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thornton suspension

Tom Gaynor

Well Known and Active Website User
VOC Member
Thornton

Dave Molloy. Address in MPH. A minor complication is that one has to sign a "release" to keep Thornton free from liability. I imagine this is because the cost of insuring against someone spilling a cup of coffee while unpacking a Thornton and suing for zillions is too costly.

They're very, very good units. They completely transformed my bike, and allowed me to cut back on the spring weight (take one inner out of one front spring box..) without converting it into a motorised pogo stick.
 

John Appleton

Well Known and Active Website User
VOC Member
Dave Molloy. Address in MPH. A minor complication is that one has to sign a "release" to keep Thornton free from liability. I imagine this is because the cost of insuring against someone spilling a cup of coffee while unpacking a Thornton and suing for zillions is too costly.

They're very, very good units. They completely transformed my bike,

I agree with Tom, but.........The location of the rear springs within the spring boxes leaves a bit to be desired. There is no provision for locating the springs on the axis of the pivot ends,hence the springs fall to the lower side and rely on the telescopic spring boxes to hold everything in line, which they dont and wear very quickly to a razor sharp edge. I have overcome this by making up replacement alloy packing discs, in place of those provided, having a register which locates in each end of the springs and hold everything in line.
Our Dutch members have,I believe , gone one further and fixed the springs to each end similar to Vincents original design.
This critisism apart,the ride is transformed and you are very aware that the front forks are moving far more than you became accustomed to with the original springing, and comfort and roadholding is improved accordingly.
John
 

Tom Gaynor

Well Known and Active Website User
VOC Member
Thornton

The Thornton rear springs appear to be a problem, "cocking" being mentioned (and cured) by Reg Bolton among others. I retained my Petteford springs, and have had no problems.
(An idea from John Emanuel is to dispense with the Vincent rear springs entirely and use Girling springs. He says that this liberates a great deal more rear wheel movement, much of which is lost by the anchorages. I don't know what rear damper he uses, but it is an interesting idea. Particularly if one had been wondering what to do with those old Girling units that have been hanging on a nail in the shed since God was a boy...)
 

John Appleton

Well Known and Active Website User
VOC Member
The Thornton rear springs appear to be a problem, "
I would not say it is a problem, more of a minor hitch which could easily be rectified in the manufacturing. It is easy to overcome if you have access to a lathe, but I cannot see why you should have to. The improvement in ride is well worth the trouble and I feel more at ease with matched dampers front and rear, although I doubt I ever ride to the point where mismatch would be an issue.
We have another bike we are building at the moment, and have fitted it with Avo adjustable suspension units of a similar type to those fitted by Tim Welsh and Russ Kemp. I hope we can report back on their performance in due course. These are particularly interesting as a comprehensive range of spring rates are readily available.
John
 
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greg burt

Well Known and Active Website User
Non-VOC Member
springs

Laney Thornton has a Mono Shock on the rear of his Rapide, He told me, He modified the rear of the oil tank to fit it.
There is a bloke here in NSW (OZ)with a sidecar,runs a Spax Mono Shock on the rear , and can still fit the tool tray and NO MODS to the oil tank.
Greg:)
 

Tom Gaynor

Well Known and Active Website User
VOC Member
Rear suspension

Greg: some questions: hope you don't mind giving answers. Does the guy who runs the Spax have a series B, C, or D? (I guess B or C...) Is it what is apparently called "a spring-over" unit, i.e. damper and spring together in one unit? And the $64,000 question, what bike was it originally intended for?
Thanks for a very thought-provoking post: I can get a spring-over unit from any scrap yard for about 2d, and it might liberate a few more inches of rear-wheel travel. (My Ducati Monster has an almost unbelievable 10" of travel, only discovered when I realised that what was hitting the underside of the rear number plate was the tyre...)
 

greg burt

Well Known and Active Website User
Non-VOC Member
shock

G'day Tom
Series C, Spring over shock,with a couple of Dials to adjust rebound etc.
I dont know what it was mean't to fit, The bloke who owns it told me to get on the Spax Site ,but I could'nt find any thing and I have'nt seen Him for a while to pick his Brain again, It seems to work OK, He sure punches this out fit along
with a 1200 RTV Power plant.
Greg:)
 

Pete Appleton

Well Known and Active Website User
VOC Member
VOC Forum Administrator
suspension without springs

No I don't see how you could use these units as just a damper, without some major surgery. If you follow the link and look at the drawings you will see that they are quite bulky and wont easily fit between the existing spring boxes. You would also lose the benefit of the adjustable spring pre-load.

Pete
 

vin998

Well Known and Active Website User
VOC Member
VOC Forum Moderator
If you only want to use the Avo damper, you could use http://www.avouk.com/pm/29.
I fitted one to the front of my C rapide and it was a vast improvement over the worn out Vincent item. You need to modify the top eye though by reducing its width to fit the top link. I used the TA 100/075.
It can be also fitted to the rear, but the eyes need a lot more modifying to fit. Don't forget any modifications at all to the dampers invalidates the manufacturers warranty.

Cheers,
Simon.
 

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