Interest piqued in DIY ebike conversion

[imagineaudio]

I'm toying with the idea of converting a Giant Suede to an ebike. Just recently started thinking about it and never built one before so immediately have some questions. I'll primarily be riding in Los Angeles, think I'd be happy to do 18-20 MPH and be able to do around 20 miles on a charge, and I'd like to keep it as economical as possible. I'd like to have both a throttle and pedal assist, and the ability to ride non motor assisted. I'd be easy on it, no off-roading, mostly just running errands around town.

What are the options for low cost rear geared hub motors? Is there anything that would keep my costs under $700 including battery? Or am I going to be looking at direct drives?

 

[spinningmagnets]

Is your commute going to be fairly flat, or do you have some hills?

 

[imagineaudio]

Most of the riding will be on flat roads, but LA does have some hills... guess it'd be great to be able to climb them. EDIT to add: I'm 5'10" and 190lb

 

[Jabotical]

Are you hoping to avoid direct drives? Because those do seem to be the crazy cheap entry point option that is well-reviewed. Under $200 for a full conversion kit from ebay, just add battery and you're good to go. That said, there are ebay geared hub kits that are about as cheap, but I haven't heard much about their quality/people's experience.

Then again, you might be able to save a little on battery costs with a geared hub, since you don't need as much power to generate useful/satisfying torque. Maybe that would make it easier to justify dropping ~$300 on a MAC (which is what people here mostly seem to talk about). Probably someone will chime in eventually with other geared hub suggestions though.

 

[dogman dan]

City riding,,, you will be better off with a 500w sized geared motor IMO.

But the 700 buck budget,, that pushes you to the really cheap sometimes unreliable DD kits on ebay or amazon. Don't get me wrong, the cheap kit might go 20,000 miles. But I've also seen them go less than 20.

Typically, a really reliable e bike build ends up being closer to $1500. If that's too much, go with the cheap DD. That will save you about $400, and it won't suck in city riding. It will just be a tad less efficient leaving each stop light, costing you a few miles of range. 20 miles will require a 48v 15 ah battery, or 36v 20 ah. This is where your money will really be spent. If you can charge half way, ( like at work) then a 10 ah will be plenty.

Totally possible to get some decent range under $700, by using both the cheapest possible kit, and the cheapest possible battery. But for a good reliable ride, going cheapest is not the ideal approach.

 

[imagineaudio]

Are you hoping to avoid direct drives? Because those do seem to be the crazy cheap entry point option that is well-reviewed. Under $200 for a full conversion kit from ebay, just add battery and you're good to go. That said, there are ebay geared hub kits that are about as cheap, but I haven't heard much about their quality/people's experience.

Then again, you might be able to save a little on battery costs with a geared hub, since you don't need as much power to generate useful/satisfying torque. Maybe that would make it easier to justify dropping ~$300 on a MAC (which is what people here mostly seem to talk about). Probably someone will chime in eventually with other geared hub suggestions though.

That's a good point about saving a little power on the battery vs a DD. I initially thought DD would be the way to go for cost/simplicity reasons, but the more I think about it, I'd really like to pedal the bike unassisted.

City riding,,, you will be better off with a 500w sized geared motor IMO.

But the 700 buck budget,, that pushes you to the really cheap sometimes unreliable DD kits on ebay or amazon. Don't get me wrong, the cheap kit might go 20,000 miles. But I've also seen them go less than 20.

Typically, a really reliable e bike build ends up being closer to $1500. If that's too much, go with the cheap DD. That will save you about $400, and it won't suck in city riding. It will just be a tad less efficient leaving each stop light, costing you a few miles of range. 20 miles will require a 48v 15 ah battery, or 36v 20 ah. This is where your money will really be spent. If you can charge half way, ( like at work) then a 10 ah will be plenty.

Totally possible to get some decent range under $700, by using both the cheapest possible kit, and the cheapest possible battery. But for a good reliable ride, going cheapest is not the ideal approach.

Understood. I'm a freelancer that has to carry a car full of gear with me to jobs, so I'm not looking for a commuter. This is purely for recreational riding and maybe the occasional trip to the beach, which is where I'd need the 20 mile range. But maybe I can start with a lower capacity battery and add another in parallel later? I don't want to be limited to taking the bike out because the battery isn't charged, and from what I've read that's why I'd need a geared motor. I've got some more reading to do.

 

[docw009]

I found that geared rear motor kits that were price competitive with DD motors to be uncommon with US sellers. I have bought two of this guy's geared hub kits on ebay.

I paid $199 for the initial one and mated it with a $280 (shipped) 36V 10AH Dolphin battery from elifebikekits.com via ebay. It might not stand up to commuter use, but mine has been a good recreational bike. It can do the things you stated, 25-30 mile range, 18-mph, easy to pedal. I suppose the gears will wear out in the future. Not really concerned.

Perhaps DD's lack of moving parts means less headaches for the vendors as far as returns hence the greater numbers. Or maybe that's what sells. I can accept that. Not for me though.

 

[dogman dan]

FWIW,,, that ebay motor is not what I meant by 500w rated geared motor. That's a 350w rated motor, running on 500w. I meant a 500w rated motor, running on 750-1000w.

The smaller motors are fine until a bigger guy rides up too big a hill,, the company I work for suggests a max weight of 200 pounds for those motors. You, bike, motor, battery,, 200 pounds. That does not mean you could not choose that kit, just plan on lots of pedaling to help it up hills, which is how you plan to ride anyway. A very low powered kit will also stretch your range.

But the 500w geared kit E bike kit sells is beyond your price range. You'll have to find one straight from china most likely, to get the price low enough for your 700 buck budget.

 

[docw009]

If you buy it straight from China, you will probably have to get rim/spokes and lace it yourself. The single piece shipping for a complete wheel is $100 or more higher than the motor alone, not counting the cost of the wheel. Of course, it might cost you $40-60 to buy the rim/spokes too.

I just received a 250W Bafang SWXH from China for $80 plus $40 shipping. A little 6 pound motor. Will it hold up at 48 volts?

The first geared motor bike, battery and me are 245 pounds these days. We still have some hills in river valleys, but the ice age scraped this part of the USA flat. I get around fine, and sometimes I tow the grand kid in her cart. That's around 300 pounds, but I'm always pedalling.

 

[RLD70]

You could just buy a MAC from Paul at EM3ev which IMHO is the best priced geared hub out there.

 

[heavymetalthunder]

I do most of my riding in the San Gabriel nearly all street, a few river trails, and have on occasional rides into downtown LA. I currently use a DD 1000w 48v purchased several years ago from China installed on a cheaper all steel frame, full suspension mountain bike. I have about 15K miles on it and it has worked well, parts of the bike have not held up so well, a few broken spokes, pedals, and cables goes with the conversion. It might cost you a little more to set up your bike as you would want to get some decent road tires, a rack or panners, head and tail lights, on board tools, air pump, fuses, main power switch, a decent helmet, and gloves. Using up to 20ah worth of lipos batteries depending on how far I want to go. All up the total weight including rider is about 260 pounds. I picked a DD system over a mid drive for ease of maintenance and reliability. You might consider spending a little more and getting a 1000w system as a little extra power and speed can get you out of tight situations.

 

[imagineaudio]

Will the Mac 500/1000 work with a 52v pack from Luna? Do I want it to? Thinking of the 10T with a 9fet controller, 20 amp... have I confused myself researching in a vacuum here?

Another consideration for the battery, is that if I could step down the voltage from 48 or 52 to 14.4, I could use it to power equipment at work thus a deductible expense. I'd need to look into this a little more...

 

[RLD70]

Yes the MAC will work with a 52v battery pack. Ive used the MAC for nearly 3 years now and Ive even used a 60v pack with it using the 9fet 30A controller so no worries.

 

[imagineaudio]

What kind of stats were getting?

What amps should i be shooting for on the controller? 20, 25 or 30? A. 9fet controller that can handle up to 72v would be good for a 52v battery, or is 60v workable?

Any economical controllers that will do tourque sim?

 

[spinningmagnets]

A few years ago, the MACs came with the common 0.50mm thick laminations. Worked fine at 48V, but...at 60V or more, there was excessive eddy-current heat. A couple years ago, Paul at em3ev ordered a batch of low-kV MACs with the thinner 0.35mm laminations, for ebikers who wanted to run higher volts (since the amps were limited by the heat they generated). The results were so good, that Paul now only carries thin-lam MACs, regardless of the kV.

Ben Chiu's "Duty Cycle" runs twin MACs on a 2WD ebike at 60V, and it is a BEAST! Same copper mass as a single Cromotor, but with the traction of AWD...

 

[imagineaudio]

Good info. So mac from paul at 10T 9fet controller with torque sim limited to 25A and a 52v luna dolphin battery on a 2010 giant suede, rim brakes, 7 speed freewheel, torque arms, 26"wheels with ~2.15 tires seems like a sensible first build? For someone that will use it for all noncommute transpo needs?

 

[imagineaudio]

...and FUN!?
EDIT: I've never ridden an ebike.

 

[spinningmagnets]

Add a Suntour NCX, or Thudbuster, and you've got a winner...

 

[nutnspecial]

Good info. So mac from paul at 10T 9fet controller with torque sim limited to 25A and a 52v luna dolphin battery on a 2010 giant suede, rim brakes, 7 speed freewheel, torque arms, 26"wheels with ~2.15 tires seems like a sensible first build? For someone that will use it for all noncommute transpo needs?

I might get the motor and controller from the same source for simplicity on the first build. Paul/em3 can confirm average and max suggested settings, and advise on torque sim. (I think some kelly controllers do that, or you could use a CA3, which they can preset for the motor/controller combo)

The build sounds great!

...and FUN!? // I've never ridden an ebike.

And yep, there's almost no ways it won't be ALOT of fun!

 

[imagineaudio]

Ok, so i've spent the last few months researching....

The other day I rode a townie electric with a bosch motor. I really liked the torque assist. What are my options for incorporating this into my build? Tdcm and a cadence sensor feeding a CA3? are there any controllers that have torque sensor input so i can skip the ca3? Still make sense to use the updated mac motor for this? Or are there other geared motors that have torque sensing built in?

I'm still planning on building on my giant suede frame.

 

[imagineaudio]

Well, I was really looking forward to doing thjs conversion, but alas, my Giant Suede was stolen out of the garage the other night.

I may have found a deal on a Cannondale CX4 I'm thinking of picking up in the interim, but maybe it'd make a good project?

Bottom bracket Tange Cartridge
Brakes Tektro Novela mechanical disc, 160/160 mm
Cassette Sunrace CSG66 11-32, 8 spd
Crankset Shimano M171 48/38/28
Features Travel in Style With sleek, functional tube shapes, oversized head tubes, and suspension forks on most models, the Quick CX makes a statement on the city streets but is up to the challenges of excursions on rougher roads and bike trails. SAVE Vibration Damping Stays Optimised rear stay shaping provides bump absorption, comfort and enhanced control with no loss in power transfer. Heads-Up Riding The Quick CX geometry delivers an upright, stable riding position for increased comfort, visibility and enjoyment. Relax and enjoy the ride.

Fork type Fatty Rigid Disc
Frame type Quick CX Rigid, Optimized 6061 alloy, SAVE, 1-1/8" head tube
Front derailleur Shimano M191, 34.9 clamp
Headset Tange 1-1/8"
Rear derailleur Shimano Acera
Recommended for Commuting/Trekking/ City
Rims type Maddux DC3.0, double wall w/eyelet, 32 hole

Shifters Shimano Altus
Spokes Stainless Steel XD Black, 15g
Stem Cannondale C4, 1-1/8", 31.8, 12 deg
Year 2012
Tires Continental Double Fighter II, 700x37c