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hi all, ive been searching for a mk1 lazer zxr for sometime, but havent found one reasnobly priced as yet. i was thinking about buying a lazer zx and converting to a mk1 zxr, just wondered if anyone could tell me the differences between both cars, from what i understand so far there are the differences
shock towers
wing mount
ball diffs (zxr)
wishbones
top deck
body / wing

anyone know of any other differences? or or anyone selling a stock mk1 zxr?

thanks in advance.

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Most difficult parts to find I think are the proper square post battery holders, and the mk1 front shock tower. Seems like Nobody has them stashed away anywhere.

I cant remember if zxr mk1 used medium or short front shocks,, but good luck finding mediums at a realistic price.

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Question is what is it for?

If for racing buy the chassis for the zx as it was better, top deck for mk1, towers, well I prefered the mk1 rear tower but the front mms semi circular tower was and still is the best made, then the mk1 steering brace as its better than the mk2 angled version plus easier to cancel out bumpsteer, mk1 L brace, the servo plate is the same, the zx battery brace and poles are what I still use and better than cf. All flat bits available from fibrelyte in my links below, the bodyshell I use is a tomcat on the Kamtec link also below in my links but youll need ebay to find a ZXR undertray. Shocks standard associated will do but would advise using much longer ball joints on the shafts as there isnt as much droop and is costly if your aiming for an A final using them.

Ujs you can use kyosho LA245 with a different axle 231.02, think its LA as well for the rear (if I recall) and think LA232 for the front axles but with the wider front end with the mk2 castor blocks. Its a start so hope its of use.

Also as per Terry below mentioning I did forget wheels, Ansmann Mad Rat wheels are identical in depth and width to the 2.2 wheels used on the MK1 & 2 ZXR's but are as good quality as well plus yes the zx wing mount tbh was pants so the mk1 version is what I use with two steering poles between them as it gives strength so longer life for the wing.

It does depend on how accurate you want to be, and there are a lot of differences that haven't been mentioned.

ZX transmission is front and rear gear diffs with a centre ball diff on the layshaft. The ZX-R has ball diffs front and rear and the centre diff replaced with a slipper clutch. Also the ZX uses a 0.6 module metric spur gear while the ZX-R changed to 48dp.

The chassis plates are the same between the ZX and ZX-R Mk1, but the ZX-R got rid of the belt guard and replaced the two piece top deck with a one piece version.
The ZX-R Mk2 moved the batteries back in the chassis to change the chassis balance, this meant the ZX-R Mk2 also had a new chassis, top deck, rear deck mount, motor mount and gearbox side plate.

The battery holders first used the round posts and body clip fixing from the Optima Mid, but with a fibreglass strap. The ZX-R Mk1 changed to the square posts with the battery strap held on by moulded in clips. For the ZX-R Mk2 they reverted to the original standard posts and body clips. Most racers swapped out the square ones for the original ZX ones anyway.

The suspension is the same, the ZX-R version of the wishbones are just ZX ones without the extra webbing. New shock mounts and medium length shocks on the front while the ZX uses short front shocks. If you are planning on racing your ZX-R then a shock mount which has a bridge joining the tops of the shock mount together will stop the front gearbox getting destroyed in a roll. Fibrelyte make a suitable shock mount. Steering centre link is different, the ZX uses a straight link while the ZX-R uses a link with each end angled forwards, this is to reduce ackermann in the steering for a more aggressive turn in.

Wing mount is different, the ZX mount is the same as the Mid, mounted on the shock mount support. The ZX-R uses the Triumph wing mount bolted onto the shock mount. Finally the ZX uses 2" wheels from the Optima Mid, the ZX-R uses 2.2" wheels.

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The zxr mk1 I built years ago from the box was one of those oddities. I remember distinctly it had the mk2 front tower, but it also had 7 cell chassis, and older style slipper clutch. It did have gold shocks. I thought it also had the round battery posts,, but not sure. it was a long time ago. A guy on fb posted an addendum to zxr manual, that was supposed to be the addition for zxrr, but it seemed incomplete. I thought there were more differences between zxrr and mk1 models.

I think what happened, is that updated parts were put into kit boxes, and only some of them were documented in the instructions and addendum.

I know that my instructions for zx-s is little more than an add in, even though its a totally different car!

Did any of the Lazers ever use the plastic otw-9 battery straps?

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I think some of the lazer kits had the plastic battery straps on the parts tree, but those kits likely also had the frp battery straps in a bag. Lots of un used parts on the plastic parts trees.

Every set of frp battery straps I see is one short and one long but the la-60 chassis would need two short. Is it possible to get a pair of short straps?

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I've got a couple original Lazer ZX's if you need pics of anything.

Thanks for all that info. I didn't realise Kyosho also changed the length of the front la-26 wishbones, I'll have to compare all the arms I have now. I also have two sets of the la-104, one for my zx-s and one for my runner
So many little differences, you always learn something new.
I have many NIP parts here and trying to put aside in three boxes what is required to build a ZX, ZX-R MKI and ZX-R MKII and build a spare car with the leftovers to sell. I think I'm pretty close now.