An ebike for the hills?

[paultrafalgar]

As you live in a cabin I guess you might have a portable generator already. I'm wondering what range you need; you sure have a lot of long hills to climb and this might be a solution: use a generator with cheap SLAs. I don't know if the output of the generator would be sufficient to charge the batteries fast enough to compensate for the high power drain on hills. and I don't think you necessarily need a trike but take a look at this video:
http://www.youtube.com/watch?v=PJDNWcnYlFo
The other question is hub-motor or non-hub drive. Others above have dealt with this, but a hub-kit is the easiest to fit although less efficient.
Good luck.

 

[Icewrench]

A 36 volt E V Global bike with the 500 watt Heinzman geared rear hub motor is a serious hill climber ! And it makes some noise.
Also have a direct drive 9 c set up quieter not so much torque , more top end.
If you are in Seattle stop by for a test ride or two.

 

[hillbilly]

I'm getting so many great suggestions to my original question that it will take a while to sift through it all and come to some kind of a decision. I have to say, however, that Mikefish's suggestion of a iZip kit from Currie is starting to look like a winner. If nothing else it would get me on the road before summer ends (and when summer ends in the Great Pacific North-Wet, it really ends!). Besides wanting to ride logging roads my main need for an ebike is to visit my friends five miles down the road -- I can't do that on my pedal bike because of a mile-long hill that would put me into cardiac arrest on the return trip. In the other direction it is 8 miles to the post office and general store but with another killer hill.

I can manually pedal everything but these two hills, so even with a basic SLA battery I assume I could make the round-trip with an iZip conversion if I rely primarily on pedal power?

One member here warned about sharing the road with log trucks -- I actually live on a logging road so that is a familiar hazard and one that I am very careful about. I prefer to use logging roads after normal working hours and on weekends. If trucks are hauling I can hear them coming, often miles away, so I find a good safe spot and get well off the road until they pass and the dust settles.

Someone else mentioned resting-and-cooling the motor. That will be no problem for me as my purpose in riding in the mountains is to enjoy the view, not to cover a lot of miles. I used to do these roads on foot (before being injured in a near-fatal horse wreck) and stopped often to look for wildlife, rest, or just enjoy the solitude. Regardless of how you feel about logging, there's no denying that the roads can make for some great hikes and rides.

PaulTrafalgar gave a link to an electric trike with a generator on board. My first thought was "this is nuts!" but on second thought... what a great idea to extend the range of the bike deep into the mountains. It would make extended camping trips possible and I could take along an electric blanket for those cold nights

I wish I could share some of the blueberries we picked this morning as a way to express my appreciation for your help, but I guess I'll have to settle with photographs of some of the beautiful country around us here... coming soon.

 

[Anonymous]

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[johnrobholmes]

I would suggest one of two ways-

1st would be a currie/Izip bottom bracket drive. Easy to get good geardown, but not my favorite setup.

2nd solution would be a push trailer. You could mount everything on there and even use heavy batteries without too much consequence to the bike balance. Unhook it for normal biking.

If you used the push trailer a geared hubmotor built into a small 20" wheel would give plenty of hill climbing power. Super simple. You could also use the currie drive unit with a few stages of geardown for a very effective and cheap solution.


At any rate, you won't be able to use something that is commonly available. I would vote heavily for a push trailer with geared hubmotor laced into a 20" BMX size wheel.

 

[GTA1]

There is nothing that beats gearing to handle hills.

What I am searching for is a much stronger chain (derailler use ---- with the intentional slack between links) but strong enough to handle the increased torque of a strong Cyclone motor.

Not much luck sourcing this thus far.

May have to go to a commercial / industrial equipment chain and adapt it.

If you are going to go that route --- most commercial / industrial grade chains will not let the chain bend as much to accommodate deraillers, so something has to be given up --- fewer gears on cones, perhaps, but wider ratios on the cone might compensate.

 

[johnrobholmes]

Have you tried a bmx chain ran into a 6 speed freewheel? They have some flex.

 

[dogman dan]

The only reason I didn't suggest the EVG's heinzmann motor is that they are hard to find in 36v. I found the 24v version nice on less steep hills, like to 5%, but I think those logging roads will be steeper in many places. A 24v one run at 36v will get overheated fast on steep roads, but at 24v would be likely to perform as good as a currie. Gmouchawar has one (24v) for sale now I think in the sale section of the forum.

By all means, a 36v heinzmann would be a good solution if you can find one.

 

[jag]

A problem with hill riding is that it will often put the motor out of its best efficiency range. In the ebikes.ca simulator http://www.ebike.ca/simulator/ study the efficiency graphs. As a motor spins up to near top speed its efficiency goes up to nearly 80% (+- a few percent depending on motor). However, at full throttle and low speeds, as would be the case up a steep hill, efficiency can be 30,40, or 50% all depending on the hill, torque/power required to overcome that hill. Hence, it is common that 1/2 of the available energy just goes to waste/heat in motor and battery, while in normal biking this loss is neglible.

For each motor, and rider/bike weight combination there is a maximum road gradient at which the motor is just barely able to hold the bike still (stall torque). At this point the motor is 0% efficient. All power goes to waste heat. With a just slightly less steep hill it may be possible to go a few km/h. At that point the rider might think that all the energy (often kW's) is used to take him/her up the hill, but the reality is that most of it is wasted.

Some formulas for calculating the work needed to bring a bike up a hill are at:
http://www.bikesatwork.com/hauling-cargo-by-bike/hpv-cargo-capacity.html

Is there already a calculation program that combines this with ebike motors, like on ebike.ca's site?

 

[Miles]

Is there already a calculation program that combines this with ebike motors, like on ebike.ca's site?

http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=6892&p=119810#p119810

 

[johnrobholmes]

This illustrates why proper geardown is needed. A motor geared for 30mph will certainly run hotter than the same motor geared for 10mph.

 

[Fishmasterdan]

Thats why you need to design a WAY lower KV geared motor John

 

[Miles]

Unfortunately, a motor's torque output is pretty much directly proportional to its volume/weight

 

[johnrobholmes]

Hubmotors laced into 20" wheels have lots of torque

 

[torker]

Hubmotors laced into 20" wheels have lots of torque

My 9c in a 20" seems pretty torqey even at 36 v I'd like to see what the 9 turn motor would do in a 20" wheel, of course that puts us in a push trailer config.. I think he's going to run 26" so running through the gears on the bike seems the best for slow hillclimbs.

 

[Miles]

Hubmotors laced into 20" wheels have lots of torque

How do they know what sized wheel they're laced into?

 

[johnrobholmes]

The hub doesn't, but I do Power is of course the same, but wheelspeed is traded for torque just like changing gears any other way.

 

[Miles]

 

[HighTekBikes]

I might as well throw in my two cents as I have researched this area and have strong opinions. First, forget about the 5300 series of crystalite motors. They are super heavy and suck power big time. They only start to come alive at 48V. As for the chain drive cyclone kit, I have seen a few installations that looked clean but they can be a nightmare trying to mount and keep aligned. They are very noisy and the motor is only 24V, so draws huge currents. Depending where the motor is mounted, the chain could be dangerous. The ezip motors are walmart garbage and will burn up or fall apart in less than a year.

What I would recommend is one of the following. The minimum would be a Bafang run at 36V and 25 amps which would provide about 700 watts to the wheel. Preferably, the frame would be light. You want the motor in the rear for optimum hill climbing. You could either buy a kit, or find a production ebike that already has the Bafang motor and just upgrade the controller. You would need an additional battery for long range, as production bikes have 10AH packs.

An ideal hill climber is a dual hub motor setup. This would blow your budget though. You can't beat the performance of two motors digging in providing power on both wheels. You could use two bafangs or a direct drive in the front. You need two controllers and two battery packs. Figure $1500-$1800.

Perhaps the ultimate all round bike that can climb hills is the Optibike, which utilizes a mid mount motor that is integrated into the bottom bracket. The motor drives the chain so it can make use of the gears on the rear freewheel. Only problem is the price which starts at five grand. Up until now an advanced design like this was only available to the well heeled ebike connoisseur. I say up until now because our company is about to release a new product with such a drive system. We haven't promoted this because we don't sell vaperware, however the shipment is on the way. You can get the first peek. The retail will be higher than your budget at $1595 for the base model, however we are accepting advance payments at a substantial discount of $1295 for a limited time. Not much over your budget for an incredible ebike. Options include an 8-speed internally geared Shimano hub and the Nuvinci hub. You can contact me directly for more info.

 

[Miles]

There's also:
http://www.ecospeed.com/emtndintro.html
http://www.ecospeed.com/prodemtndu.html

 

[spinningmagnets]

HTB_terry, I'm always glad to hear about new options. I'd like to make a suggestion. I understand that customers can often be way too price-point conscious, and will buy a cheaper product. Then they either complain about it, or upgrade the part they don't like (spending more money in the long run rather than paying less in the beginning for a factory upgraded model). However...

If there was one thing I could change about your new model ($1600 E-MTB) it would be to add factory lugs for a front disc, and a front wheel with a 6-hole disc hub. If a customer wanted to add a front disc later (trust me, they will) they wouldn't have to buy a whole new fork and wheel. Just a thought...

 

[torker]

Oh man you shouldn't have put that ecospeed link It even had a picture of one mounted on an EZ-Rider. My other ride I want to electrify.. Someday.. It is a little over budget but I think it would be the winner hands down for hill climbing. And for running cool at any speed.

Terry has got the same idea ready to go. Looks good Terry.

 

[pwbset]

Up until now an advanced design like this was only available to the well heeled ebike connoisseur. I say up until now because our company is about to release a new product with such a drive system. We haven't promoted this because we don't sell vaperware, however the shipment is on the way. You can get the first peek. The retail will be higher than your budget at $1595 for the base model, however we are accepting advance payments at a substantial discount of $1295 for a limited time.

I can appreciate you promoting your business I really can, but I'm hoping the original poster also can appreciate that your comments are biased and saying things like "forget about the 5300 series" for hill climbing is absurd. I also am glad you are bringing more options to the table and at more affordable prices though! Thank you for that. That bike looks sweet!

 

[hillbilly]

Terry, Miles, others:

Terry, if you'd posted that invitation two days ago I believe you would have had me knocking on your door.
Miles... the links you posted are going to keep me awake at nights, thinking about my next ebike. But first, I need my first bike....

I almost hate to post this message because I'd hate to see an end to the excellent information and suggestions that my original question about "an ebike for the hills" have led to. But, in the interests of "full disclosure", I've now ordered all of the components for an ebike.

Thanks to the generosity of a member here, I've finally been able to test ride a couple of bikes... and he has offered to convert my Trek hybrid to an ebike. (I'm not naming him in case he prefers anonymity but I hope he'll allow that or do it himself.)

Although I am going over my original budget by about 20%, that's because I've opted for a larger battery and motor. Had I stuck to the original setup we agreed on the final cost would have been quite close to $1000. It probably wouldn't have been the serious hillclimber I originally dreamed of but after a short test ride on a gravel washboard hill, I clearly understood that $1000 wasn't going to meet the hillclimbing challenge. (By the way, here in the foothills of the North Cascades a steep 1000' elevation increase on loose gravel and cobble is considered a "hill".)

Once the bike is finished and I've had a chance to ride it, I'll post a review here with the specs and costs. I'm optomistic that it will at least get me up the easier logging roads while also performing well on the paved hilly arterials around here.

Thanks again for such a great forum.

 

[dogman dan]

Ok, so what did you settle on, a BMC?