V7 SLR Posted September 2, 2002 Share Posted September 2, 2002 Not knowing much about suspension geometry and how it relates to handling, I was wondering whether there is any accepted wisdom and even some practical examples of adding toe-in/outthe rear. I know (guess) that to do this on a de Dion Caterham would mean shaving the ears appropriately, meaning it's a one-way modification, hence my call for anyone having done this for real (proof required). Curious of Worcs. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Fred Posted September 2, 2002 Share Posted September 2, 2002 a few people i know put shim washers in the bottom bolts on the ears dont know if this was for toe-in/out. fred Link to comment Share on other sites More sharing options...
Chelspeed Posted September 2, 2002 Share Posted September 2, 2002 Don't trim your ears, sounds too painful, fit shims under the bolts. Shims under the bolts between the ear and the de dion tube will adjust the toe, under the back pair for more toe out and under the front pair for more toe in. Shims under the bolts between the hub carrier and the ear will adjust the camber, under the bottom pair for more negative. Mines been shimmed for about 4 years now. Someone will be along in two ticks to tell you that shimming the ear will risk breaking the bolts due to loading them off centre but in my experience this is not the case. Guess it must be due to my de dion tube being less likely loaded than most..... Link to comment Share on other sites More sharing options...
Chelspeed Posted September 2, 2002 Share Posted September 2, 2002 Opps, vice verse for toe of course, behind the back bolts gives toe in. Link to comment Share on other sites More sharing options...
JAG Posted September 2, 2002 Share Posted September 2, 2002 I believe, but wait to be corrected, that permanent toe-in at the rears will generate more grip in a straight line and improve cornering ability - upto a certain point of course. Honda and others have tuned the rear suspension on some of their saloons to generate more toe-in under compression i.e. when the suspension is compressed by body roll and the wheel is on the outside of the bend the toe-in will increase. JAG Link to comment Share on other sites More sharing options...
EFA Posted September 2, 2002 Share Posted September 2, 2002 Afternoon Graham.... I broke the bolts setting washers to increase/reduce rear camber. The ears were more susceptable to cracking when riding kerbs on track. On the road you may well be OK. As for rear toe, I have no comments to make. Fat Arn Visit the K2 RUM site See the Lotus Seven Club 4 Counties Area Website here Link to comment Share on other sites More sharing options...
Nick Woods Posted September 2, 2002 Share Posted September 2, 2002 Ive just had my tracking checked and part of the readoud including the rear toe-out , which was +3 minutes on the left and +9minutes on the right = 12 minutes in total. No idea what effect this has but i'm hoping that changing the fron from +20 to -20 will make it a bit less twitchy. I'm now for a blat to the Carrotland meeting to find out... Nick P8MRA - The green one with red wings Link to comment Share on other sites More sharing options...
scooby dooby doo Posted September 2, 2002 Share Posted September 2, 2002 rear toe in will increase stability. eventually it will hurt straight line speed if you have enough of it. I had lots (8 degrees) in finland as the dedion was bent and had to make the front ARB full soft and the rear full hard (with a lesser case of this on the dampers) to get the car vaguely neutral. It was still VERY stable and I could break STUPIDLY late into corners on the track with impunity. Going to have to be careful at Cadwell with a straight dedion... HOOPY CYCLE WINGS CUCUMBER Link to comment Share on other sites More sharing options...
felix.klauser Posted September 2, 2002 Share Posted September 2, 2002 8 degrees? That must have destroyed the rear tyres in short order?! Link to comment Share on other sites More sharing options...
scooby dooby doo Posted September 2, 2002 Share Posted September 2, 2002 the rears and fronts were ALL dead in 1600 miles. But i did do three track days (about 400 miles worth ) in that time HOOPY CYCLE WINGS CUCUMBER Link to comment Share on other sites More sharing options...
Harvey Posted September 2, 2002 Share Posted September 2, 2002 Toe in on the rear, on one side to stop "crabing" off the line. Link to comment Share on other sites More sharing options...
Fast Westie Posted September 11, 2002 Share Posted September 11, 2002 V7 My Westfie1d used to toe out by 10' each side and was v. unstable coming out of the bends (resulting in several spins). I now have set it to approx 10' toe in and have knocked 1 sec off my lap times at Lydden. The car in front is a Westfie1d (or was) Link to comment Share on other sites More sharing options...
stevefoster Posted September 11, 2002 Share Posted September 11, 2002 Ok Neil, You answered the question I put on the Lydden thread... That explains it... /Steve My racing pics, 7 DIY, race prep. Updated often here Hants (North) and Berkshire area club site here Link to comment Share on other sites More sharing options...
Richard Ince Posted September 11, 2002 Share Posted September 11, 2002 The new stronger de dion tubes have had all toe removed. Link to comment Share on other sites More sharing options...
StewartG Posted September 11, 2002 Share Posted September 11, 2002 Anyone had any experience of the freestyle rear geometry mod. seems cheap what does it do any is it any good? Link to comment Share on other sites More sharing options...
scooby dooby doo Posted September 11, 2002 Share Posted September 11, 2002 the freestyle "rear geometry" mod. as far as i knew they were only offering adjustable roll bars (slung under the petrol tank at the rear or normal position at the front) and spring/damper combos. ah! I think len did say they were working on something. I guess this is the something. except we don't know what "something" is ❗ how much is it 🤔 does it have a name that might let us devine its purpose 🤔 HOOPY R706KGU CYCLE WINGS AEROSCREEN K SERIES CUCUMBER Link to comment Share on other sites More sharing options...
pie_boy69 Posted September 12, 2002 Share Posted September 12, 2002 The freestyle kit is labled "Dedion shim kit" and they rate it to be quite good, but then they would. Costs £29.50 which is cheap enough to make a call see if it is what you want and buy it if it doesn't work then you have not lost much and should give you something to do over the winter. Link to comment Share on other sites More sharing options...
scooby dooby doo Posted September 12, 2002 Share Posted September 12, 2002 i'm intrigued..... I may give them a call.... HOOPY R706KGU CYCLE WINGS AEROSCREEN K SERIES CUCUMBER Link to comment Share on other sites More sharing options...
Chelspeed Posted September 12, 2002 Share Posted September 12, 2002 And report back I trust? If it's something that they post then it must be a predetermined deliberate adjustment to, say, add a bit more negative camber or add a bit of toe in. My comment on this is that it's all very well doing this BUT it relies on the de dion tubes all being accurately made and installed to give a common starting point. In my experience that is not the case. So make sure you get the geometry checked after fitting it and make sure it ends up where Juno (sorry Freestyle) were intending it to be. Link to comment Share on other sites More sharing options...
JonP Posted September 12, 2002 Share Posted September 12, 2002 Hi To quote the Freestyle ad in latest LF... Its called a De dion shim kit and..... "They work by moving the yaw centre closer to the centre of gravity and hence reduce the polar moment of inertia" Cost a reasonable £29.50 Translation for 'non suspension expert' anyone Back, poorer and Se7ening again! Link to comment Share on other sites More sharing options...
JonP Posted September 12, 2002 Share Posted September 12, 2002 Now awake and read page 2....DOH! 😬 Does anyone know what they are on about anyway?? Back, poorer and Se7ening again! Link to comment Share on other sites More sharing options...
Peter Carmichael Posted September 12, 2002 Share Posted September 12, 2002 The yaw center is a theoretical vertical axis on which the chassis responds to driver inputs. Ideally located directly in the vehicle center for predictability and reassuring feedback, Link to comment Share on other sites More sharing options...
Chelspeed Posted September 12, 2002 Share Posted September 12, 2002 So how do you change it's position? Will toe in change it? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted September 12, 2002 Share Posted September 12, 2002 Rear steer is a strong influence on it, but I just got my quote from a Google search. I submitted an article to Low Flying but it was deemed too technical... Link to comment Share on other sites More sharing options...
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