Geoffrey Carter (Buttercup) Posted December 20, 2014 Share Posted December 20, 2014 Hello all. For a while now I have been thinking about changing my seats. I have previously spoken with JK Composites and I am interested in their seats. I have seen that they attach to the rear of the to support them. However the drivers seat needs to be all the way fully forward for me as I have short legs and just reach the pedals now. There is a video on YouTube showinga seat flexing and I just wondered about people's experiences with the seat fully forward on its runners. Quote Link to comment Share on other sites More sharing options...
Rory's Dad Posted December 20, 2014 Share Posted December 20, 2014 There are two types of JK seats. The first are single skinned and seem to be flexible. They are just fixed at the front (I think). The others have a reinforced base with 'legs' up the back. These will fix to a frame or direct to the floor and are fine. Quote Link to comment Share on other sites More sharing options...
clansman Posted December 20, 2014 Share Posted December 20, 2014 This too is going to be one of my winter tasks and have got two JK's, must say they look fairly rigid with the reinforcing for runners and the rear fixing bracket. Not in the car yet but had to have wee trial seat in the living room when they arrived 1 Quote Link to comment Share on other sites More sharing options...
Steve M Posted December 21, 2014 Share Posted December 21, 2014 From what I've read in the past, if you want the rigidity you need to fit them with the bases ( £50 per seat ) which will enable the seats to be mounted on runners , or fit them with the brackets that atatch the seat to the rear interior panel, but then obviously that would be in a fixed position 1 Quote Link to comment Share on other sites More sharing options...
Dave Eastwood (Gadgetman) - Club Chairman Posted December 21, 2014 Share Posted December 21, 2014 The fixed position seats really need attaching to the car at a minimum of six points; two through the front lip that sits on the floor, two more in the bowl of the seat, (under the cushions for your bum), also through the floor. Then one either side of the seat back, with the supplied aluminium brackets, to fix it to the rear bulkhead. Even then, because none easily fall on existing steel work*, as a bare minimum, you need large spreader washers. Ideally, you would weld in steel straps or box section anchorages. *unless of course it's a car with the lowered steel floor pans. If it was purely for road use with a lightweight driver, you could probably get away with just the front edge and the rear brackets being fixed. But be warned, under serious cornering loads, they flex and move. Personally, I wouldn't have the fixed position JK's again, for the lack of strength and stiffness the single skin construction causes. 1 Quote Link to comment Share on other sites More sharing options...
Dave Eastwood (Gadgetman) - Club Chairman Posted December 21, 2014 Share Posted December 21, 2014 From what I've read in the past, if you want the rigidity you need to fit them with the bases ( £50 per seat ) which will enable the seats to be mounted on runners , or fit them with the brackets that atatch the seat to the rear interior panel, but then obviously that would be in a fixed position For heavy track use, by any but the lightest driver, I have increasing doubts that any single skin grp seat would really be strong enough to not flex, unless you went to extraordinary lengths with the number of fixing points. TBH though, having seen the particular way a single skin seat failed in a bad accident, I just wouldn't personally have one again. Quote Link to comment Share on other sites More sharing options...
Geoffrey Carter (Buttercup) Posted December 21, 2014 Author Share Posted December 21, 2014 Morning men. Thankyou again for the detailed replies. I am the wrong side of 17 stone and this has given me slightly child bearing hips. I am not the lightest of slimmest of people and that's a fact. the reason I want to change my seats is that from the back they are both different heights and the backrests appear around shoulder height. The position though is so comfy and I feel more refreshed getting out of the seats I have than I did getting out of my Jaguar XJ portfolio, all singing all dancing type seats. The flex does concern me a bit but the car will only be used on the road and not on the track. I have to have the seat as far forward as it will go and then I can reach the pedals. If the seat is one click back from the front then I cannot operate the clutch comfortably and have to really point my foot to do so. Why I didn't want the seats fixed is that I would then limit the driving position to just me but to be honest that is no really big problem. My ideal scenario would be as follows. Two, correctly fitted seats that are both the same height or very similar. Seats to be comfy. No flex. Drivers seat to be on runners. I have looked at the Tillets but these are out of my budget at present. As it stands I have spoken with the chaps at JK and I intend to drive Buttercup to them from Scarborough so we can have a "fitting" for car and driver. Quote Link to comment Share on other sites More sharing options...
jim_l Posted December 21, 2014 Share Posted December 21, 2014 I really like the JKs, they are light, look good, comfortable and are great value for money. I have one of each in the car (Drivers with base on runners, Passenger fixed no base) I would though, agree with Dave that you need to think about what you are using them for and the kind of G forces you are going to apply. For the seat without the base if you are going to track it you need additional support - I sat my passenger side in a box of expanding foam in order to make a 'mini base' for it - works surprisingly well and the seat feels well fixed. Perhaps next time I might just get both seats with bases. The one with the base does feel solid and only begins to flex at shoulder level really, I have found it good for road and track day use. Someone driving competitively may be unhappy with the flex at shoulder level. Note that with even the rather expensive carbon Tillet single skin seats support at shoulder and headrest level is recommended. If I was available you could try mine on your way to see JK but either way given budget constraints and what you are using the car for I think you are probably doing the right thing paying them a visit. Quote Link to comment Share on other sites More sharing options...
s2rrr Posted December 21, 2014 Share Posted December 21, 2014 Gents, Purely by coincidence I was about to make a post next week regarding JK seats once I had collected my 2nd seat. I have a pair of there seats which have attached bases and are fitted with my sliding adjusters into a dropped floor car. I found that they are an excellent and comfortable product and have used them for the last 3 years with no issues whatsoever. On or before my last track day I believe I sat into the car rather clumsily and may have strained the drivers seat a little, not damaged but giving me a little concern. Because the seats are base mounted only to allow for the adjusters ( for IVA I thought it best to have adjustable seats) the back of the seat does/did flex a little as would be expected especially when you throw 16 stone at it. If it doesn't flex it breaks. The result being a very minor crack in a small area of the joint surface coating between base and seat at the rear. On closer examination the minor crack was only on the surface matt coating and was not really a problem. I took the seat up to JK for them to have a look at and the response was excellent. They agreed with my diagnosis and could if they so wished have charged me for a minor repair to the resin joint which was what I was half expecting. However they immediately suggested that as they have upgraded there product since mine were made they would remove my original base and fit a new style and in my considered opinion a much stronger base unit with a newer type of attachment bonding agent, and I may add at no cost to me. This to me these days is truly refreshing, to have a company offer a proper solution and in fact a modification is exceptional and these two guys should be complimented on there business strategy and customer service. Whilst they had the seat I asked them to carry out a further mod by attaching one of there rear brace units which further strengthens the rear and provides bolting positions for brackets to go onto the bulkhead. As Dave (Gadgetman) recommended some time ago for heavier than general road use it would be sensible to have fixed bases and upper rear braces. The original decision to go for base mount only was made due to the need in my mind to have adjustable seats for IVA. For track days etc the current mounting is superior to previous. I have literally just bolted in my drivers seat to enable me to measure up for the brackets when I saw this post. As my car is only driven by me the need for the adjusters is no longer necessary and I am currently awaiting my passenger seat which is having the upper brace/bolting attachment bonded on, expected maybe tomorrow. So to sum up, the decision to go for base mounting only was mine and has and probably would be good enough for years to come. The new base and bracing is in my mind an upgrade and JKs assistance and response was brilliant. They are only a small team working out of their property in Southport and are striving to make there operation more efficient and I personally wish them well . If you discuss your requirements with them they will help you out and make you a set of bespoke seats to your specifications. Can't ask more than that can you. I must also say I am in no way connected to JK nor looking for preferential discounts etc just giving credit where credit is due. Bob Quote Link to comment Share on other sites More sharing options...
peet Posted December 21, 2014 Share Posted December 21, 2014 My JK's are the best upgrade I made to my car. I have later type base on the driver seat and the passenger seat has a large flat bar with 3 bolts and the brackets which I have fitted to a beefed up section of the rear panel. I can't use the brackets on the drivers side as I only have little legs and they'd be very long!! I bought an OMP slider for the drivers side which has very little movement. I always weld bolts to seat frames as it helps keep them in place with no slipping plus it makes life easy!! I am however thinking of fitting a lowered floor now as I sit level with the screen top. Quote Link to comment Share on other sites More sharing options...
Steve M Posted December 21, 2014 Share Posted December 21, 2014 Do Jk usually attend the Stoneleigh show? I think I'll wait to try the options for size in person Quote Link to comment Share on other sites More sharing options...
DerekJ Posted December 21, 2014 Share Posted December 21, 2014 Hi All, Can anyone do a comparison between the JKs and Kit Spares two part seats? Cheers DerekJ Quote Link to comment Share on other sites More sharing options...
CraigHew Posted December 21, 2014 Share Posted December 21, 2014 Glad your recent wheels/tyres/bodywork nightmare hasn't dented your upgrade enthusiasm. I look forward to your future posts about seat problems, flexibility, runner offsets and bums fouling the bodywork............ Quote Link to comment Share on other sites More sharing options...
Dave Eastwood (Gadgetman) - Club Chairman Posted December 21, 2014 Share Posted December 21, 2014 Do Jk usually attend the Stoneleigh show? I think I'll wait to try the options for size in person No, to the best of my knowledge they don't do any shows. In fact word of mouth keeps them so busy I don't think the poor lads get out of the workshop for much longer than it takes to make a cuppa! You need to visit them if you want to try anything. (Or trying examples in other members cars at shows or Area Meets is usually the most popular method of giving them a whirl) You'll be hard pressed to find a friendlier, more helpful company than JK Composites. Bob, any chance of some photos of the new mods to the seats, be great to get some up on the Boardroom? Quote Link to comment Share on other sites More sharing options...
s2rrr Posted December 21, 2014 Share Posted December 21, 2014 Dave, the seat base is similar to that of previous but is made out of what appears to be a denser plastic material than before. The corner supports are the same thicker material. I will whip my seat out tomorrow now and take some photos of the base and the rear support bracket. Bob Quote Link to comment Share on other sites More sharing options...
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