Converting a beach cruiser with front wheel motor.

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rootshell   1 W

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Converting a beach cruiser with front wheel motor.

Post by rootshell » Apr 01 2020 8:59pm

Last year I converted my first ebike and posted about it here: viewtopic.php?f=3&t=100409

Love the build and use the bike all the time reliably thanks to all the help on this forum. :D

A friend of mine was asking for my help with plans to convert his beach cruiser. The bike is a 26" sixthreezero. The issue is that the bike has 3spd internal gearing in the rear wheel and coaster brakes which he'd like to retain. Any extra considerations with using a 500W or 1000W front wheel ebay hub conversion kit on this type of donor?

I was also thinking he could put a basket on the front to contain/conceal the wiring and controller.

I have no experience with front wheel motor hubs, so I am unsure what challenges they present.

Any advice appreciated. Thanks again.
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Wolfeman   100 W

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Re: Converting a beach cruiser with front wheel motor.

Post by Wolfeman » Apr 01 2020 9:26pm

I paged through your build thread on your bike, very nice looking. I know the hub motors are cheaper, but for that three speed cruiser I would absolutely recommend a BBS02 mid-drive. That would allow him to keep the coaster brake (not correct, sorry), use all three gears and completely eliminate the rolling drag of the front hub motor. The BBS02s are easy to install, don't have the associated wiring bird's nest of the separate controller AND the bike can be ridden normally when the motor is not on. It is more expensive, but both of mine have been totally reliable and I've come to prefer them over direct drive hub motors for most things. I run one on 12S, the other at 14S and have had NO problems. Just my 2 cents....
Last edited by Wolfeman on Apr 06 2020 10:44am, edited 1 time in total.
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rootshell   1 W

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Re: Converting a beach cruiser with front wheel motor.

Post by rootshell » Apr 01 2020 9:45pm

Thank you for your experiences with the mid-drive, but it's way out of his budget for this project unfortunately.

Curious though, what do you find advantageous about them over hub motors?
Wolfeman wrote:
Apr 01 2020 9:26pm
I paged through your build thread on your bike, very nice looking. I know the hub motors are cheaper, but for that three speed cruiser I would absolutely recommend a BBS02 mid-drive. That would allow him to keep the coaster brake, use all three gears and completely eliminate the rolling drag of the front hub motor. The BBS02s are easy to install, don't have the associated wiring bird's nest of the separate controller AND the bike can be ridden normally when the motor is not on. It is more expensive, but both of mine have been totally reliable and I've come to prefer them over direct drive hub motors for most things. I run one on 12S, the other at 14S and have had NO problems. Just my 2 cents....

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Re: Converting a beach cruiser with front wheel motor.

Post by Balmorhea » Apr 01 2020 11:45pm

That cruiser will have a strong rear weight bias, so a torquey front hub motor is likely to spin the wheel on takeoff. That’s more of an annoyance than a hazard, but it’s reason enough to refrain from getting too ambitious with the power output. I think a 500W motor with a 20 mph top speed and the battery mounted in a front basket would be just about right.

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Re: Converting a beach cruiser with front wheel motor.

Post by MikeSSS » Apr 01 2020 11:51pm

I've been riding a direct drive front hub motor, 26" conversion bike since 2014. 410 miles last month and 31.6 miles today.

Front hub motors work, both direct drive and gear hubs work well. Mine runs fine on 48 volts and 36 volts, there is little difference in performance but I never use a lot of throttle when using my wife's 36 v battery. I can't tell the difference between front hub motor, rear hub motor and mid drive when riding.

With the front hub motor, the battery is mounted over the rear rack. Rear rack, topped with a plastic cutting board, topped with a 15" Harbor Freight bag, bubble wrap padding in the bottom of the bag. The bag holds battery, Kryptonite Keeper chain and insulated water bottle and some flat fixing stuff.

I use throttle and pedaling. PAS using rpm sensing seems very unnatural to me and some have been dangerously high risk. Torque sensing pedal assist, like on Trek and Cannondale bikes also works well.

Watts: the following is based on recharge data, charge time and charge amps to determine watt hours into the battery and actual ride time to determine average watts, again based on recharge. Riding between 13 and 19 mph, I'm using between 125 and 200 watts from the battery. Pedal effort is between medium low and medium high. Watt use is very dependent on ride speed. Faster uses more watts. Point is that actual watt usage is pretty low. Top speed with my DD front hub is 25 mph, pedaling really hard does not increase this much, because of something called Back EMF.

Front brakes on the bike in question would be a really good thing, if they can be fitted. For rear coaster brake only, limit ride speed and anticipate need to slow or stop.

A front hub leaves your gearing unchanged and it can be easily transferred from one bike to another, but not to a bike with a suspension fork. A rear hub motor allows transfer to a bike having a suspension fork or even a full suspension bike. A suspension seatpost helps tame a hard tail bike.

I'd rather have a rear hub motor, if I had one it would be transferred to my full suspension bike. Were I to buy a new kit, it would be a rear hub motor.

Hope this helps, keep us posted on what you do.

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Re: Converting a beach cruiser with front wheel motor.

Post by amberwolf » Apr 01 2020 11:58pm

i may just be confused or misremembering, but:

are you sure the coaster brake will still work with a bbs02? i thought it was setup so the crank freewheeled if pedals were held still, but the motor was still turning? thus, the cranks couldn't apply force to the chain going backwards?

or is there a specific version that doesnt' have those freewheeling clutches in there? (this would cause the pedals to move with the motor whether you pedal or not)



regarding the op's question...the front hubmotor will be fine, as long as you use good torque arms on both sides, and keep the torque low (because of the wheelspin mentioned above, and to

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Re: Converting a beach cruiser with front wheel motor.

Post by amberwolf » Apr 02 2020 12:05am

MikeSSS wrote:
Apr 01 2020 11:51pm
Watts: the following is based on recharge data, charge time and charge amps to determine watt hours into the battery and actual ride time to determine average watts, again based on recharge. Riding between 13 and 19 mph, I'm using between 125 and 200 watts from the battery.
do you mean watt-hours?

i hope so, because you can't tell how many watts you use during a ride by recharging it; you can only do that during the actual ride, with a wattmeter or similar. ;)


it is a very very important difference--watts (and amps) are a measure of power (and current), while watt-hours (and amp-hours) are a measure of capacity.

even though the one has part of the other's name in it, it doesn't mean the same thing at all. :)

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Re: Converting a beach cruiser with front wheel motor.

Post by dogman dan » Apr 02 2020 6:22am

Best bet for that cruiser is a front motor for sure. Only thing to be sure of, is use a sturdy torque arm, and C washers to get the best fit of the motor into the lawyer lips common on front forks.

If it has the two little tabs, lawyer lips, you can just flatten them. More common now is a small cup shape in the fork dropout. The smaller c washer is needed to fill in the small cup, then you can put a torque arm, or larger washer on it. the tabbed washers typical in the kits work only on a fork with no cup, or with flattened lawyer lips.

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Re: Converting a beach cruiser with front wheel motor.

Post by wineboyrider » Apr 02 2020 9:10am

dogman dan wrote:
Apr 02 2020 6:22am
Best bet for that cruiser is a front motor for sure. Only thing to be sure of, is use a sturdy torque arm, and C washers to get the best fit of the motor into the lawyer lips common on front forks.

If it has the two little tabs, lawyer lips, you can just flatten them. More common now is a small cup shape in the fork dropout. The smaller c washer is needed to fill in the small cup, then you can put a torque arm, or larger washer on it. the tabbed washers typical in the kits work only on a fork with no cup, or with flattened lawyer lips.
Yep. Also will have good traction on sand and light trails.
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Re: Converting a beach cruiser with front wheel motor.

Post by wineboyrider » Apr 02 2020 9:11am

I have a bbs02 and don't think a coaster brake is compatible with it as the crank gear free wheels.
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rootshell   1 W

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Re: Converting a beach cruiser with front wheel motor.

Post by rootshell » Apr 02 2020 11:41am

You guys are great. Thanks for all the input. Do you think installing a 1000W as opposed to a 500W will be an issue?

I went with a 1000W on my rear motor hub ebike and am glad I did now since I am a big guy (tall, not overweight) and wanted to have the power to climb modest hills without pedaling if desired.

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Re: Converting a beach cruiser with front wheel motor.

Post by Balmorhea » Apr 02 2020 1:31pm

rootshell wrote:
Apr 02 2020 11:41am
You guys are great. Thanks for all the input. Do you think installing a 1000W as opposed to a 500W will be an issue?

I went with a 1000W on my rear motor hub ebike and am glad I did now since I am a big guy (tall, not overweight) and wanted to have the power to climb modest hills without pedaling if desired.
A 1000W motor is likely to be wound for 28+ mph, which is too fast for a beach cruiser's brakes and riding position. A 1000W motor with a fast winding may not have any more torque for climbing and accelerating than a 500-750W motor with a slower winding.

If you can find a 1000W motor that tops out in the 20mph range, then it is likely to be a really good climber. But keep in mind that the motor and the battery required to feed it will be heavier and costlier than a lower powered one.

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Re: Converting a beach cruiser with front wheel motor.

Post by markz » Apr 02 2020 2:28pm

Geared rear hub, means the rear dropouts are narrower and you have to spread the rear dropouts for motor to fit.
Going front motor fixes that problem.
Coaster brakes creates problems, when going rear hub, but your going front.

You can do 500W or 1000W front hub, and be sure to install torque arms on both sides. Hopefully your fork is steel but if not, you should be alright, I've ridden around in similar hub with no problems on my Costco fat bike. It was a dream not having lots of flats like I was having a rear hub, but 375lbs on the rear wheel does cause problems for me.

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Re: Converting a beach cruiser with front wheel motor.

Post by 2old » Apr 02 2020 2:29pm

I built a Bikes Direct Nexus three-speed cruiser with ebikeling 1200w front motor (ebikeling is excellent IMO) and 52V rear rack Luna battery. Fun ride on a bike capable of 33 or so mph. Biggest problem, which you'll also encounter, is braking. The rear coaster is adequate as long as you're able to avoid any situations where more is required (I used it for out of the way, no traffic places). Your options are 1) new fork (not much available for a 1' threaded system; check Amazon for one with "V" mounts, about $35) or 2) welding mounts on the frame.

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Re: Converting a beach cruiser with front wheel motor.

Post by markz » Apr 02 2020 2:41pm

2old wrote:
Apr 02 2020 2:29pm
I built a Bikes Direct Nexus three-speed cruiser with ebikeling 1200w front motor (ebikeling is excellent IMO) and 52V rear rack Luna battery. Fun ride on a bike capable of 33 or so mph. Biggest problem, which you'll also encounter, is braking. The rear coaster is adequate as long as you're able to avoid any situations where more is required (I used it for out of the way, no traffic places). Your options are 1) new fork (not much available for a 1' threaded system; check Amazon for one with "V" mounts, about $35) or 2) welding mounts on the frame.
Yeah, a new front with v-brake posts. Hopefully the OP's bike doesnt just have rear coaster brake, some bikes do.

I'd personally look for one with V-mounts and disc mount.

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Re: Converting a beach cruiser with front wheel motor.

Post by john61ct » Apr 02 2020 3:30pm

That coaster brake will become pretty irrelevant for hard stops at 25+mph.

Add a good front brake whichever way you go on the motor.

I agree PAS over throttle, cheap hub OK but get a CAv3 and/or high quality controller in there.

If the budget's not there to do it at least minimally right then just wait keep saving up.

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Re: Converting a beach cruiser with front wheel motor.

Post by Balmorhea » Apr 02 2020 9:02pm

john61ct wrote:
Apr 02 2020 3:30pm
That coaster brake will become pretty irrelevant for hard stops at 25+mph.

Add a good front brake whichever way you go on the motor.
The only kind of rim brake that fork will accept directly is a center bolt mounted caliper. There are both single-pivot (lame) and dual-pivot (somewhat lame) varieties. The problem with both is the amount of reach from mounting bolt to pads— there’s no getting around the flex and twist that weaken braking and cause brake pads to rub on the tire when braking is hardest.

Probably the best workaround is to get a U-brake adapter plate, and use it to mount a U-brake like Odyssey Springfield or Diatech Hombre. That would provide the maximum braking power and reliability you can get with the original fork:
Image
Image

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Re: Converting a beach cruiser with front wheel motor.

Post by john61ct » Apr 02 2020 9:07pm

Whatever you gotta do!

Stopping is a higher priority than going.

thanks for the details.

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Re: Converting a beach cruiser with front wheel motor.

Post by MikeSSS » Apr 02 2020 10:50pm

Brakes like the Odyssey Springfield or Diatech Hombre require some sort of cable housing stop, for the end of the brake cable housing.

Typically, the cable stop would be mounted on the stem, the end of the brake cable housing rests in the housing stop, the cable extends down to a yoke that pulls up on the transverse short cable between the brake arms. Note, the cable housing stop has to fit the stem and stems come in more than one size. 22.2 mm and 25.4 mm are common sizes, they are 7/8" and 1" respectively.

The Springfield and Hombre should be very effective.

I use a Grin, ebikes.ca, torque arm on one side of my front direct drive hub motor axle. This is a thick torque arm that fits snugly on the axle. Torque arms on both sides are better still.

The axle wants to rotate in the opposite direction of the tire. The top of the tire rotates forward, the top of the axle tries to rotate toward the back of the bike. If the torque arm is installed on the back side of the fork, axle torque will press the axle up into the fork dropouts, this is good. Were the torque arm installed on the front side of the fork, axle torque will press the axle downward and maybe out of the dropout. I've seen this happen, a front side torque arm ejected the hub motor axle down and out of the dropouts. I'm guessing that the axle nuts were not tight enough. Also, the torque arm was made of thin, soft steel that did not fit the axle snugly. It was replaced with a Grin torque arm, installed on the correct side and there was no problem until the rider ran into something, but that's another story.

This is a big deal: torque arm on the back side of the forks. So axle torque presses the axle upward into the dropouts.

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Re: Converting a beach cruiser with front wheel motor.

Post by Balmorhea » Apr 03 2020 3:56am

MikeSSS wrote:
Apr 02 2020 10:50pm
Brakes like the Odyssey Springfield or Diatech Hombre require some sort of cable housing stop, for the end of the brake cable housing.
That used to be true, but for the last 25 years or so, such brakes offer linear pull versions that stop the housing on one arm and pull across to the other.

Image

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Re: Converting a beach cruiser with front wheel motor.

Post by dogman dan » Apr 03 2020 6:30am

One way to improve brakes easy, is just swap the fork on the cruiser. Anything will work, so long as it has the right headset size, wheel size, and headset length, and rim or disc brake mounts.

And btw, that motor likely has a disc mount too. Welding a simple steel plate to a cruiser fork is quite easy. See details in my cruiser build thread, in my signature. Its actually easier than welding on rim brake mounts.

1000w is ok for front hubs, but without better brakes, a 36v 750w kit would be better.

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Re: Converting a beach cruiser with front wheel motor.

Post by aroundqube » Apr 03 2020 9:14am

Looking at the new model of that bike on the sixthreezero website , I see a front fork with linear pull brakes. Try and contact their tech support to find out if they can sell you a fork and brake that can be swapped .

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Re: Converting a beach cruiser with front wheel motor.

Post by MikeSSS » Apr 03 2020 12:15pm

Love that U brake with the built in housing stop. That really makes sense and makes things easier.

My host bike is about 45 years old, just moved the ebike stuff over to a modern bike, only a 17 year old design.

Had not a clue about a U brake with built in housing. Thanks for posting that pic and letting us know about it.

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Re: Converting a beach cruiser with front wheel motor.

Post by dogman dan » Apr 04 2020 5:42am

https://www.walmart.com/ip/Mx-Brake-Rea ... 0000004105& If you can find a regular caliper brake, it just needs the hole drilled in the fork to mount it. These cheap calipers are not great, but hey, better than nothing. It could do till you get a fork with the brake mounts on it, preferably a disc mount.

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Re: Converting a beach cruiser with front wheel motor.

Post by 2old » Apr 04 2020 9:53am

There's a hole in the fork for the reflector which I used for a Tektro caliper brake with about 100 mm (AIR) reach ($20 Amazon). Didn't mention it because the performance doesn't compare to a disc or "V" brake. Someday I'll procure Koolstop pads and determine how much that improves performance, but for now, I moved the motor to another bike.

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