New Member with Rickman MZ

[traderyoda]

Greetings All,

I have a rare Rickman with an ISDT 250 MZ motor in it. Restoring it now. Looking for old pics of the bike if anyone has any.

Happy for the chance to contribute to the Forum!

Cheers,
Lee

[Puffs]

Welcome Lee!

That sounds very interesting - can you show us some pics please?

[traderyoda]

Will do - I'll shoot some as soon as I can.

[Blurredman]

[traderyoda]

Here are some pics of the Rickman MZ Metisse. I've torn the bike down to gently restore the nickel plated frame which is overall in excellent condition. The motor is a 250 ISDT motor. It has great compression, but the dynamo is a wreck.

[Puffs]

Thanks!

What I'm seeing looks quite gorgeous. Front hub looks similar (if not same) to my '68 CZ 980. Are those footrests really non-hinging?

In classic MX, at least here in Europe, everything needs to remain as close as possible to how the bike was originally made. But an exception is made for the ignition: electronic ignitions are accepted, and many people have them. Don't know what it's like for enduro machines, but for a bike like this I would consider one of those nice Vape sets; that would sort out your dynamo.

[traderyoda]

Those Rickman "ankle buster" foot rests are strong but somewhat impracticable. Slippery too!

The MZ has a Rickman aluminum conical hub up front. Good unit, but not the best brake setup out there.

I won't change anything on the bike. I do need to ensure that no one removed any parts over the years though. I'm trying hard to find earlier pictures of the bike, including when it was offered on on eBay in December 2009 - hopefully someone on this Forum kept those pics.

It was built as an experimental machine for a fellow in California (Lynn Wineland) and tested in the desert to evaluate the capabilities of the motor. The exhaust is the ISDT version, but it wasn't initially shipped for England this way. I suspect the pipe Rickman installed was a poor match for the power band of the motor, so it was removed and the ISDT pipe installed; I'll leave it this way.

I suspect the electrics on this bike were never really sorted out properly. I see signs of burned out parts and the wiring harness was hanging loose. The case was left loose and a mouse ate all of the wiring on the dynamo. Perhaps the dynamo, designed for bike with lights, was never adjusted for a MX/desert racer with no lights. I'll first try to see if I can rebuild the dynamo and ensure the output is matched to the twin-coil ISDT setup. If not, I did find the VAPE setup and will go that way. I'm sure someone on this extensive site has set things up on a machine with no lights.

[Puffs]

Of course MX bikes don't have lights (and you can buy ignition-only sets, from Vape & others too), but I believe ISDT machines are Enduro bikes, so road-legal & with lights. At least they were the time I joined in ('93 Assen ISDE).

Let's hope someone else chimes in.
In the mean time some internet pics of the factory MZ ISDT machine:

MZ ISDT ('69 - '74), RH.jpg (54.36 KiB) Viewed 110 times

MZ ISDT ('69 - '74), LH.jpg (53.93 KiB) Viewed 110 times

Rickman's version, with the beautiful Zündapp 125cc engine:

Rickman Metisse ISDT Zündapp 125, '74.jpg (37.17 KiB) Viewed 110 times

[traderyoda]

I gained a lot of respect for these motors in starting to go through it. Easy to see why it did well in the ISDT.

Here's a picture of the dynamo after I cleaned it up. I'm about to pull it out.

Are there any manuals for rebuilding these motors in English. I purchased a maintenance manual in German, but it doesn't cover tear down in much detail. I have a wiring diagram for the ISDT bike, but I'll have to sort out the dynamo by just learning as I go.

[Puffs]

That looks quite familiar. Does it have a battery?
Anyway, I'd think improvement is possible, unless of course you aim at keeping it entirely original.

In English you might find much on the engine in the ES and/or TS manual, kindly provided by member Blurredman on his ftp://blurredmanswebsite.ddns.net/Vehic ... Documents/. In German, look at http://www.miraculis.de/aw/download/load.html.

[traderyoda]

That's incredibly helpful - thanks!

No battery and no room in this machine. And no electronics to accompany the dynamo - just direct output sent to the dual-coil arrangement with a small capacitor bridging across each coil. A toggle switch was mounting to switch between coils.

[Puffs]

OK, then they replaced the standard battery-driven field coils by magnets. Makes sense.

Yes my CZ also has 2 plugs: with the mineral oils of the era you needed a very rich mixture, causing frequent plug fouling. Either that, or you use a warmer plug to start & warm the bike up, that's how I use the dual plug arrangement. But I don't really need it, with an NGK 8 + modern synthetic. That's good, as I don't have a switch - just a single coil & a single plug cap. So I have to press the Kill Switch.

Btw, I also still have points on that bike.

[traderyoda]

I'm not sure that they performed any mods on the dynamo - I'll be excited to see what I find when I pull it out!

[breakwellmz]

Those Rickman "ankle buster" foot rests are strong but somewhat impracticable. Slippery too!

The MZ has a Rickman aluminum conical hub up front. Good unit, but not the best brake setup out there.

I won't change anything on the bike. I do need to ensure that no one removed any parts over the years though. I'm trying hard to find earlier pictures of the bike, including when it was offered on on eBay in December 2009 - hopefully someone on this Forum kept those pics.

It was built as an experimental machine for a fellow in California (Lynn Wineland) and tested in the desert to evaluate the capabilities of the motor. The exhaust is the ISDT version, but it wasn't initially shipped for England this way. I suspect the pipe Rickman installed was a poor match for the power band of the motor, so it was removed and the ISDT pipe installed; I'll leave it this way.

I suspect the electrics on this bike were never really sorted out properly. I see signs of burned out parts and the wiring harness was hanging loose. The case was left loose and a mouse ate all of the wiring on the dynamo. Perhaps the dynamo, designed for bike with lights, was never adjusted for a MX/desert racer with no lights. I'll first try to see if I can rebuild the dynamo and ensure the output is matched to the twin-coil ISDT setup. If not, I did find the VAPE setup and will go that way. I'm sure someone on this extensive site has set things up on a machine with no lights.

A bit more background here -

"In March of 1965 MZ sent Lynn a factory works ISDT style 250 cc two stroke bike asking Lynn to test it in his environment. By this time the Rickman kit was finished, with Triumph 500cc power. The first race on Saturday was a European Scramble with two races and the total scored for the day. There was a separate Enduro on Sunday. The Rickman chain popped off three or four times during the race and Lynn still won his class. The Mark III and Mark IV Rickmans use eccentric washer for the chain adjusters and they were back at home. The race referee allowed Lynn to ride the 250 MZ and it won the second race competing against 500cc machines. The next day the MZ finished the enduro but without a speedometer Lynn only finished 17th. When all was over Lynn was allowed to keep the MZ which he only recently sold to a collector in Iowa. Lynn snagged another MZ factory engine and sent it to the Rickmans in the UK to make a prototype frame. Lynn still has that bike today. The plan was to buy engines (both 250 and 350 cc), hubs and brakes (innovative brakes that reside on the exact centerline of the wheel reducing any tendency for the bike to pull to one side on slippery surfaces). But there was an up rising in Czechoslovakia which East German solders helped the Russians put down and the US government increased the duties from East Germany from 9% to 45% as a sanction against their actions. So there went the MZ Rickman."

[Puffs]

Very interesting story!

Now I guess that with the Ostmark having the value that it had (typically 5-10 to the DM), anything coming from the DDR was cheap, and still cheap even if its price increased by 36%? Ah well, maybe too simple a view.

Focussing on the technical: I don't quite understand the story on the hubs, with brakes that reside on the exact centreline of the wheel to reduce any tendency for the bike to pull to one side on slippery surfaces. Can anyone explain how that works? I suppose the hub is stiff, so for the hub it does not really matter where in the hub the braking torque applies, right?

However, the counterforce (via the brake plate) is conventionally on just 1 fork leg, so very much off-centre, and that will cause the forks to twist a bit (or pull to 1 side) during braking. It will do so on any surface, though less on a slippery surface as there the braking forces will be lower.
Sometimes you see a bracket connecting the top parts of the 2 lower fork legs over the wheel, or a stiff mudguard, to reduce this & other instabilities. But of course on an enduro or MX bike that is impractical, mud build-up (or a rock) will block the wheel.

What can cause some effect during braking is that asymmetric hub, causing the spoke lengths to be different, the spokes to be attached at a different distance from the centre, and under different angles. Under braking that might cause the rim to move a little sideways wrt the hub.

Anyway, on a slippery surface (say, a frozen wet underground with the top 1-2 cm thawed) all that is less important. Keep your balance, look ahead & keep rolling is all that counts.