amorti

https://rebrickable.com/mocs/MOC-87577/A_morti/motocross-bike-self-balancing-rc-motorcycle/#details

Not in the slightest tiny bit. Some of us need more important things to worry about!

Free instructions are available!

Nope... Denied. Rebrickable says I can't submit a free moc I didn't design by myself even with the designer's permission. Resubmitted with a 1€ price tag, since you can submit premium MOCs as part of a partnership. Let's see if they allow it.

FREE PDF instructions, coming soon on rebrickable...

For me, as it is, the panel looks too bulky since it's 11 long where it only needs to be 9. If it were made as a set you'd use the panel and put a sticker on it which replicated a real bike's swingarm. Maybe put the motor on the left where the chain would normally be on a real bike and the panel on the other side and have a brake caliper illustrated.

@Mechbuilds - think it was you who didn't like the gap in the swingarm. I'm not fully sold... but what says EB? Swingarm from liftarms? or Swingarm from a panel? The panel is simpler with 8 less pieces. You could probably argue the panel is stronger, but I reckon they're about equally strong for practical purposes.

Since @Piterx has created a buzz around Lego motorcycles, I decided to give this one its own thread at last. It's a self-balancing RC motorbike, based around a buwizz and a buggy motor. It's an evolution of @piterx's Fastest Bike, made and published with his blessing. In the evolution it got much more rigid in the frame and swingarm (it can do @20 km/h so you need the wheels pointing the same direction), and got various visual tweaks converting it from a motocross to a naked street style bike. But... Does it really work? Is it fast? Yes, and yes. There's nothing rare/vintage except the tyres (you can use the more common 81.6mm motocross tyres) and nothing expensive except the electric parts. You can do the bodywork in a whole bunch of colours depending what you have available. For those who aren't purists and/or don't have loads of expensive RC parts lying around, you can also use a CaDA or MouldKing battery with a few small pieces and adding 10g-20g weight either side with a few pennies, etc. Replica buggy motors work fine too, and replica servos are fine if you're not using a buwizz. If you don't like the 3L crank handles on the front fork, remove them and put a 3L axle with stop each side instead of an 8L with stop the whole way through. It'll lose a little rigidity, but looks nicer. It's a fun build with a lot going on with all the angle beams, especially around the steering neck. But the focus is on playing, and marvelling at what Lego can do. More images and instructions available on Rebrickable: https://rebrickable.com/mocs/MOC-83960/A_morti/fast-street-bike-self-balancing-rc-motorcycle/#details

Instructions for another here :) https://rebrickable.com/mocs/MOC-83960/A_morti/fast-street-bike-self-balancing-rc-motorcycle/#details

@piterx was kind enough to give me a preview of this one some weeks ago. On the last thread there was a feedback that being a self balancing motorcycle wasn't cool enough, the model needed to be a model of something. Also it needed more details and a mudguard. @Mechbuilds also said how about if it could be an e-bike, to "explain" the bulk of battery in the middle of the bike. Well, I've had a shot at modelling a 2015+ KTM e-SM. There are obvious limitations from building it in Lego, such as Lego tyres having an unrealistically low profile (scale is pretty well correct to the wheel rims but not the tyres), and servos needing a lot of space, but other than that I'm quite pleased how it turned out. What do you guys think? Unfortunately I also have no video of driving it either, as I need an 8L gear rack for the steering and don't have one.

@astyanax I saw the video on YouTube but using these in an actuator hadn't occurred to me. Potentially very interesting for a lot of construction machinery MOCs. Even if they don't have so much power, shouldn't be an issue as the actuator clutch will probably slip before these run out of power? Now if they can come up with a mini servo that sells for <80€, I reckon that even the purest purist will have to take pause for thought. How hard are these to turn by hand? could you use rubber bands to pull them back to centre like some guys did with M motors?

I think with "twisted", he's not asking if you built it wrong, but whether there's age related warpage to any of the parts. Even if a lower wishbone had warped just by having the model's weight sit on it, it might cause this issue. It's very old plastic after all. Did you understand it the same?

Apologies - I was thinking of Didumos's Rocky, not Greyhound. Ignore my previous post. The PU motors would be a squeeze, since they're a stud longer. Might be possible though, as looking at my model here, I don't see any real no-go's. The buwizz 3 is the same but 9 studs long instead of 8, right? You can probably find a way to make that work by leaving out the frame bracketing them at the front and replacing the strength some other way. However, the cables sticking out the ends instead of being on the top could be a problem. Worst case scenario, you could lose the seats and shove the batteries inside the cabin. Either way, would be interesting to see a PU motor for the steering, since the PF servos are expensive/rare now, and always were weak/unreliable, and inaccurate.

You'll have more chance to fit the buwizz in place of the technic hub, than PF motors in place of PU motors as the design uses the extra mounting options of the new XL motors integrally in the design. Even then the battery box is pretty well integrated, so you'd probably have to replace that lost strength with some frames or liftarms.

Thanks :) You could start stacking liftarms there, you could put a 5x3 "L" reinforcement in there from top to bottom (but it really doesn't need the strength), you could maybe go the other way and add some deco by putting a 24z gear there and a pulley wheel brake disc on the other side. However, that's all just adding decoration/weight, and so I think I'll leave that to whoever's building it. Besides, within the limits of Lego, I don't think it looks out of place. Here's the swingarm from the 2021 CBR600RR for reference: Yes, I'd have preferred a straight beam at the bottom and the "J" beam at the top, but it's not possible as it limits ground clearance when the bike leans.

It still has a wheel at the front, and the stand attaches too far forward and should be taken off before playing... But ... I think it's better now. Rebrickable will be updated once I shuffle the instructions.

Be reasonable. If you want the secrets, pay the 10€ for the instructions and find out.

Funny you mention an ebike. Not giving too much away, but you may like the next bike more. I'd like a nicer headlight, but it's not easy to make it nicer, while having it point forward not up, and still be strong. I tried for a while IRL and in stud.io, failed, and left it where it is now. Any ideas? I'll happily give it a try and post a render, if nothing else so you see my struggles with it. I'm not adding deco elements like mirrors and brake levers, but if you build it ofc you're welcome to add those (and go looking when they ping off). A mudguard isn't possible on this one due to the scale (bear in mind this uses the old 81mm wheels not the newer 94mm wheels). In general it's not easy on Lego bikes due to no suitable attachment on the forks. I have another project from P-Lego which has one though. When I eventually get it finished, the reason it can have a mudguard while this one can't will become clear. There's no spare pin holes at the bottom to mount a kickstand in a realistic position, hence the simple 5*7 stand. I agree with you though it would look better, and I will have another try. Footrests - again, nowhere to mount them, plus they would be extra width low down, which reduces ground clearance. Swingarm stays as it is. It is very sturdy, which is essential for keeping the wheels in line so it doesn't wobble. Anything added would be deco only, but it can't be bigger without reducing ground clearance. Anyway I like it, reminds me of some real ones, for example below, metmachex, cbr600rr4, and others. Its ethos is to play well, and especially not to grenade when you crash. Greebling isn't compatible with that, so it won't be getting an exhaust from me, although you could always add one. As for what it could be, I had a gsxr-1100 Streetfighter in mind. Big square frame, short ish high up tail, no mudguard, chunky yet skeletal swingarm... it looks at least a little familiar. Another headlight would probably fit this look better.

There's two things to consider on looks. First is that the battery (or a weight brick) needs to slide left to right. This means you can't build a fully faired Lego RC bike. But is that so bad? The Ducati is the first one Lego did, we were happy with naked bikes until then. Second is that you will crash this thing. It can do something like 25km/h, and the steering does not react instantly. You can't be adding system bricks for looks, or panels held on by luck and goodwill. Well, you can, but you'll be looking for them often. Within those restrictions, I think it turned out pretty well. However, I'm definitely open to improvements if you have any

Depending how purist you are there's always CaDA metal u joints. Every other piece on the model will break before those fail. I like how you used that angular motor. I assume it has a position sensor like the XL and L motors?

It's a headlight (obvs ) There's not a lot of other ways to build a headlight that I could see. I wanted a big round headlight as it's like my first bike, a Honda CB-1. It had to be level to the ground, not follow to the headstock angle (which would be a lot easier), so that meant putting a mounting part to get that angle. Anything I tried with dish parts looked like it was hanging way in front of the frame, whereas the wheel extends back over the mounting point and just about touches the frame at the bottom. That being said, I am interested in any ideas you may have. While the bike is entirely made of Technic parts for stability reasons, there are certainly system parts I am not aware of, and attaching parts here using a pin with bar is pretty solid.

Thanks for the feedback that led to those changes, and the kind words. About the price drop, I still think it's worth a fiver, but maybe I can look at cranking it up again after a few more people built it and left nice feedbacks on the comments page. I did sell one more copy at 3€ through linking it at "Lego Technic & Creator Mocs & More" on FB, so you could argue he'd have paid a fiver, or maybe only bought it as it was 3€, who knows :D I think it's going to be the struggle for me. Piterx and I love motorcycles and Lego, so it's natural to build bikes out of Lego. Everybody on Rebrickable loves Lego, but only a minority also cares about bikes. However Lego continues making bikes as official sets, so it must be some overlap there :)

A WIP topic can suck you into the subject matter more, however it may give away enough that people don't need to buy it to get the joy of the reveal you get when building it, IYSWIM. The trouble with presenting a MOC all at once, is it will often tend to drop off p1 here very quickly, because there's not much need for reader interaction. Therefore you read the topic, buy it or more likely don't, and move on with life.

:)

It's a good point. I know very well that this one is incredibly stable, but of course no one else does. I only have a potato camera, but I'll put a couple of real photos in the gallery. By part count I have to agree, it's expensive. Humbly, I'd be impressed if anyone can reverse engineer what's going on around the steering neck to be just as sturdy, but yes I guess with patience it's possible. I'll try dropping it to 3€, see if I get more bites. Thanks for the feedback :) Now with real (potato) photos, and price drop to 3€. edit: oops, I included the 8L axle with stop which I snipped down to 6.5L on the front axle. It was damaged anyway, and only done to make it a little neater.