First attempt at DIY conversion -- compatible frame?

[moffbits]

So, I have what I think is a <2012 Trek 7.2 FX WSD bicycle. Intention is to install a TSDZ2 on this. After I got the crank arms off, I noticed that the plastic shift cable guides are too thick to clear the motor. Also, I noticed this plate that is welded behind the BB. Is this going to cause a problem for installation also?

 

[JES2020]

So, I have what I think is a <2012 Trek 7.2 FX WSD bicycle. Intention is to install a TSDZ2 on this. After I got the crank arms off, I noticed that the plastic shift cable guides are too thick to clear the motor. Also, I noticed this plate that is welded behind the BB. Is this going to cause a problem for installation also?

Don't do it!
Save youself tons of trouble and install a rear geared hub. You will thank me after you learn how complicated to install, prone to falure and difficult to work on mid drives are, compared to hubs. All for the addition of torque sensing PAS.

 

[moffbits]

Don't do it!
Save youself tons of trouble and install a rear geared hub. You will thank me after you learn how complicated to install, prone to falure and difficult to work on mid drives are, compared to hubs. All for the addition of torque sensing PAS.

Thanks, that would definitely be a way to simplify things. If you have a rear hub recommendation for towing a cargo trailer up steep hills that won't accidentally start moving when the pedals are bumped on the sidewalk, I'm open to suggestions.

 

[indianajo]

Deleting the PAS pickup is a way to prevent the bike taking off when you wind the pedals backwards to start off with the pedal up. Or you can turn pas off every time you stop and back on again after you are started. I hated that.
I like the mac motor, now available only from china. Grin has the gmac specially modified to drag the motor with your feet when pedaling unpowered. Like after the rain takes out your throttle, or you run the battery down. Mac12t has served me well, high torque, but max speed on flat is ~23 mph. Mac10t is faster & less torque. I carry 330 lb gross up 15% grades, so you may not need Mac12t in Florida. I think em3ev has them, or we could buy 8 of them for $1600 from alibaba direct, then go halves. I got mine from luna for $750 with controller & wheel. Don't buy the ASI+mac kit from luna, an ASI pin burns off in the rain & ruins the Mac harness.
Ebikeling.com sells complete power wheel kits with included reliable battery. He is in Michigan. His motor I bought for $221 without battery lasted ~4500 miles before the gears wore out. plastic gears. Mac has phenolic composite gears.
Note last time I checked Luna had quit selling 48 v batteries only had 52 v. I have a 3 1/2 year old Luna battery I use 70 miles a week in summer.
www.batteryclearinghouse has 500 w bafang front geared hub motors in wheel, used, not guarenteed, for $45. https://www.batteryclearinghouse.co...er-rx-rd3-electric-bike-wheel-with-tire-brake These have weird tamper proof axle & cover screws, which need to be replaced. The motor connector is weird 9 pin julet, the wrong sex from everybody else, and only a converter harness from china is available to convert the input to the 6 hole rectangular connector (hall effect pickup) and .157" bullet connectors used by most controllers. The bafang motor also has plastic gears. I use a front hub motor on my cargo bike, my weight on the front tire gives adequate traction.

 

[George S.]

I think em3ev has them, or we could buy 8 of them for $1600 from alibaba direct, then go halves. I got mine from luna for $750 with controller & wheel. Don't buy the ASI+mac kit from luna, an ASI pin burns off in the rain & ruins the Mac harness.
Ebikeling.com sells complete power wheel kits with included reliable battery. He is in Michigan. His motor I bought for $221 without battery lasted ~4500 miles before the gears wore out. plastic gears. Mac has phenolic composite gears.
Note last time I checked Luna had quit selling 48 v batteries only had 52 v. I have a 3 1/2 year old Luna battery I use 70 miles a week in summer.

I was a big fan of the MAC. Got one in 2015. It made quite a bit of noise. A year of silence with the BBS02 has made me think noise is for Chiefs home games. Eunorau has been listing the MAC as a motor they sell, but it's always on the wrong listing page. EM3ev lists some maintenance stuff for the MAC, but no actual motors. You could actually maintain a MAC, redo the gears and all. I just couldn't find one a year ago, went with the Bafang MD. But I would say the BBS02 is all around a better motor.

48V1000W MAC geared rear 8T cassette hub motor Kit 45km/h

EUNORAU BTN version hub motor kit have 36V250W version ,36V500W version,48V500W version,48V750W FAT version,48V1000W version. 36V250W version is for street use, 500W version 750W FAT bike kit,1000W version is for off road use. It will make your life with fun after make the bike to electric, all...

eunorau-ebike.com

 

[tomjasz]

Looks to me like a TSDZ2 will not fit.
A BBSHD would be a better choice than a BBS02B since you want to tow a trailer and ride up steep inclines.
Definitely use a Stabilizer Bar to hold motor in place and off the BB cable guides.

 

[JES2020]

Thanks, that would definitely be a way to simplify things. If you have a rear hub recommendation for towing a cargo trailer up steep hills that won't accidentally start moving when the pedals are bumped on the sidewalk, I'm open to suggestions.

The only way the bike would move w/PAS is if the pedals were rotated for forward movement.
If you pedal backwards the PAS is programed to NOT respond. Also most ppl set their PAS to kick in after 1/4 or more turn of the crank.

If you are carrying a heavy load then you want a geared rear hub motor, they are lighter and are better for climbing hills than direct drive. Gross weight and steepness of the hills will determine the best amps of the motor and amp hours of the battery to install.

Please don't put a motor on the front wheel, especially hauling trailers, the fork is not strong enough for all that weight and torque.

 

[tomjasz]

Please don't put a motor on the front wheel, especially hauling trailers, the fork is not strong enough for all that weight and torque.

Hey JES, have you seen steel fork failures? I run a 1000W front DD and have for 6 years hauled my trailer with the bike.
I realize that's an anecdote, I'm genuinely interested in any known failures.

 

[indianajo]

The only way the bike would move w/PAS is if the pedals were rotated for forward movement.
If you pedal backwards the PAS is programed to NOT respond. Also most ppl set their PAS to kick in after 1/4 or more turn of the crank.
Please don't put a motor on the front wheel, especially hauling trailers, the fork is not strong enough for all that weight and torque.

Wrong. I've been whacked in the shin by the pedal when the motor jumped.
Possivly wrong depending on what a trek 7.2 FX is. I've done it to two bicycles with steel front forks.

 

[JES2020]

Wrong. I've been whacked in the shin by the pedal when the motor jumped.
Possivly wrong depending on what a trek 7.2 FX is. I've done it to two bicycles with steel front forks.

Mind explaining what was "wrong"? If your PAS kicks you when pedaling backwards you wired it wrong (somehow).
There is no way that the front fork is stronger than the rear, period.

 

[tomjasz]

There is no way that the front fork is stronger than the rear, period.

Based on what? I'm trying to understand how a rear dropout is stronger than a front?

 

[moffbits]

Does a GMAC or MAC motor let you pass a quick release skewer through it?

 

[JES2020]

Wrong. I've been whacked in the shin by the pedal when the motor jumped.
Possivly wrong depending on what a trek 7.2 FX is. I've done it to two bicycles with steel front forks.

Wow...do you have good life insurance???

 

[JES2020]

Does a GMAC or MAC motor let you pass a quick release skewer through it?

Why do you want quick release?

 

[indianajo]

Does a GMAC or MAC motor let you pass a quick release skewer through it?

No, they have an internal axle, 14 mm. It is flattened down to fit in fork slots, but may require a little grinding on the slot to fit. Did on my nineties Murray Savannah cruiser. Real steel frame & fork. Use safety glasses using power tools.
I've got ~6800 miles on my yuba bodaboda front motor conversion. I carry 160 lb me + up to 80 lb cargo to my summer camp, weekly. Up & down ~80 hills over 30 miles in Clark Cty IN. Bodaboda is a much more stable bike than the Murray cruiser or Pacific & Diamondback MTB's I had previously. I was pitched off on my chin 5 times since 2008 on those bikes. I haven't been thrown off the bodaboda yet.

 

[JES2020]

No, they have an internal axle, 14 mm. It is flattened down to fit in fork slots, but may require a little grinding on the slot to fit. Did on my nineties Murray Savannah cruiser. Real steel frame & fork. Use safety glasses using power tools.
I've got ~6800 miles on my yuba bodaboda front motor conversion. I carry 160 lb me + up to 80 lb cargo to my summer camp, weekly. Up & down ~80 hills over 30 miles in Clark Cty IN. Bodaboda is a much more stable bike than the Murray cruiser or Pacific & Diamondback MTB's I had previously. I was pitched off on my chin 5 times since 2008 on those bikes. I haven't been thrown off the bodaboda yet.

As long as you don't go over 5 mph and know how to take a front fall, you shouldn't die or anything . Just hope you don't break down in front of a speeding Mac truck !

 

[tomjasz]

Why do you want quick release?

To release quickly?

 

[moffbits]

Why do you want quick release?

My reason is that my bike trailer uses a Chariot ezHitch axle mount cup. It looks like this.

 

[JES2020]

They do exist. A quick search landed me on this Bafang review.

Bafang introduces versatile new e-bike rear hub - BikeBiz

Bafang has introduced a new e-bike rear hub motor, which will debut at the Eurobike 2017 show.The H8

www.bikebiz.com

 

[moffbits]

They do exist. A quick search landed me on this Bafang review.

Bafang introduces versatile new e-bike rear hub - BikeBiz

Bafang has introduced a new e-bike rear hub motor, which will debut at the Eurobike 2017 show.The H8

www.bikebiz.com

Interesting. I can't seem to find that model anywhere, but it's nice to know that they may exist.

I'm going to 3D print a thinner cable guide and it looks like the bridge plate might actually line up with the hole in the plate on the chainstays, so I'll first give this a shot. Since we have two bikes, it might be fun in the future to try both motor types and see how it goes. What's most important for me at the moment is that any system I use has to be extremely intuitive, since I'll be sharing the bike with another rider who isn't necessarily into this kind of thing.