GNG mid drive Trials bike build

[Denisesewa]

The GNG has a really nice motor that we should find a source of. I'm ridng trials stuff a lot those days and the GNG is prooving to be a really nice plateform do do so, I had my bike stuck with the motor on a rock multiples times without damage.


I just got the duro leopard 24x3" tire for my rear wheel 8)

Cool, I have been trying to find a source for an Arrow racing wide bite in 24 x3 but no luck, its supposed to be a very high volume tire , I would buy a spare motor if someone finds a source for it, I think I'll be riding this bike ALOT !!

 

[spinningmagnets]

I still want to be able to raise the seat so I can ride it normally, in order to get any kind of decent look to the seat I'd have to cut down the seat tube and its just long enough now to get to a comfortable height

One option might be to get a short section of seat tube (there's only a few diameters of tube for this, should be easy to find), and a short section of seat-post tubing. Cheap to try it out and see if its rigid enough.

 

[Denisesewa]

I am actualy working on a teloscopic seat post this morning, I think its going to work, I'll post a pic if it works out,
thanks for the ideas !

 

[Denisesewa]

Got a bit more done , built and Installed the battery pack which turned out to be a super tight fit, turned out ok but I would have done the box a little different if I had the batteries on hand when I built it.

I decided on the seat and built a telescopic post so I can raise it high enough to pedal and I shaped the seat to get it as trialsy as possible , pretty happy with the look of it ( when its down, looks pretty silly when its up ).
I did get a quick test ride in, just up the street and back since things arnt buttoned down yet, I had it single speed and it was geared pretty high, since then I have installed a cassette and shifter, I am going to go with the original idea of a 3 speed. Too bad winter is here with snow for tonight and tomorrow, I'd like to ride it a bit before tearing it down and doing all the final details.
Oh Ya, I weighed it 57 lbs and the weight bias is virtualy even front to back thats half the weight of the MX er I built a while back.

 

[LI-ghtcycle]

Very nice looking build!

I'm interested in why if full suspension is supposed to be the ticket, then why are trials bikes & dirt jumpers hard-tails?

I like how the saddle just blends into the frame when down, and now that I see the battery enclosure finished, I think it looks right at home with the lines of the frame and fender.

Nice job, now just have to see how it works for ya!

I'm very curious to try something similar with a GNG kit once I am done with my main ride and some other projects.

 

[Denisesewa]

Chain drive primary conversion is finished.

 

[Ariane]

Hi Denise,

Any update about this project ?

Good day!
Black Arrow

 

[Denisesewa]

Hi Denise,

Any update about this project ?

Good day!
Black Arrow

Basicaly I have been testing the chain drive system and upped the amps in the controller to get 25 amps which is an amazing differance, also swapped the forks to a dual crown boxxer.
Its a blast to ride but far from finished, waiting on some carbon fiber cloth to arrive so I can finish the bodywork along with a bunch of other details, I'll post some pics when there is something new to show.

 

[Ariane]

Hi Denise,

Ok then i will try to be patient :lol: :lol: but it's fun to see your progress, and I understand :wink:

Have fun and take care, good day!
Black Arrow

 

[crossbreak]

looks awesome! now i understand why you took the GNG, with a chain mod it's perfect for trial It's heavier than brushed, but has just more bite

 

[Denisesewa]

looks awesome! now i understand why you took the GNG, with a chain mod it's perfect for trial It's heavier than brushed, but has just more bite

Yep. I really like this setup but it would be nice to have foot pegs instead of pedals like you said, funny I can wheelie a motorcycle a long way and can do the same while pedaling a bicycle but with my feet offset with this bike, powered wheelies always lean in the direction of my back foot, something I'll have to get used to.

 

[gwhy!1]

looks awesome! now i understand why you took the GNG, with a chain mod it's perfect for trial It's heavier than brushed, but has just more bite

Yep. I really like this setup but it would be nice to have foot pegs instead of pedals like you said, funny I can wheelie a motorcycle a long way and can do the same while pedaling a bicycle but with my feet offset with this bike, powered wheelies always lean in the direction of my back foot, something I'll have to get used to.

I found this as well... and gave up in the end

 

[bzhwindtalker]

I think it is doable. But yeah it's probably way harder. Having pedals open too much riding possibilities to use pegs. I have my handlebars leaning in the direction of my back foot too when wheelying.

 

[Denisesewa]

Very nice looking build!

I'm interested in why if full suspension is supposed to be the ticket, then why are trials bikes & dirt jumpers hard-tails?


Ooops , wonder how I missed your post? , Thanks for the compliments!
I think with Dj bikes people want a consistant launch from the frame which wouldnt happen with a rear suspension due to compression and unloading on the face of the jump.
As for trials bikes( Bicycles) I know I want all my energy to go to the ground rather than being soaked up by suspension, I ride my 29er full rigid for XC so that all my energy goes into making the bike move and save the Maverick ( full suspension) for riding downhill on the ski slopes.
Building this bike with a hardtail for a couple reasons, the first is that I already had this bike and like the geometry, 2nd, it makes the bicycle part of the drive train much more reliable and easier to set up perfectly, its brutaly strong and it had the lines to make it look more Moto-trialsy.

 

[parajared]

Your build is looking great so far, keep in mind if you oompf down on your bike hard enough the frame will actually flex a little. Be sure your battery bay is set up to take a little flex too.

 

[Denisesewa]

Your build is looking great so far, keep in mind if you oompf down on your bike hard enough the frame will actually flex a little. Be sure your battery bay is set up to take a little flex too.

I actually built the battery box using a piece of nylon reinforced plactic for the base and the rest is assembled in a modular fashion, I considered impact from crashes but not really frame flex but I think that is covered, it will be easy to repair and should absorb shock pretty well.
I recieved the carbon fiber cloth and started on the bodywork today , laying it up is the easy part, the finish work will take several days of hard work but should be worth it.

I also set up my 3 speed which works really well, I am using a 9 speed cassette at the moment to allow experimenting with different gear combos, right now its running 34t, 26t and 20t, using an Sram X-9 9 speed derailiur and X-9 3 speed shifter, it works out to shift 2 gears at once which seems to be a good gap between gears and shifts flawlessly, no issue with chain drop at all due to the double chain guide on the front chainrings, I think having the perfect chain length along with being a hardtail with short chainstays will eliminate any final drive issues.
also installed my Turnigy watt meter and Rockshox boxxer fork.
I also ordered a Lyen 12 FET 3077 extreme modder mark II controller.
I am thinking about replacing the chainring freewheel with a white industries ENO freewheel, I have used these before on my trials bikes, they have 80 engagement points rather than the 12 to 20 most freewheels have which would eliminate alot of "takeup" in the drivetrain, I already have a high engagment point rear hub, not sure what to do about the freewheel on the jackshaft though.

Anyway, a bit more progress

 

[Denisesewa]

Carbon work is coming along, one more sanding and top coat should do it for these parts, still have a couple more parts to fabricate.

 

[bandaro]

really nice looking finish to the guards you got there, was hoping you were going to put some more carbon on it, or you could have had some major issues with the thing splitting along the uni.

Wondering about the layup though, did you bag or clamp it at all? the finish on the guards looks to me like you didn't, but then the side panel looks like the fibres were pressed on the right there, so did you pressure the inside, then chuck on the final layer and let it open set to get the gloss finish? But the post before shows them all open drying, with no pressure at all?

Either way, they and the whole bike looks amazing, can't wait to see it all put together, going to look very clean!

 

[Denisesewa]

really nice looking finish to the guards you got there, was hoping you were going to put some more carbon on it, or you could have had some major issues with the thing splitting along the uni.

Wondering about the layup though, did you bag or clamp it at all? the finish on the guards looks to me like you didn't, but then the side panel looks like the fibres were pressed on the right there, so did you pressure the inside, then chuck on the final layer and let it open set to get the gloss finish? But the post before shows them all open drying, with no pressure at all?

Either way, they and the whole bike looks amazing, can't wait to see it all put together, going to look very clean!

Naw, these are all just hand layup, you know, kitchen table work, it is after all a dirt bike. I really didnt want to get involved in making plugs, then molds ect. and I gave up my vacume bagging stuff when I quit making kitesurf boards, the parts will hang in there though, I built all the bodywork for my Moto-trials bike the same way years ago and they still look good.
The layup is uni carbon , bi-directional 12oz fiberglass with some matt in certain areas and then the 4.5 oz carbon cloth using resin research epoxy. not exactly ultra light but strong enough to do the job.
Thanks for the comps!!

 

[Denisesewa]

Parts loosely assembled , still need buffing, the pics dont do the carbon justice but you get the idea, I cant do final assembly untill I recieve the new controller since its a bit bigger and I may need to change some things to get it to fit.
Kinda thinking about doing the seat in carbon as well but that might be overkill?

 

[melodious]

It's looking really really nice! I may have to copy your build. 8)

A few posts back you were commenting on about "pegs vs. pedals" for wheelies. What if you use really short crank arms to get the benefits of both

 

[Denisesewa]

It's looking really really nice! I may have to copy your build. 8)

A few posts back you were commenting on about "pegs vs. pedals" for wheelies. What if you use really short crank arms to get the benefits of both

Thats a good thought, I am pretty sure I can get 155 length trial cranks threaded for forward freewheel, I know I can get 165 but since the kits cranks are 170 I wouldnt be gaining much with either one, otherwise I'd have to make them. might help a bit with the cadence issue as well.

 

[bandaro]

Without a doubt you need to change that seat. Carbon may well be the easiest way to make one, just carve a block of foam to the rough shape, chuck it on and fine tune the shape before you add the carbon, but I would not use the carbon finish. If you use a carbon seat I think it will turn it into a wanna be carbon gansta ride, instead of making it clean and minimal like carbon should. IMO, you need something the full width of the battery compartment, and some lines to compliment that top tube of the frame, tie it in with the battery covers and tail. Also, having a longer motorbike like seat on it could add a lot of support to the mud guard.

I think a moto style lightly padded and upholstered seat in either a red or yellow and some polished aluminium highlights along the battery covers would look absolutely mint, would it be possible to get an orthographic side view of the bike? I would like to have a tinker with the seat design, see if I can't tie the whole design down nicely. May even be possible to have a small compartment under the seat for lunch

As for pedals vs. pegs, I don't ride trials but imagine having that instant punch from the pedals could be nice, unless the motor is geared low enough/has enough power to do this. Also the legal aspects, it will look fairly moto already, and using pegs means you cannot try the push bike trick to get off, as it is certainly not electric assisting pedals, at least in australia...

 

[Denisesewa]

Without a doubt you need to change that seat. "
trials bikes dont have seats per-se , the idea of my bike is to have a hybrid but still a working bicycle which has a very moto-trialsy flavor, the present seat is teloscopic and can be raised to a suitable pedaling height if needed.
I could have easily built a seat/fender unit like I did on my modified TY350 but thats not really what I'm after.

When I street legalized my Beta Techno I put a mini moto seat on it and I think it made it look like a enduro rather than a trials bike.

Before --

After-

Color scheme however is another matter, it already looks too carbon wannabe to me but I dont really know what to do about it, the side panels will have aluminum trim on two sides and there will be some red graphics along the upper edge of the triangle, I guess I'll just have to wait a see what it looks like when its done.

 

[Ariane]

Hi Denise,

Both are really nice i love your trial motorcycle and the work you have done on your ebike, really well executed.

Black Arrow