MOC: Technic Motorcycle

[Front]

Here is my first real Technic moc, a motorcyle based on the wheels of the 2004 set, 8420 Street Bike. These wheels are a great starting point, and they include to disc-like parts that act as disc brakes (the actual discs). The only downside is that the rims on both wheels are asymmetrical, fitting the design of 8420 with single sided front fork and single sided rear sving arm.

Now my moc is very different, here are some basic features:

1: Classic rear sving arm, with monoshock acting in a progressive linkage mechanism, as seen on nearly all Japanese sports bike in the last 20 years.

2: Double wishbone type of front suspension, with the fork carried through ball joints on the two wishbones. Steering is done through two arm connected at another ball joint. This front wheel suspension type is truely magnificient, but really only seen on very few motorcycles. Examples I know of is the Britten V1000 from New Zeeland, , and the currently in mass-production BMW 1000cc sportsbike (four cylinder in-row).

3: V2 engine with cylinder-angle equal to what is seen in 8420 (but that one is V4), and with crankshaft perpendicular to the bike's lenghtwise direction (like on a V2-Ducati). The 8420 crankshaft is along the lenght of the bike, though the cylinders are placed like on a Moto-Guzzi.

Opposed to all other official technic bikes I know of, the chain sprocket is not placed at the revolution point between the rear svingarm and frame, but is placed somewhat further foreward, as on nearly all "real-world" motorcycles with chain drive.

Right hand side of the bike with the chain drive. The rear chain wheel is surrounded by two half-width beams, and the chans is as close to the rear tyre as possible.

When the rear wheel moves upwards, a linkage attached just in front of the rear wheel, pulls at a traingle linkage placed underneath the rear arm, that push the spring in a progressive way.

Left hand side of the bike, showing the small gear wheel at the end of the crankshaft, connected to the output shaft (where the sprocket is placed on the right hand side of the bike), through a bigger gear wheel.

The engine is connected to the frame at two points, and it's placed at a small angle, compared to the lower beam on the bikes frame. This was chosen to reach a good point for the chain sprocket, in front of the rear "sving-arm-point".

The front of the bike with the special suspension (the newer wishbones (three) were taken of the huge 2009 Ferrari 1:9 system set). These wishbones are half a module shorter than the old type.

The really cool thing about this suspension is that the forces from suspension and steering, are seperated in each their own mechanisms. A normal front fork has the built in problem of handling suspension and steering forces through the same joints, making steering rather "tricky" during heavy breaking.

A top view on the bike. The only non-Technic elements used is for the exhaust and the water cooler at the front of the bike.

Bike turned up-side-down. The lowest point on the frame is a "dead end" beam, which sticks out one unnessecary module. I haven't found a way to avoid this yet, but maybe I should use this dead end to fit a bike stand (the grey bike stand added on the other pictures is just a temporary one).

Now I need to consider how to complete this bike with tank, fairings, seat and other body works. I'm not sure if I should stick to technic panels etc. or if I should use system bricks, plates etc. to get the "right" shapes.

I hope my explanation of this moc makes sense also to folks not really into motorcycles. Thank you for looking and any comments are welcome.

Front / Erland

Edited March 26, 2009 by Front

[furious]

good work.

[CP5670]

Cool model, and you explained everything in a lot of detail too. It's good to see more people getting into Technic MOCing around here.

The front suspension is quite an interesting design. I can see how that would be smoother than the standard system used on 8422 or 8838, where the shocks had a tendency to lock up on sharp turns as you said.

Now I need to consider how to complete this bike with tank, fairings, seat and other body works. I'm not sure if I should stick to technic panels etc. or if I should use system bricks, plates etc. to get the "right" shapes.

I think the latter is definitely a better idea, at least for the seat.

[Asuka]

A very clever and ingenious work! I especially like that interesting double wishbone front suspension and the neat rear wheel suspension as well.

The whole gear work and chain drive looks great, and the water cooler´s a, um, cool detail too. I´m curious how the complete bike´ll look like!

[Rijkvv]

Not bad for your first TECHNIC moc. Not bad at all! I can't wait to see this with body work!

[pe668]

Great design. I also found the explanation an interesting read.

[Darth Legolas]

So, wait you design technic/Bionicle parts but you don't build with them? Or am I totally misinterpreting your title?

I'm going to say from the point of view of a not so technical Lego fan that this bike looks great! Of course it could use some "armor" or whatever, but I love the use of the ridgey 1X4 bricks. I need some more of those. Perhaps you could add some springs/shock absorbers in there though? It would be so great if the back wheel could bounce up and down but still be able to resist the strain of the chain, and not pull the chain apart.

EDIT: Oh! There is! I feel dumb now. Taking a second look, I saw both of the shock absorbers. You hid them well!

Edited January 16, 2010 by Darth Legolas

[Milan]

Excellent motorcycle frame!

Suspension is very nice, and tricky to build.

I like it!