Newb quest. (9 speed rear in 135mm dropout)

[bachmaninoff]

Looking to "e-bike" a Trident Stowaway II tadpole (20", 9 speed rear hub, 135mm dropouts). So it's my understanding that a typical 7 speed freewheel made for a mountain bike will not be an easy install for a tadpole with road bike components(?), with the different sized chain... I would prefer not to change out the shifter/chain and 3 ring cranks... I understand that on an e-bike, the amount of gears is not that important; however, I don't want to have to convert everything else on the bike over to match... If that makes any sense. (Please let me know if I'm incorrect on this)

So from the research I've done, it seems my choices are as follows:

1. BionX (price is holding me back though, and some users having questionable experiences)
2. Hi-Powered Cycles/BMC with HPC 9 speed freewheel

Any alternatives? I don't want to spend any more than a BionX kit, and I'm thinking that for that price I could get a much more powerful/reliable setup.

I already have a 36V 15AH LiFePO4 from pingbattery (awesome!), and it would be great of I could continue to use that towards this new setup. I'm continuing to research, but finding this forum made me think that someone out there's already 'been there done that'. Any input would be greatly appreciated!

 

[amberwolf]

The Fusin kit I'm testing now should be capable of a 9speed cassette (I'm using an 8) in 135mm dropouts.
http://endless-sphere.com/forums/viewtopic.php?f=4&t=39877

 

[bachmaninoff]

Nice, thanks for the post! Looking into it...

Also just noticed:

http://electric-bikes.com/betterbikes/bmc.html
"*We have fit all rear frames so far with 8, 9, and even 10 speed freewheels."

Nice to have choices!

 

[bachmaninoff]

Looks like the Fusin motor has the exact same connector as my E-Bike Kit! Hmmmm...

 

[motomech]

It would appear the the Fusion is still in need of development.
The small Ananda Q100 mini motors accept a 9-speed free wheel in a 135 mm dropout with out any modifications.
But this is a mini motor and would not overwhelm at 36 Volts. It really needs at least 44V.
The price of the kit from BMS Battery can't be beat, though. $123 plus shipping.
Here is the motor installed on a conversion that I am currently working on.



Only a slight spreading[by hand]was necessary to insert a washer inside the motor side drop-out.
The are only 7 sprockets because I cut the two larger ones off the DNP free wheel.
The deraileur is not quite as bent as it appears in this photo. It's on the third gear index while the chain is is still on the second gear.
But it isn't straight either
Anyone know the best way to straighten these things?
B ig Cressent wrench?
Amazingly, it still indexs fine.

 

[neptronix]

Get a real motor and just use a 7 or 8 speed. You will have to change your crank drive sprockets, maybe your derailleur, and your chain.... not expensive. Certainly less expensive than overpaying $500-$800 for an underpowered motor kit with proprietary components.

You will find yourself in the tiniest 11t or 13t gear >95% of the time anyway.

There are 9 speed freewheels with the proper gearing out there anyway.

http://www.universalcycles.com/shopping/product_details.php?id=49868&category=402

 

[bachmaninoff]

I certainly appreciate the suggestions! I looked at the Q100 and it looks interesting! The 9 speed freewheel doesn't appear to be in stock at Universal Cycles, but I did find one on Ebay and ordered it. Also ordered a 20" rim and spoke set with Bafang BPM 36V500W (393 rpm version) from BMS Battery. Hopefully it'll just be a simple plug and play into my existing E-BikeKit once the the motor's laced into the rim (and I have a 26" front wheel version of the e-bikekit motor if anyone's wondering - probably will put on Ebay after this is finished and tested). Might need to do some minor working of the frame to fit the new one in.

Exciting stuff! Yeah, my expectations for this equipment isn't as high as if I'd ordered a BIonX system, so maybe I won't be as disappointed if I run into a challenge! Can't wait until it all gets here!

 

[Chalo]

Looking to "e-bike" a Trident Stowaway II tadpole (20", 9 speed rear hub, 135mm dropouts). So it's my understanding that a typical 7 speed freewheel made for a mountain bike will not be an easy install for a tadpole with road bike components(?), with the different sized chain... I would prefer not to change out the shifter/chain and 3 ring cranks...

9 speed chain works fine on 7 speed freewheels; only the rear shift lever must be changed to 7 speed. The front shifter and crank can stay the same.

Chalo

 

[motomech]

I certainly appreciate the suggestions! I looked at the Q100 and it looks interesting! The 9 speed freewheel doesn't appear to be in stock at Universal Cycles, but I did find one on Ebay and ordered it. Also ordered a 20" rim and spoke set with Bafang BPM 36V500W (393 rpm version) from BMS Battery. Hopefully it'll just be a simple plug and play into my existing E-BikeKit once the the motor's laced into the rim (and I have a 26" front wheel version of the e-bikekit motor if anyone's wondering - probably will put on Ebay after this is finished and tested). Might need to do some minor working of the frame to fit the new one in.

Exciting stuff! Yeah, my expectations for this equipment isn't as high as if I'd ordered a BIonX system, so maybe I won't be as disappointed if I run into a challenge! Can't wait until it all gets here!

The 9-speed free wheel will not work with the BPM.

..my expectations for this equipment isn't as high as if I'd ordered a BIonX system, so maybe I won't be as disappointed if I run into a challenge!

Since the value per dollar of the aftermarket products greatly exceeds that of the BionX, that is a given.

 

[neptronix]

I would have said to go with the BMC/MAC motors because they are more reliable and you can actually get replacement parts for them, but it is too late.

The big BPM motor is not *too* bad, it's just that support and parts for it are nonexistant. It can put out similar power as the BMC/MAC motors, a bit less maybe.

 

[neptronix]

The 9-speed free wheel will not work with the BPM.

I believe that 9 speed gear clusters have more narrow spacing, so the total diameter of the freewheel may be the same as a 7 or 8 speed. At worst, you might have to use a little bit of spacing to make it work.

 

[Chalo]

The 9-speed free wheel will not work with the BPM.

I believe that 9 speed gear clusters have more narrow spacing, so the total diameter of the freewheel may be the same as a 7 or 8 speed. At worst, you might have to use a little bit of spacing to make it work.

8 and 9-speed cassettes are the same width, but 7-speeds are 4mm narrower.

Chalo

 

[Ben Wilson]

I'm running a 6t MAC with a 7 speed in my stowaway.

I converted the bar end shifter to a 7 speed twist shifter and everything else seems to work nicely.

http://endless-sphere.com/forums/viewtopic.php?f=6&t=38203

 

[bachmaninoff]

I like your setup Ben! So you didn't have to swap out your chain or crankset then?

If for any reason this Bafang motor doesn't work out, I'll probably switch to a BMC/MAC as neptronix suggested. Probably should have held off on ordering it until I spent more time reading up on this stuff. I'll post my lessons learned as I go.

 

[MadRhino]

On a tadpole, you are not stucked building with the hub freewheel. A mid drive dog shift is easy to add to a trike, and would give you freedom of any ratio and gears that you want.

 

[bachmaninoff]

Wow, I figured a mid-drive system would be complicated to setup.

 

[Chalo]

Wow, I figured a mid-drive system would be complicated to setup.

He's not talking about a mid-drive. Normal (well, you know, "normal") low-slung tadpole trikes don't have any place to put one.

Chalo

 

[bachmaninoff]

Just got an email from BMS battery with tracking info, according to FEDEX should be here by cob June 11th. Seems pretty optimistic!

And I'll still need to lace the motor into the wheel...

The wife expressed interest in getting a hub motor, so maybe I could outfit her's with this one... Perhaps I should go with the BMC/MAC after all?

 

[Chalo]

Just got an email from BMS battery with tracking info, according to FEDEX should be here by cob June 11th. Seems pretty optimistic!

And I'll still need to lace the motor into the wheel...

The wife expressed interest in getting a hub motor, so maybe I could outfit her's with this one... Perhaps I should go with the BMC/MAC after all?

It's worth considering that cassette bodies for big-axle hubs are on average a lot more failure-prone than regular ones for 10mm axles. A cassette body is only about 32mm on the minor diameter of its outer spline, and that doesn't leave a lot of space for pawls and bearings. The bigger the axle passing through, the smaller those highly stressed parts must be to fit in there.

I don't think mixing cassettes and 14mm axles is a good idea at all.

Chalo

 

[bachmaninoff]

I won't be using a cassette, it's a freewheel - which just came in today from ComCycle USA! It's a DNP Epoch 9 speed freewheel. Matches the spacing of my existing cassette. Appears to be 43mm wide, and since I won't be running disc brakes on the rear, I should have some room to play with. If not, I'll just cold set the frame to accommodate it.

So I have the Bafang BPM enroute which is supposed to arrive on Monday, which may need to be installed into the wheel, then trued. Gonna find out best place to acquire a BMC/MAC. Looking at possibly ElectroRide LLC or ?

 

[motomech]

Cyclecom does not lube the DNP free wheel and you will have to before installing. There is a pricey little tool to inject grease that your local bike shop may have, or you can soak it in gear oil and deal with the mess. It's only oil
The 9-speed DNP is 40 mm wide, about 3 or 4 mm too wide for the 135 mm drop-out.

 

[bachmaninoff]

Oh, ok I was measuring from side to side. Good to know about the lube...

http://sheldonbrown.com/freewheels.html <-- what a great site!

I really appreciate all the input on this thread!

 

[Chalo]

I won't be using a cassette, it's a freewheel - which just came in today from ComCycle USA! It's a DNP Epoch 9 speed freewheel. Matches the spacing of my existing cassette. Appears to be 43mm wide, and since I won't be running disc brakes on the rear, I should have some room to play with. If not, I'll just cold set the frame to accommodate it.

DNP freewheels are iffy quality, but should be OK for this application.

You'll probably need a spacing washer or two to allow the wider freewheel to clear the frame. That will significantly increase rear wheel flange offset, so you should strongly consider adding the same amount of spacing on the opposite side so that the integrity of the wheel is not undermined. Adding spacing on both sides will most likely require widening your frame.

Trikes strongly side-load their wheels, and hub motor wheels have narrow flange spacing that causes spoke tensions to fall disproportionately out of balance with small changes in flange offset. These two factors together suggest that it would be better to widen the axle or let the rear rim run off center (bad for a two-wheeler, but insignificant for a three-wheeler) rather than increase wheel dish (flange offset).

The rear brake may be difficult to adjust properly if the rim is much off center, which is why I suggest adding spacing to both sides.

Chalo

 

[motomech]

Yup, A whole lot of work to save that shifter.
Bachmaninoff, you really should consider trying out a 7-speed before going though all that.
The fact is, with the big geared Bafang, you are going to end up using three, maybe four of the lowest[numerical] gears anyhow.

 

[bachmaninoff]

Yeah, I think I understand what you're saying about going with the 7 speed. I won't always be using the motor though, guess I should have said that before. Well it's not installed on anything yet, hasn't even arrived. Not too late to do something different! I do just want to see how it is prior to going another route though...