First ebike for DIYer, advice on hill climbing, mid-drive or hub??

[ctrace]

Hi all,

Thanks in advance for any guidance the folks here can provide.

I am looking to *build* an ebike specific to my needs for my work commute.

The place I live in is almost completely flat (Sacramento area), around my home, around there I don't have much of a need for an ebike at all. There are a lot of people who have them on cargo bikes around here (Bionx on Yuba Mundos are very popular), and we actually own a Nihola as well (not electric, just an 8-speed IGH) and it does just fine to get around town even with kids and groceries and a trail-a-bike...

Going to work is a different story though. I commute to the Bay Area 3 or 4 days/week. I haul my bike on/off of the Amtrak, since Sacramento is about 75 miles away from the Bay Area. All is good until the very end of my commute. The last 3.5 miles into work are basically an 800 ft climb uphill, with the last 1 mile being the most brutal (~520 ft of the climb, ~9-10% grade).

I have knee problems & asthma, fortunately I have the option to take a shuttle bus (with a bike rack) for the last 1 mile, otherwise commuting by bike would not be an option for me. I *love* the rest of my bike commute.

I hate having to wait on the shuttle bus, and want an ebike that can do twice that kind of climb -- as there are two routes I can take into work, and the other way (which I see many people biking up) is more like a 900-1000 ft climb over 2.5 miles instead of 500 ft over 1 mile.

After reading about the various motor options, it sounds like what I want is a mid-drive. I am a DIYer with a lot of electronics background, so I had been really looking forward to the more open kits that are based on direct drive or geared hubs, but it sounds like the mid-drive is going to do better for the long hill climb that I am trying to tackle. I first came across the mid-drives after reading about how well they do in San Francisco, so I thought they would do well in the East Bay which has very steep hills around Tilden Park. It seems like most of the mid-drive kits are well-integrated, but you have to use their controller/etc.

I am looking for any advice on whether or not I am on the right track here, e.g., is this the best thing for the type of riding I will be doing? I am leaning towards the Bafang BBSHD after reading a lot of reviews about them. Then there is the battery....52V with the BBSHD? I'll probably buy as many Ah as I can afford, but what is the minimum Ah that I should be considering? Being in California, it looks like there are some local dealers who have these in my area, so I plan to get out an try one. I prefer to build the whole bike from scratch, I have a lot of tools and some friends who build bikes and can get help if I get stuck in the process. I plan on doing this commute for many more years -- I have already been doing it for 3 years.

My main concerns are:

- Weight: I need to haul the bike on/off of a train, which means lifting it several feet and also stowing it vertically on a hook (front or back wheel up). I try to plan for the rain, but if it is suddenly pouring down rain and I'm not prepared, I have bus and subway options too, but this could mean stairs, etc. I want to go as light as I can without sacrificing the hill-climbing ability or amp-hours that I need -- since that is the whole point of building this bike...

- Hill-climbing: I don't want an ebike that is going to feel like it is 'bogged' down or whatever from a 1000 ft climb over 2 miles. Since I know relatively little about them (besides what I've read), this is the main thing that concerns me with the direct drive or geared hubs

- Budget: I have some flexibility, I am not trying to go with the cheapest thing -- I don't want to have a pile of busted or burned up ebike parts in one year. I don't mind paying for quality components that are going to last for a few years. I understand that with the mid-drive option, there is a lot more wear and tear on the drive components. I'd like to understand how I can mitigate this as much as possible. I know a little, but I am not super knowledgeable about bike components.

- Shifting: If mid-drive is the best thing for me, and if I go the BBSHD route, how do I make sure shifting is going to be smooth? I have heard about people putting IGHs on ebike with mid-drive motors... Do I need a shift sensor? Do I want one of the CVT IGHs on a setup like this? (Yes, I understand you may be voiding the warranty by putting an IGH on an ebike...so be it, if that is the case.) My commute is through the city (Berkeley), so there is a lot of stop-n-go (stoplights, intersections, etc). I don't think I would like the jarring shifting that some people have described on mid-drive setups, so I am looking to understand how to make sure shifting will be smooth and efficient, but also try to minimize the wear and tear on the components.

 

[ctrace]

Here is a google map w/ terrain showing the ~1000 ft climb over 2.5 miles that I describe. Thanks again for any feedback!!

 

[George S.]

(Link Removed - No Longer Exists)

This might be close to what you want. The 02 is lighter than the HD. You might ask Luna what this weighs.

Since this is a complete bike with a gear sensor and an IGH, it's a starting point and you could figure what you want in your build.

I think weight will be the problem.

 

[ctrace]

That looks nice, the closest thing I have ever seen to what I am envisioning! I actually just came across Luna for the first time last night and was checking out some of the information on their website (same for this website too, actually, and I was reading some of your posts ). Good starting point indeed.

I am not too worried about having to lug the bike on and off of the train - I see people with Pedego electric bikes on the Amtrak commuter trains, I do agree though that weight is probably going to be what I'd like to optimize for. I think the likelihood that I am going to *want* to lug the bike up or down subway stairs, or on or off some kind of a rack should be pretty low. I can pretty much avoid those scenarios by just being prepared for rain and dealing with it, my only transportation is my ebike. My normal commute does not involve any stairs, but I do put my bike on a shuttle bus rack (which is what I'm trying to avoid -- so I'm mainly just dealing with getting on/off the train)

A bike like (Link Removed - No Longer Exists) seems like it would be easier to deal with on the train than many ebikes that I've seen. I was also thinking that getting the battery low and in the middle would be the way to go since I am going to have to pick up the bike a good deal. Having never picked up a bike like this, it seems like the bike would have good balance/etc. The bike storage area on the train gets crowded during rush hour, and any kind of really long bike is a problem, so I want a pretty normal sized bike. The Pedego electric bikes look massive compared to normal bikes, but it still fits in the bike storage area without blocking an adjacent space.

 

[MLB]

Yes, you're on the right track with all your thinking I'd say.
Since you ride a regular bike and presumably understand how to shift to the gear you need BEFORE hitting the hill then you'll have no problem. You shift when the load on the chain is light, THEN accelerate.
A geared hub motor may well do just fine on that climb, it's ------------------- where I live, so hard to tell. LOL My dual hub motored Big Bud outclimbed (barely) my Haibike (mid drive Bosch) up a hill (in Michigan) where I had to pedal smoothly to not have the front end up on each stroke. And that's 600w COMBINED motors, so a big hub motor can presumably climb a bunch. And might be the lightest setup.
Bafang will pull it with ease. You can build an awesome bike with a Bafang. Fair amount of posters have had warranty issues too.
Internally geared hubs very heavy. Just like E motors. And batteries.
Use a good, solid, preferably steel bike to begin with. More weight, but you want an aluminum bike DESIGNED to be an Ebike. JMO!!
No rim brakes.
Decent wheels are a must at the speeds and weight or you'll regret not.

 

[ctrace]

Hey MLB, thanks for your reply and insight. With all things considered -- especially the timeframe that I'm interested in -- I am thinking of going with a donor bike such as the Diamondback Overdrive Sport. They are $450 + $15 shipping right now, which seems like a decent deal -- and there is already at least one detailed BBSHD build report using this exact bike.

I would swap out the original disc brakes for Tektro Dorado ebrakes + 203mm rotors ($140), swap out the tires ($130 ?), add the BBSHD 1000W motor, 73mm ($669), Luna DPC14 controller ($45), gear sensor ($45), a Panasonic Shark 52V 14Ah ($525), Lekkie 42T chainring ($90), 300W charger ($80), programming cable ($20). Total would end up being about $2,200, not including any tools needed or other accessories (which of course there will be many more).

I'm thinking to leave the rear hub idea as a future upgrade, maybe after others have done more testing. As you said, I already done this commute for a number of years, it didn't take long to figure out how you need to be shifting on any particular incline. My understanding with these motors is that you basically want high RPM candences, tap the ebrake right before shifting to cut the motor, you and/or the motor shouldn't be torquing hard (downshift) -- it should be relatively smooth. With the upgraded ebrakes and gear sensor, my hope is that I'll learn quick enough how to ride the thing so I'm shifting smoothly and not destroying components.. Plus no hub means it'll be a bit lighter..

It sounds like people have had mixed reliability results with using the hubs with the BBSHD, and not having to mess with the back wheel a whole lot will make my build proceed a lot quicker. I don't mind waiting to see if they prove to work out for other builders who are testing and pushing them, maybe one preferred one will emerge at some point. Do you have any recommendation on tires? It comes with Schwalbe Rapid Rob 29x2.25. The bike also comes with a Shimano HG300 9-speed Cassette, 12-36T. Not sure how long that will last (it's aluminum IIRC), but I assume it'll be one of the first things I'm replacing after modifying it.

Would be happy to hear any suggestions or feedback on my proposed build, thanks!

 

[MLB]

Sounds nice! You know enough to know what you want and need. I will throw out that I paid $1790 for my 2015 Haibike FS RX full suspension mtb. Rockshox Reba fork, Fox shock, Bosch mid drive, DT Swiss rims, etc. It was a demo and had 14 miles on it. Shipping was about $200. It's amazing and I love it like my dog. LOL Lists for $4200? when I bought it.
IF you love to ride bikes, you'd love love love the Bosch setup. Very bike-like, only gives you what you "earn" with your effort. (good torque sensor!)
As opposed to the very strong, very fast Bafang that isn't all that much bike-like and much more moped in nature. JMO!!
Point being, there are crazy deals on demo's all the time. Just another valid and very workable way to a REALLY nice bike.

 

[topaz024]

It's weird that I cant find a single review for that Luna SF City bike. It looks like a really good deal, except is it really running at 1500W?!?

If so, seems a little mad to have rim brakes!

 

[flymeaway]

Would be happy to hear any suggestions or feedback on my proposed build, thanks!

You can build a very capable and light mid-drive using either the Bafang 02/or the /HD. The 02 series is all most people need. Depending on what you're willing to spend you can end up with a great bike that weighs 45 pounds, There are many options and components to choose.

One note.....there are many discussions concerning reliability of Bafang mid-drives. As with any machine proper application and operation will assure long maintenance free life of the drive. Proper use of power and gear selection are important considerations. Also, you can buy the programming cable and set the function of the controller and motor to fit your riding style. Something as simple as reducing maximum allowed amperage output to reduce heat. Luna ships the controller programmed to 25A, I reprogram the maximum to 18A. Much less stress on the controller and I still can apply all the power output I need to climb all the hills on my daily work commute.

Good luck on whatever you choose.

Court J.

 

[harryS]

Weight really doesn't matter that much on ebikes or even commuter pedal bikes until you have to sling them over your shoulder and tote it up the stairs.

The Diamondback Overdrive Sport is 42.2-43.7 pounds depending on frame size. Add 6 pounds for battery and 8-9 pounds for the mid drive and it's your typical 55 pound e-bike.

My wife's 700cc Diamondback (alloy frame) started around 35 pounds, but after adding a 6 pound hub motor, 6 pound battery, and a rack to hold the battery, it's coming just under 49 pounds. I think I can feel the lighter weight on the road compared to my other bikes when pedaling with no assist. Maybe it's in my head.

Unless one opts for a 3 pound 14 cell mini battery, the typical mid drive motor/battery will be 14-16 pounds. You might have to look at skinnier tires, fixed fork, and other places if it were important to get the weight down.

Whew, at least all this riding around and using the pedals has helped me lose weight off myself.

 

[Kingsinger]

One thing to consider is that at least in Seattle, the bike racks on the metro buses here have a weight limit of 55 lbs. So if you anticipate ever putting your ebike on that kind of rack, you may want to keep that in mind (i.e., you want to keep bike's weight under 55 lbs with the battery off of it).