...A new one! [low-cost dirt bike] -- second test video

[silvocross]

wow excellent job in such a short period. The swingarm looks a bit on the weak side, but I dont know the thickness of the tube, and I also tend to overbuild everything and make it too heavy :lol: .

keep up the good work

Rodger

Thanks Rodger, maybe it could seem weak because of you're used to build aluminium frames..
From my simulations it should be rigid enough, but real conditions are much more accurate then a FEM simulation, so maybe more torsional rigidity may be required. :wink:

Very nice. !
What is the weight of the bare frame ?
..and the target weight of the complete bike ( less batteries)

The bike will be so heavy, the bare frame is 4,4kg and I hope to get the entire bike under 50kg.
Unfortunately, the less you pay for the bike the higher the weight..

Hey very interesting build and nice frame design.
I´m really impressed by your idea for the gearbox, looking forward to the progress.
Could you please tell me more about your fork?
Whats the weight? How much travel does it have(250mm?) ? How long is it? and What Size of Bearings do you use for it?
I am planing a frame to and haven´t really decided which fork to use.

Thanks
Dennis

Many thanks Dennis, the fork is not designed for a bike, it has 250mm of travel and tubes are 35mm (chromed steel).
It weights like 5 DH forks (10kg here), but I paid it just 25€.
By the way I like it, I run motocross so I prefer it's internal hydraulics compared to a DH fork one.

 

[silvocross]

I covered the internal side of the frame with foam, to reduce the noise:

then I mounted the transmission:

 

[Byte]

Niceeee! Do you think the foam will make a big difference in noise level?

 

[Idontwanttopedal]

Shame can't seal that bit and oil fill it

 

[Whiplash]

Awesome! Is the transmission to be run dry?

 

[silvocross]

Niceeee! Do you think the foam will make a big difference in noise level?

with my previous bike the foam reduced the noise a lot, this frame is much more rigid, the important thing is to avoid the resonance.

Shame can't seal that bit and oil fill it

Oil lubrication would be cool, but too complex to be implemented, keep in mind I've to move the engagements of the gear with two electronic servos.
Also in this case, based on what was experienced on my last bicycle, even without an oil lubrication (only grease) it should be ok, they're a module 1.75mm hardened gears.
The biggest problem is of course that the transmission will be noisier then an oil bath one.

 

[silvocross]

Rear hub is almost finished (aluminium):

 

[sigimem]

How about a scottoiler or similar system? http://www.scottoiler.com/us/products/aprilia-motorcycle-accessories.html
There are people building them themselves with succes.
It would only be a tiny bit of oil but when applied precisley it might help?
Just a thought though. good work with the hub.

 

[crossbreak]

you could fill the unused space with styrodur, fix it with glue. This way there would be only very little space left for the oil.

Using servos to shift the gears is a nice idea they shouldn't be bothered by oil. an oiled transmission just runs better

 

[silvocross]

How about a scottoiler or similar system? http://www.scottoiler.com/us/products/aprilia-motorcycle-accessories.html
There are people building them themselves with succes.
It would only be a tiny bit of oil but when applied precisley it might help?
Just a thought though. good work with the hub.

this is not a bad idea, maybe I can add it later.

Oil lubrication is absolutely the best way, but it needs a different design.
"Just" a single casing with inside transmission and engine, all filled with mineral oil, so I can combine lubrication and cooling needs. 8)
looking for someone with a furnace :wink:

 

[Whiplash]

A really sticky chain lube might get you by for now... Especially since you are pushing less power than it was designed for right?

 

[silvocross]

Rear wheel completed:

 

[Idontwanttopedal]

I am liking to build keep up the good work

 

[silvocross]

Thanks!

Bottom cover:

 

[Paul.............D]

I like have you had the motor running on your gearbox?
Did you rewind your motor to lower rpm

Paul

 

[silvocross]

I like have you had the motor running on your gearbox?
Did you rewind your motor to lower rpm

Paul

Yes, It's now a 118kV with two parallel 14AWG wires.
I need to finish the primary transmission on the left side in order to try the gearbox.
Unfortunately, I'm leaving to another city, so my work will slow down for sure.

 

[silvocross]

Ok, I finished and mounted the two wheels, many things to be done yet.
These 1.95" tires are really obscene...

 

[Paul.............D]

Looking good on its wheels, The back wheel would look mint with a wider rim and a big fat ass tyre on it, still well impressed.

Hopefully wont be long for a video :lol:

Paul

 

[Whiplash]

Looking great! Loving the custom hubs! How are you planning on shifting the trans?

 

[silvocross]

Looking great! Loving the custom hubs! How are you planning on shifting the trans?

Thanks!
I'll use 2 electronic servos to shift the transmission.

Unfortunately this week I moved to another city for study, so the building will slow down a lot..

I am now so far from my house, but my bike is here with me:

 

[bzhwindtalker]

I feel your pain man, I just moved to Lyon for studies too, I only have a dirt mtb and no tools, I had to let my beloved angle grinder home (and too much work to build much stuff :/)

Btw, I like the panoramic

 

[silvocross]

I feel your pain man, I just moved to Lyon for studies too, I only have a dirt mtb and no tools, I had to let my beloved angle grinder home (and too much work to build much stuff :/)

Btw, I like the panoramic

Oh, what are you studying in Lyon?

 

[bzhwindtalker]

I'm starting my third year of mecanical engeneering at Insa of Lyon, the level is really step compared to my last two years of studies, I hope to have some time to build stuff by spring but for now it's very complicated :| I take you are into mechanical engeneering too? The good part about engeneering schools is that they usualy like those kind of projects and let you acces the tools and machines to build cool stuff

 

[sigimem]

I love the bike already very nice silvocross. Also it might look better with some proper tires on it

So there are 3 Mechanical Engineers in only one thread nice to hear that (I am in 6th semester as well).
Maybe we can build the Europe Eletric Bike together :wink:

 

[silvocross]

I'm starting my third year of mecanical engeneering at Insa of Lyon, the level is really step compared to my last two years of studies, I hope to have some time to build stuff by spring but for now it's very complicated :| I take you are into mechanical engeneering too? The good part about engeneering schools is that they usualy like those kind of projects and let you acces the tools and machines to build cool stuff

I already had my bachelor degree in mechanical engineering and I am now studying for mechatronic engineering (robotics) specialization in english language.
Tryin' to escape from Italy... :wink:

I love the bike already very nice silvocross. Also it might look better with some proper tires on it

So there are 3 Mechanical Engineers in only one thread nice to hear that (I am in 6th semester as well).
Maybe we can build the Europe Eletric Bike together

It would be like a dream coming true!
But you know, without a small budget you can't start anything new, especially here in Italy.