Hi All!

I'm developing a 1:5 motorbike at the moment. Since TLG will release a new 1:5 motorbike with a similar engine setup, I decided to share the WIP, just in case there would be similarities, and I have some questions too.

Anyway:

This will be a naked motorbike, maybe a café racer (whatever the difference is....).

I didn't know any single thing about motorbikes when I started the project, and since I don't even know the proper terms, I find it surprisingly hard to fing technical info about motorbikes.
Some basic info about the model:

• double wishbone fron suspension, standard rear suspension
• V4 engine
• 1+N+2+3 sequential gearbox

First design problem: The engine position of my model looks like a Ducati V2 engine (one piston is pointing almost straight forward), but it's V4, I just couldn't wrap my head around different setups while developing.
(Note, that I know that the V angle should be 90°, but the source Ducati V2 has valve control+cover that looks more like 110°, and that's very prominent visually. For reasons, I chose the compromise of having 110° pistons too.)

Anyways: is this engine setup I have (V4 but front pistons pointing horizontally forward) an unrealistic setup, or just stupid, lame etc? It is a custom bike, but I want it to be believeable. I don't want to change for V2, becasue the stock pistons and cylinders are so small for the scale, I had a more standard V4 setup too, but the engine looked a tad too small and was quite meh. This one looks acceptable, with proper colors, I think it may look quite good.

 

I also tried working rear breaks, I had an almost working prototype, but since it's not having actual function (not able to effectively stop the wheel) and having a totally unrealistic linkage, I ditched the idea. Opinions?

Thanks for any opinions, and sorry for the rushy post, I don't have much time nowadays.

Edited November 21, 2024Nov 21 by Lipko

Hello!

IMHO, the engine design is credible! Doesnt the radial engines of oltimer airplane have cylindres pointing to the ground?

The one thing for me on your WIP is the saddle's hight that seems a bit too high .

Have you any blue prints for comparaison?

38 minutes ago, steph77 said:

Hello!

IMHO, the engine design is credible! Doesnt the radial engines of oltimer airplane have cylindres pointing to the ground?

The one thing for me on your WIP is the saddle's hight that seems a bit too high .

Have you any blue prints for comparaison?

Thanks for the reply! I don't use blueprints, as I haven't decided yet what shape to follow, I haven't even decided to go for a café racer shape or not (the handlebars changed vertical positions at least five times). That's Lego design for me. I don't want to draw everthing on paper up front, only to realise something's not possible to properly model with Lego.

Yes, the saddle may be a bit too high, though the position you see now is the final, no "meat" would go on top of it. Maybe you are right, but it can simply be changed.

There's also another proportional mistake: The rear suspension arm's pivot is too far back, the clutch is a bit too far forward, though I don't see how I can improve that, the gearbox is in the way. I will cheat it with aesthetics, the frame looks like crap anyway so will be covered with an aeshtetic non functional frame. Though I may be totally off. Is the red circle the pivot point of the suspension?

You should use my gearbox design on my katana I désigner on previously contest. Its compact...

Keep on this good job!

1 hour ago, steph77 said:

You should use my gearbox design on my katana I désigner on previously contest. Its compact...

Keep on this good job!

I can't find info about it. The Eurobrics thread has lost the images.

Actually there's an extra gear to have a convenient power take off for the chain (and for better modularity), but there might be enough space to ommit it. 3rd redesign...

I reworked the chassis and made the rear arm pivot position more realistic.
I'm still struggling hard with the bodywork, but the overall proportions start to look okay (especially in comparison with the previously posted state), though the rear arm is one stud too long. I don't know if I want to put too much effort into it, I kind of like long motorbikes.
The clutch cover is fake unfortunately, just like in the new set.

 

A bit of biking terminology for you:

A traditional cafe racer is a post war era machine designed to mimic race bikes of the era with street available parts - a tuned motor and frame mods to 'improve' handling.

The stereotype is the Triton - a Triumph vertical twin motor in a Norton featherbed frame, clip ons, polished alloy tank, rearset, minimal seat with a back stop hump and steepened fork rakes

 'clip-ons', these are short sections of handle bar (one for each side) that are clamped (or 'clipped') onto the fork tubes under the top fork yoke so as to leave the rider almost lying on the tank for least air resistance.  Rear sets are when the foot pegs are moved backwards from the frame manufacturers mounts usually with alloy plates. This would necessitate reversing the gear box pedal and so changing the direction of gear change, alternatively a small parallel linkage would keep selection direction as original. the rear brake pedal was often just shortened.

Many old brit bikes had gear levers that operated in reverse ie 1 up N 234... down - this is the opposite to most modern bikes which are 1 down N 123456.... up

The 'double wishbone' suspension you are implementing is similar to what would be known as 'springers'  or 'girders' very prevalent in seventies 'choppers' where you can see some pretty extreme examples with radical rakes (search Arlen Ness for show bikes)

Telescopic forks are the norm in standard bikes, originally with tubes at top and stanchions (the larger diameter part) containing the damping mechanisms at bottom, nowadays 'upside downs' are the desired look as they are stiffer and look better - these are what the current lego 1:5's use.

Over the years many front suspensions have come and gone, Earles type front forks, a type of front swingarm  on BMW's MZ ETS's and bikes with chairs(sidecars) otherwise known as outfits, common on Moto Guzzi outfits, the front swing arm taken to the extreme on the Bimota Tesi with its 'hub centre steering.

BMW have utilised something they call telelever which is a combination of a wishbone at high level in combination with telescopic struts, the springing and damping being in a coilover on the wishbone not the teles, had its merits (looks were not one of them!) but was (is?) largely superseded by upside downs.

The look that you appear to be developing would often be called a 'streetfighter' with styling cues taken from the drag bike scene -lengthed swing arms etc.  the other polarisation is with very sloped high back ends for the wheelie/stunt fanatics.

Urban is often the combination of large capacity cruiser power plants (Harleys etc) into streetfighter type chassis - Buell's would be an original exemplar

All these styles from the custom scene are eventually imitated by the mainstream manufacturers.  Looking at online articles in Back Street Heroes magazine and its offshoot Streetfighters magazine (amongst many othe rsources) will show you the wide range of styles - what is currently fashionable and its terminology but pretty much anything goes so do what looks right for you!

 

18 minutes ago, Plumber said:

A bit of biking terminology for you:

A traditional cafe racer is a post war era machine designed to mimic race bikes of the era with street available parts - a tuned motor and frame mods to 'improve' handling.

The stereotype is the Triton - a Triumph vertical twin motor in a Norton featherbed frame, clip ons, polished alloy tank, rearset, minimal seat with a back stop hump and steepened fork rakes

 'clip-ons', these are short sections of handle bar (one for each side) that are clamped (or 'clipped') onto the fork tubes under the top fork yoke so as to leave the rider almost lying on the tank for least air resistance.  Rear sets are when the foot pegs are moved backwards from the frame manufacturers mounts usually with alloy plates. This would necessitate reversing the gear box pedal and so changing the direction of gear change, alternatively a small parallel linkage would keep selection direction as original. the rear brake pedal was often just shortened.

Many old brit bikes had gear levers that operated in reverse ie 1 up N 234... down - this is the opposite to most modern bikes which are 1 down N 123456.... up

The 'double wishbone' suspension you are implementing is similar to what would be known as 'springers'  or 'girders' very prevalent in seventies 'choppers' where you can see some pretty extreme examples with radical rakes (search Arlen Ness for show bikes)

Telescopic forks are the norm in standard bikes, originally with tubes at top and stanchions (the larger diameter part) containing the damping mechanisms at bottom, nowadays 'upside downs' are the desired look as they are stiffer and look better - these are what the current lego 1:5's use.

Over the years many front suspensions have come and gone, Earles type front forks, a type of front swingarm  on BMW's MZ ETS's and bikes with chairs(sidecars) otherwise known as outfits, common on Moto Guzzi outfits, the front swing arm taken to the extreme on the Bimota Tesi with its 'hub centre steering.

BMW have utilised something they call telelever which is a combination of a wishbone at high level in combination with telescopic struts, the springing and damping being in a coilover on the wishbone not the teles, had its merits (looks were not one of them!) but was (is?) largely superseded by upside downs.

The look that you appear to be developing would often be called a 'streetfighter' with styling cues taken from the drag bike scene -lengthed swing arms etc.  the other polarisation is with very sloped high back ends for the wheelie/stunt fanatics.

Urban is often the combination of large capacity cruiser power plants (Harleys etc) into streetfighter type chassis - Buell's would be an original exemplar

All these styles from the custom scene are eventually imitated by the mainstream manufacturers.  Looking at online articles in Back Street Heroes magazine and its offshoot Streetfighters magazine (amongst many othe rsources) will show you the wide range of styles - what is currently fashionable and its terminology but pretty much anything goes so do what looks right for you!

 

Thanks for the comments!
I posted of a real motorbike photo too for reference, that's kind of what I have in mind behing the thick fog of laymanship.

The double wishbone suspension is there for two reasons: 
-a bit unusual, so for coolness effect
-handles better in Lego version. I want the model to be playable, which means I want to give them to kids without explaining how to handle and without the risk of serious damage. The telescopes are prone to get stuck when pushed in a too slanted position, which is the default position in a bike. So instead of actuating, the whole assembly would bend (I hope that makes sense). My setup has much less problem with it, it actuates however I push the bike and the fork assembly doesn't get damaged.

If you have trained eye: does the current version's proportions look acceptable for a streetfigher style bike? Do you notice something that's off? I'm a total layman when it comes to bikes.

It looks very good for now! The engine looks perfectly Ducati

Looks good to me, there is no right unless you're trying to model an existing object!

Like you say the double wishbone 'girders' front suspension is far more robust when large degrees of rake are applied hence why they were so popular on more extreme choppers.