First ebike build done!

Jae

Jae

1 W
Joined
Oct 23, 2023
Messages
50
Location
Ma
Just completed my first build and I'm very pleased.Mongoose Malus with Sabvoton 72100,5000w rear hub and 2 72v 20ah batteries in parallel.I Wasn't expecting the power it has for sure.Got it to 68mph and i think it had a little more but it got sketchy fast.1719440752497.png
 
Yeah, don't do that. Not one single part of your bike is designed for highway speed. How did you determine speed, GPS phone app?

Also, you put the fork on backwards. I think you should slow down, both your riding and your project execution.
 
Yeah i noticed the fork as soon as i saw the picture.I bought the bike from a guy on Marketplace so i Don't know It's history but it was new.
 
And I'll probably never slow down,i've always ridden fast.
 
Jae said:
And I'll probably never slow down,i've always ridden fast.
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Then get a much, much better bike. The one you have is no good for what you're doing. To be frank, it's not even good at what it was made to do.
 
Probably gonna get a bomber clone frame at some point in the future.
 
72v 40ah is a big battery. Great job for a first build sir. I love speed also but 68 on that machine is very courageous bro. Especially on those big tires can you imagine a front tire blow out at 60 mph? Give me a 5” motorcycle tire for sustained speeds above 50 mph thank you very much! My humble opinion of course. Hope you get many happy miles no flats! Thanks for sharing. 👍
 
And whatever you do, do not ride your newly built bike to the local drinking establishment for a celebratory drink or two.:rolleyes:
 
I have never been too bright but I guess the eyes go first. I didn’t even notice the fork was backwards. I would have downgraded to good first build had I noticed. That makes 68 mph even more absurd! That’s like 2 inches shorter wheelbase and all screwed up geometry. Sketchy indeed! You are a wild man! Should feel a lot better now! 🙏
 
Chalo said:
We'll have to disagree on that.

The fork agrees with me, by the way.

www.mtbr.com

Backwards fork thread! Post pictures of incorrectly...

www.mtbr.com www.mtbr.com

When I see easily avoided errors, it makes me wonder what subtler problems lie just under the surface. In this case mistake number one (and it's a biggie) was using a kid's toy to do a daredevil's job.
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Listen,i bought the bike like that I'm not a bike person so i just Didn't notice.There are NO OTHER errors i spent a good ammount of time thinking of how to make sure the rear wheel was secure and i would never have a problem with spinout.And i am 100% sure that i accomplished that.And It's not a kids toy,It's an adults steel frame fat bike.Granted It's a cheap one,but It's not a kids toy.
 
Jae said:
And It's not a kids toy,It's an adults steel frame fat bike.Granted It's a cheap one,but It's not a kids toy.
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If it's a one-size bike from a department store, its purpose is to go under the Christmas tree for someone who's too young to be dreaming about his driver's license yet. After a few years of not getting ridden, its next destination will be the custody of a bum or a hard bitten poor relative, where it will die an ugly but relatively quick death as it is used harder than the manufacturer ever intended.

If it were a bike for adults, it would come in a range of sizes, and the place that sells it would be willing and able to service it.
 
Didn't know this forum could be so negative. It's a great rocket, and the batteries & controller installation and cabling look all quite neat. Early (and maybe even not-so-early) 50cc two stroke race bikes looked flimsier than this. Just wear a helmet, boots and abrasion-resistant clothing. Good motorcycle clothing (not the usual Harley rider stuff).
 
Gruesome said:
Didn't know this forum could be so negative. It's a great rocket, and the batteries & controller installation and cabling look all quite neat. Early (and maybe even not-so-early) 50cc two stroke race bikes looked flimsier than this. Just wear a helmet, boots and abrasion-resistant clothing. Good motorcycle clothing (not the usual Harley rider stuff).
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No, its a scary life threatening contraption.
 
Well, a great rocket most likely is also a life threatening contraption. As were those two stroke racing bikes.
Update/edit: I'm not arguing the OP should not be super careful when using their new race bike, but why all the negativity?
 
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A lot of times the rear frame triangle by the crank about one of the bend is that's where the rear end brakes on the old pedego bikes at 750 watts. Oh they were aluminum but that Ben is stressful. And another thing is the front rim doesn't like to hold the tire on all the time so be careful they have been known to jump the rim yeah those big four inch tires.
Hell go for it you have many times I crash my bike concussion broke the collarbone three times. My bike only goes 45 mph. Maybe get one of those inflatable vests for motorcycles I see on TV. That's your next buy I could tell and do you have a good enough helmet.
Or leathers with one of those turtle shells on the back or when you fall off you slide on your back I've seen that in action work good.
I sure love going fast 46 mph on E50 rated tires made for a pedicab. Plus I always forget to wear a helmet.
Yeah put that motor in a clone frame And use a leaf motor at 72v 40amp with a temp gauge.
 
Jae said:
I'm not a bike person
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Not the response you were hoping for, I suppose, it sounds generally negative. Sorry about that.

The people here are trying to keep you alive.

I would consider that I input an incorrect setting before thinking that machine would reach 68mph. Tires like that are supposed to run with 5-10 psi in them.

And consider context, please: "I'm not a nitroglycerin person". It will still blow up, and it's still not wise to continue playing with it if I don't know.
 
Chalo said:
If it's a one-size bike from a department store, its purpose is to go under the Christmas tree for someone who's too young to be dreaming about his driver's license yet. After a few years of not getting ridden, its next destination will be the custody of a bum or a hard bitten poor relative, where it will die an ugly but relatively quick death as it is used harder than the manufacturer ever intended.

If it were a bike for adults, it would come in a range of sizes, and the place that sells it would be willing and able to service
Click to expand...

99zip99 said:
A lot of times the rear frame triangle by the crank about one of the bend is that's where the rear end brakes on the old pedego bikes at 750 watts. Oh they were aluminum but that Ben is stressful. And another thing is the front rim doesn't like to hold the tire on all the time so be careful they have been known to jump the rim yeah those big four inch tires.
Hell go for it you have many times I crash my bike concussion broke the collarbone three times. My bike only goes 45 mph. Maybe get one of those inflatable vests for motorcycles I see on TV. That's your next buy I could tell and do you have a good enough helmet.
Or leathers with one of those turtle shells on the back or when you fall off you slide on your back I've seen that in action work good.
I sure love going fast 46 mph on E50 rated tires made for a pedicab. Plus I always forget to wear a helmet.
Yeah put that motor in a clone frame And use a leaf motor at 72v 40amp with a temp gauge.
Click to expand...
I had my MotoX gear on for that ride.
 
Jae said:
Got it to 68mph and i think it had a little more but it got sketchy fast.
Click to expand...
No suspension. Fatbike tires. Cheap Chinesium cable-pull disc brakes. Bicycle wheels and axles. Short wheelbase frame(compared to a motorcycle).

Either you have balls of steel, and/or you don't have much knowledge of physics.

Either way, respect, fam. 68 mph is hilariously fast for something like this. Just make sure you don't go splat. It can happen to any of us.

I wouldn't recommend anything over 30 mph on this build as it currently is. 35 mph if you put a front suspension fork on it. Maybe 40 mph with front suspension, DOT rims, Schwalbe Marathon Plus e-bike tires, and hydraulic brakes. Anything over 40 mph won't work with that frame as you'll need nothing less than a longer wheelbase and full suspension in addition to the aforementioned.
 
The Toecutter said:
No suspension. Fatbike tires. Cheap Chinesium cable-pull disc brakes. Bicycle wheels and axles. Short wheelbase frame(compared to a motorcycle).

Either you have balls of steel, and/or you don't have much knowledge of physics.

Either way, respect, fam. 68 mph is hilariously fast for something like this. Just make sure you don't go splat. It can happen to any of us.

I wouldn't recommend anything over 30 mph on this build as it currently is. 35 mph if you put a front suspension fork on it. Maybe 40 mph with front suspension, DOT rims, Schwalbe Marathon Plus e-bike tires, and hydraulic brakes. Anything over 40 mph won't work with that frame as you'll need nothing less than a longer wheelbase and full suspension in addition to the aforementioned.
Click to expand...
Has Ebike tires,and hydraulic disk brakes.
 
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