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Rear Shock Absorbers


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28 minutes ago, Jase said:

What is the feeling about converting the rear setup (IRS) to adjustable shocks and removing the standard lever shocks?

Thanks

Dont bother just get the shocks rebuilt by this company http://www.stevsonmotors.co.uk/Stevson Motors - Homepage.html

Stuart.

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Why? that would mean taking my car off the road if I had to send them away to be rebuilt? Wouldn't a modern setup be better?

 

Thanks for the link

Edited by Jase
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8 minutes ago, Jase said:

Why? that would mean taking my car off the road if I had to send them away to be rebuilt? Wouldn't a modern setup be better?

 

Thanks for the link

Personally the tube shock conversion unless properly fitted with the correct shocks fitted is no better if not worse than the original lever arms. Your not using the car at the moment anyway are you?

Stuart.

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Yep, I'm using it as much as I can in the lockdown, want to get used to it and keep it going. I fitted brackets to my GT6 chasis many years ago to take the pressure off the wheel arches on my rotoflex car. These seemed like a sensible upgrade?

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Jase

I fitted the conversion to my 4a that uses the bump stop as a extra mounting and have found there is an improvement I would recommend them over the

originals but that's just my preference 

Chris

 

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1 hour ago, Jase said:

Why? that would mean taking my car off the road if I had to send them away to be rebuilt? Wouldn't a modern setup be better?

 

Thanks for the link

Modern is better..........modern is more profitable...modern is more plastic...

if you wanted modern buy a Lotus Elise...they are great fun.... but upgrading a TR......because you want to handle like a lotus? you need to loose 300Kg for that....

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If you are heart-set on a telescopic conversion then I'm sure you will go that route - if you wish to keep the set-up per Mr Triumph and minimise the time your car is off the road then you could buy a secondhand pair of (4a not 4) shocks, get those reconditioned, then fit at a convenient time.  

..... Andy

Edited by AndyR100
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Thanks guys, just after a little bit of feedback, not come across these lever shocks before and was exploring alternatives. Buying another set sounds a good plan.

Edited by Jase
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3 hours ago, trchris said:

Jase

I fitted the conversion to my 4a that uses the bump stop as a extra mounting and have found there is an improvement I would recommend them over the

originals but that's just my preference 

Chris

 

Agreed on the 3 point fixing, shares the loads between the diff bridge and the chassis. Also have found koni shocks to be good and reliable. One thing I can say is my rear suspension has worked much better and smoother since I fitted the CV driveshafts 3 years ago.

Chris 

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Hi 

I was thinking of having rear shock conversion on my 4a.Recently the bracket that lever arms bolt onto had split where it joins the chassis on passenger side.It started banging loudly over bumps so It was brought to my attention.i ended up taking lever arms off and strengthening around the joints.i checked lever arms and there was resistance on both of them but wasnt sure how much there supposed to have.without checking a new one it's hard to tell.im happy to stick with lever arm dampers if new ones will stop this happening again.There is alot of stress around that bracket area.Thoughts on this would be appreciated.

Thanks

Nige 

Its solid axle 4a by the way 

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9 hours ago, Peter V W said:

Jase,

you will transfer loads and forces to parts that were not

designed to carry them.

Really?

The brackets bolt to the shocker mounts and to the trailing arms where the lever arms did. Some of the brackets also use the redundant bump stop mount too and some have a mount that has a bolt to the rear wheel arch which stiffens the connection between body and chassis. Avoid the very early mount kits that simply bolts to the wheel arch alone and not to the chassis at all. (Not sure anyone sells them any more)

There are concerns with the conversions that go inside the coils overloading the rear diff bridge. They also mount to a part of the trailing arm not designed to mount the shocker. This may be related to the shockers working through a short movement compared to the lever arms or the usual  telescopic conversions. Their USP was that the damper works in the same plane as the coil but I haven’t been convinced this is a significant performance advantage over the Chassis bracket type and as I mentioned they work through a shorter range of movement as they are much closer to the pivot point of the trailing arms and have to be firmer to achieve the same damping effect compared to the bracket type or the original lever arms.

The trailing arms work well with telescopic dampers - effectively the same trailing arm set up was used on the 2000/2.5s and Stags. I haven’t come across too many people wanting to retro fit lever arm dampers to them. Why did Triumph use levers at the back yet telescopics at the front? Did they think lever arms are better, if so why not use at the front too? Ok that’s not so practical to do. Would Triumph have used telescopics at the rear? Probably but the constraints of fitting IRS to the evolution of the TR4 to 4A be they financial or simply design time may have been this overlooked.

Unless you wind up adjustable shockers too firm telescopic shockers work well. 

I for one would not go back to lever arms. Unless you fixed on originality go for telescopics. Having used Konis, Spax and Gaz on different cars I would say Konis are the better but have to be removed to adjust (not too bad on the rears but a time consuming pain on the fronts) Little  to choose between Gaz and Spax but the latter wins on price - both are easy to adjust on car.

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10 hours ago, Andy Moltu said:

haven’t come across too many people wanting to retro fit lever arm dampers to them. Why did Triumph use levers at the back yet telescopics at the front? Did they think lever arms are better, if so why not use at the front too? Ok that’s not so practical to do. Would Triumph have used telescopics at the rear? Probably but the constraints of fitting IRS to the evolution of the TR4 to 4A be they financial or simply design time may have been this overlooked.

 

 

If you look at earlier posts regarding lever arm versus tele shocks you will actually find a lot of people have gone back to lever arms for comfort and a more controlled ride. Triumph Engineers were obviously constrained by cash concerns all through the life of the company but they did understand handling. You cant compare the suspension fittings of Saloons or Stags with TR`s as its chalk and cheese for weight and design parameters.

Properly rebuilt and maintained and if you do want a slightly firmer ride then slightly uprated lever arms work very well indeed and if you fit better drop links as well (The cheap repros dont last very long and also contribute to a lot of the criticism of lever arms) then the car handles very well indeed.

Your car your choice obviously.

Stuart.

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Apols for slightly hijacking the thread but while we're on rear suspension and some knowledgeable folks are tuned in...

Please can I have informed opinions on the best upgrade path for rear suspension on a TR4 (not 4A) to improve ground clearance and handling on tarmac and gravel (not severe stage gravel), with a medium-loaded car (road/endurance rallying so tools and spares etc carried).

I have standard dampers on at the moment and do want to stay with lever arms (for classic type compliance) but am assuming new springs - but what rating and mountings?

Anything else?

(On the front the car is fairly standard with no ARB, neg camber conversion, Spax that are probably overdue replacement/upgrade. I run on standard profile 165s.)

Thanks,

Nigel

 

Edited by Bleednipple
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Revington’s 161 lb road/rally springs will suit you well. Mount them with the front location kit and Superpro shackle bushes. 
Match then with 450 lb red stripe front springs when you can. No ARB will be required for normal quick road driving. 

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19 minutes ago, Drewmotty said:

Revington’s 161 lb road/rally springs will suit you well. Mount them with the front location kit and Superpro shackle bushes. 
Match then with 450 lb red stripe front springs when you can. No ARB will be required for normal quick road driving. 

Many thanks Andrew. That Revington uprated spring is listed as standard ride height... how would I achieve a bit of lift? (Although not 100% sure if I need that as occasional crashing on gravel may be more about current spring rating than ground clearance per se?).

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You won’t need anything more than standard ride height once it’s properly controlled. Mine copes with fully loaded two up trips around the appalling Irish side roads and my home Devon lanes without a problem. You can’t really raise the ride height without major chassis surgery as the axle bump stops are usually very close to the chassis as standard. 

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2 minutes ago, Drewmotty said:

You won’t need anything more than standard ride height once it’s properly controlled. Mine copes with fully loaded two up trips around the appalling Irish side roads and my home Devon lanes without a problem. You can’t really raise the ride height without major chassis surgery as the axle bump stops are usually very close to the chassis as standard. 

Many thanks that makes sense!

Nigel

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Going back to the original question, historically part of the reason people moved to tube dampers from lever arms was the impossibility of getting lever arms repaired at a cost-effective price. Given that many now recommend staying with levers, I guess that situation no longer applies.

Various types of brackets have been offered as has been noted. What is most important should one choose the tube conversion is to verify for yourself that when fitted the damper does NOT fully compress on full bump. Only the bump stop mounted between body and t/a should be used for controlling full bump. If the internal tube damper bump stop is used then you will probably break the lower mounting off the trailing arm as it was never designed for this use.

This check needs to be made by removing the spring and checking full bump, and must be done whenever you replace the dampers.

Otherwise, I'm happy with my koni conversion and have been for many years.
Jerry

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6 hours ago, stuart said:

If you look at earlier posts regarding lever arm versus tele shocks you will actually find a lot of people have gone back to lever arms for comfort and a more controlled ride. Triumph Engineers were obviously constrained by cash concerns all through the life of the company but they did understand handling. You cant compare the suspension fittings of Saloons or Stags with TR`s as its chalk and cheese for weight and design parameters.

Properly rebuilt and maintained and if you do want a slightly firmer ride then slightly uprated lever arms work very well indeed and if you fit better drop links as well (The cheap repros dont last very long and also contribute to a lot of the criticism of lever arms) then the car handles very well indeed.

Your car your choice obviously.

Stuart.

The design may well be different - separate chassis v monocoque but the geometry is remarkably similar.

In many ways the weight is not a significant issue. The level of damping needs to be set to an appropriate level but that applies to lever arms as much as to telescopics. This is also affected by spring rates and so on. I wasn’t suggesting you could use the same dampers on aTR as a Stag any more than a Mini but the principle is similar. 

I suspect many people’s view of telescopics has been affected by using adjustable wound up to stiff making the false assumption that stiffer is better in the same way springs need to be firmer. The same applies to levers too but there’s minimal scope for user adjustment on lever arm dampers.

A rock  hard spring and high levels of damping might suite a race car used on a smooth track yet may well be awful on our roads.

Mention “updated” and the price goes up as does the bling factor and there is a risk of fitting parts that are unsuitable and with it disappointment.

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If you can find a set of Twin-Valve lever arms, they are a very nice improvement over standard - I have them on my TR4 and the improvement is good!

TrTony occasionally has a set knocking about, there was a pair on ebay last week.

Cheers

Adey

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I also see that Revington also offer an "uprated" lever arm (RTR3119) that seems to sit between the standard DAS9 and the bigger DAS10 types but unlike the DAS10 doesn't seems to need any mods to the mountings.

Anyone have experience of those?

Nigel

Edited by Bleednipple
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1 minute ago, Bleednipple said:

I also see that Revington also offer an "uprated" lever arm (RTR3119) that seems to sit between the standard and the DAS10 types but unlike the DAS10 doesn't seems to need any mods to the mountings.

Anyone have experience of those?

Nigel

Thats the same as you would get if you have Stevsons rebuild yours as they will uprate them anyway.

Stuart.

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I need to strongly second what Stuart is saying here. Properly set up and if necessary rebuilt lever arm shocks can work very well indeed on a 4a. The difference comes when you are doing seriously hard driving (ie racing or rallying) when the oil in the lever shocks start heats up considerably because the pistons inside the lever shocks are moving much more. This simply won’t happen on the road under normal, even spirited, driving conditions in my experience. Getting shocks rebuilt well by someone who knows what they are doing with shimming and piston spring rates is everything - putting thicker oil in is pretty temporary and some might say shortens the life of the shock as the seals take more load. Choose your rebuilder carefully - I also go to Derek Stevson.

There is a twin valve adjustable DAS10 shock available but hard to find and those can be fitted pretty much ‘bolt on’ to the TR IRS chassis. This gives a MASSIVE improvement to hand,in and can be tuned depending on what you need, have a rear ARB etc etc whilst still seemingly working within the bounds of chassis rigidity (or lack of) so works very well indeed, but come at another order of cost.

You CAN make a set of telescopic shocks work really well, but this needs to be accompanied by a lot of properly thought through chassis stiffening to deal with all the extra loads and twisting induced into the IRS chassis and this sort of arrangement does indeed change the character of the car. You then get into the process of chasing out all the foibles, so having done this myself and worked my way through it all I’d suggest that you need go into it eyes open and expect a load of work and trial and error, and this is a further order of cost and time by the time it’s done. My experience is that the effect of bolting on a set of telescopics on brackets ranges from not much differences to awful, ie not particularly better. I returned my 4a to nicely rebuilt DAS10’s and everything else well maintained after a lot of playing around, but the chassis stiffening remained and was really good.

I would also suggest as Stuart has that you consider all the various bushes and links in the IRS and at the back end, driveshafts and UJ’s etc as all of the above have an effect on well an IRS car handles.
 

Hope the above is useful. You can do a lot to make a 4a handle well in standard form at moderate cost, so I’d humbly suggest you try that approach first.

Regards

 

Tony

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