Build for bikepacking?

[Jahbak]

I want to build essentially a bikepacking mountain bike for cross country touring. With the primary use of the motor being to offset the weight of cargo needed for long remote trips, mostly for assistance climbing. Ideally I'd be using my own energy to push myself around most of the time, but I want to make the hills a little easier with the assistance of a motor. I was thinking a hardtail mountain bike build would be ideal since I want to be able to unload the bike for exploring wherever I end up, while using solar panels (I plan to have a trailer) to charge the batteries for the trip to my next destination. I'm guessing it will take a bit of time but I'm not in a hurry and would like to spend time in each park I reach to really get to know it and document the plants, animals, and geology.

I have no idea where to begin, I've looked at Bafang motors and they seem great but probably too powerful for what I need and I'm guessing that translates to being less efficient even when tuned down to my needs. Something like the new Trek EXe 9.X motor seems like it would be optimal, super lightweight but still enough power to send a rider uphill with minimal effort when desired, with very little pedal resistance when riding unassisted, if I could acquire one and attach much bigger 700wh+ batteries I would think that is enough to offset the cargo weight on hills for long distance trips.

It probably shows but I really know nothing about bicycles at all, electric or otherwise. I just have been fixating on this idea for a long time now, I'm used to being in a 4x4, but I want to experience more, feel the weather, be forced to stop more often and get to know towns and people along the way. I'm aware people do this with regular bicycles but I'm more interested in being exposed to the world than testing my endurance, although I'm keen for a bit of that which is why I'm mostly interested in an electric bicycle of some kind over taking a motorbike.

Would really appreciate any tips toward similar builds or general advice.

 

[Mabman]

"With the primary use of the motor being to offset the weight of cargo needed for long remote trips,"

So you want to offset the cargo weight by adding more weight that is complex and needs to be re-charged in remote situations? Not to be harsh but you would be better served starting out with as light a bike as possible and just plan on pushing a few of the hills.

 

[Jahbak]

So you want to offset the cargo weight by adding more weight that is complex and needs to be re-charged in remote situations? Not to be harsh but you would be better served starting out with as light a bike as possible and just plan on pushing a few of the hills.

Can you elaborate, you say that as if adding a motor to the bike is nothing but dead weight. From what I understand these motors are capable of driving a bike and a heavyset rider up a steep incline with throttle alone. Don't worry about being harsh, I won't take it personally.

 

[chrismechmaster]

Depend on your fitness level eg if you want a full fat or a light weight

i assume your looking at lightweight as you mention the new trek fuel

it’s worth looking at the orbea rise !!

I have a rise carbon model and its a very good bike for long distance/ flat riding / bike packing if that’s what you like

it can be pedal off / over the limiter easily and couple with the optional range extender in eco with both batteries on the flat your looking at a range of over 100 miles from the main battery and extender combined

I did a 40 miles gravel ride the other day and only used the extender the main battery was full so would of got another 60-70 ish miles

it’s a great long distance bike

 

[Mabman]

Can you elaborate, you say that as if adding a motor to the bike is nothing but dead weight. From what I understand these motors are capable of driving a bike and a heavyset rider up a steep incline with throttle alone. Don't worry about being harsh, I won't take it personally.

While it is possible to configure an e assist system that will do as you suggest it will end up being on the even heavier end of the e assist spectrum due to the necessary large stator type motor and a battery big enough to satisfy the watt output it will demand doing so. Your off the bike shop floor type bikes won't do the job.

If you are going into remote territory there could be a problem having access to recharge the battery. A few solar panels, which add even more weight/bulk are not a viable option I feel. So not necessarily dead weight because it is possible that it will do what you desire but the complexity part comes when/if it fails miles away from anywhere. I would just say keep it simple and as I said just be prepared to push a few hills.

 

[djol]

@Jahbak while most of us doing DIY eMTB are using M500/600/510 Bafang motors now, a light(er)weight option would be the M820 (2.3kg) - though after battery etc. you’ll be hard to get away without adding an extra 5kg even before charger & solar panels.

I don’t think it’s necessarily an unwise plan, but there are obviously weight trade-offs that you’re already aware of. Why not give it a go!

M820: Products

Some earlier threads on eMTB bikepacking too:
- Bikepacking on an emtb?! - EMTB Forums
- Long distance bikepacking - EMTB Forums

 

[Jahbak]

Depend on your fitness level eg if you want a full fat or a light weight
it can be pedal off / over the limiter easily and couple with the optional range extender in eco with both batteries on the flat your looking at a range of over 100 miles from the main battery and extender combined
I did a 40 miles gravel ride the other day and only used the extender the main battery was full so would of got another 60-70 ish miles

I'm not sure how my fitness will translate to biking, but so far as hiking is concerned I often go on trips like this. The only extra weight will be the bike and the solar system, which I was hoping would be offset by the motor.

The Orbea Rise looks good, over 100 miles is awesome! I'm intending to build my own though, from battery pack to bike. I only mention the Trek as an example as from the videos I've seen it looked capable of offsetting some weight up hills and allowing me to maintain my pace while taking a rest on flat and was the lightest motor I had seen so far. Appreciate it!

If you are going into remote territory there could be a problem having access to recharge the battery. A few solar panels, which add even more weight/bulk are not a viable option I feel. So not necessarily dead weight because it is possible that it will do what you desire but the complexity part comes when/if it fails miles away from anywhere. I would just say keep it simple and as I said just be prepared to push a few hills.

I agree in the case of a failure it would become an issue, that is why I wanted to build something like the Trek Exe 9.x because from what I've seen if it all fails it can still be used as a bicycle, if I was unlucky enough for it to fail at the worst time, I would stash the unnecessary cargo and return for it later. I'm lucky to say I have a deal with a good friend that so long as it's national we will always drop what we are doing in event of an emergency and recover each others vehicles for the cost of fuel + a good dinner, something we agreed on a decade ago when having to split the bill for an off road recovery service. I do respect and understand the keep it simple philosophy, it's worth keeping in mind, cheers.

@Jahbak while most of us doing DIY eMTB are using M500/600/510 Bafang motors now, a light(er)weight option would be the M820 (2.3kg) - though after battery etc. you’ll be hard to get away without adding an extra 5kg even before charger & solar panels.
I don’t think it’s necessarily an unwise plan, but there are obviously weight trade-offs that you’re already aware of. Why not give it a go!

Thank you, I had not seen that motor definitely another one to look into. Appreciate the links and encouragement too!