Ideas for a salvaged Bike chassis

[CONSIDERABLE SHOUTING]

I apologize if this is a little slapdash in how I'm thinking.

So the other day down at the scrapyard I found this bike for $8. My bike knowledge isn't good, but I think it's a downhill bike? Full suspension? not sure. Anyway, the big reason I snagged it wasn't just because it's (sans front wheel) in great shape, but because it has a 155mm dropout- my initial dream was to smash a leafmotor into the rear with the existing gears and to make something sketchy, except reality came knocking.

I barely know bikes, and I'm a total novice with their mechanics so gunning for such a powerful motor seems foolish (but fun!). I still have the motors from this thread (https://endless-sphere.com/forums/viewtopic.php?f=9&t=106233&start=25) but they fit 135mm dropouts, not 155, and I'd need to find another scrap bike to get one to work unless there's some way I can replace the through-axle on my own. I have 2 controllers and throttles I can use at 48 volts but no idea if they work. This site (https://e4bike.ru/page/battery-shape-configurator) shows that I could make a 13S5P pack for it and NOT hit the shock, but it likely won't be big enough for anything like the Leafmotor's capability. Basically, I have informational paralysis and I would love help in brainstorming

I'd be making this first design just for dickin' around and learning. My college is a few miles away and so are the shops, so a huge pack would really just give me the ability to go for longer; 20 miles would do me fine, but I have tons of cheap cells i'd love to use up. I'd love to hear any ideas you've got!

 

[calab]

Its a p.o.s. walmart b.s.o. aka bicycle shaped object with 29" wheels, plastic pedals and Frame: aluminum frame
https://www.walmart.com/ip/29-Genesis-V2900-Full-Suspension-Men-s-Mountain-Bike-Blue-White/22899842
The best you can do with that p.o.s. bicycle is fix the broken wheel, shove any old hub motor on it and have fun, its really not that hard to figure bicycles out. Its just that there are so many different sized components now that you need special tools, but your bso is a pos that is easy enough to convert and ride, its really no big deal, just dont be dropping off of ridges and cliffs and think it will hold up, all its good for is beginner trail riding and cruising.

Its a great score even if you overpaid for it paying 8$, should really be free if you know what I mean :wink:

It is better to actually spend some money on a used bicycle from the better brands like kona, stumpjumper, giant, trek

 

[CONSIDERABLE SHOUTING]

Its a p.o.s. walmart b.s.o. aka bicycle shaped object with 29" wheels, plastic pedals and Frame: aluminum frame
https://www.walmart.com/ip/29-Genesis-V2900-Full-Suspension-Men-s-Mountain-Bike-Blue-White/22899842
The best you can do with that p.o.s. bicycle is fix the broken wheel, shove any old hub motor on it and have fun, its really not that hard to figure bicycles out. Its just that there are so many different sized components now that you need special tools, but your bso is a pos that is easy enough to convert and ride, its really no big deal, just dont be dropping off of ridges and cliffs and think it will hold up, all its good for is beginner trail riding and cruising.

Its a great score even if you overpaid for it paying 8$, should really be free if you know what I mean :wink:

It is better to actually spend some money on a used bicycle from the better brands like kona, stumpjumper, giant, trek

That... actually makes me feel good about this, because I have tons of shitty parts thanks to a local amazon returns reseller (also explains why, even though it claims to be alloy, it's frame is heavy as hell). Like this battery pack would be a salvaged laptop cell pack, nothing I seriously spent money on lmao
Do you think for the rear motor, best I can do is just getting a different hub that has a 155mm axle? All the ones I have are 135mm.

 

[calab]

I say fuc.k it and squeeze the dropouts in 20mm or if your lucky and have a large hub motor axle you can throw in spacers but I would say 20mm is to much to squeeze in because the chain stay is under stress by it being squeezed in. I again say fuc.k it and find another bicycle that has 135mm dropouts, fix that pos bso with the pos parts you have and sell it for 20$

Do you think for the rear motor, best I can do is just getting a different hub that has a 155mm axle? All the ones I have are 135mm.

 

[spinningmagnets]

Do your own research, but if you are certain you will be using a hubmotor instead of a mid-drive, compare all hubmotor options to a rear Leafbike 1500W @ 48V (*or 52V).

Use two torque-arms.

 

[E-HP]

I'd replace the front fork with something decent, and with disc brake mounts (my preference). The triangle has enough space 20 miles worth of battery, if you use high capacity cells. Rear suspension components may suck, but I'm going to call them better than nothing (or at least as good as a suspension seat post), since the front fork will give you better control, and the rear will still help your back.
Some cheap frames will still use steel for the swingarm, so check it. Steel would be preferred for a hub motor. The dropouts also have a pretty wide flat surface, so can be drilled for a solid connection when you add torque arms. I'd remove the smaller front chain rings and derailleur and just keep the big one to shed some useless weight.

 

[CONSIDERABLE SHOUTING]

I'd replace the front fork with something decent,

I have one from a junked Schwinn. Are the diameters for the front tube hole pretty standardized?

and with disc brake mounts (my preference).

I don't think I have the skill to do that.

The triangle has enough space 20 miles worth of battery, if you use high capacity cells. Rear suspension components may suck, but I'm going to call them better than nothing (or at least as good as a suspension seat post), since the front fork will give you better control, and the rear will still help your back.

I figured as much.

Some cheap frames will still use steel for the swingarm, so check it. Steel would be preferred for a hub motor. The dropouts also have a pretty wide flat surface, so can be drilled for a solid connection when you add torque arms. I'd remove the smaller front chain rings and derailleur and just keep the big one to shed some useless weight.

I'm not sure how to check if the swingarm is steel, but I wouldn't doubt the whole thing is because of it's weight.

Do your own research, but if you are certain you will be using a hubmotor instead of a mid-drive, compare all hubmotor options to a rear Leafbike 1500W @ 48V (*or 52V).

Use two torque-arms.

From reading the Leafmotor thread I know it would be hard to buy literally any other motor when directly compared.
I'm decently certain on the hub over the mid; I just lack the skills and the tools currently to really experiment. I COULD do some small Mid like the cheap MY1016 motors Dark Angel is a fan of, but to be frank their reliability is questionable and for 3 times the cost I get more than 6 times the power and a huge upgrade capacity; though I won't lie, I have lots of little electronics meant for 24 volt systems that would work well with it.

 

[LewTwo]

I'm not sure how to check if the swingarm is steel ...

Try a magnet. There only a few rare Aluminum alloys that are magnetic.

 

[99t4]

I'd replace the front fork with something decent,

I have one from a junked Schwinn. Are the diameters for the front tube hole pretty standardized?

Might (probably) not be any better. :wink:

Helpful head tube info: https://www.sheldonbrown.com/cribsheet-headsets.html

 

[LewTwo]

I have one from a junked Schwinn.

The original Chicago based Schwinn bicycle company went bankrupt in 1992.
The trade name was traded back and forth a bit.
Today there is virtually no difference between a Schwinn bicycle and any other Chinese commodity bicycle.

 

[CONSIDERABLE SHOUTING]

Try a magnet. There only a few rare Aluminum alloys that are magnetic.

I'm mad I didn't think of that. Thank you. Chassis is aluminum, front for is steel!

Might (probably) not be any better. :wink:

Helpful head tube info: https://www.sheldonbrown.com/cribsheet-headsets.html

... oh god. Whelp, guess I'll be tossing that schwinn frame then.

 

[Chalo]

Whelp, guess I'll be tossing that schwinn frame then.

The weird Schwinn sizes for things are mostly confined to 1982 and earlier bikes. Later models can have "American/OPC" dimensions in the case of cruisers and BMX bikes, but most use customary world standard dimensions for their respective times.

 

[CONSIDERABLE SHOUTING]

Okay so not AS bad. Then if the Schwinn frame is still possibly usable, What do I do about rim breaks? It's got the mounting points for them, are they pretty modular or are they also a mess to find?

 

[Chalo]

Okay so not AS bad. Then if the Schwinn frame is still possibly usable, What do I do about rim breaks? It's got the mounting points for them, are they pretty modular or are they also a mess to find?

Is it cantilever brake posts, or just caliper mounting holes? If it's posts, brakes are cheap and easy to get, but you're limited to a specific wheel size. V-brakes are easier to set up than cantilevers, and don't require housing stops or straddle wires. If you use V-brakes, you have to match them with long pull levers.

Caliper brakes are also cheap and easy, and they allow some range of wheel sizes-- but the longer the reach to the rim, the weaker the braking tends to be. Caliper brakes use short pull levers.

Rim brakes are generally much more interchangeable and configurable than discs.

 

[CONSIDERABLE SHOUTING]

Is it cantilever brake posts, or just caliper mounting holes? If it's posts, brakes are cheap and easy to get, but you're limited to a specific wheel size. V-brakes are easier to set up than cantilevers, and don't require housing stops or straddle wires. If you use V-brakes, you have to match them with long pull levers.

Caliper brakes are also cheap and easy, and they allow some range of wheel sizes-- but the longer the reach to the rim, the weaker the braking tends to be. Caliper brakes use short pull levers.

Rim brakes are generally much more interchangeable and configurable than discs.

Looks like posts. Rear drop is 135mm but the bafang wheels and axle doesn't fit that either! Would all I need to measure wheels for this just be measuring from the axle "up" to where the posts are?

 

[LewTwo]

I barely know bikes, and I'm a total novice with their mechanics so gunning for such a powerful motor seems foolish (but fun!). I still have the motors from this thread (https://endless-sphere.com/forums/viewtopic.php?f=9&t=106233&start=25) .....

Maybe I am a bit confused. The post that you reference is about Front wheels with Bafang motor hubs.

 

[Chalo]

Would all I need to measure wheels for this just be measuring from the axle "up" to where the posts are?

Brake posts need to be 1"-1.25" below the brake track of the rim. So for 26" wheels, they'll be very approximately 10" from the axle.

 

[CONSIDERABLE SHOUTING]

Maybe I am a bit confused. The post that you reference is about Front wheels with Bafang motor hubs.

CAUSE I DIDN'T KNOW LMAO
The rear Strumey archer hub DOES fit perfectly, which would keep me from messing with a dureliur for the first time... in a way that's a good thing, because then it knocks down the number of options. I'd like to start with something small that I can break and not be too broken up about, but I obtained a basic 48/60v controller on the mega cheap that could drive a leafbike motor at basic speeds assuming it works properly.

Brake posts need to be 1"-1.25" below the brake track of the rim. So for 26" wheels, they'll be very approximately 10" from the axle.

Mine are about 11". Maybe 28" wheels then?

 

[Chalo]

Brake posts need to be 1"-1.25" below the brake track of the rim. So for 26" wheels, they'll be very approximately 10" from the axle.

Mine are about 11". Maybe 28" wheels then?

Almost surely 700C wheels. Also known as 29" when you can use a fat tire.

 

[CONSIDERABLE SHOUTING]

Almost surely 700C wheels. Also known as 29" when you can use a fat tire.

Okay! I'll pop open my Park Tool manual when I get home to look up some deets on them: looks like 700Cs are pretty common and Leafbike even sells pre-laced motors in 700C wheels, but not 29s". I think having a 29" would be better, because if I would do this I'd jump headfirst into going the full 60v monty for the hell of it, but would 700C rim breaks fit 29" wheels and vice versa?

As for the blue walmart frame, those Bafang front-wheel motors might actually fit into the front fork no problem, I just have to pop the rim break off when I get home to see! If so, I might finally be making my first battery pack here very soon, 'cause all I'd need is to convert one of these basic switching power supplies to have a usable plug and get my cheapass spot welder modded for proper work- Just so long as I can remove a front wheel rim break and not have to worry about taking something out of alignment for whatever reason :lol:

 

[Chalo]

but would 700C rim breaks fit 29" wheels and vice versa?

Yes, but only if the wheels have braking surfaces. Many rims these days are coaster brake specific and don't have sidewall braking surfaces.

 

[99t4]

Almost surely 700C wheels. Also known as 29" when you can use a fat tire.

Okay! I'll pop open my Park Tool manual when I get home to look up some deets on them: looks like 700Cs are pretty common and Leafbike even sells pre-laced motors in 700C wheels, but not 29s". I think having a 29" would be better, because if I would do this I'd jump headfirst into going the full 60v monty for the hell of it, but would 700C rim breaks fit 29" wheels and vice versa?

700c and 29 are essentially the same diameter. 700c caters more to roadbikes so usually narrower than 29er that caters to offroad (so wider).

More reading material for you!
https://www.sheldonbrown.com/tire-sizing.html

There is a tire width/rim width crossref chart there that can suggest compatible tire widths for your 700c rims you are getting from Leaf.

Note the note there following the chart.

 

[CONSIDERABLE SHOUTING]

Yes, but only if the wheels have braking surfaces. Many rims these days are coaster brake specific and don't have sidewall braking surfaces.

Thank you, good to know! Looks like the blue bike uses 29", and the rear wheel is still decent so it looks like I'll be going 29" across the board for both of them.

700c and 29 are essentially the same diameter. 700c caters more to roadbikes so usually narrower than 29er that caters to offroad (so wider).

More reading material for you!
https://www.sheldonbrown.com/tire-sizing.html

There is a tire width/rim width crossref chart there that can suggest compatible tire widths for your 700c rims you are getting from Leaf.

Note the note there following the chart.

Thanks friend! I swear, this is just as complex as cars.

Looks like I'll be calling around to see whom can re-lace and balance one of these bafang motors I have; It'll probably be cheaper to research spokes and buy everything off amazon, but I'll see what price they can quote me just to help support my local merchants.