Skorpion parts

[Dullthud]

Bill.

Thanks again. After a bit of investigation I've found a place selling new Brembo calipers pretty cheap. In fact, way cheaper than the MZ/Grimeca replacement I had been considering to get round my problems.

I'm aware of Helicoils. Usually for all the wrong reasons. They have saved the day in the past. Did the TZR/SZR brake plate fit straight on? Same thickness, swing arm pin in the same place?

Cheers

Andy

[Bill Jurgenson]

No, the Paioli brake plate fits together with the Brembo wheels it goes with. Offset is different than the MZ and the rotor is smaller.Those are the various rear wheels of the SZR, TZR and TZ250 3MA I repeatedly try to convince Skorpion riders to use. The 1993 prototype has exactly the TZR wheels at the top of this list. All can be had new of course from Yamaha - but don't ask the price unless you are seated.

sorry, I don't have a better pic.

TZR: 2.75/17" & 3.50/17";
TZR: 3.00/17" & 3,50/17";
SZR: 3.00/17" & 4.00/17";
3MA: 3.00/17" & 4.50/17"; pretty rare
3MA: 3.50/17" & 5.00/17" these are rarer than hen's teeth.

That's right: 2.75 & 3.50 running 110/60 and 140/70 tires.
That is more than enuf for the weight and possible performance of any street legal Skorpion.
Why on earth they went to the Grimeca crap after the extensive Spain testing is anybody's guess and one reason some very good and faithful MZ dealers were more than just pissed off, having ordered as many as 100 Skorpions based on the testing they had been a part of.
Whatever.
All those wheels can be mounted more or less easily. The 2.75" front has the advantage, if one thinks it is an advantage, of being able to use the stock mechanical speedo drive. I have fitted it once for a customer who absolutely wanted to retain the original instruments. The other wheels are too wide in the hub and only fit without the speedo drive. Initially, I didn't even notice this because I had replaced the original instruments long before I started to fit these wheels.
Anyway, the Yamaha/Brembo wheels have a 17mm axle in the front and 15mm in the back.
The 3.00"/17 wheels are all the same wheel regardless of the bike it came from and color; TZRs are black, SZR and SRX are gold. you must use the 17mm axle; there are no bearings with 20mm ID that fit the wheels. This is not a problem since the original TZR/SZR axle fits fine; the threading is M16 in any event. The spacer on the right must be shortened a little bit, that is all. Nothing must be done otherwise, caliper and rotor are perfectly in line when the wheel is centered.


At the rear, you can either change the bearings to 17mmID, drill out the brake plate and use the MZ axle or make a new rear axle in 15mm, putting 17OD/15ID bushings in the chain tensioners, and leave the Brembo/Paioli parts alone. Both ways work. You have to make the spacers one way or the other. Rotor/caliper alignment is always correct simply because the brake plate and wheel belong together and the spacer between them remains the original OEM part.
http://www.zabernet.de:16080/bill/pdfs/Distanzhuelsen.CAD%20(Brembo%20spacers).pdf
The pic a couple postings farther up shows the SZR/TZR 4.00" rear wheel. The SZRwheels were also used in the last model of the SRX, a bike well worth consideration but pretty hard to get; it was not imported to continental Europe nor to the US as far as I know:


monostrut in back, 17" modern wheels, larger fork, better brakes, oil cooler, electric starter...

here is the 5.00" rear wheel from the 3MA mounted in the Skorpion:


Fits just as well and with no more work than the 4.00" wheel. That 4.00" wheel farther up has in fact a 15mm axle.

I ran the 3.00" and 3.50"/17 wheels in my Tour with 110/70 and 140/70 tires.

The Tour is dismantled now and a friend has those wheels in his Tour. He had been here for routine maintenance, new tires, along with mounting a smallish fairing. I talked him into mounting my wheels which were just standing around in the corner, putting his Grimeca wheels with the new Bridgestones on the shelf - where the still are.
He was flabbergasted at the difference in handling and performance those wheels made. As soon as he got home, about 70mls from here, he called me. Almost like a bicycle he said, comparable to his Simson Sperber he had had as a kid. Here is that Tour with the streetfighter fairing and wheels mounted:

He also has the lightened flywheel.freewheel assembly I do and a TDM CDI, but those mods had already been done a couple of years before. He now claims that he can give those KTMs a really hard time, With a straight-forward stock engine.

Lower mass, lower rotating mass means better acceleration, better braking, easier turn in. You also get better tire wear, possible use of softer springs and the possiblity of a generally better springing/damping setup due to the reduction of unsprung weight.
Add to that a shorter final drive ratio and really good chain and you have gained the equivalent of about 5hp in real-world, on-the-road performance without so much as touching the engine.

[Dullthud]

Shame it won't fit straight on. I just found a whole SZR rear brake assembly on e-bay. I think next year I will think about better wheels. Too much work right now and I don't have a way to make up spacers. I just need a working rear brake for legal road use. I'm not sure what size the standard wheels are or the axle. I only have an SZR manual. I'm working blind and guessing on all the Skorpion cycle parts. I must get the ruler out next time I'm with the bike.

Which TZR are you talking about? The 250, I guess. I may set up a standing e-bay search. I'm certainly not going to pay Yamaha prices. I'd rather keep the standard clocks as I got the bike for it's looks. Clocks included. I just had the movement replaced in the watch.

Thanks for all your time Bill.


Andy

[Bill Jurgenson]

Skorpion wheels are 3.00/17 and 4.00/17 just like the SZR and the last SRX.
Front axle is 20mm with M16 threading
rear axle is 17mm with M16 threading, the same as the swingarm axle.

TZR is the 125, the 250 is only TZ or TZ250R.
I mean the Belgarda (Italian built) TZR as opposed to the Japanese model.
The TZ model is the last one, 3MA, also referred to as "reversed cylinder" because of the V engine with the exhaust port of the standing cylinder towards the back.
The TZR wheels are relatively plentiful and not expensive. I have a set here that could go, too. As well, I can supply the spacers if necessary. SZR wheels are not so easily come by and not cheap, especially the back one which is also relatively rare since it was used in only a very few models. The SZR front wheel is more expensive than the TZR wheel, too, altho it is exactly the same wheel except for the color. The more common 2,75" front of the TZR 4FL is usually cheaper.
Set up a eBay standing search for all those wheels. When the TZ250R wheels do turn up, make an announcement in every forum, please.
go for the SZR rear brake assembly in any event cause it gives you both pump and caliper. You can always sell the brake plate in the end. I'd buy it. Or keep it until you do have time to rebuild.

[Dullthud]

Bill.

http://cgi.ebay.co.uk/YAMAHA-TZR250-FRO ... dZViewItem

Seems there may be a slight nomenclature issue on the TZs. We seem to have TZR250s and TZ250Rs here in the UK. I don't know enough about them, how they differ and how they were marketed. I'm more of the RD generation. I found this front wheel though. A lot of people seem to be adding 2MA to there listings. Don't know what that means, but you mention 3MA in your post. I know people race these and other Yam 2Strokes in the club level Past Masters series here.

Thanks for all the info about dimensions on the running gear. Changing the axle width must create havoc with the forks, no?

By the way, I have bought brand new Brembo front and rear plus all unions and washers, delivered for 160quid. Could have been a bit cheaper for P32f rear caliper but it's not threaded. P32g can be ordered ready threaded, so no helicoils. Price increase about the same as two helicoils.

Have a good weekend.

Andy

[Bill Jurgenson]

the wheel looks right; ask the seller what rim size that is.

TZ were made with 18" and 17" wheels in widths from about 2,50" on up, depending how far back it goes.

the 2MA is the older parallel twin version and it has narrower wheels, too narrow for us, most 18" as well. Often TZR 125 wheel are fitted to these.

I found something:
http://cgi.ebay.co.uk/YAMAHA-TZ-250-350-RG-REVERSE-CYLINDER-WHEEL-RS250_W0QQitemZ330190697111QQihZ014QQcategoryZ10490QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Not a brembo, biut the right size. Looks like a Dymag which would not be at all bad.

http://cgi.ebay.co.uk/yamaha-TZR125RR-front-wheel_W0QQitemZ160182631833QQihZ006QQcategoryZ10490QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
This is the 2.75/17 wheel.b This one works.