Guest Biffo Posted October 8, 2004 Report Share Posted October 8, 2004 As I got such a great response to my MX5 seat question, rather than struggle alone I thought I'd post this as a plea for help ! I recently bought a rear shock conversion kit (from TR Shop). The brackets are the three bolt mounting type - two to the lever arm mounting bracket and one to the bump stop bracket on the chassis. The kit came with Koni adjustable dampers. Shortly before, I had already fitted uprated and lowered springs front and rear. When I fitted the kit, everything went OK. Allowing for wheel settle I have about 2 - 2.5 inches of clearance between the bumpstop on the trailing arm and the body. So I was expecting no problems. However, my first test drive proved that there is no travel left in the Koni's. With the car at rest, there is no downward movement at all - they are FULLY compressed (I proved this by drawing a pencil line on them then taking them off an compressing by hand). There is a rubber "bung" inside the top of each Koni that I could remove, but it is only about half inch thick so not only will it not make a lot of difference, but potentially damage the damper when it bottoms out. I have a few questions: 1) Has anyone fitted this type of kit, with Koni's and lowered springs, and had similar problems or no problems at all ? 2) Has anyone got a kit from someone other than TR Shop and would they be prepared to measure some of the important dimensions so I can compare to see if it the brackets that are at fault. 3) Has anybody got a set of dampers other than Koni that they could fully compress and measure so I can see if it is the Koni's that are at fault ? The rear springs are not extreme. I have 195/65 15 inch tyres on standard steel wheels and I measure the clearance between the chassis and the ground (about level with the door opening) at a little over 4 inches. The front is just under 4 inches, so the tail is not drooping. I live in Devizes, any local help would be much appreciated ! Biff Quote Link to post Share on other sites
scotty Posted October 8, 2004 Report Share Posted October 8, 2004 Hi Biff , I am mid resto at the moment but have fitted uprated shorter springs to my chassis and have a similar sounding rear damper arrangement from CTM . I have not fitted the GAZ adjustables to it yet - they are still in the Garage , give me til tomorrow and I will measure for you. Quote Link to post Share on other sites
scotty Posted October 8, 2004 Report Share Posted October 8, 2004 23.5cm - does not include any washers or rubber bushes Hope this helps. Quote Link to post Share on other sites
Guest Biffo Posted October 9, 2004 Report Share Posted October 9, 2004 Hi Scotty, Thanks for this ! The Koni's also measure 23.5cm without rubbers etc. So its not the make of damper then..... With the car on its wheels, no dampers fitted, there is a distance of between 27 and 28 cm available between the damper mounting points of the bracket and trailing arm. The rubbers and washers for the Koni add up to 5cm, so thats why the dampers are fully compressed when fitted. Its got to be the brackets (or my chassis ???). Any chance you could measure the CTM brackets ? Quote Link to post Share on other sites
scotty Posted October 9, 2004 Report Share Posted October 9, 2004 Biffo , yes will do but the chassis is in my Dads garage in the next village - will try to measure later Quote Link to post Share on other sites
Guest Biffo Posted October 9, 2004 Report Share Posted October 9, 2004 Thanks Scotty. I've examined my brackets, they are made by Bastuck in Germany. I have emailed to see if they have any ideas as well. FYI, measuring from the mounting for the top of the damper, to the "foot" that bolts to the bumpstop bracket, the Bastuck brackets are 26.5 cm. Thanks again Biff Quote Link to post Share on other sites
jonlar Posted October 9, 2004 Report Share Posted October 9, 2004 Hi Biff, I'll be very interested in how you get on, I was planning to use the CTM, but my main question was which make of S/A to use? http://www.tr-register.co.uk/cgi-bin....;t=3335 Quote Link to post Share on other sites
Guest ron Posted October 9, 2004 Report Share Posted October 9, 2004 Hi Biff This is just a suggestion, but could it be you need shorter Konis if you have lowered springs and you have been supplied with ones to suit standard length springs? Ron Quote Link to post Share on other sites
Guest harry dent Posted October 10, 2004 Report Share Posted October 10, 2004 Hi Biffo, I am not teaching you to suck eggs but have you got back to the TR Shop and consulted them about your problem.I have fitted CTM and Revingtons kit and had no problem with both.You can adjust Konis by taking out the bump stop,compressing the shock absorber and turning it clockwise to stiffen or anti clockwise to soften,(or is the other way round) then put the rebound rubber back in. Regards Harry TR5 nutter. Quote Link to post Share on other sites
Guest Biffo Posted October 15, 2004 Report Share Posted October 15, 2004 Hi Harry, I have been back to the TR Shop for advice. Jeff said he'd try to get hold of another manufacturers kit and see if there were any differences, but said that would "take time". I have heard nothing back in about 3 weeks. I have even contacted the manufacturer, they are going to look at their test bed TR and let me know next week. The settings on the Koni make no difference to the ride height. I am hoping to get to the spares day tomorrow, see if I can compare with other kits etc. Thanks Biff Quote Link to post Share on other sites
Guest ron Posted October 15, 2004 Report Share Posted October 15, 2004 Biff I've a Spax conversion on standard springs, but it does look as if they would bottom if I fitted shorter springs, it might be worth contacting Koni to see if the make a shorter shock absorber to the same spec. Ron Quote Link to post Share on other sites
Guest Biffo Posted October 16, 2004 Report Share Posted October 16, 2004 Hi Ron, That is interesting and thanks for the info. Are the brackets by Spax as well ? I'll give Koni a go, see what they say. TR shop and the bracket manufacturer say they have had no problems in the past, but I wonder how many kits have been fitted with standard springs not lowered ones ? The other thing is that I really only noticed the problem because the roads round here are really bumpy. On a fairly smooth road the ride just feels "stiff" because of the pliance in the rubber bumpstop inside the Koni. I suppose you could put this down to the uprated springs or dampers set too hard if you did not investigate further.. The other solution is to re-fabricate the brackets (let in a couple of inches) to give enough range for the dampers, but I'm a bit "annoyed" having paid good cash for this set up ! If I make progress I'll post an update. Oh yeah, and I know the spares day is Sunday not today. Good job I didn't get up early and only realise my mistake when I checked the start time in Triumph World...D'oh ! Biff Quote Link to post Share on other sites
Guest ron Posted October 16, 2004 Report Share Posted October 16, 2004 Biff Don't know who made the brackets, they came with the kit, and they're not really the best type as they only fit to the old shocker mounting, not to the bump stop as well, I was intending modifying them this winter. I think you're probably right about them not having had experience of these kits with lowered springs, I get the impression because it's such a small market that some aftermarket extras for TRs are not all that well thought out! [look how long the rear shocker mounting to the inner wing was on the market] Do you particularly want lowered springs? I would be inclined to go back to standard springs rather than modifying the brackets. Ron Quote Link to post Share on other sites
Guest Biffo Posted October 17, 2004 Report Share Posted October 17, 2004 Up early for the show today (again... ;-I) You have a point ! I only have 4 inches ground clearance under the chassis (slightly less at the front) and I have a couple of speed bumps to negotiate where I live so maybe standard height springs would be better anyway. I'll see how I get on today ! Thanks Biff Quote Link to post Share on other sites
jean Posted October 17, 2004 Report Share Posted October 17, 2004 Biff, Ron is right, the 6 originally has rather little ground clearance and setting it even lower will be create never ending problems. In general the car might look standing high on wheels but the body sits a few inches above the bottom of the chassis frame and there is very little room underneath. In most countries on the Continent the MOT requires 11cm ground clearance and you probably need these to clear some of the da** speed bumps especially if you fit twin sport exhaust pipes. Jean Quote Link to post Share on other sites
Guest Biffo Posted October 20, 2004 Report Share Posted October 20, 2004 All, Well, I HOPE this is the final installment ! I visited the Sandown show on Sunday and compared my brackets with another couple of sets from Bastuck on the TR Shop stand and the Moss stand (couldn't find any CTM ones anywhere) and they were identical. Bastuck themselves have replied to me telling me they have the same brackets fitted to a race TR which is VERY lowered (though they did not specify by how much exactly) and they have no problems. So, I came home and removed the stub axles, the trailing arms etc to get a really good look at what is going on down there. On inspection there is no damage, twisting, repairs etc - its all in pretty good condition actually. On advice from Scotty I even measured the height of the upper spring mounts and compared with the dimentions in the manual - they were fine. Still scratching my head, I refitted the brackets and called Ian at CCRR for some wisdom. He suggested I check that the upper part of the brackets were perpendicular (i.e. parallel to the inner wheel arch) when fitted. I checked this and.....mine are not ! They point outwards (though not by much at all). Now this may sound obvious to you more experienced TR'ers out there, but it wasn't to me ! By removing all the mounting bolts from the bracket, apart from the uppermost one on the lever arm mounting which I just loosened, I could pivot the bracket until it was perpendicular (used a spirit level). This lifted the upper mounting point for the shock by 2.5cm ! I managed to measure the difference in the angle - its out by 6 degrees. Looking into the history of my car, it had an early Heritage chassis fitted in 1993. I have all the paperwork so looked up the body shop that did the work. They still exist, whats more I rang up and they remembered the car AND the chap that did the work is still there ! He remembered the chassis and the body were a "pig" to fit and get right. The early Heritage stuff apparently left a lot to be desired ! The conclusion I have drawn is that there is a dimensional problem with the angle and possibly the position at which the lever arm mounting brackets are attached to the chassis. Not somethign I am going to try and rectify ! I have therefore taken the brackets to a local engineering firm who are going to "adjust" the brackets to fit properly. I have calculated the changes needed so that the Koni sits just around the middle of its travel range, so it will work well with the lowered springs but would still allow me to fit standard or even lower springs should I feel the urge ! Thanks to everyone for their help, support and advice. Its certainly been a learning curve for me and if you are reading this and intending to fit a telescopic damper kit and you have a heritage chassis, hopefully this will save you some time and grief ! Biff Quote Link to post Share on other sites
scotty Posted October 20, 2004 Report Share Posted October 20, 2004 Glad to hear there is light at the end of the tunnel Quote Link to post Share on other sites
Guest Biffo Posted November 18, 2004 Report Share Posted November 18, 2004 This IS the final installment ! Brackets received back from the engineering shop on Saturday, all the adjustments made, shot blasted and zinc plated - they look better than the originals. Fitted them up, spot on ! The car is all back together now and it all works fine. Phew. Quote Link to post Share on other sites
Richard M Posted July 26, 2021 Report Share Posted July 26, 2021 On 11/18/2004 at 1:03 PM, Guest Biffo said: This IS the final installment ! Brackets received back from the engineering shop on Saturday, all the adjustments made, shot blasted and zinc plated - they look better than the originals. Fitted them up, spot on ! The car is all back together now and it all works fine. Phew. Hi Biffo, I have just purchased the rear telescopic conversion with Konis's from the TR Shop for £339 only to find the same problems as you have had hence why l started to look on the internet to see if l was the only one to suffer this issue. You thought it was your Heritage Chassis that had caused your problems but this not the case as l have a standard factory Chassis that is giving the same problems. Most people who fit these conversions never check whether there bumps stops work & are unware of the bumps stops not being able to do there job as the shock absorber is bottoming out first due to lack of travel before it hits the bump stop.The Shock has now become the bump stop taking all the stress through the bracket that holds the shock right through to the Chassis which eventually will end up cracking the Chassis. This all due to the brackets not being manufactured long enough to allow the shocks to travel further up into the wheel arch. They need extending approx another 50mm which you seem to have done to solve the problem which l will also have to do. Its unbelievable to think you pay good money for a product that is suppose to be proffessionally designed & manufactured & you end up either damaging your cars Chassis or having to modify it yourself to the correct specification l might as well have made the brackets my self in the first place. Quote Link to post Share on other sites
stuart Posted July 26, 2021 Report Share Posted July 26, 2021 53 minutes ago, Richard M said: Hi Biffo, I have just purchased the rear telescopic conversion with Konis's from the TR Shop for £339 only to find the same problems as you have had hence why l started to look on the internet to see if l was the only one to suffer this issue. You thought it was your Heritage Chassis that had caused your problems but this not the case as l have a standard factory Chassis that is giving the same problems. Most people who fit these conversions never check whether there bumps stops work & are unware of the bumps stops not being able to do there job as the shock absorber is bottoming out first due to lack of travel before it hits the bump stop.The Shock has now become the bump stop taking all the stress through the bracket that holds the shock right through to the Chassis which eventually will end up cracking the Chassis. This all due to the brackets not being manufactured long enough to allow the shocks to travel further up into the wheel arch. They need extending approx another 50mm which you seem to have done to solve the problem which l will also have to do. Its unbelievable to think you pay good money for a product that is suppose to be proffessionally designed & manufactured & you end up either damaging your cars Chassis or having to modify it yourself to the correct specification l might as well have made the brackets my self in the first place. Are you sure that the chassis fitted to your car hasnt had work done on the shock bridge? These chassis are getting on a bit and are well known to break in places like that so any repairs have to be done exactly to original spec, Have you had the car from new? This thread is 17yrs old and Im sure that had there been problems with those brackets Im sure that the manufacturers would have altered them by now. Stuart. Stuart. Quote Link to post Share on other sites
Andy Moltu Posted July 27, 2021 Report Share Posted July 27, 2021 In theory the bump stop should meet the chassis before the shocker is fully compressed. Simple to test - remove the spring and jack up by the trailing arm - if the bump stop makes contact with the trailing arm before the shocker is fully compressed then good. If the shocker is fully compressed before the trailing arm meets the bump stop then things are not good. Hit a bump and the force will go through a solid shocker and break the trailing arm. The shockers are too long when fully compressed. Some Koni's have a rubber "doughnut" inside the top, if it has remove it and see if it allows enough compression for the bump stop to work. Quote Link to post Share on other sites
Richard M Posted August 5, 2021 Report Share Posted August 5, 2021 On 7/26/2021 at 11:37 AM, stuart said: Are you sure that the chassis fitted to your car hasnt had work done on the shock bridge? These chassis are getting on a bit and are well known to break in places like that so any repairs have to be done exactly to original spec, Have you had the car from new? This thread is 17yrs old and Im sure that had there been problems with those brackets Im sure that the manufacturers would have altered them by now. Stuart. Stuart. Hi Stuart, Bought car in 2010 restoration finished 2019 chassis was restored by CTM. I agree thread 17 years old same issues in 2021. Went for a ride out with TR register yesterday firsy guy l spoke to with no mention of my issue has bought a week ago Telescopic conversion from TR shop brackets wont fit has had to get them modified. TR shop said they never had a problem l spoke with them 3 weeks ago they told me the same. Quote Link to post Share on other sites
stuart Posted August 6, 2021 Report Share Posted August 6, 2021 Well Ive just had a long chat with Loukas at TR Shop regarding these brackets and investigations into this problem are ongoing, as they buy them in from Bastuck who apparently arent the easiest to deal with we shall see what happens Stuart. Quote Link to post Share on other sites
AWM Posted August 26, 2021 Report Share Posted August 26, 2021 Which Konis are you using? They are supposed to be used with a shorter travel model. The Bastuck website shows 80-2167. Andrew Quote Link to post Share on other sites
dpb Posted October 9, 2021 Report Share Posted October 9, 2021 Hello I have a TR4A irs with the rear shock (damper) conversion. I am replacing the springs now, but saw this thread about bump stops etc. I just did the test outlined above. The koni shock was fully compressed and the bump stop still had about 2 inches, maybe a bit less, to go. I thought it was a bit harsh when driving over bumps. The koni I have is adjustable (although I don't know how to do that), with nr 80 2167. It would appear I need a shorter one. Also, as to the debate about the bracket fitting above, mine have been hacked about to fit, but are still not good. I suspect mine are several years old, certainly earlier than 2013. Dave Quote Link to post Share on other sites
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