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6981marlin 23rd January 2014 17:55

Sportster Seats
I am looking for some cheap seats for my marlin sportster, can anyone recommend some ( I need to get through iva with them)?

MartinClan 23rd January 2014 19:09

I used seats from an MX5. They just about squeeze in. I recovered mine using some leather covers but you could use them as they are if you are on a limited budget. They are considerably stronger and more comfortable than most aftermarket seats.


peterux 23rd January 2014 19:59

Ditto what Robin has said. I've been in Robin's car and his MX5 seats are very comfortable. They come up regularly on ebay.


morris 23rd January 2014 21:23

Do the MX5 seats flip forward too. That's something I was looking for to provide easy access to the boot (if you can call it that). I saw some Alfa GTV seats on ebay but they looked a little wide

cabrioman 23rd January 2014 21:41

Morris, It might be worth checking out Porsche 997 seats, there are a couple of pairs on ebay at the moment. See item 161177135076

They are pretty narrow, i was told 440 mm at the widest point on the seat bolster but that might not include the adjust lever.

I have not measured them in the flesh myself but requested measurements from the seller to see if they would fit in my Cabrio.

They are always in leather and around £500 a pair but quite often seem to be in as new condition.

morris 23rd January 2014 22:51

They do look quite nice actually, very similar in design to some of the MX5 seats too. £595 plus delivery is quite a bit though but I bet that they're still more comfy than aftermarket ones that cost close to that each. I'll keep them in mind


MartinClan 24th January 2014 08:27

The back of the MX5 seats does flip forward but movement is limited as it is a very tight fit. In order to fit them I had to

1. Reverse the seats so the passenger one is on the drivers side and vice versa
2. Remove the integrated seat belt mounts (angle grinder!)

I was able to use the standard seat sliders that came with the seat to allow for front/back adjustment although they did require a bit of modifying.

In my view one of the big advantages of this seat is that it has a very sturdy steel frame and would certainly contribute towards safety in the event of a prang. A lot of the cheaper aftermarket seats are extremely flimsy being no more than a thin plastics shell with a bit of padding.


morris 24th January 2014 17:12

I'm not so worried about the integral seat belt mounts as I think I'm going to have to go for over the shoulder type straps anyway so swapping sides doesn't matter too much. What mods did you have to make to the sliders?

What are peoples verdicts on the Interior Seating offerings?

I know that Nigel and Jason fitted the 1191s.

I'd be quite happy going for the RX 777s style wise

The main thing putting me off these seats (apart from the price) is the lack of any rake or adjustment to the angle of the base which you'll probably get in most seats from more modern production cars.

MartinClan 24th January 2014 19:15

I think all I did to the sliders was to mount them off the floor using some spacers as on the mx5 the seat is located in a dip on thefloor. I may have shortened them as well but I dont fully recall. It was over 5 years ago. There may be some pictures on my web site.


NigelB 24th January 2014 23:14


Originally Posted by morris (Post 51279)
What are peoples verdicts on the Interior Seating offerings?


I'm really pleased with the 1191s I fitted. I think I'm a similar height to you (6ft 2in) and I haven't missed the lack of adjustment at all. There's been a couple of occasions when I have driven for 2 1/2 hours with out a stop with no discomfort whatsoever. I would have no doubts about recommending the seats but they do come at a price compared to what is available on Ebay.

Cammy 26th January 2014 16:49


I managed to get a pair of Suzuki Cappuccino seats from my local dismantlers for £120 because there was a small tear in the drivers seat. Very comfy and compact - they fit nicely into my Sportster, they slide backwards and forwards as well as folding forwards and the head rest is adjustable. Have not past IVA yet but am not anticipating any issues with them.

I am about to post a link to Flick where you can see some pictures of the seats and my build so far.



morris 27th January 2014 18:35

Nigel, yep I'm a good 6' 3" and shall we say "big boned". The main reason I want rake adjustment is I get neck problems so need my seat very upright but good to know they are generally comfortable.

Cammy, yes I was just looking at your photos and the Suzuki Cappuccino had completely slipped my mind. they look quite smart too. The other one I was looking at today was MGF seats but they appear to have a strange arrangement on one of the sliders at the rear where the mounting hole is in the vertical plane rather than the usual horizontal. No doubt some bashing and welding would solve that. The leather ones actually look quite nice for a rover derived part. These are the ones that caught my eye though there are much cheaper ones around

morris 16th February 2014 17:17

OK, so I've bought some MX5 MK2.5 seats in very good condition.

They have the rake adjustment but the problem is, with the plastic cover for the rake mechanism on, the seats won't go back past the wide point in the foot well. If you take the cover off and the seat belt mount, it goes back a little further but still not enough. Swap sides and it's even better but the rake adjuster spring mechanism still juts out too far.

So here's the question. Is there any reason why the rake has to be sprung loaded for IVA or MOT? If I remove the spring and chop off the pin it sits on I'm pretty confident the seat will go right back against the rear bulkhead. This is all the IVA manual section 15 says

"3. Each seat, seat back adjustment and seat displacement system must incorporate an automatic locking system which operates in all positions provided for normal use."

I read that to mean as long as it locks in position, the fact you may have to move the seat back into position by hand is irrelevant?

I also need to modify the runners as the bolt points are angled and need flattening out. That should stop my knees from getting stuck on the steering wheel. if the seat can go back another 10cm I may stand a chance of getting my left foot comfortably on top of the clutch rather than under it too :) I'm going to have to put my strengthening bars under the chassis rather than in the foot well just to get the seat low enough to drive let alone pass the "effective seat belt mount point" test

Cammy 16th February 2014 19:28

My Suzuki Cappucino seat mounts
Hi Morris,
I can't really help with the query about the Mazda seats but I did have the same issue with teh runners on my seats being angled. There are some photo's on my Flickr account but all I did was bend the angled bits to 90 degrees then mount the seats on some box steel section. Both seats fit nicely into the chassis and I have clearance for the seat runners as well. I plan to put some bracing at the points where the seats/box steel will be mounted and just need to make sure there is room for the seat belt mounting bolt.



MartinClan 17th February 2014 09:49

I used the earlier style seat with seperate headrests. I had to reverse sides and remove seat belt anchors and modify runners slightly to change the fixings. Other than that they fitted ok. But I am only 5ft 6in so they didn't have to go right to the back.

Cheers Robin

morris 18th February 2014 18:13

I've found this guidance on an MOT rules website

There's some overriding guidance
"When checking the driverís seat adjustment it is not necessary to check that the seat can be secured in all possible positions.
In the case of electrically adjusted seats, it is not necessary to check that any Ďmemory positioní function is working."

And then these 3 specific tests

1. Method of inspection: Check the driverís and all passengersí seats for security.
Reason for rejection: The security of the driverís or any passengerís seat is significantly reduced.

"2. Method of inspection: Check that the backrests of all seats (front and rear) can be secured in their normal upright position.
Reason for rejection: seat back that cannot be secured in the upright position.

3. Method of inspection: Check that the driverís seat position can be adjusted forwards and backwards and secured in the selected positions.
Reason for rejection: The driverís seat fore and aft adjustment mechanism not functioning as intended.

So I read that together with the IVA manual to mean I can remove the big spring that makes my seat come upright automatically when the lever is pulled so long as the seat still locks when the lever is released. The lever itself has a separate spring that returns it to the rest position so as long as that is retained, I should be ok. I'll get my hacksaw warmed up!

Cammy, I also found some websites showing how people have retro fitted MX-5 seats into MGBs, TR6s etc and they've all gone for some reshaping of the bolt points on the runners but flattening rather than increasing the angle as you've done (but I think how Robin did it). As I need to gain as much drop as possible I think I'll need to go the flatten route and stick my reinforcement under the floor.

morris 16th March 2014 13:07

Morning all,

I just wanted to check what people's thoughts are on seat load spreading plates/bars. I've noticed a number of other builders have put a piece of steel box section or flat bar under the mounting holes on their seats which is then attached to the floor pan flanges on the chassis. I'd assumed this was a mandatory thing for IVA to show the seats were secure in the event of an accident. When you think about it the person is the thing that will carry all the momentum hence the strict requirements on seat belt mounting points, not the seat which is relatively light. If the seat belt is fixed to the seat as in production cars it makes perfect sense but not if it's only attached to the chassis.

If you look at section 15 (Seat strength) of the IVA manual it says

" RS - 1. Every seat must be securely attached to the vehicle structure, or other obvious suitable load bearing parts of the vehicle (see notes 1, 2, and 3).

Note 1: If attached to a non-metallic floor pan separate from the chassis, adequate support to spread the load of the anchorage is required, eg spreader plates/stiffening ribs etc.

Note 2: In respect of a seat that comprises of a ďlift-outĒ backrest and/or squab it will be considered secure providing, when in the operational position, it is located such that there is no possibility of accidental lateral or longitudinal movement within the vehicle whether it is in use or not.

Note 3: On a seat to which a seat belt is mounted (integral seat belt) consideration must be given to the seat mounting as part of the seat belt anchorage. "

I read that to mean that as I have a metallic floor pan and the seat doesn't form part of the belt mount, just a high tensile M12 with some decent size washers will qualify?

The only other reason I can see for adding in extra bars is if the floor feels flexible (which it doesn't seem to for me).

Have I missed something?

MartinClan 16th March 2014 18:18

I used 4 off m8 per seat with some small plates about 50mm square under the floor to spread the load. M12 seems rather large to me.

Cheers Robin

morris 16th March 2014 21:15

yeah, M12 is a bit big but the holes in the runners are 16mm so I needed to scale up to something a bit close that a washer would fit over properly without stretching

I've ordered some extra thick M12 repair washers (40mm diameter) which I personally think should be enough to go underneath. Even with the seat bolted straight to the floor with standard washers it feels solid and you're not aware of the flex in the floor pan getting in and out.

NigelB 16th March 2014 23:09


Originally Posted by morris (Post 53454)
Morning all,

If the seat belt is fixed to the seat as in production cars it makes perfect sense but not if it's only attached to the chassis.

Hi Ian,

I laboured with that one for a while too and came to the conclusion, like you, that it's the seat belt / harness secured to the chassis that holds the seat and occupant in place in the case of the unthinkable.

The only reason the seat needs to be secured is to stop it moving backwards under hard breaking (or hard acceleration!!) when your legs / feet are applying pressure to the pedals. Maybe its a bit more than that!! But I don't think the loads on the mountings are significant if you have chassis mounted seat belts

I riveted a piece of galvanised right angle steel to the underside of the floors and into the chassis supporting lips and put my front seat bolts through that, and that was simply to reduce any perceived flex in the floor panels. For the rear bolts I bolted straight through the floor with M8s and penny washers with no galvanised section as the bolts were close to the rear supporting chassis lip.

The IVA man seemed happy, having already checked the chassis seat belt mounts.


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