Build option for hunting camp E-bike/Dirtbike

Hi.

This is my first post - I’ve never ridden an electric bike or an electric dirt bike so please go easy on me.

I’ll try to keep this as straight to the point - here is my performance criteria:

Range - 15 km
Top speed on flat terrain - 25 km/hr would be fine with me
Climbing ability - biggest elevation change on property is 60m over a 1 km trail.
And finally - I don’t want to sweat - if I sweat on my way to my hunting stand I’ll be freezing my but off in an hour.

The preferred option I’m looking at is mounting a KunRay 3000w - 72v motor (direct drive) onto something like an old Honda CR80 dirt bike (I’m 5’6” and 170 lbs). I’m thinking I can make this happen for around $1500 Main concern with this option would be not enough power to get up the hill without pedal assist.

My 2nd option is throwing a 750 or 1000 w mid drive kit onto a cheap mountain bike - I’m thinking $1500-2000. My main concern for this build would be getting up the hill without breaking a sweat.

Please keep in mind I’m looking for advice on what would best meet my criteria as opposed to what would be the best all around bike someone else would want to build. Also this would 100% be on private land so street legal is of zero concern.

Thanks in advance for all thoughts and opinions.

Getting up hills won't be any problem at all whatsoever. Especially if you want to gear as slow as 25 kliks. Actually you can do twice that speed on the budget you want. You will probably be falling off the bike before it stalls up a hill.

There are quite a few motors that should do what you want. I dunno about the kunray tho. It looks questionable and haven't heard a lot of people using them on here. QS has a big beefy "3000W" (can do much more) sealed mid drive motor that about $400 that would be a good option, and will have tons and tons of power.

A dirt bike chassis will be sturdier, more rugged, probably have more suspension travel and a better ride, have thicker tires that stand up to damage and punctures more easily, and of course be heavier than a mountain bike. It also comes ready for a heavy duty chain which will be more reliable and last longer. If you want to carry stuff, or want a more comfortable and reliable platform, it's not a bad choice.

A mountain bike can be fine too but they tend to be pretty expensive by the time you find one with decent specs.

Forget about pedaling. You don't need to.

Wow, thanks. I don’t know what to be more impressed by - the speed of the reply or that a 3000w motor will crush the hill no problem.

Yes, I am leaning towards the dirt bike because if the ruggedness - I find decent used mountain bikes are crazy around here and since I don’t know anything about them in terms of how to tell what kind of shape they are in, I’d rather steer clear of option 2.

how cold is it going to be? batteries don't like freezing temperatures too much, you might need to figure a way to keep them warm while youre in the stand for a couple hours

Overnight/early morning temps have been as low a -18c/0f but that is very rare. We are usually looking as a couple of degrees above or below freezing as the normal night time lows.

I hadn’t really thought about the affect of cold on the battery - but my plan was to keep a burlap blanket at the stand (or take one with me) so I can cover the bike to camouflage it. I wonder if that would be enough to hold a bit of heat in for the few hours I am out in the morning?

One thing that I have found on some larger AC electric motors I use for work is the bearings do not like the extreme cold - that might be something I need to take into account on an e bike motor. One particular high RPM motor I use for work sounds like an ostrich at the dentist when it’s really cold out (-15 c or lower). I suspect that is due to the fact that the only replacement bearings I’ve been able to find locally are from either Mexico, China or Italy.

Well, the climb doesn't sound too hard to me, even for off road where a short bit might be very steep.

You are getting advice to go higher power simply because you are on ES. Homemade electric motorcycles with pedals, as I call them, are quite popular here.

Actually a very modest setup will do your needs, a typical cheap 48v 1000w direct drive kit. Mount it on a very cheap bike, if the trail is not all that rough. Not a crap bike, but I'm just saying a $150 buck used stump jumper mtb or something like it will do fine. Battery will need to be decent, meaning a bit of money spent there, for something not the cheapest cells inside. 10-12 ah in size is fine.

Cold battery is a problem, but just warm it before you start out, to room temp. Hot water bottle in an ice chest, reptile heater if you have AC power overnight, something like that. then when you start out, mount it on the bike, then cover it with some kind of insulation. Carpet pad, modify a puffy vest, whatever works to keep that warm in a few hours. As long as it does not freeze solid you are good. On the way back, the battery will be sluggish, but it will warm itself inside the "tea cozy" you made for it.

I LIKE the electric pit bike Idea, but unless you have the carcass laying around, it will be much cheaper to just build an entry level electric mtb. You can pedal some without sweating btw, on the e bike you can avoid all sweat easily. You just pedal a few strokes here, a few more there, as needed for the worst part of the trail. No sweat, from just a few hundred feet of pedaling.

Lastly, I'd leave that bike 500 feet from the stand, and do the much quieter foot stalk creep up to it. Wheels on dirt does not sound natural.

I was kind of wondering what the sound would/will be like. When I ride a gas atv I can hear the dry leaves crunching under the tires but when I’m in a stand and someone drives past on a trail 100-150 yards away I only hear the motor.