[MOC] Cruiser motorcycle with a HUGE single-cylinder engine

[Hedgie]

What's up everyone? I created another motorcycle which I call the "Big Thumper". Why? Because this bike has the biggest cylinder ever seen in a Lego Technic motorcycle! Here is a picture of this monstrosity:

When you push the motorcycle forward, you can actually hear the distinctive "thumping" sound characteristic of big-bore cruisers!

Despite its size, the cylinder fits nicely inside a hard-tail frame:

As you can see, the other main feature is the steering mechanism, which allows the ape-hanger handlebars to be placed on top of the fuel tank. Combined with the engine-mounted floorboards this provides the ideal feet-forward riding position!

As always, the building instructions are available for free on my website and on Rebrickable.

[2GodBDGlory]

That piston looks bigger than the one I took out of a rototiller! Wow!

[DrJB]

Beautiful ... but that 'exposed' chain, is going to be rather dangerous ;)

[Scoar Sonander]

My oh My. That's one 'uge piston! Apart from that, the design is lovely, but I have concerns about the exposed chain, same as DrJB. Great work! 

[Hedgie]

And there's not one, but two chains! It's a pretty hardcore ride

[jorgeopesi]

Cool bike and rear wheel  .

[Hedgie]

3 minutes ago, jorgeopesi said:

Cool bike and rear wheel  .

Thanks! I'm particularly proud of the way it's mounted using two angular swingarms:

It leaves exactly as much room as is needed for the wheel, the gear, and the chain to spin freely.

[Jurss]

Interesting build.

Those chains are really for balls of steel.

What provides structural stability to rear axle? I checked instructions, it definately will move side to side, and do some kind of steering. Maybe I missed something?

[Gray Gear]

It's a original looking ride, and the colorsceme looks good. I like the engine idea. 

But some of the building techniques, especially the way the rear swingarm is constructed, is what I would call "questionable". Did you build this irl too?

[Lira_Bricks]

Nice motorcycle :)

How do you prevent the cylinder engine from dropping? In the steps of page 11 I see a few tiles being placed to hold the cylinder, but that is at the top. I see nothing on the bottom to prevent it from scraping the floor.

[Hedgie]

50 minutes ago, Gray Gear said:

It's a original looking ride, and the colorsceme looks good. I like the engine idea. 

But some of the building techniques, especially the way the rear swingarm is constructed, is what I would call "questionable". Did you build this irl too?

Don't worry, of course I built this in real life first and I took great care to make sure everything is legal and sturdy.

13 minutes ago, Lira_Bricks said:

Nice motorcycle :)

How do you prevent the cylinder engine from dropping? In the steps of page 11 I see a few tiles being placed to hold the cylinder, but that is at the top. I see nothing on the bottom to prevent it from scraping the floor.

The cylinder is 4 studs wide, but the opening on the bottom is only 3 studs wide. It's impossible to fall out!

2 hours ago, Jurss said:

Interesting build.

Those chains are really for balls of steel.

What provides structural stability to rear axle? I checked instructions, it definately will move side to side, and do some kind of steering. Maybe I missed something?

The secret lies in this little Technic Pin 1/2:

It brushes up against the rim of the wheel. Not so much to cause any friction, but enough to prevent the wheel from moving side-to-side.

[Hedgie]

Update: I have submitted this model to Lego Ideas! I know the chances are slim, but if you really like this model please consider supporting it.

https://ideas.lego.com/projects/c6cc0051-b6c8-40a3-a64f-7d80501f690d