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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Mon Jan 23, 2006 10:25 pm Post subject: AVO Shockers |
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Has anybody fitted a set of Club supplied AVO shock absorbers? If so Would you help me out with spring rates and free length. I have done a few fag packet calculations and can see problems looming.
Are you there Alan Farrar?
Dave-M _________________ Ph.2 Ford 1500 GT
GT with Rochdale Chassis |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Thu Feb 16, 2006 11:23 am Post subject: |
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Ok, No takers.
Since I asked the above question I have been doing a little research and come up with the following. This is all based on using ROC supplied AVO dampers.
For a firm sporty ride with the accent on performance:-
Front springs 110 lb/in rate and free length of 10 in
Rear springs 150 lb/in rate and free length of 10 in
For a less firm and gentler ride:-
Front springs 100 lb/in and free length of 11 in
Rear springs 120 lb/in and free length of 11 in
The front suspension will have The following travel at the wheel
Front Total travel :- 4.2 in (2.7 bump & 1.5 rebound)
Rear suspension travel:- 5.6 ( 3.5 bump & 2.1 rebound)
The above information is derived from Alan Staniforths Race and Rally car source book.
I knocked up a spreadsheet to make things easier and quicker for me.
The calculations are based on the natural frequency of the suspension which is the common parameter between all suspension systems and lets you compare different cars easily to determine the ride quality you can expect. It does not determine the handling characteristics, just the correct spring selection and suspension travel.
Information used in the calculations is as follows:-
Corner weight, unsprung weight, suspension leverage, spring fitted length at normal ride height and damper travel available.
I am sure there are many knowlegable people out there, Keith Hamer and Alan Farrer being two names that spring to mind, And I would be grateful for your observations on the above as I am just about to assemble my suspension and would like it as near to right as I can get it.
Regards
Dave-M |
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MMcKays Registered User
Joined: 06 Feb 2006 Posts: 9
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Posted: Wed Feb 22, 2006 11:53 pm Post subject: |
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Dave, I can't help I'm afraid but I'm very keen to hear how you get on!
Richard Parker's ethos with the Olympic was very much to go for softish long-travel suspension with firm damping, giving a good ride/handling compromise, so I'd be inclined to try your softer option first. I know a lot of people in the past have gone too hard and had to soften their suspension later. I guess a lot depends on the working angle of the suspension units and how much/little it varies from full bump to full rebound, too, plus whether it's restricted, or its spring rate increased, by other components such as metalastic bushes, by imperfect suspension alignment, etc...
Malcolm |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Thu Feb 23, 2006 12:41 am Post subject: |
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Malcolm,
I think that the problem MAY be that the AVO's supplied by the club have less travel than the original Triumph? based units and to contain the travel and maintain a sensible bump and rebound will need springs of the order mentioned.
I seem to remember my Olympic being quite stiffly sprung as compared to the baby elan I had at the same time which would figure if the original springs were from the heavier Triumph Herald?
Hopefully this summer we will see if Mr Staniforths calculations work out
Regards
Dave |
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keith hamer Site Admin
Joined: 28 Jan 2006 Posts: 312 Location: Ellesmere Port
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Posted: Sat Apr 29, 2006 12:21 am Post subject: |
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Sorry to make light of your plee Dave, just had to do it! I have just got my name mentioned against 'all' the topicxs in the forum........... Hmmmmmmmmmm |
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calex_fr Registered User
Joined: 18 Jul 2008 Posts: 408 Location: Champagne (France)
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Posted: Thu Aug 07, 2008 1:28 pm Post subject: |
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Dear Misters,
where can I find 4 springs for AVO for a firm sporty ride with the accent on performance ? _________________ Alexandre Contat
from France |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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calex_fr Registered User
Joined: 18 Jul 2008 Posts: 408 Location: Champagne (France)
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Posted: Tue Sep 30, 2008 2:32 pm Post subject: |
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Thank you, prices are very interesting !
But in first I want club answer about AVO ans stenless springs....
I am waiting... _________________ Alexandre Contat
from France |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Tue Sep 30, 2008 2:56 pm Post subject: |
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I do not think stainless steel is very good for use in springs, others may disagree but I certainly would not use them.
Are they the right length and rate?
are they the corret diameter for AVO shockers, ie 2.25" ID.
Regards
Dave _________________ Ph.2 Ford 1500 GT
GT with Rochdale Chassis |
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calex_fr Registered User
Joined: 18 Jul 2008 Posts: 408 Location: Champagne (France)
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Posted: Tue Sep 30, 2008 3:04 pm Post subject: |
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I share your opinion, and I ask all these questions which the club has made no response. _________________ Alexandre Contat
from France |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Tue Sep 30, 2008 4:57 pm Post subject: |
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I suspect the stainless springs are the original size and they will not fit the AVO dampers
Regards
Dave _________________ Ph.2 Ford 1500 GT
GT with Rochdale Chassis |
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Dave-M Registered User
Joined: 20 Jan 2006 Posts: 377 Location: Yorkshire, England
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Posted: Tue Sep 30, 2008 5:09 pm Post subject: |
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Can you post them here? I would be most grateful.
Dave _________________ Ph.2 Ford 1500 GT
GT with Rochdale Chassis |
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calex_fr Registered User
Joined: 18 Jul 2008 Posts: 408 Location: Champagne (France)
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Posted: Tue Sep 30, 2008 5:51 pm Post subject: |
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Yes, good idea James !!
Thank you.
Alex _________________ Alexandre Contat
from France |
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Rodsmith Registered User
Joined: 16 Jun 2008 Posts: 187 Location: Pembrokeshire, West Wales
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Posted: Tue Sep 30, 2008 7:29 pm Post subject: |
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James , would you mind emailing them to me please? My Phase 2 has the Club AVOs and Club stainless springs fitted, so the springs obviously fit the shockers. I haven't had the car long and the work was done by the previous owner. In my opinion, and it is just my opinion, the suspension is way too hard. I now have a split, horizontally, in the fibreglass, forward of the top spring mounting. This split is about 4" long and on pushing up and down on the rear corner of the car you can see the split opening and closing. Obviously it is a fairly easy repair, but shows what stress there must be on the bodywork in this area, probably more so if the suspension is too stiff.
The other problem that I have is the front tries to dart to the left and right at speed, 65mph or so. The suspension/steering is all new, and is not binding. It may just need the tracking fine-tuning, or is it something to do with spacers on the front hubs?? Or, as was suggested to me, is the front trying to lift off the road?
Rod |
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calex_fr Registered User
Joined: 18 Jul 2008 Posts: 408 Location: Champagne (France)
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Posted: Wed Oct 01, 2008 9:35 am Post subject: |
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James scans :
Mag N°57
Mag N°102
_________________ Alexandre Contat
from France
Last edited by calex_fr on Thu Oct 09, 2008 7:56 am; edited 1 time in total |
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