444.html

it's a good summary of frame and wheel alignment basics. In it Rob describes a very effective method for measuring the variation between front and rear wheel alignment. I"ve applied this method to my bike before and after the head steady work. For me the proof is in the numbers, and then the handling. With regard to measuring on a Commando, one has to fully understand the isolastic system with subframe. You cannot accurately measure alignment unless the frame is suspended, or not resting on the subframe (centerstand). My method is as follows: Working from a Handy Lift, I hang the frame from a overhead winch (skyhook). I level the frame by measuring plumb across the rear downtube abutment at the backbone. I then align the front and rear wheels via a circular string drawn around the front and rear wheels (I won't go into the full process on this right now). Once the frame is plumb, and the wheels are properly aligned on the horizontal plane, I then drop a fine thread plumb line over each wheel, setting the line against the face of the wheel rim (I have Akront flanged wheels, so this is a precise surface to work from). With a plumb line suspended from the front and rear, and checking that all references are correct for level frame, and straight wheel alignment, I can then compare the angle of the dangle from front to rear wheel. With the TT Commando Head Steady, or any other head steady with an adjustable link, I can dial in the head/frame/rear wheel assembly into perfect vertical alignment.

Thank you for asking the essential question. I hope this is helpful. There may be other methods for getting straight, but this one works very well, and is not very complicated once done a few times.

Really, I think the only essential difference between this and Ludwig's approach is that I don't believe there is any adjustability in his devise. Mechanical things being what they are, they tend to wear over time and need adjustment, just like the suspension and wheels on a car!

maylar said:

Mark - What criteria do you use for vertical alignment? How do you determine that the rear wheel is "vertical"?

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I didn't give you the best link, try this one. This is the alignment process, that when I did it on my Commando with other head steadies, I could not achieve "perfect" alignment. This realization is what led me to make my own ADJUSTABLE unit. I'm not a compulsive or anal retentive sort, but - improved precision in my motorcycle is indeed something I continue to strive for. Both the process and the results are very satisfying.

http://www.rg500delta.com/RG500_chassis ... 0part1.pdf

On further thought, I don't think Ludwig's solution provides comparable lateral control to a heim link. Sorry Ludwig, your solution is simple, but not precise enough for me, and I just don't see how it will accommodate future adjustement as normal wear takes place and things need to be maintained. (No offense intended.)

ludwig said:

Ok , I said that I would not react , but I guess I just can’t resist .
1.why a clamp , while you already have a perfect fixing point in the threaded cross tube of the original head steady ?
( I find RR's expanation about adjustability not convincing )
2.the max amplitude of the vibration is less than 2 mm .Using rose joints to control this is technological overkill .
3.an adjustable link to correct the vertical alignment of the rear wheel ??
if the rear wheel is not in the same plane as the front wheel , that is because of faults in the the frame , engine cradlle , or swing arm .
If you can’t live with that , correct it .
It seems silly to me to put a lot of torsional load on the isolastic system , in order to compensate for a warped swingarm ( and many are ) .
4. sidenote : by using an undamped system like a DT , even more stress is put on the exhaust system .
The way the mufflers are fixed to the frame is an engineering mistake .
The entire system should be bolted to the engine cradlle to prevent cracking .
5.The job of a headsteady is essentially to allow free movement in a vertical plane , and limit lateral movement to a preset value .
Damping , friction reduction or a compensating spring are optional .
This goal can easily be achieved by a simple strap of steel bolted to the head ; held in check by a U- shaped clamp on the frame , or something similar , using the existing fixing points .
Ok , maybe slightly more complicated , but anybody who can drill and weld , can make it in an afternoon for less than 5 dollars material cost .

Click to expand...

Ludwig, I shall try to respond to each of your points:

1) The geometric orientation of the heim link doesn't lend itself to connecting to the existing threaded holes without having to fashion a more complicated connection. The clamp is very simple and very effective. With this approach, an adjustable armature is created which can be placed as necessary to properly align the plane of the heim link to the plane of the motor and frame; as the length of the link varies, so too must its connection point to the frame in order to retain proper alignment; thus the rotating armature is the simple approach.

2) That's a straw dog argument. The heim is designed to accommodate a small amount of movement, just as you've measured. Read the specifications of a heim joint and you will see that this is precisely the appropriate application for the devise.

3) You are grappling here with the essential facts of the isolastic system as applied to the Commando frame. This is precisely why an adjustable method for aligning the motor/frame/wheel assembly is necessary for precise vertical wheel alignment.

4) Damping occurs via the two lower isolastic units, quite obvious really. The head steady accommodates the resulting up and down movement - no stress, just simple motion.

5) The preset value for lateral movement with a heim joint is exactly zero (0.0000) That is why they are used in aviation applications, including helicopters, and other critical moving situations that require movement in a precisely controlled plane. I don't see any value or need for the MK 3 suspension spring and therefore don't use it or recommend it. It's basically complex and superfluous.

Your suggestion for using a simple strap of steel bolted to the head seems contrary to all the points you've raised, such as damping, stress, torsional load, and so on.

Sidenote - My bike uses the original 750 headers, and all the standard hanging brackets. There has never been a failure due to stress cracks, or any other type of failure. Suspending the headers/mufflers on rubber grommets is the logical extension of the isolastic system. Some wiser Triton and other custom bike makers have borrowed those parts for precisely the same reason - to isolate vibration and reduce failure due to stresses. Bolting the system to the engine makes no sense at all, but maybe I'm missing something there.??

The notion that a better system is one that is cheaper to make reminds me of the guys here in the USA who wear these little beany helmets. As some of us are prone to observe, Five dollar helmets for five dollar brains. Just my opinion.

Mark

daveh said:

Correct me if I'm wrong, but is this not a better way to solve alignment problems than using a DT-type head steady to align the rear wheel? I have used some of Dave Taylor's basic design for my own head steady, which mounts to the frame via the threaded cross tube and it works. That said, Redrider's head steady looks like a fine piece of machine work.

Jean — what do you mean when you say '"... Jim's idea for the lower isolastic"? And how exactly does HD do this? I've never looked at a modern HD close up.

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I think you are not wrong, and you are, I think, almost entirely on the right track. The goal, ultimately, is simply to have your front and rear wheels truly "aligned". It's only by virtue of the complicated and interdependent nature of the isolastic Commando frame that the head steady takes on a particular importance because it is indirectly connected to the rear wheel. Of course, you could do away with it entirely, as Dreer, and others, have done by locating an alternative lower placed third (triangulated) mounting point. Again, the simple point here is to get the wheels vertical and aligneded. Once done, we can move on to caring for all the other critical components of the bike's suspension, and applying remedies for their known weaknesses - internal flexing of the swing arm, movement of the swing arm spindle, flexing of the front forks, shortcomings of the Roadholder dampers, importance of balanced front and rear suspension damping, foremost among them. Like any machine, all these parts are interdependent and strength or weakness in one component will affect another. Fixing just one of these components will not result in "fixed" handling. As some say, perhaps good enough is simply good enough for some of us. For others, the fun is in the pursuit of "best" handling. The nice thing about all this modern interest in Commandos is that there are truly excellent remedies for all these conditions.

Last point here. Having an adjustable head steady on a Commando is no different than having adjustable shocks, adjustable suspension, adjustable tie rod ends; for that matter, adjustable valve clearance, adjustable timing, and so forth on any vehicle that is designed to perform well and endure the rigors of roadway use.

Red rider, All this talk about wishing to share technical knowledge in an open and frank manner doesn't convince me. Your first post was simply an advert for a product, subsequent posts seem merely an attempt to move the dialogue away from this demonstrable fact. You disparaged the original product from which it was copied telling readers to dump it in the bin and making disrespectful comments about others who made genuine comments - putting the words "with respect" at the end of a sentence doesn't mitigate any insult at all.

You seem to assume that you are the only one in the world who knows anything about the Commando isolastic system and frame geometry. Furthermore as justification for your activities you quote Jim Comstock and his open attitude to enthusiasts copying his work "for their own use", However you omit that Matt Rambow from CNW was particularly ticked off - quite rightly in my view - and at pains to point out that he wasn't happy about people copying for commercial gain something that CNW had spent time and money developing.

Your claim of expensive CAD CAM and CNC programs doesn't hold water as the head bracket and other parts of the assembly seem identical copies of the Dave Taylor unit.

If the Dave Taylor headsteady was patented I have no doubt that you would be in contravention of this patent. You are essentially selling someone else's intellectual property. No talk of cottage industry and keeping the home fires burning disguises this fact.

With respect.

Dave M