Frame mount electric motor

[Retmachinist]

After building 16 two stroke bikes a few years back, then moving on to a couple other hobbies, I have now decided to build an electric bike. I don't want to invest to much money in my first one so I am using SLA batteries and a 24 volt 450 watt motor, on a very nice older chromoly frame Trek bike. I don't like the way currie mounts the motor on the rear axle so I am mounting mine in the frame similar to the way the two strokes are mounted. Just wondered if anyone else has tried this method and how it worked out. I have most of the mounting parts made so I will include some pictures on my next post.

 

[2door]

Good to see you again, John. Welcome back.
Our fearless leader, Paul, has also gone electric. I'm sure he'll chime in soon to add his input.

Tom

 

[racie35]

sla,s are gonna be bulky and not offer much duration...its also a low watt application that'll require pedal assist alot im sure.
the higher watt brushless hubs and controllers arent too cheap and neither are the batteries..they do perform however....esp on lifepo4 batteries or just lipos from hobby king.
the higher you can get your voltage the happier youre gonna be....amps start dropping and total watts climbs fast.

 

[Retmachinist]

I figured I would get alot of negative comments about using SLA's. This is just a first time build with e-bikes so I am seeing how well it will work on a small budget, and only for pedal assist. If I decide to spend a couple Grand on my second one I will go with the Lithium batteries and a high watt brushless motor.

 

[Intrepid Wheelwoman]

Well I use SLAs and I'm very pleased with them. My last set lasted four years with fairly heavy useage at times, but I will point out that I'm a 'peddler' and not a 'sitter' when it comes to riding my e.trike.

 

[paul]

i look at it like our first bicycle gas motor. we get the cheapest Chinese gas motor we can and you know how it goes from their. lots of upgrades. the electric is the same, my first one was a cheap one with sla batteries however it was a blast and i got the fever, now i have a nice hub motor, 48v lifepo and feel it is the best money i ever spent, it has already given me over 6 months of pleasure this year. its hard to imagine a motorized bicycle can be so much fun but the torgue of the electric bicycles and every thing else about them is a unique and wonderful experience. look forward to hearing about your build. i think you are going to find a new addiction

 

[Retmachinist]

i look at it like our first bicycle gas motor. we get the cheapest Chinese gas motor we can and you know how it goes from their. lots of upgrades. the electric is the same, my first one was a cheap one with sla batteries however it was a blast and i got the fever, now i have a nice hub motor, 48v lifepo and feel it is the best money i ever spent, it has already given me over 6 months of pleasure this year. its hard to imagine a motorized bicycle can be so much fun but the torgue of the electric bicycles and every thing else about them is a unique and wonderful experience. look forward to hearing about your build. i think you are going to find a new addiction

Hey Paul, good to see you and Tom are still on here. I am afraid this electric thing could turn into the way I was with the two strokes, ended up building 16 of them. This first e-bike is just kind of an experiment.

 

[gokart25]

it's good to see another Iowan back on here!! Can't wait to see your bike.

 

[2door]

it's good to see another Iowan back on here!! Can't wait to see your bike.

If his electric looks anything like his gas powered bikes, you'll be impressed. He does nice work.

Tom

 

[Retmachinist]

Here is where I am at with the first e-bike build so far. Waiting on a couple back ordered parts. I am machining all the mounts out of aluminum, trying to keep the weight down as much as possible since I am adding about 10 lbs. with the SLA batteries. I think I will still be 20 lbs. lighter than if I would have used the kit from Currie.

 

[paul]

WOW! very nice clean electric, is that a headlight on the front? i really like the mount, good work retmachinist. i know i am looking forward to hearing and seeing more about your motorized bicycle

 

[Retmachinist]

Yes that is a little headlight I machined out of a piece of aluminum tubing. I use 12 volt l.e.d.'s in the headlight and the little tail lights I picked up at the auto parts store.

 

[Dave31]

Good to see you back John Build looking good!

 

[wheelbender6]

Looks slick. SickBikeParts sold a 24v electric kit for a while that mounted a similar motor in the frame and drove the pedal chain rings. The kit provided an L shaped motor bracket that mounted to the down tube with U-bolts. SBC is planning to launch a similar 36v kit before Christmas this year.
I bought a Currie 24v kit for the same reason as you. I didn't want to ruin an expensive kit with inflammable batteries while I tinkered with wiring, batteries upgrades, overvolting.

 

[wheelbender6]

I just thought of something RETMACHINIST - Will the motor turn the correct direction as shown in your pics? You may not be able to reverse polarity and direction because of the gear reduction box.
If that is the case, you can turn the motor around and drive the pedal chain rings with it.

 

[wheelbender6]

The faculty over at Endless-Sphere.com said the Currie gearbox will not cause any bother if you reverse the direction of the motor. That opens a lot of possibilities.

 

[Sidewinder Jerry]

Have you considered using a double freewheel shift kit?

 

[Retmachinist]

No, on this first e-bike build I am keeping things simple. That is if I ever get the rear wheel that is on back order. Anyone know where I can get one of the rear wheels with a left side free wheel. All the venders I found have them on back order.

 

[wheelbender6]

Some of the bike motor vendors sell just the hub, with the left hand threads in one side. You would still need to get a shop to lace it to a rim.

 

[Retmachinist]

I will give it a little more time, then I may order a hub. I built the wheels that are on this bike so I guess I could do another one. Its not a bad job just time consuming indicating them in to run perfectly true. Thanks.