Newbie Build

[TOC]

Thanks for all the great knowledge you give out for free on this forum!!! You guys rock. I had a similar awesome experience when I got into arcade building a few years back at byoac.org and wound up building a nice Golden Tee ‘MAME’ machine.

I am an avid mtber but, due to injury, I have been road riding with a hardtail carbon Trek Superfly 29er mtb, with skinny tires, that I want to convert to ebike. I would like to commute but it is a bit long, maybe a day or two a week. The route is 25 mi but 18 is flatter railtrail. There is climbing in the other 7 mi with 950 vert ft going in when I would need motor most. Plan is to pedal little on the way in and a lot on the way home. I can recharge at work.

I have done a lot of reading on here and I have zeroed in on BMSBattery.com and their BPM2 kit https://bmsbattery.com/ebike-kit/583-bpm2-36v350w-front-driving-e-bike-motor-wheel-ebike-kit.html with either the 12.5a https://bmsbattery.com/ebike-battery/679-36v125ah-bottle-09-e-bike-battery-pack-battery.html or wondering if it’s worth the extra $100 to go for 14.5a?

Hopefully no flaws so far, bms confirmed that these are compatible.

I am 200 lbs and a somewhat fit rider, I even considered pedaling to work but have not tried it. Do you think this set up would get me to work with minimal pedaling?

Do you think it is worth considering a rear rack or a seat bag battery to try and balance the bike, the bike weighs 25 lbs so adding 18 lbs to the front half of the bike will obviously change things.

I am wondering if there are small upgrades I should be getting, like upgrading the LCD3 screen, I think I saw a throttle with battery gauges on it, anything like better wiring that would be worth spending a few extra dollars.

Should I be doing all of this in 48V?

Thanks again,
Tim

 

[DAND214]

Hi Tim, welcome to ES. Where are you located? That helps us to know where to recommend a source.
Carbon road bike? You want a frt hub motor? Is the fork steel, alloy or carbon? The most here don't recommend a frt hub install. Alloy is dangerous, steel not to bad but I don't remember reading about a frt hub in a carbon fork. Lots of torque in these small hub motors and they can spin the axle in a steel one if not installed properly. Alloy is more dangerous than steel since it is brittle and can snap I'm not sure about carbon but it is also brittle. You need to tighten the nuts real tight and that might damage the carbon. In any case you will need 2 torque arms for sure with a frt mount.

You said your a MTBer, why not use one of them? That is the best setup to start with, more rugged than a road bike.

As for upgrade the meter, why not and make sure to get the speed pickup. Don't know if they put all needed in the kit. They don't list in the parts what is needed to make it run properly. BMS has gotten better over the years but aren't shy with shipping cost and to contact you later thery need more money for shipping.

Dan

 

[wesnewell]

Please read this.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302

 

[d8veh]

I'm not sure that it's a good idea to fit a kit to that bike. Carbon frames aren't designed to resist the twisting forces of a front or middle motor. If it looks like your bottom bracket is really well supported, a middle motor might work. A 4.5 kg motor, like a BPM will spoil the action of your forks, and there's a fair chance that it'll,break your drop-outs. I think it would be better to get a cheaper bike that's better suited to convertion.

 

[TOC]

Yes, I know the bike is a little too nice to convert, frustrating. The bottom bracket shell is really wide, like 95mm, and I think that puts a middle motor out. It also has a funky bottom bracket that I think will make the PAS install a pain.

The only reason for a front motor is to save my gears in tact and to make conversion back to a regular mtb easier. I'm not too worried about fork action on the road and the fork does have a lockout that I would prob just leave locked. Its an aluminum Fox29 fork and I had planned on two torque bars.

I am located in New York.

Thanks.

 

[LewTwo]

Have you checked to see if the BMP2 will fit in your suspension fork?
The 100mm between the dropouts is NOT the only dimension you need to be concerned with.
Be sure to check the axle length as well.
https://bmsbattery.com/628-thickbox_default/bafang-36v350w-bpm2-front-driving-hub-motor-ebike-kit.jpg

 

[TOC]

Be sure to check the axle length as well.

No I'm not sure what this means. My fork is similar but it has a quick release rather than the thru axle shown in the pic. Not sure any of the motors out are compatible with that thru axle.

 

[TOC]

Considering swapping out to a steel fork to make it happen:

http://www.jensonusa.com/Bicycle-Rigid-Forks/Surly-Karate-Monkey-29-Fork

 

[LewTwo]

No I'm not sure what this means. My fork is similar but it has a quick release rather than the thru axle shown in the pic. Not sure any of the motors out are compatible with that thru axle.

Something more like this?

'Tis hard to find a picture of the Fox Series 29 fork you mentioned. Lowest series number in their current line is 32.
The one thing that is common for all the forks currently shown on their web site is those really wide through hole mounting points.
That raised a red flag.

What I am trying to say (probably badly) is that suspension forks bring their own set problems to the task.
Those can include miscellaneous interference points, axle sizes/lengths, inability to mount torque arms, etc.
All of those without even mentioning the materials (often cast aluminum or worse yet cast magnesium) used for the dropouts.

 

[TOC]

No I'm not sure what this means. My fork is similar but it has a quick release rather than the thru axle shown in the pic. Not sure any of the motors out are compatible with that thru axle.

Something more like this?

Yes, more like that, the model is F29 (for 29er). The 32 relates to the 32mm stantions, they also make larger 34mm and 36mm models.

I think it makes the most sense to go with a steel rigid fork to make the project work.

Thanks Lew.

 

[dogman dan]

First thing, Rear motor!!!

if it's got through axles in the back, then get a good, but normal 10mm axle bike.

I think you need 48v 20 ah, for a commute that long. You will want to use the motor even on the flat part, to improve your time. Commuting is not la de da riding for fun. You'll want to run 25 mph the entire ride, except for the hill, which will go at 15-18 mph.

 

[TOC]

Thanks Dan. Coming around to the idea of 48v and rear motor.

Mountain bikes have been converting over to 12mm rear through axles and 142mm dropouts. My Trek Superfly carbon mtb is convertible between a regular quick release, 9mm or a 12mm thru axle with 142mm. Do you think I could make a rear motor work?

I not sure any motors out there are compatible. I would also really like it to be compatible with a cassette cog rather than freewheel. I see BMS has the Q128C in 135mm and cassette cog. I wonder if I could make that work?

 

[TOC]

So I obtained a steel fork for my Trek mtb and am going forward with the front hub install, I realize it is not ideal.

I am wondering what you think is better, given the same budget: A 48V500 BPMII w a 48V11.6ah battery or a 36V350 BPMII with a 36V14.5 ah battery?

As an alternative on the 48V I am considering the Q128 48V 350-500W thinking that the BPMII may be too powerful.

 

[dogman dan]

Not on the website, but E-Bikekit does have a few prototype cassette ready rear 500 watt geared motors laying around the shop.

They came out too wide, about 140mm, so perfect for your 142mm frame, 10mm dropout, so you'd have to get the frame pieces for 10mm drops to make this work.

Not cheap, so forget it till you have a budget for an off road bike that won't suck to ride like a front hub with no shock.

Other places do have cassette motors, but in direct drive type.

 

[d8veh]

With a BPM, you have to choose one with the right speed winding for the speed that you want. A 36v 260 rpm one at 20 amps will perform the same as a 48v 260 rpm one at 15 amps. 260 rpm is code 12 for a 36v one and code 14 for a 48v one.

The code number is stamped on the motor and is the number in brackets next to the wheel size, e.g. 36V500wBPM 26(12), where 12 is the code number.

Don't buy a BPM unless you know the code number. If you tell us the code number, we can trll you the speed at any voltage.

 

[TOC]

Thanks Dan but I don't have budget for an off road rig at this point. I am nervous to put a rear motor on the carbon frame and don't have the funds to source a new bike for conversion at this point. Will try the rigid mtb on the road for a while and maybe a true off road bike later.

I emailed them to ask but is BMS able to tell us, reliably, what winding they are sending?

Is the Q128 more predictable? Maybe I should just go for that, its listed as a 260rpm.

I am planning to get their 48V11.6ah (or the 36V14.5ah) Panasonic battery with the built in 18A controller.

 

[ScooterMan101]

Toc,

First, do not even consider a front hub motor, that is only for someone with a department store bike , and even then, Only with a steel rigid front fork.
So
That leaves you with options 2 and 3
2 ) a rear hub motor
or
3) the befang BBS02 Mid drive

Since you have a carbon bike, and since replacing a carbon frame would be costly , and since most great bikes ( quality bikes ) these days have very little drop out material for a big axle and nut of a hub motor to bolt onto, Your best bet it to get the Befang BBS02
That is if you have standard threaded bottom bracket.

Do you have a BB30 / BB86 / BB92 or Praxis Works Press Fit Bottom Bracket ( BB ) ?

You can see my build here, https://endless-sphere.com/forums/viewtopic.php?f=3&t=71378
however keep in mind , I bought the bike in large part because it has the biggest and thickest drop outs on a bike that I have seen in quite a while. Sometimes I wish I had gone with a BBS02 but a year ago when I bought the parts, there were still some problems with the befang which have mostly be improved upon.
I am waiting for further improvements on the Befang before I buy one, namely a better / lighter weight chainring and better lighter crank arms, and Made to bolt onto a bike with BB30/ BB86 / BB92 / Praxis works press fit type Bottom Brackets on the Frame.

Here is my conversion : https://endless-sphere.com/forums/viewtopic.php?f=3&t=71378
Keep in mind though you have a carbon frame with probably little material at the drop outs, so again look into the Befang BBS02

 

[ScooterMan101]

Ops , I just read you bought a steel fork for the Trek Superfly, did you order the motor yet, if not you could still get the Befang BBS02 , it is more money , but you will still be able to keep the suspension fork, which is useful on speeds over 12 mph , unless you only ride on the / a smooth road. The faster you go the more suspension you will want to have. That Steel front fork and a front hub motor will not make you as happy on speeds over 10-12 mph as the mid drive set up.
and when you start going faster , get a suspension seat post.

 

[TOC]

So BMS tells me the BPMIIs they are shipping are code: It is 26(code:13).

Which I looked up somewhere to be 192rpm. Probably too slow for me.

I have two priorities for my commute, a 1/2 mi 6% climb right at the beginning of the ride and an 18 mile bike path where speed is king. I know it is asking a lot.

With the BPMII, I would certainly appreciate the torque getting over the hill but too slow on the bike path. There are 2 BPMIIs listed, a 36V350W or a 48V500W, I was asking about the 48V, not sure if both would have the same code. EDIT: The 36V w/RPM 201=code:11

The Q128 is either 260rpm at 48V or 201rpm at 36V. Not sure which would be the best compromise speed? Weird thing about the Q128 listing is the title says V-brake but the pic clearly has disc threads.

Not sure I understand the pros & cons of using a 48V batt with a 36V motor but it may be the way to go?

Thanks.

 

[LewTwo]

Weird thing about the Q128 listing is the title says V-brake but the pic clearly has disc threads.

I think that I might trust their picture more than their English translation.
https://bmsbattery.com/ebike-kit/414-q128-48v350-500w-front-driving-v-brake-hub-motor-ebike-kit.html
Then again they are not known for keeping the photos up to date:

You need to get them to clearly state on the quote what they are selling.

P.S.
You are going to be shocked by the shipping charge when you get the final quote/invoice.

 

[TOC]

Weird thing about the Q128 listing is the title says V-brake but the pic clearly has disc threads.

I think that I might trust their picture more than their English translation.

P.S.
You are going to be shocked by the shipping charge when you get the final quote/invoice.

I find it hard to believe that a newer motor like the 128 would be made V-brake only. I agree to trust the pic more but I will confirm as you suggest.

Already got a quote and you are correct...over $200 motor wheel and batt

 

[LewTwo]

I find it hard to believe that a newer motor like the 128 would be made V-brake only.

You have a point there as I have just the opposite problem --- try to find one without extra material required for the disk brake.

 

[TOC]

you could still get the Befang BBS02 , it is more money , but you will still be able to keep the suspension fork, which is useful on speeds over 12 mph , unless you only ride on the / a smooth road. The faster you go the more suspension you will want to have. That Steel front fork and a front hub motor will not make you as happy on speeds over 10-12 mph as the mid drive set up.
and when you start going faster , get a suspension seat post.

Thanks Scooter, I am gonna ride the road for a while on this and save some cash for an off road machine down the road, even saw a big thread about converting a hub motor to a mid-drive, looks interesting.

The Superfly frame does have a funky 95mm BB shell and an even funkier proprietary press fit BB. I am concerned about being able to install a PAS properly. Have not even researched it yet but and planning to buy an extra or two in case I screw it up. Can the PAS magnet be installed in place of a granny ring on a three ring crank?

http://www.bing.com/images/search?q...993&thid=JN.DLInq0F8ybmFpTprOB2d7w&ajaxhist=0

The suspension seatpost is a good idea

 

[LewTwo]

The Superfly frame does have a funky 95mm BB shell and an even funkier proprietary press fit BB.

You may find these links useful:
http://blog.artscyclery.com/ask-a-mechanic/ask-a-mechanic-fixing-foot-problems-and-more-bottom-bracket-answers/
http://www.slowtwitch.com/Tech/Bottom_Bracket_Standards_2573.html


and another one ...
http://www.bikeradar.com/us/gear/article/complete-guide-to-bottom-brackets-36660/
"Aside from omitting the cups, the BB90/95 setup is functionally identical to conventional threaded bottom brackets, in that it uses the same bearings and the same bearing locations as before. Crankset compatibility is thus unchanged, although you do lose the ability to run chain guides that sandwich between the driveside cup and frame."
Note that 'conventual' in this case refers to 24mm spindle bottom brackets rather than 'conventional' 17 mm spindle bottom brackets.

 

[ScooterMan101]

I have not done that yet myself , however someone explained to me how to do it,
Buy the PAS Ring with the largest outer diameter, because you are going to cut out the center of it,
Then you will glue/epoxy it directly to the inner/smallest chainring . then find a way to attach the magnet part to the frame at the BB shell so that it is close enough to pick up the other magnets/metal on the PAS sensor ring. ( like when you put a magnet on your spokes and then put the other magnet on your bike frame close enough to give it a signal when passing the spoke magnet, the same thing applies , the outer ring that you must cut out in order to fit over your spindle to then be able to glue onto your small chainring is like the spoke magnet, only many of them in a ring, then like the computer wired part , you connected to your frame )
Hope that explains it, I have not done it myself, because I ordered a PAS sensor that looked right, but was not large enough to cut out the center, and buying the better one for under $ 5 was good , but not the $ 35 shipping from China. one of the many problems that can occur when buying from China ! so I am only going to use the throttle.

I have not looked into it , but you can, Contact Praxis Works in Santa Cruz California, and ask them if they make an adaptor that can fit into your BB of your bike, with threaded inner, so that you can use a threaded Bottom Bracket, You might or might not want to tell them about the Befang BBS02 . Which if you can get an adaptor , would be the better and easier way for you to convert a bike with rear through axle.
I just found out lunacycles sells the Befang BBS02 here in California , and for the same price , or less than the price plus shipping from China.
But alas, I have the same problem in regards to Bottom Brackets, that is I have a BB30 on the other bike I am going to convert to e-bike.
The problem is , NOT , my bike , since the/my bike with BB30, pedals much more smoothly than the cartridge BB's
the problem , IS with Befang , not making a more modern version of the BBS02 ! or anyone else not yet making a better version
of the Befang BBS02 !

Scooterman101
>

>

you could still get the Befang BBS02 , it is more money , but you will still be able to keep the suspension fork, which is useful on speeds over 12 mph , unless you only ride on the / a smooth road. The faster you go the more suspension you will want to have. That Steel front fork and a front hub motor will not make you as happy on speeds over 10-12 mph as the mid drive set up.
and when you start going faster , get a suspension seat post.

Thanks Scooter, I am gonna ride the road for a while on this and save some cash for an off road machine down the road, even saw a big thread about converting a hub motor to a mid-drive, looks interesting.

The Superfly frame does have a funky 95mm BB shell and an even funkier proprietary press fit BB. I am concerned about being able to install a PAS properly. Have not even researched it yet but and planning to buy an extra or two in case I screw it up. Can the PAS magnet be installed in place of a granny ring on a three ring crank?

http://www.bing.com/images/search?q...993&thid=JN.DLInq0F8ybmFpTprOB2d7w&ajaxhist=0

The suspension seatpost is a good idea