Mongoose Cx's!!! fun

diggler

1 kW
Joined
Mar 24, 2014
Messages
308
Location
Twin Cities, Minnesota, USA
Picked a couple these up.
One will have the bht big block prob 12fet infineon and the other I'll keep the 450w in it with a 48v 1000w 26a 54v max brushed controller I found for 18 bucks till I burn them both out or get board.

[youtube]mpzCpZzrxXQ[/youtube]
 
Yes, the concept of a mid-motor mounted on the swingarm has many virtues. The CX is stout except for the forks, which are weak.

I'm surprised there aren't aftermarket swingarms available for the standard bearing mount found on so many MTBs. My plan is to mount the CX swingarm on a MTB frame that has acceptable forks.
 
gogo said:
Yes, the concept of a mid-motor mounted on the swingarm has many virtues. The CX is stout except for the forks, which are weak.

I'm surprised there aren't aftermarket swingarms available for the standard bearing mount found on so many MTBs. My plan is to mount the CX swingarm on a MTB frame that has acceptable forks.

Yes, the forks are crap, but you can swap in any 1-1/8" steerer fork (as long as it the steerer is long enough).
And the cx frame has room for batteries (though it is heavy). Unfortunately the rear swingarm is kinda short.

Search for the "farfle swingarm" not sure if they're still available...
 
I got some good pics of the inside of the box but there too big to upload.
I can take more when I take the box out and switch from the 36v pack apart to make a 48v one.
plenty of vids coming though.
maybe I can just use youtube for the picks too.
or some converter
 
allinv said:
gogo said:
Yes, the concept of a mid-motor mounted on the swingarm has many virtues. The CX is stout except for the forks, which are weak.

I'm surprised there aren't aftermarket swingarms available for the standard bearing mount found on so many MTBs. My plan is to mount the CX swingarm on a MTB frame that has acceptable forks.

Yes, the forks are crap, but you can swap in any 1-1/8" steerer fork (as long as it the steerer is long enough).
And the cx frame has room for batteries (though it is heavy). Unfortunately the rear swingarm is kinda short.

Search for the "farfle swingarm" not sure if they're still available...
The Farfle swingarm is specific for the Genesis frame. I think something like this CX swingarm that uses a generic pivot mount would be popular as an aftermarket item. It shouldn't cost much if sourced from Taiwan by the container load.

Diggler, I like the background tune! The stock motor is fine for lightweight riders, but the 'big-block' motor with a quiet sine-wave controller is a nice upgrade for more power.
 
The stock motor is fine for lightweight riders, but the 'big-block' motor with a quiet sine-wave controller is a nice upgrade for more power.
Cool. I was pretty set on the 12 fet Infineon. Figured that was plenty of controller for the bht.
But if there is a comparable (price and amp/volt capable) progamable sine wave controller I'm in.
Did you have one in mind???

And O yeah! I love how light it is. In fact I'll have to weigh it. I bet its about 60-65lbs. Its sweet I can ride a mile to the bus stop and put it right on the rack in the front of the bus. Or they have racks in the light rail too.
 
Some of those pics of the inside o da box
[youtube]3maWzXjFlHk[/youtube]
 
some pics of the bike with the forks and rear shock and seat.
Forks were 125 used off craigslist air/oil. Guy said they didn't leak and seals were replaced 6 months ago but they leak.
Just something I wanted to learn how to do anyway, to refurbish some forks.
The rear cheepo shock was 35 I think off ebay. I get the 350lb one.
Seat 15 buck off craigslist. Ktm dirtbike seat. I'm assuming 125.
Good two inches of travel in fear shock and 120mm in front fork.
Plus the fork is super light! I almost didn't want to put the seat on because I was like this is as light as the bike will ever be.
But the seat doesn't weigh that much more.
[youtube]1fGG9NyLL7c[/youtube]
 
a vid of the bike with them forks and shock and seat. I had a video in the day on the same rout with stock parts but the cam was pointed too far down.
In the vid the spring on the rear shock was just about all the way out, since then I have put it about an inch and a half from the min.
I'm just not that tall 5' 10.5" with stubby legs. And it feels like it handles better too.
The seat is awesome though. I can actually peddle a sitting down now! Though it still needs to be a bit higher be correct for me.
[youtube]1Bsf8P12vYQ[/youtube]
 
Totally awesome man!
I'd recommend 15 or 18fet if you think you might want to get the most from bht. Also, I use infineon 18fet, and the motor is quiet enough- chain and freewheel make more noise imo. I went with #35chain. Also, simply reaming and welding a sprocket on the shaft has worked great for me so far. No quick changes tho :lol:
 
more video. I was up late when I made this so excuse me if I sound tired.
I figured out the next day I needed to just use 72v because that's what it was at and now I have brake.
[youtube]hhYhpJb8wmE[/youtube]
 
nutspecial said:
Totally awesome man!
I'd recommend 15 or 18fet if you think you might want to get the most from bht. Also, I use infineon 18fet, and the motor is quiet enough- chain and freewheel make more noise imo. I went with #35chain. Also, simply reaming and welding a sprocket on the shaft has worked great for me so far. No quick changes tho :lol:
Hay thanks!
Well that's cool I already have the 18fet.

I think I'ma take the motor apart and have the shaft machined though.
I already got the motor smoken hot (it just didn't smoke) once when I was running it wrong.
I think its okay but I might as well take it apart now. :x
I might just try that trick though if I have everything ells ready.
What Size I.D. #35 did you use? 5/8 right???

I also jimmy'd a 68mm crank for the four stroke jack shaft kit to fit the 100mm BB on my fat bike gas electric.(when it worked :cry: )
So I'd like to get a rod with threaded ends and the 68mm rod (I cut in half and put a pipe and roll pin in it to hold it together) threaded so I could actually have a legit set up when I try gas electric again. right now it's all wankie.

I plan on doin the #35 to a freewheel front crank to a 5 or 7 speed rear right side gearset. Though an internal gear changer would be better.
Do they use the planetary gear system for those internal gears? There only 3 speed right? I still would use over the standard.
 
nutspecial said:
Totally awesome man!
I'd recommend 15 or 18fet if you think you might want to get the most from bht. Also, I use infineon 18fet, and the motor is quiet enough- chain and freewheel make more noise imo. I went with #35chain. Also, simply reaming and welding a sprocket on the shaft has worked great for me so far. No quick changes tho :lol:

What kind of amps you think I could get away with at 96v to the motor? 60amp is probably plenty wouldn't you say?
Is this not 12fet territory or more like 15fet to be safe?
 
Can stop watching after 320. I thought I turned it off.
[youtube]afC5rlA6RXQ[/youtube]
 
Haha roomie
[youtube]z0I7vzvGP5I[/youtube]
[youtube]c6y86EWRMnU[/youtube]
Here is the real video.
[youtube]h3J17F008AA[/youtube]
 
12509588_10205475904273100_6742758324149543845_n.jpg


Heres my mine
 
evolutiongts said:
Heres my mine
I've been lurking at yours for a min.
Okay so...
What size tire is that in the rear?
What KV is that motor? And the wattage of the motor? Link?
What are the front and rear sprocket tooth count?
Have you been happy with the zoom forks?
Is that still a 8" shock in the rear?
I like the big hydo brake in the front?
Any plans for rear brake?
Got any videos of the new motor in action?

O and can you post up a close up pic showing how you had the old bht mounted in the swing arm?
O and a close up pic of the weld job the shop did to extend the swing arm.

Thanks
 
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