MAC motor + Trek 4300 build

So the build is finally nearing completion!

I first joined this forum in June of 2010, spent ~4 months reading about eBikes constantly, and asking stupid questions ( thank you dogman, mwkeefer, and all others that were helpful.. ).. spent another 3 months trying to get the right frame for the job and discovering what was good and what wasn't ( went through 5 different bikes, literally ).. and another 3 months doing the rest.

This is the product of a lot of trial and error, wasted money, blazing forward even when people told me it was a bad idea, and finding what works for me the best.

Weight, elegance, hill climbing ability, and the ability to pedal and freewheel was paramount to this build. I wanted to be able to add all my human power into the equation, in order to get a workout, so i went with a MAC geared motor and lipo batteries as they fit the bill.

So i present to you.. my creation









Bicycle:

Mid 2000's Trek 4300 MTB.
48t front chainring, single gear.
13t-28t 7 speed freewheel.
Avid BB7 180mm front disc.
Tektro 160mm rear disc.
RST Suspension fork.
1.95" Armadillo puncture-proof tire in the rear.
1.75" Forte tire on the front.

Electrics:

Mac "500w" motor from cell_man
Infineon 30a 9fet controller ( turnigy watt meter says it peaks at 38a but i don't believe it )
Standard issue thumb throttle.
2x 5ah 5s 20c lipos for the small pack, so 37v 5ah.
8x 5ah 5s 20c lipos for the long haul pack, so 37v 20ah.
Turnigy watt meter, and 2x celllog 8s for monitoring cells & beeping at me if one goes too low.
iCharger 1010b+ for charging all the cells in their serial configuration.
15.8ah junky radioshack power supply, paid $30 for it used.

Other:

Topeak MTX rack for the rear ( will eventually switch out for mid-frame mounted 30 caliber ammo can )
~1/4 in. Torque plates courtesy of li-ghtcycle ( thanks dude!!! )

Speed:

10s ( 37v )
25-26mph not pedaling on flat ground.
26-28mph pedaling on flat ground.
15-18mph on a 5% grade, pedaling.

14s ( 52v )
29-31mph not pedaling, flat ground.
32-33mph pedaling, flat ground.
18-25mph on a 5% grade, pedaling.


14S run, with pedaling. Notice that i ran out of gear ratio..

[youtube]pCFQN5Q5ApU[/youtube]

10S run, with pedaling. Can still pedal at 28mph.

[youtube]ZIRwUgPKdrY[/youtube]

Showing off the excellent freewheeling of the MAC motor. It freewheels better than any geared motor i've seen.

[youtube]JM_rX-toEI4[/youtube]

Problems i had:

1. Axles would have started cutting into rear dropouts at this power level, so we had to make torque plates.

2. 13t is the lowest gear you can get on a quality 6-7 speed freewheel, which lowered my top pedaling speed drastically over the bike's 9t lowest gear. Changed over to a 3 speed roadie crankset, but the middle gear was grinding into the frame. Tried to offset the bottom bracket, but could never get the front derailleur adjusted right due to chain angle. Went to a single speed setup.

3. integrated shifters got in the way of the thumb throttle, and front gear was converted to a 1 speed, so i got a discarded lookalike shimano integrated shifter and dremeled off the gear part.

4. frame was a bit too small, so added handlebar extenders.

5. vbrakes were entirely inadequate for downhill, or slowing down quickly from 20mph. Went to disc brakes because of this.

Future upgrades:

1. Green or gray gears for longevity of the motor.

2. Ammo can mounted in center triangle, probably painted black.

3. Suspension seatpost, although the front suspension and fat rear tire do a good job.

Charging setup & battery notes

( reserved post, more on this later )

Squeaky clean build. Unlike the crap I throw together. It'll be perfect once you mount that can in the frame. You might look for an old school seat, with the big coil springs built in. I love em on my hardtails.

Making the torque plates just got easier, for sale new, magudaman has tooled up for custom stuff. I have two 4x4 steel plates with an axle hole coming to me soon.

Thanks dogman.

Let me know what those torque plates look like when you get them.

Yes, very clean.

Did you over-look Cycle 9's 11/32 7-speed freewheel?

http://www.cycle9.com/c9store/electric-a-la-carte-freewheels-torque-arm-c-21_22/7-speed-freewheel-11-32-p-136

That's a DNP epoch, which is known to be unreliable, unfortunately.
So i stuck with the Shimano.

Yes, I see.
I just read this;

http://endless-sphere.com/forums/viewtopic.php?f=2&t=25424&start=0

It's an old thread, I wonder if there has been any developments since?

DNP is testing a new 11t 7/8 speed freewheel, which is aimed at these eBike hub motors.

With the current ones, the metal is extremely cheap and the freewheel mechanism does not last long.

This may be worth investigating:
http://www.bikepro.com/products/freewheels/tnt.html

Anyway, the gearing i have is acceptable for about 20-25mph. 30-33mph is fun but it eats too much power due to aero drag. I think it is also really unsafe in the city, which is where i operate my bike the most. It's really hard to keep the speed around the legal 20mph, lol...

Maybe i'll add one tooth in the front though, as my bike looks like it can handle exactly 1 more tooth in the front.. lol.

.

Nice build...i like it. I plan to do my own Trek conversion soon, looks like the frame makes for a good conversion.

Clean build.

Doesn't look like enough room for a suspension seatpost. At least the thudbuster takes quite a bit of space. Maybe others don't.

20-25 mph is a good speed. Stay safe.

Danos said:

Nice build...i like it. I plan to do my own Trek conversion soon, looks like the frame makes for a good conversion.

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You should really hunt down a used Trek 4300 if you like the style. The frame is really perfect for the job.

It has been stable at 35mph which is impressive for a bike of this grade. The aluminum is very very strong. The dropouts are wide and flat with many holes for bolts to a torque plate. The center triangle has a lot of room in it for a battery. I could easily fit 25ah of 36 or 52v lipo in there.
Even the v-brake frame has a tab for a rear disc brake.

Oh, and the frame will take 700c wheels. You could totally do a 29'er with it, if you were okay with 1.25in. wide tires. for a 26" size, it should be able to accept a 2.5 or 2.75in. wide tire.

Alan B said:

Clean build.

Doesn't look like enough room for a suspension seatpost. At least the thudbuster takes quite a bit of space. Maybe others don't.

20-25 mph is a good speed. Stay safe.

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Thanks. Yeah, the rear rack will be gone once i get greenerwheels to make me an ammo can mount for the center triangle

Oh, and the frame will take 700c wheels. You could totally do a 29'er with it, if you were okay with 1.25in. wide tires. for a 26" size, it should be able to accept a 2.5 or 2.75in. wide tire.

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Good to hear that some nice fat tires fit in the frame, i'll be staying with the standard 26" wheels. I currently own a Trek 4100 which will be the donor...hence my interest in your build. You've already provided some much appreciated advice to my noob questions about a month ago. I was interested to see you have such good hill climbing performance with the MAC...are they long hills or reasonably short? Cell man did recommend the 500w MAC to me but, following a lot of reading and much deliberation, i'm leaning towards a locally sourced 2808 DD. I could still be swayed to a cheaper, lighter MAC if i'm sure the performance on the short steep hill i need to climb will be satis.

Cheers.

Squeaky clean build. Unlike the crap I throw together.

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That's the same thing I do Dogman don't feel bad. I am always doing something different trying this or that, but haven't perfected any of my rides yet....

@ Neptronix: Nice build and well thought out. Your setup is just like mine (except the bike is crap ) I have a BMC 600w (via Lyen) and a 9 fet Lyen controller with 12s lipo I see 31 mph on the flats and I am a 200lb rider. I have a specialized hardrock frame that is stripped, but eventually the BMC will be it's home
I like experimenting with setups riding them and then tweaking them as I go. Problem is I got too many pots cooking.. :wink:

Nice build Im lookingfor a new motor and this mac from cellman now is my numero uno, but... second option is dd drive. And the question is: Onthe movies this engine sounds loudly? Its true is it loud?

Danos said:

are they long hills or reasonably short?

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I have yet to test the long term hill climbing. But at ~26mph for a few blocks on ~7% grade on 14s, i think it does well..

Same hill.. 10s.. i did about 15-18mph..

And that is one of those hills that there is no way you can pedal up... you have to walk !

toft said:

Nice build Im lookingfor a new motor and this mac from cellman now is my numero uno, but... second option is dd drive. And the question is: Onthe movies this engine sounds loudly? Its true is it loud?

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It is not as noisy as in the video, really. All geared motors make noise though. Fact o' life.

Wineboy; cool man. Yeah, don't let the pile accumulate too far. I suppose i am on limited $ so if something doesn't work for me, it's sold in short time to go towards the next project.

I am really happy with this motor. It does everything i want it to do. Of course i will probably need the green/gray gears soon if i keep abusing it like this ( 1500-2000watts ran through it already.. ).

I cannot see driver... It is inside frame bag? This 30A infineon is from cellman?. You bought this driver with a motor? from ceelman?

toft said:

I cannot see driver... It is inside frame bag? This 30A infineon is from cellman?. You bought this driver with a motor? from ceelman?

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Yep, the infineon 30a 9fet is in the topeak seat bag.
I got the 9fet and MAC motor from cell_man, all as one package.

neptronix said:

. But at ~26mph for a few blocks on ~7% grade on 14s, i think it does well..

Same hill.. 10s.. i did about 15-18mph..

And that is one of those hills that there is no way you can pedal up... you have to walk !.

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I am confused ? :?
you say 26mph on a 7% grade .. ? which is a hill you cannot pedal up ..??
Why can you not pedal up a 7% grade ?
I am the first to respect a hill and admit defeat, but even i can pedal up a 7% ...most cyclists would not flinch on a grade double that steep. :?

Conversly... 26mph on a grade that is too steep to pedal up ...is really impressive ! :lol:

Hillhater said:

I am confused ? :?
you say 26mph on a 7% grade .. ? which is a hill you cannot pedal up ..??
Why can you not pedal up a 7% grade ?
I am the first to respect a hill and admit defeat, but even i can pedal up a 7% ...most cyclists would not flinch on a grade double that steep. :?

Conversly... 26mph on a grade that is too steep to pedal up ...is really impressive ! :lol:

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Long hill. One that would be difficult to walk up. 220lb, and out of shape due to winter

This is my test hill. This data is according to google.


Yeah, it is not all 7%, but sections of it are close. It is the steepest hill i know of.
How could i more accurately measure grade?

wow 1 ..7% grade is the steepest hill you know ? !..seriously ?
That is not much more than a SLOPE to most folk !

Hillhater said:

wow 1 ..7% grade is the steepest hill you know ? !..seriously ?
That is not much more than a SLOPE to most folk !

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Hillhater
Location: Sydney ..(Hilly part !)

Ahh.....
There are some steeper grades, but yeah it is fairly flat here.
I'm a bit of a wimp because i have cardiovascular problems. But i also don't see any other bikers on this hill, unless they are walking up it.

Where i live is relatively flat. The road from where i live to get into Portland is a non-stop 2%-10% grade though. This goes on for about 3-6 miles. Many bicyclists avoid it and drive or take the local transit instead.

neptronix said:

...I'm a bit of a wimp because i have cardiovascular problems. .

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Aahhh ! dito here too. (HOCM ..Hypertrophic cardiomyopathy) .. hence the powered bikes.
I have also developed a inbuilt ability to detect any slight incline ,whether cycling or walking, and gauge my ability to make it up or not !