Z1OwnersClub GB

Can anyone positively ID this 18 inch aftermarket wheel ? It has no cast markings anywhere. I picked it up recently, it seems to be the standard 4 bolt Kawasaki disc fitment with a couple of (with some difficulty) removable additional pegs on each side too (what the hell do they do ?)

It looks like it has been modified at some point in its history to take a speedo drive. I was hoping (long shot I know) that it might drop into my modified Zed, but initial checks show that where my front discs measure 126mm OD outside to outside, this wheel would come in about 7/8mm wider in that area, so I guess I'd need to find someone that can machine the hubs so it'll go between the forks.

I "believe" the wheel may be CMA ? or possibly early Dymag even, but trying to find any info on CMA is very difficult. It seems the company popped up and popped off in the Ipswich area quite a few years back. Someone suggested CMA Aero, but I have not heard of those. The holes to mount the disc are 10mm, but curiously are 10mm coarse at 1.5, not 10mm fine 1.25 as most Jap bikes use.

Any ideas ?

It looks like a cma aero,made in mildenhall suffolk

Thanks

After going lightweight caveman with a hammer and punch this afternoon I have sussed the peg thing, which may also sort the disc spacing issue.

Those are actually machined 4mm alloy spacers in the middle of the hub, that were held in place by pegs and interference fit. They had been machined so precisely that they seemed to be part of the hub ! They are off now.

The wheel hub has no stops for the wheel bearings though - there is a centre spacer, but it's guesswork getting them in the right place. A bit industrial for what would have been an expensive wheel ?

CMA, definitley

Thanks guys

My CMAs use a circlip on one side of the hub as a bearing stop. Fit the bearing on that side first. The axle tube / bearing spacer then dictates how far the bearing goes in the other side.

Watch when you are drifting the bearings out that you aren't hammering against the circlip else you could damage the wheel.

I'll wager that you have at least one blackened nail per set of wheel bearings changed.

Fred

There were no circlips on this one Fred. The bearings seem to line up by being flush to the outer edge of the hub, at least that's where they sit with the centre spacer in place - give or take a couple of mm either way. Maybe the circlip had been taken out and discarded, I hadn't noticed a groove - or maybe it never had one ?. Next time out I will look more closely.

The bearings themselves were actually quite easy to drive out once I realised I could move the centre spacer to one side in order to get a proper purchase on the bearing outer race using a long punch. ( I have done the black fingernail thing before too - I use longer bars now lol)

I am glad I got them out, whoever had drilled those additional spacer/peg holes must have done so with the bearings in situ, cos all the swarf was still floating about inside the (very roughly cast) hub centre, where it could make contact with the bearings. The centre spacer in particular was covered in swarf.

Fortunately the bearings (6203DDU) being sealed both side had stopped any real damage being done. It's all nice an clean in there again now

What was the score with CMA though - does anyone know ? The only CMA's I had seen previous were 3 or 5 spoke ribbed types. I think Warren has some 3 spokes on his Z650 rebuild ? I had seen nothing on the Aero's though. I had heard of CMA and I can find a company record in companies house that said they went bust in the early 80's, but even in my old bike mags, I can find no adverts or anything at all about them ?

I seem to remember that CMA wheels got a reputation for cracking, but I could be wrong, which is probably why they went bust, and that reputation could be entirely undeserved.
I read MCN, Bike and Mechanics at that time, so the info would have came from one of those

Julian,
I never heard of anything, but Maybe the early CMA's 5 or 7 spoke ones but even those are heavy.

I believe they may have done Magnesium racing versions of these wheels and the road wheels which were aluminium. Maybe it was the magnesium ones?.

These ones look aluminium as they have exposed rims. So should be fine.

TPS are a good company to use if you have any doubts run by an ex dymag guy he can scan the wheels for cracks and does powder coating etc.

Personally I dont think these ones would be an issue but would get magnesium ones checked first before use.

These are the same wheels fitted to my B2, I bought them new in 1989 I think, took ages to arrive and although the finish quality isnt the best I've never heard of them cracking, I had them powder coated last year so they were blasted and inspected for cracks at the same time, still good though. They are made of aluminium and are quite heavy, not a dymag by any means (at the time were about half the price) but they allowed me to fit a decent width 18 inch front wheel which improved the handling no end.

Nice B2

I'm probably wrong about it being CMA wheels that were cracking, as I said it was a memory from a long time ago, but I thought I should say something just in case.

Thanks for all the feedback. That GPz looks ace What are the discs on that ?

I have been cleaning the one I have up and its coming up nicely. I always prefer polished rims, so I will get the paintwork refinished and have the rims polished again. (I don't have a pair of CMA's so, I will be using a GSXR slabby 3 spoke rear wheel that looks very similar, taking off my Metmachex swingarm and using a polished Zephyr item)

My front also has a 110/80 x 18 tyre fitted to it, but I have a couple of issues with that. a) I am not sure if I will get a 110/80 under my stock Z1000 Ltd style mudguard and mainly b) I want to run Pirelli Phantoms.

The new Phantoms are radials and so lighter and better made than x ply's, but still give that period look.

I have the rear (150/70) 17" Phantom on the way, but on the front it'd either mean fitting a 100/90 x 18 (dont do a 110) on to this CMA rim and using my existing front end set up (its already uprated with floating discs and 4 pot calipers)

....or I use a ZXR750 front 17" wheel I have ready, which means changing the front end to ZRX1200 too ... I have all the bits to do that, but like the chrome mudguard and setup I already have.

1985 - 87 GSXR750s have 18" 6 spoke wheels
1986-87 GSXR1100s also have 18" 6 spoke wheels
1988 GSXR1100s have 18" 3 spoke wheels
All of the Slingshots have 17" wheels
Just saying in case you need to buy parts for it.

Thanks JB

I have a GSXR750M/GSX600F/GSX750F 17" rear, technically not exactly from a slabby, I know lol.

I only said that to differentiate it from being one the later, fatter rears. I don't want to go too wide, just wider than the stock rear tyre This one will take tyres from 140/80 to 160/60. I am going right in the middle of that at 150/70. All those rear wheels are basically the same. It has been painted now, I just don't have it back yet.

This is it post polishing and pre-paint.



It all gets a bit convoluted after that, but I have a suitable disc, caliper, sprocket carrier and sprocket machined/adapted to make it fit into a polished 400 Zephyr eccentric axled swingarm. The front of that arm I had machined to fit straight into my Zed frame and existing pivot bolt. I always try to modify the bits to fit the bike - not the bike to fit the bits wherever possible. It can always go back to stock(ish) that way should I choose . The wheels will end up dropping the bike by an inch front and rear when its finished, which will help keep front and back in proportion. (near enough)

I am undecided whether to drill the CMA casting to match the rear wheel .... Its a case of balancing aesthetics with possible safety issues though....I think safety may win out, unless it really looks odd.

My J has a 750 Zephyr swingarm (I think, it might be from an 1100) and a Kawasaki wheel the same width as yours, it has a 160 tyre on it, chain clearance is fine, it has a dished front sprocket to maintain chain alignment.
All fitted to the bike before I bought it.