Mark_ Posted February 24, 2019 Share Posted February 24, 2019 I have a 07 Roadsport SV150 on 15s and the handling could be much better Im sure.It bump steers quite badly, to to the point of a 60mph B road becoming a white knuckle ride.Im going to get the car geo'd and corner weighted, and a set of JWM bump steer BJ's. but Im interested to know your views on what to do to improve the handling. Link to comment Share on other sites More sharing options...
Area Representative Kingsley Young Posted February 24, 2019 Area Representative Share Posted February 24, 2019 MarkI have the same model as you, I had Team Leos Motorsport set all the suspension up, and the car handles really well. You are thinking down the right lines to get it set up properly , I would definitely go to someone who knows Sevens. Kingsley. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 24, 2019 Share Posted February 24, 2019 You can make shims to dial the bump steer out for under a fiver ...... first though you need to get it checked and see what you car needs - raising the rack is the more common requirement. Link to comment Share on other sites More sharing options...
Mark_ Posted February 24, 2019 Author Share Posted February 24, 2019 It would only be done by a 7 specialist for sure....I dont have the facilities or time to be machining stuff up sadly guys. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 24, 2019 Share Posted February 24, 2019 If your one of the very few that needs the rack effectively lowering then you can use the pins from CHV engineering and shim the rose joints.Caterham sell the shims for raising the rack https://caterhamparts.co.uk/racks/1039-spacer-steering-rack.html?search_query=steering+rack+shims&results=399 Link to comment Share on other sites More sharing options...
Ralph45 Posted February 24, 2019 Share Posted February 24, 2019 What size or depth would the shims need to be and what material is needed? Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 24, 2019 Share Posted February 24, 2019 Ally is fine, if you have some made in various thickness so you can use whats needed for you car, mine needed 8.25mm some need less, some moreyou may also need longer rack bolts too Link to comment Share on other sites More sharing options...
Bricol Posted February 24, 2019 Share Posted February 24, 2019 Check your tyre pressures - if you've got tin-top values, it will leap all over the place. I run 16 ish on 14" wheels.A simple tracking check might be good - too much toe out and it will follow the road all over the place. Link to comment Share on other sites More sharing options...
john milner Posted February 25, 2019 Share Posted February 25, 2019 I have had it where the car sort of steers itself and it can be a bit like fighting the steering. The steering can also be heavier than usual. For example applying some pressure on the steering wheel to the left to make it keep straight and later have to do the opposite. I think the switch has something to do with a change in road surface so could be bump steer related. This effect can creep up on me but each time it does this a dollop of grease or thick gear oil through the 36mm adjuster bolt in the steering rack has cured it. The cure for me lasts about 20,000 miles. Link to comment Share on other sites More sharing options...
p.mole1 Posted February 25, 2019 Share Posted February 25, 2019 I had the same problem, my car was possibly the worst handling car I have ever owned ( on bumpy roads )First check the toe in/ out it wants to be about neutral for the road, the rake of the car, it should be around 10/15 mm lower at the front. Also check your bump steer mine was horrendous! I can't believe a car could leave a factory so bad.Don't listen to pundits who tell you need shims, you need to measure it , in my case my rack needed lowering by quite an amount and it took some doing to come up with a solution. I ended up using taper pins and ditching the track rod ends and using spherical rod bearings. The car is sorted and bumpy roads do not have you darting from one side of the road to another.I have to say I'm not impressed with some of Caterhams engineering, although mine is a 1995 vintage Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 25, 2019 Share Posted February 25, 2019 pundit....?I mentioned getting it checked in my first post........ also offered an option for those that need the rack lowering too... Link to comment Share on other sites More sharing options...
Nigel Riches Posted February 26, 2019 Share Posted February 26, 2019 Interesting reading, as I am now putting my car through an inspection procedure to allow it on the road, one of the checks is for "bump steer" apparently way out of allowable limits, and it did move about a lot on bumpy bends or uneven road surfaces.Turns out it left the factory in 1982 with the steering rack mounting blocks upside down, so the rack was "high" (different size mounting blocks, about 8mm originally taller block below the rack) simple fix, use the shorter mounting blocks below the rack tube, bringing the tie rods and track rod ends into alignment with the centre line of the rack, when viewed from the front all are horizontal, and after Mr. Inspector had me subject the car to a wheel alignment check, which didn't need any adjustment, I went for a quick drive, and can confirm the drive is much improved.Aim to get the track rod end ball joint inline with the centreline of the rack when viewed from ahead, made all the difference to my car.Hope this helps.Nigel. Link to comment Share on other sites More sharing options...
nickh7 Posted February 26, 2019 Share Posted February 26, 2019 Speak to Dave at Gemzoe Motorsport. He dosnt just flat floor your car he sets it up for you. He transformed my car , best upgrade I ve done. I can’t believe the difference, 2nd gear corners became 3rd gear , handling on West Yorkshire’s shocking roads is remarkable. Talk to him he knows his stuff http://www.gemzoe.com/about-ushttp://www.gemzoe.com/about-us Link to comment Share on other sites More sharing options...
Nick T Posted February 26, 2019 Share Posted February 26, 2019 Mark,Not sure where you are but take it to a good suspension 7 specialist. I had similar issues (a CC built car brought from a 7 specialist) and the rack was incorrectly fitted. Had it flat floored at PGM, they found a number of improvements as well as the rack and it totally transformed the car. Nick Link to comment Share on other sites More sharing options...
Mark_ Posted February 26, 2019 Author Share Posted February 26, 2019 Thanks for all the input guys. Ive spoken to a number of the specialist guys, and for me DPR stand out.Ive being doing a lot of research and 'net reading, and I think Im going to try a set of 6/8"x13" on it before going forward for a full geo.... Link to comment Share on other sites More sharing options...
chisel86 Posted February 27, 2019 Share Posted February 27, 2019 I've been reading this thread with interest, can anyone recommend somewhere near Warwick that could do the full flat floor and bumper steer/handling set-up specially for a caterham?ThanksDavid Link to comment Share on other sites More sharing options...
Northantsbedsbucks AR Posted February 27, 2019 Share Posted February 27, 2019 Macmillan in Hinckley or Northampton Motorsport. Link to comment Share on other sites More sharing options...
p.mole1 Posted February 27, 2019 Share Posted February 27, 2019 Sorry not meaning to upset anyone, when I was researching my bump steer problem the general consensus was to use shims. What is important is measurement. In my case if I had fitted shims it would of made a bad car even worse! Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted February 27, 2019 Area Representative Share Posted February 27, 2019 MarkThere is a lot of experience here and a lot of good advice. My advice is to go to a specialist, talk to them, take them out or let them take it out. Talk to them about how you use the car, what is critical to you and let them transform the car.The only check to make before doing this is to check the tyre pressures. Start from 18 psi. Link to comment Share on other sites More sharing options...
chisel86 Posted February 28, 2019 Share Posted February 28, 2019 Thanks Link to comment Share on other sites More sharing options...
Paul Deslandes Posted February 28, 2019 Share Posted February 28, 2019 If you're interested in bump steer and how to measure it, there's my Low Flying article describing how to measure and correct it here.Paul Link to comment Share on other sites More sharing options...
Mark_ Posted March 4, 2019 Author Share Posted March 4, 2019 I was talking wheels and tyres to a specialist today and told him how much I disliked the current drive of my 7....After getting a quote for new 13" CXR/ZZS for just over a grand, we started to discuss variuos cheaper options...He said to ditch the current ZV3's on the car and replace them with Yoko AD08r -something he had done to a simiar spec car to mine with great success.... What do you think of this idea chaps ? Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted March 4, 2019 Area Representative Share Posted March 4, 2019 I had ZV3s on the 21 (ok, they were oldish) but I felt they were too stiff. Happier with the Toyo T1Rs I had afterwards. Now using Uniroyal Rainsport 3s. Note:- these were on 15" and 16" wheels not 13". Link to comment Share on other sites More sharing options...
Roadsport06 Posted March 4, 2019 Share Posted March 4, 2019 Your ZV3 aren't the best. Hard rubber and I bet yours will be quite old now too so even harder. Different tyres will make a big difference. Various options about too, and opinions on tyres will be vary. I run R888 l. What tyre pressure are you running? That makes a difference. Going from 14" to 13" would need you to consider the drop in ride height. Do you have adjustable ride height? Link to comment Share on other sites More sharing options...
Mark_ Posted March 5, 2019 Author Share Posted March 5, 2019 Well,after many, many hours on the 'net, I have been offered a set of new CXR's and Toyo 888r in 185/205x13 and have pretty much decided to bite the bullet.Time will tell of this (not cheap) option was or is the way forward, but hey, its only money right ? Link to comment Share on other sites More sharing options...
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