Biggest direct drive recommendation for a steel frame MTB?

[Snarf]

I personally wouldn’t put the QS 205 in any mountain bike frame, it’s way too heavy. Unless it had a custom swingarm/chainstay they could handle the extra weight.

Also note the mxus 3K is 142mm dropout

I remember when I went from the mxus 3K in my stealth bomber clone frame, and then switched to the QS205 I could feel a tremendous amount more upspring off road when hitting roots, rocks, etc.

I think the mxus 3K is more suited for an actual mountain bike frame. Comparing it to the QS 2000 or 3000.

Hello I’m new and not sure where to post, but I’m trying to build a similar bike as 999zip.
What is the most powerful 72v setup you would put on a MTB frame?
I really like the look of the grin all axle with the nifty mounting features and torque arm. I also really like the bear bones kit as I like the cleanest build possible. I don’t want to go 50 mph, but I would like to do 30 mph up an decent hill. I think I’m just looking for a motor and controller recommendation, unless there’s something I’m missing. A simple controller where I could control the amps from the battery sounds perfect

 

[Snarf]

Hello I’m new and I’m trying to build a fast MTB. I have a CYC photon on a trek dual sport, and want to plan out something different. I’m interested in dual suspension if its recommended.
What is the most powerful 72v setup you would put on a MTB frame?
I really like the look of the grin all axle with the nifty mounting features and torque arm. I also really like the bear bones kit as I like the cleanest build possible. I don’t actually want to go 50 mph, but I would like to do 30+ mph up a decent hill. I think I’m just looking for a motor and controller recommendation. A simple controller where I could control the amps coming from the battery sounds perfect.

 

[amberwolf]

Since it's not very helpful if a system doesn't do what you want after you spend all the time and money to build it...you should start from the other end of things:

Make a list of all the details of what job do you need the system to do, under what riding conditions and terrain, and riding style, etc.

Knowing those, you can use calculators or simulators like those at ebikes.ca to figure out how much power it wil take to do the job, It will also help you see how much battery capacity you'll need for whatever runtime or range you want. (you don't give enough detail for us be able to estimate this for you)


Then knowing those things, you can see if you can even fit a system with that much power and battery onto the type of bike you're after.

 

[Snarf]

Hey I appreciate your time and consideration. I already built a fabulous e-bike for fitness and street cruising. I’m hooked and want to plan out a faster build with at least front suspension to do some light trails and moving fast on the streets without heat issues. I would like it to do 50 mph just so it could hold 30 mph up a reasonable hill. 40 is about the fastest I really want to go. 20 miles is about the furthest I would ride in a day. I really don’t want to pedal this bike at all, except maybe to help it on a steep hill or to get it going from a stop. I want it disguised as a MTB to avoid registration and insurance. I live in Oklahoma, so it’s usually very flat around here.

I also want a 2nd bike so friends and family could go riding with me. The rear hub seems perfect for someone who’s never ridden a e-bike before to have no learning curve and be able to hop on and enjoy.

 

[calab]

Biggest is the 45h hubs is about the max for 135mm rear dropouts, mxus 3kw 45h or the qs options.

Depending on the freewheel or cassette (if its available on the hub) you might have to spread the dropouts by 2mm or so, but sometimes the fw sticks out to far and rubs on the dropouts and grinds your frame down a bit but you'd notice it as the fw wont spin. Washers help but the middle hole isnt a common size for common washers, the slotted washers for ebikes might fit, but the easy way is to but less gear fw on to shorten the total width.

Everything else like the battery voltage, battery size and its ah, wh is dependent on placement of battery. A full suspension bike you get less room in the triangle, the best place to put a battery is in the triangle. Controllers can be placed anywhere, but size might be important and some controllers are double the length of a 36v controller.

25mph is more reasonable on a bicycle then 50mph is, you ever go 50mph on a bicycle before?

 

[Chalo]

25mph is more reasonable on a bicycle then 50mph is, you ever go 50mph on a bicycle before?

While that's also my opinion, he says the main goal is to climb hills at 30mph (also too fast for a regular bicycle IMO). To do that implies an ungoverned top speed quite a bit higher. If the controller is programmable or has a programmable head unit, then a top speed restriction can be added.

I have the best bike lights on my main e-bike of anybody I know. But at 25 mph in dark, lightly rainy conditions, that didn't keep me from slamming into a stupid piece of transit infrastructure without seeing what was going on. I was lucky in that I didn't get seriously hurt. But the bike was a total loss. So be careful; as the saying goes, speed kills.

 

[Snarf]

Biggest is the 45h hubs is about the max for 135mm rear dropouts, mxus 3kw 45h or the qs options.

Depending on the freewheel or cassette (if its available on the hub) you might have to spread the dropouts by 2mm or so, but sometimes the fw sticks out to far and rubs on the dropouts and grinds your frame down a bit but you'd notice it as the fw wont spin. Washers help but the middle hole isnt a common size for common washers, the slotted washers for ebikes might fit, but the easy way is to but less gear fw on to shorten the total width.

Everything else like the battery voltage, battery size and its ah, wh is dependent on placement of battery. A full suspension bike you get less room in the triangle, the best place to put a battery is in the triangle. Controllers can be placed anywhere, but size might be important and some controllers are double the length of a 36v controller.

25mph is more reasonable on a bicycle then 50mph is, you ever go 50mph on a bicycle before?

After building an e-bike and riding with a speedometer, I believe I went 50mph all the time as a kid down hills etc. You guys might be right, I don’t need to go faster than my photon already takes me. I might still build this bike, but I’m not gonna rush into it.

 

[E-HP]

Hello I’m new and not sure where to post, but I’m trying to build a similar bike as 999zip.
What is the most powerful 72v setup you would put on a MTB frame?
I really like the look of the grin all axle with the nifty mounting features and torque arm. I also really like the bear bones kit as I like the cleanest build possible. I don’t want to go 50 mph, but I would like to do 30 mph up an decent hill. I think I’m just looking for a motor and controller recommendation, unless there’s something I’m missing. A simple controller where I could control the amps from the battery sounds perfect

You don't need the "biggest" motor to do what you're describing. A decent 1500W direct drive motor with Statorade has enough performance and will be much lighter. I did a search on the steepest grade hills in Oklahoma, and there aren't any that would present a problem (looked like the steepest grades were below 8%, so not much). At 72V, you'll need a battery that can provide around 60 amps.