Build a bike to commute not sure what I need.

[Drynk]

Hi, I want to build a bike to commute 13 miles back and forth mostly flat but on rough gravel not much potholes/washboard more loose unpacked or packed snow/ice. I like to build things myself and get the best bang for my buck. I already got a few good condition solid and heavy 90s no suspension mountain bikes and managed to find locally at reasonable price not selling nos 5 or so years old power tool batteries containing samsung inr21700-30t which still got their full capacities (at least the few i tested). I think it would be nice to put 3 inch semi slick tires on it and add chains for the winter, thought it might soften up the ride a bit, probably not necessary, the stock 2''agressive mtb tires should do the job and i'll save a bit plus some custom fitting work. I'd be happy if I can maintain 30 mph. I was thinking of going dual direct drive hub motor for more traction and backup if one fail. I like silent things and ebrake would be nice too. I think I'll need more or less 1kwh to do the run I've been doing research for the last month or so and I am as much confused as I began. Do i go awd fwd or rwd? If awd do i use 2 direct drive or 1 direct drive and 1 geared? Could i use 2 smallish 500w dd and over volt them a bit or should I just use the larger(s) 10''ish since my bike is gonna be heavy anyway? How much power do i really need?

 

[calab]

Choose a bicycle you like to ride before you convert it.

 

[scianiac]

You should make sure you're comfortable riding at that speed on those roads with the frame you chose then I would keep it simple with something like a direct drive rear hub like a leaf 1500w, grin all axle or any equivalent sized off brand motor. Just go play around with the grin motor simulator to pick your motor size for target speed and such. I would recommend against awd as it's a lot more complicated for little gain and fwd just generally has more control issues. Also just get some studded tires for winter, they work great and don't have all the issues of chains at anything above quite slow speeds. Yes to the widest tires you can fit although that may not be very wide due to frame and rim limitations.

 

[Bullfrog]

I'd start with a steel framed Mongoose or Schwinn Mountain Bike frame that has disc brakes front and rear. In the US you can get a good one at Walmart brand new for around $250...it is called the Mongoose Durham. The link to it is below...even though it says "Robot or Human?":

Robot or human?

26" wheels are my preference because they are easier on the motor than a larger diameter wheel and there are a lot of tires to choose from. If riding on decent roads, I'd go with a Schwalbe Pick Up or Super Moto X and/or a Maxxis Hookworm. A 24" rim would be even better...the smaller diameter and a higher Kv motor work well together but tire selection is somewhat limited with a 24" wheel.

You definitely want to go with a 14s/52v battery if your local laws allow it,,,it is by far the most common voltage used so you can not only find a battery but also a controller and a display. If you go with higher voltages, components are not as common or readily available. I buy all of my batteries from EM3ev.com...Joseph is their tech guy and I'd contact him via the web site if you have questions.

Motor....this is where you are going to get all kinds of different recommendations. I would go with a Leaf Motor...probably a 4T winding. You can use the Grin Tech Motor Simulator to see how fast your planned set up should go and whether it will over heat or not. Substitute the RH212 motor in place of the leaf and just change the Kv to your motor....it will give you the steady state operating temperature. You can use the Leaf Motor in the drop down menu for speed (change the Kv as required) but it has not been modeled to give you the temps.

Why the "Leaf" motor...best bang for your buck, relatively light, relatively powerful. A geared hub like a MAC is a good idea as long as you don't want to go faster than about 28 mph and it will have about five times more torque than the Leaf. Why 28 mph...any faster and you have potential over heat problems. With the Leaf you can run about 35 mph without cooling fluid and not over heat. I'd stay away from a mid drive...too much maintenance on the drive train for a commuter.

Controller...I don't have any good recommendations but I'd go with one that can handle 40A battery current. There is also "Phase" current and it usually is proportional to the battery current the controller can handle.

That should get your rolling .

 

[Zambam]

I'd start with a steel framed Mongoose or Schwinn Mountain Bike frame that has disc brakes front and rear. In the US you can get a good one at Walmart brand new for around $250...it is called the Mongoose Durham. The link to it is below...even though it says "Robot or Human?":

Robot or human?

----------.

This Mongoose Durham has an aluminum frame Robot or human? Did you mean something else that's steel framed?

 

[Bullfrog]

Even though it is aluminum, the Mongoose Durham should work just fine.

I prefer steel because it is less likely to crack both from overload and from fatigue than aluminum but all Schwinn and Mongoose frames, both steel and aluminum, are built with a fairly large safety factor so they will all be OK.

The nice thing is that Pacific Cycles owns Schwinn, Mongoose, and several other brands so you can get parts for your bike and they are fairly reasonably priced.

 

[Zambam]

$248 for a bike, how bad is the front suspension on the Mongoose Durham? How long will it last before the suspension craps out? Is it rebuildable or upgradable with a better suspension?

Can you recommend a full suspension bike to install a TSDZ2 mid motor into? I am 5' 3" 118 lbs winter, 5 lbs lighter in summer when more active.

 

[DaLanMan]

If you are in Central Cali, I have a fine selection in the bone yard, But I am fairly certain all the Schwinns are aluminum. I do have a few steel frames, I even have one legit old school mongoose from the 70's It has a square channel frame and the frame *alone* weighs in around 4kg... But man when I was a kid those were the shit...

In any case, yeah, it is often better to check out boneyards and other such places for candidates. I do pretty good getting bikes from the police auctions.

 

[nicobie]

I've been pretty lucky with police auctions too.

 

[Chalo]

$248 for a bike, how bad is the front suspension on the Mongoose Durham?

Bad. It's a stamped steel twin pogo stick, except shabbier than most pogo sticks.

How long will it last before the suspension craps out?

It comes pre-crapped. Sloppy plastic bushings, no damping except for friction between the sliding parts.

Is it rebuildable or upgradable with a better suspension?

Rebuildable, no not at all. It looks like you could install a better fork that has a 1-1/8" steer tube, but that would be pointless folly because all the bike's other parts are also garbage.

 

[DaLanMan]

FWIW, I do a *lot* of horse trading, and in the Bike world, despite being into it since literally the first day I was in Cali. I know dick all about these beasties. Chalo has been a saint putting up with my questions and helping steer me out of ignorance. And so far, no matter how weird and esoteric my questions have been, he just blithely rattles of the answer..

And for the record, Not *all* schwinns are Aluminum.. just all the ones you are gonna see that are younger than you...

and possibly younger than me.

 

[Bullfrog]

I would install a SR Suntour Raidon fork in the Durham and it will work about as good as the high dollar forks plus the Raidon is available with a straight steerer tube if you need it. IMO it is the best straight steerer fork available plus the width of the SR Suntour is a little bit wider than both Fox and Rockshox forks so it allows you to run a wider tire.

Everything above is true for most Schwinn and Mongoose Mt bikes. Plus if you need other parts you can get them from Pacific Cycles fairly cheap.

Yep, Chalo has saved me several times as well .

 

[MoneyPit]

I would try a single-motor bike first and save awd for later if you find you have issues with traction.

Awd (done right) is going to be a minor miracle on dodgy terrain with its distributed traction, which putting in a bigger motor in the back will not address. But its a lot of work to get the same end result (one electric bicycle). Its worth it if you are detail-oriented, enjoy a project and you have the time to put into it. The results can be amazing.

 

[E-HP]

I like silent things and ebrake would be nice too.

You will need a direct drive motor and a sine wave or FOC controller that support regen braking to meet this criteria.

Do i go awd fwd or rwd? If awd do i use 2 direct drive or 1 direct drive and 1 geared?

Since you can't really pedal/coast a direct drive motor, it should be one that is always driven (if you want to shut off one motor as an option). Geared motors can coast, so having two would make it so one motor isn't trying to drive the other at any given time when both are engaged, or if one is turned off. Geared motors can't provide regen/braking unless you weld the clutch.

So, a single direct drive motor, driven by a sine wave/FOC controller, will be silent, and have the ability to provide regen/braking.