Manxseven Posted February 20, 2009 Share Posted February 20, 2009 Anyone got one fitted 🤔 Worth it 🤔 Just planning the build, will get round to starting it one day !!!!!!!! 😬 😬 Form Freestyle website: Top wishbone spherical joint conversion. Converts the standard top ball joint into a spherical joint. More accurate control of upright. Increased steering response and reduced effort. Easier and more accurate camber adjustment. Top Wishbone Balljoint conversion kit £235.00   Caterham BEC here Link to comment Share on other sites More sharing options...
Pendennis Posted February 20, 2009 Share Posted February 20, 2009 I have. Advantage - ease/speed camber adjustment, reduces bump steer and looks nicer  Disadvantage - Heavier than standard ball joint and cost  Take your pick Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted February 21, 2009 Area Representative Share Posted February 21, 2009 Reduces bump steer??? How's that then? I didn't think this conversion alters the steering geometry at all. Paul Richards Area Representative - L.A.D.S. (Lancashire and District Sevens) LADS Website Growing old is compulsory - Growing up is optional Edited by - Paul Richards on 21 Feb 2009 14:03:18 Link to comment Share on other sites More sharing options...
Pendennis Posted February 21, 2009 Share Posted February 21, 2009 It raises the outward part of the top wishbone  Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
CageyH Posted February 21, 2009 Share Posted February 21, 2009 Only if you adjust it out so that it does. Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
Pendennis Posted February 21, 2009 Share Posted February 21, 2009  You cannot adjust the gap between chassis pick ups or bottom/top spherical ball joint. Adjusting it out will only alter camber  Want to rent an 18th century Farmhouse in Rural Somerset? Edited by - Pendennis on 21 Feb 2009 17:17:50 Link to comment Share on other sites More sharing options...
CageyH Posted February 21, 2009 Share Posted February 21, 2009 My comment was more aimed at Paul regarding bump steer, which has nothing to do with the top ball joint. reduces bump steer Surely only altering the height of the steering rack relative to the rest of the suspension will do this? It raises the outward part of the top wishbone How? Surely this is only raised if you lower the suspension, so the upper wishbone is pointing upwards??? The upright keeps the two wishbones in a relatively fixed position to each other. I thought it only affected the ability to make camber adjustments? You cannot adjust the gap between chassis pick ups or bottom/top spherical ball joint. Adjusting it out will only alter camber Adjusting it will alter the gap between the chassis pick up points and the spherical. Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
Pendennis Posted February 21, 2009 Share Posted February 21, 2009 Bump steer is caused by many reasons. One method of reducing it, is by decreasing the parrellity of the wishbones. Without getting too complicated it's all to do with deflection angles. Yes steering rack connection to upright is a factor. But, although it's only a slight difference, when using the Freestyle rod end conversion, the centre of their top spherical joint position is slightly higher than the traditional ball joint, thus helps 'a bit' with bump steer. So the parrellity reduces. It raises the outward part of the wishbone by using a pin that replaces the traditional balljoint. The end result means the centre of the spherical ball joint is in a higher position than before. I am not referring to a dimension from the ground, we are referring to the gap between the top and bottom spherical ball joints  You cannot alter the distance between the top and bottom spherical ball joints, nor can you alter the centre of the bushes connected to the chassis pick ups. They are fixed. Yes, adjusting it will alter the gap between the chassis pick up points and the spherical, but that ultimately is a camber issue and is nothing to do with the fixed gap between top and bottom ball joints nor chassis pick ups  I don't believe this conversion is designed to help bump steer, it's just an observation thats apparent when fitting it  Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
CageyH Posted February 21, 2009 Share Posted February 21, 2009 The spherical looks smaller/lower than the pivot centre of a large cumbersome ball joint. The distance between the top and bottom balljoints on my car is different, as I have the inboard suspension. For bump steer, the most important thing is the height of the rack. Ideally what you need is a rack where the pivot point for the steering is directly aligned with the pivot point of the top wishbone. For me, the freestyle top spherical conversion does reduce the steering effort, and also allows for easier/more accurate adjustment of the camber setting (1/2 turn as opposed to full turn). Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
Manxseven Posted February 21, 2009 Author Share Posted February 21, 2009 Thanks Guys, saving up the pennies  Simon Caterham BEC here Link to comment Share on other sites More sharing options...
Area Representative Paul Richards Posted February 21, 2009 Area Representative Share Posted February 21, 2009 So it does alter the steering geometry by increasing the distance between the top and botton swivel points on the stub axle. The difference appears to be very small and I'd be surprised if it were to make a difference at all. We'll get too complicated if we try to discuss the cause of bump steer on here, but essentially you are trying to align the top and bottom chassis/wishbone pivot points along with the end of the steering rack so that the pick up points on the stub axle (top and bottom joints and track rod end) all move through the same arc. Yes on a 7 where you are unable to move chassis pick up points, the only thing you can do is move the rack and this is by trial and error as it will vary from car to car depending on the ride height and amount of suspension travel. If you are designing suspension from scratch the best way to eliminate bump steer is to have a short rack with long steering arms at the end so that it sweeps through a wide arc and thus introduces little lateral movement. Couple this to long wishbones with pivot points aligned and very limited suspension travel and Bob's your mothers brother. Look at F1 cars -they know what they're doing. Paul Richards Area Representative - L.A.D.S. (Lancashire and District Sevens) LADS Website Growing old is compulsory - Growing up is optional Link to comment Share on other sites More sharing options...
guilleracing Posted February 22, 2009 Share Posted February 22, 2009 Sorry, but I could not let this pass without comment. I have a small amount of knowledge in this field. This is correct in my humble opinion.  Bumpsteer. This is caused by the following actions/effects. The top and bottom wisharms on a Caterham car are different lengths. As the move up and down they describe different arcs in relation to each other. When driving the car and experiencing suspension movement caused by bumps in the road surface, this has the effect of pulling in or pushing out the top of the upright in relation to the position whilst stationary. Changing the camber. This is also caused when the chassis is in roll or pitch caused by acceleration or braking. The steering rack is connected to the upright and the distance from the joint on the end of the rack and the upright is ( in the case of Caterham cars.) a different length to the length to that of the wisharms. As the link between the rack and the upright moves up and down it too describes an arc. It is the effect of these perimeters that causes bumpsteer. Put simply, as the top of the upright is pulled in or pushed out, the steering turns the upright as a cause of the relationship between its arc and the arcs of the wisharms. If the rack ball joint and its corresponding motion arc is placed in an intersecting line between the top and bottom wish arms motion arcs, a degree of bumpsteer reduction can be reduced or eliminated but only when the steering is in the straight ahead position. If you want a head scratcher, think about the consequence of turning the steering wheel and thus moving the point at which the arcs described by the rack/upright link and the wisharm arcs intersect with each other!  The of the ways to reduce the unwanted effects of these intersecting arcs interacting with each other is to have the wisharms and steering links as long as practical and to have the steering link the same length as the top or bottom wisharm so that they describe the same arc. Discuss!  Link to comment Share on other sites More sharing options...
6speedmanual Posted February 22, 2009 Share Posted February 22, 2009 Guille Good description without diagrams  The "headscratcher" you mention is what I refer to as bumpsteer in a turn.  Just to add a few thoughts to the discussion: Complete reduction/elimination of bump steer is not necessarily a golden objective. Finding the right compromise for bumpsteer when going straight and when in turns is important. Also whether bumpsteer makes the frontwheels toe in or out undercompression (eg when braking or riding yumps) can be crucial to the stability of the chassis and to the steering feel. Imagine when trying to brake and control a line towards a bend acurately if all the steering feel and turn response disappeared due to a massive slug of toe-out! I've seen pictures of the freestyle top ball joint. From looking at it I doubt it would have a very significant effect on the overall bumpsteer of the front suspension as it does not significantly change the arcs of operation of the wishbones. It does move the top wishbone to a slightly different point on its operating arc relative to those of the btm wishbone and the trackrod. It will almost certainly have some effect but whether significant is questionable. I believe the "advantages" of the freestyle top ball joint are more likely to be from reduction in play in the top ball joint and (as mentioned before) finer adjustability of camber.  Whether being able to adjust camber more finely is a benefit is debatable as there are so many other factors effecting the overall chassis set-up.  In theory though it is nice to be able to adjust everything infinitessimally! Reduced steering effort following installation of a freestyle ball joint may be as much to do with the benefits of a good flatfloor set up. When I set up my car (all CC standard parts) for cornerweights and geometry I found it much more precise and balanced with lighter steering and more responsive to turn-in and mid bend adjustment inputs. Feels more like it can be steered from the hands/wrists than the forearms/elbows. I spoke to some seveners today who, although their cars had adjustable platforms, had never had a cornerweight or geometry check. Whilst they said the reason for this being that they were happy with their cars, I think a good set up can always make a 7 more pleasurable to drive. Probably one of the most cost effective mods as it is getting the best possible from what is provided before bolting on more bits.  Peter     6SpeedManual *tongue*There's no such thing as too much BHP per Ton 😬 Link to comment Share on other sites More sharing options...
guilleracing Posted February 22, 2009 Share Posted February 22, 2009 Thanks Peter, I have actually designed a winning Vauxhall powered Clubmans Car which was based on the requirement to have soft springing. Lots of suspension movement and several mechanical effects to deal with. The hillclimb course in Guernsey has low grip and low footpaths on the track. Grip was the primary requirement. Ten years after conception, the car still holds the 2 litre class record. My personal opinion is that a properly set up car is as important as power and certainly a lot cheaper to achieve. I have a European spec prototype sports racing car running on the French long distance hillclimbs. 2/3rd scale Le Mans Prototype class. Last year I beat 2007 spec GSXR 1000 engined 178 BHP car with a very good proven driver ( record holder at several UK hillclimb events.) I run a 900 cc 125 BHP engine. The difference was that due to having a properly set up car, I was flat out in a lot of places where the GSXR couldn't get the power down. To give you a relative comparison, I was 5 seconds ahead of a very good 2 litre powered Vauxhall Caterham. My prototype is right on the European weight limit for the class of 525 kilos less driver. I weigh 86 kilos. So for no money, just a bit of care in a flat floor set up, I made up the difference in 50 BHP. Being less than awash with cash, from personal experience, I know this is somewhere you can really make a difference. 😬 Greg.        Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now