Razor upgrades? Nothing crazy.

My sister's mother-in-law is new to the country and kind of stuck at home due to no income and no transportation (she doesn't drive a car so that option doesn't work).

I just bought a Burromax pit bike for my niece so I was thinking if that is going to last my niece for decades, why not get something similar for her grandmother?

It should be cheap because I'm not rich and she's not my mother-in-law but it doesn't have to be big because she is a small woman.

What I am looking for is a Razor Pocket Mod. Used models with bad batteries are cheap, it has classic scooter styling and she won't have to straddle it like the Burromax.

I will have some 18560 cells surplus to my E-bike project so I was thinking I could add a lithium battery and try to up the power in to the 500+ watt range for a higher adult ridden cruise speed.

If anyone has experience with modding a Pocket Mod, let me know. There seem to be many eBay 500-1,000 watt motor/controller kits for cheap but I don't want something that doesn't fit, overheats, burns up, craps out or is otherwise not worth the time to install.

I am going to make the battery for my E-bike project modular with 1s6p modules and I bought enough extra cells to have 9 spare modules so I can make a 9s6p pack for the Razor. It's not quite a 36v pack but I'm hoping it can make for a 25mph top speed scooter with a comfortable 15+ mph cruise and good range since it's about 500 Wh.

Which motor or kV rating should I look for?

The idea is a convenient way for a small, non-athletic but light weight woman in her sixties to get around for short trips of less than 20 miles round trip, I don't need a hot rod and I'm not going to change the battery configuration and lose the ability to use the battery modules as spares for my bike.

I know I could use less cells to make a 13s4p 11Ah 48v pack but nope, not interested. If she winds up not using it, I don't want to have a spare battery in a useless configuration.

You're making my mistake. I have yet to succeed at anything simple because of the many shortcomings of the pocketmad. The one brake is near useless, various other problems make it unsuitable for an upgrade. You're going to replace much of it, maybe still you won't be happy. The imod starts out a little better at 350w but still you have to upgrade.

I wanted to put a stronger fork with a bigger wheel and handbrake, but the neck is too long. I could go on about what I wanted to do. So I still have several around to come up with something for.

Think instead of the Razor Ecosmart. About the same price, starts out around what you hope to build the pocketmod up to. Or the 650w streetbike.

https://www.razor.com/products/electric-scooters/ecosmart-metro-electric-scooter/

https://www.razor.com/products/electric-rides/rsf650/

The Ecosmart is a lot more expensive than a used Pocket Mod. It's also a lot bigger which I think has some drawbacks.

Any scooter without pedals is obviously not an E-bike and something that looks full adult size is going to be more of a theft target and might cause police to ask about registration, top speed or riding on the sidewalk.

A child size scooter with a petite grandmother on it is going to look like she is picking up after a grandchild unless she is riding in a place where kids wouldn't go. A simple bike lock should deter any kid that wants to steal a scooter and a real bicycle thief probably wouldn't bother with something that looks like a $100 kid's toy.

I'm going to make sure the brake is in good working order but it won't have to stop much, my sister's mother-in-law probably weighs less than 90 lbs. If I have any trouble with that, Razor makes a version of the Pocket Mod with a front disk brake, I could buy the fork, brake and wheel for that and swap it over.

I think the positives for this application are pretty strong and the negatives can all be addressed pretty easily.

I rather think they'll steal the more attractive looking pocket more. They DO steal them. Ride it with the 250W then with the 500W. I might think only an athletic person wont find it a bit panicking. If you put another battery on first it won't feel much different, but the bigger motor will. An unstable platform with bad tires and almost no brakes.

The things I'm thinking I could go ahead with on mine are not so simple as you want.

I have started looking in to the stuff people seem to be doing with Pocket Mods and other Razor products.

The 5-800 watt 36v upgrades seem to be the budget choice under $100. Some 48v stuff is cheap except the battery gets more expensive.

Then a funny thing happens and there is a 48v brushless 1,800 watt MY1020 kit for around $135.

It seems like the best move is to lean in to the crazy and gear to suit if you want more than 800 watts. 800 watts is still a decent chunk of money to put in a little scooter so I wonder if skipping that middle step might be a good idea?

One question is what happens if I get the brushless motor and run it at 32v? If it can take the same amount of amps, 1,800 watts turns to 1,200 watts and evidently the controller has a couple power limit settings so I might be able to tame it quite a bit with hopefully a smooth brushless control.

The only gotcha I can see (there may be others) is I think the controller has a low voltage cut out for battery protection. With a 48v controller and a 32v battery, that could be a problem.

I'm hoping the low voltage cut could be disabled and I could get a cheapo BMS to implement a cut appropriate to the 9s pack I intend to use.

I think the thing to do is start stock, maybe do the 36v 3 lead acid battery setup and if power/range are issues, then lean in with lithium batteries and the brushless kit and if she ever wants crazy I can give her that too.

This project got shelved last year when my sister's mother-in-law left the country for a while.

Now I'm on quarantine and looking for a project.

The lithium batteries I was intending to use have been spoken for so I decided to see what is state of the art these days. It seems to be the LG M50 21700.

That's a 21mm diameter by 70mm length lithium ion with 5,000 mAh capacity and 7.4 A sustained discharge rating. I looked at the battery tray in the Pocket Mod and I think I can egg-crate stack a 13s4p pack that will drop right in. That's a 1 kWh pack rated for sustained 29.6 A. Reading some battery discharge tests, it looks like going up to 10 A per cell discharge does not decrease battery life by much and my 1,800 watt motor should draw about 36 A at 1,800 watts which would be 9 A per cell draw. That seems well within the ability of the LG M50 to handle 1,800+ watt peaks and if it cruises around 500 watts, it will be a very easy life for the battery with possibly 40+ mile range if light on the throttle.

My plan is to install the 1,800 watt motor with the brushless controller it came with and build up that battery.

Today I started watching some disassembly videos and finally stripped down the Pocket Mod to take off the rear plastics, the chain guard, the batteries and the motor controller.

Some people seem to struggle with the disassembly but their problem is trying to start with the front. The rear plastics come off easy and once it is off, removing the front plastics gets a lot easier.

Two things are probably going to make this easy. First, the Pocket Mod seems to come standard with a brushed version of a MY1016 size motor. My 1,800 watt brushless is a MY1020 which is about twice as long but seems like it will probably share at least two of the MY1016 motor mount holes and there is room to drill the other two in the motor mount on the scooter frame. My brushless motor came with a 9 tooth sprocket but it's compatible with the stock chain and I have found sources with 11,12 and 13 tooth motor sprockets if I need more top speed. The other thing is if I build a battery that fits the stock battery tray and allows me to use the seat and storage compartment without modifications, that will result in a very clean and convenient conversion.

The thing I'm a bit worried about is the brushless motor controller. It is about 4x as large as the brushed motor controller. I think I will have to mount it differently than stock.

The stock controller mounting is vertical in front of the motor and battery tray. I just looked and I'm pretty sure I can install it above the rear tire, transversely and make a simple little bracket that sandwiches between the frame and the chromed steel handle behind the seat.

I should have started on this a long time ago. It looks like drill two holes, make one bracket, do a bit of wiring and make a battery is all there is to do. I should probably add a front brake and some lighting but that's about it to make a fully functional 1,800 watt brushless scooter with a 1 kWh battery.

I should be around $600 in to it including the cost of the scooter when it is done.

What was I waiting for?

I forgot my trigonometry for a bit and was calculating my pack size with √2 instead of √3. My battery won't fit as nicely as I thought.

My width is kind of limited by the scooter frame so that has to stay. The rear of the pack is right in front of where I want to mount my motor controller so the front is where I will expand it.

I can fold down the front edge of my battery tray and glue some foam inside the plastic bodywork to prevent the battery from moving forward.

I think I will have to move a switch and the charging port but that shouldn't be too hard.

I almost ordered the wrong size heat shrink for the pack exterior. I'm glad I double checked my math.

I hammered the front of my battery tray. It's not perfect, the tray is welded to a cross member that isn't quite underneath it so there is about a 1/4" bump at the front of the battery tray now. I'll have to glue in some foam or rubber to flatten out the bottom. The paint chipped too, I'll have to wire wheel it and spray it to prevent rust (even though it is pretty dry around here).

The good news is that the charging port and power switch seem like they are high enough for a 70mm tall battery to slide under them. It looks like there is actually more than 3" of clearance so I have space for wiring, padding and heat shrink. Measuring from the back of the battery tray forward to the plastic bodywork, it looks like I have nearly 9" and my new math puts the battery pack length a bit under 8" so plenty of space for a nice cushioning foam block.

I think I might take off the motor next to confirm the hole pattern change and sprocket alignment.

I have decided to eliminate the chain guard on the scooter but also do some splash shields inside the bodywork to protect the electronics if I ride in the rain or on wet ground. One of the Pocket Mod scooters came with a mud flap, I'm thinking about adding that.

I dislike the way my back gets sprayed with water slung up off the rear tire when riding in the wet. I think the fairings of the Pocket Mod will prevent this almost entirely. I will try to avoid riding in the wet but if I get caught out, I think it will actually do pretty well as long as the tires grip.

The 1800 watt motor is in the hole.

It physically fits inside the space available, it's not bolted up.

The hole pattern for the MY1020 seems a bit wider in the dimension I wasn't expecting. I will probably have to oval the rear chain side motor mount hole and then drill the two new holes.

Other than that, it looks like it is going to fall together easily.

I think I figured out my nickel strip layout. I ordered a couple meters of 0.2mm thick 4P style pure nickel mesh(?). I think I can cut pieces to do all the series/parallel connections without stacking and spot welding strips on to strips. I might do some stacking to reduce resistance further but it should not be as tedious as dealing with plain 12 or 15mm strip.

Another pack making detail, the spacers for doing egg crate style packing seem to only be available coming from China and all but one place taking nearly a month or more to get here. It looks like I'm going to be paying for FedEx international if I want to be ready to start pack building in a week.

Does anyone know of a US source for 21700 egg crate style battery spacer strips?

I think I'm going to give each cell a small glob of hot glue to hold it in the spacer while I am packing. It will be tape and padding and heat shrink that really holds it together in the end but a little glue will let me keep it together while I'm spot welding the nickel strip.

I've seen packs built with adhesive backed foam padding, reinforced packing tape, Kapton tape and other stuff. Is there a good reason for me to buy a roll of Kapton tape? Are there any other products I should be considering?

I know Kapton is for high temperatures but are my nickel strip going to get hotter than the cells?

I can understand for really high discharge packs but this one should not be stressed too hard.

Second issue found: I was checking the motor mount hole to sprocket spacing to make sure I can use the two chain side motor mount holes for alignment. That looks good but getting the motors right next to each other, the sprocket on my new motor looked thicker and with wider tooth spacing. I took it to the chain and sure enough, the chain pitch seems too small to wrap around the new sprocket. It looks like I will be needing a 11, 12 or 13 tooth sprocket to get the drive working.

It's a $9.95 piece but $9.95 I was hoping to avoid spending until I saw how the 9 tooth sprocket performs. I was guessing that it would have crazy torque with a slow top speed and I could pick my new sprocket to get top speed where I want it.

Other than that, I saw a product sticker from Razor on the bottom. If I read it right, my Pocket Mod is version 01. I think they are up to 31 now. I did notice that my scooter isn't made with clip on nuts. I saw one video reviewer complaining that assembly was difficult because you had to align all of them. Not for me.

So far, there is one annoying nut/bolt that holds on the rear bodywork behind the seat and another nut/bolt holding on the rear brake. The bracket that holds on the chain guard seems to be welded on the inside of the rear dropout, it looks dumb, I will remove it. I think I can go to the hardware store and get some square nuts that will be less annoying for the rear body mount and rear brake mount.

The ugly brackets are gone (mostly).

I bent them back and fourth and let metal fatigue do the job for me. Some small remnants remain but you'll never see them unless you look for them.

Metal fatigue will do that for you on those front forks too. Probably around 30mph.

Though I don't think you'll get there if you stick with the stock ear ratio and run the same rpm on the motor, you'll get to 10mph quickly but you'll stay there. What is the KV of your motor and what voltage will you run it?

I do recommend doing away with both freewheels, on the motor and on the rear wheel. I picked up those bikes from people who'd seen them break running 250w motors. I can't imagine they'll survive 1800w. I don't think I've had a 1st generation, but I doubt they're different.

Well I'm not planning to bend the fork like I bent those brackets. Just looking at the fork, it's about what I would expect for a kids BMX style bike and the welds are complete unlike those holding on the tabs for the chain guard.

I'm not planning to cruise much faster than 20 mph and a 25 mph top speed would be plenty. The stock motor has an 11 tooth sprocket and the motor speed is rated somewhere around 2,750 rpm. The MY1020 brushless motor is rated at 4,500 rpm and probably 3-4x the torque of the stock motor. I was hoping that I could use the 9 tooth sprocket to determine what gearing I should buy but I guess I have to go to 11 tooth right away and hope it's not too fast (top speed).

The motor never had a freewheel, old and new just have a sprocket on a shaft. The rear wheel is the old style which can use a 16 tooth bicycle freewheel instead of the cheap four hole freewheels that tend to disintegrate frequently.

If the fork does have issues, I think I know of a possible upgrade but I'm not worried. It's going to be a commuter on smooth pavement, not a dirt bike. I'm honestly more worried about snapping a chain than any other problem due to the power increase.

I guess I just know how it's going to be ridden. It will be fine. I'm probably even going to a 3" wide tire to give it a bit more air spring, for comfort, not durability.

Oh, I just ordered my battery spacers from China with expedited shipping.

I think that is the last thing I need that has a longish lead time.

I still need a LiPo and charger to power my battery spot welder. Hopefully I can source those in the US and have them here before my battery spacers and heat shrink arrive.

Well, good ole' internet in my neighborhood is bad tonight. Can't find it, but I'm sure the Razor Bellezza fork would fit, I'd guess it's the same frame. Should be more solid AND you can put disc brake and wheel on, so you could stop too.

I will probably add a front rim brake after I get the motor, controller and battery conversion done.

If that's not enough, I think I know of an inexpensive suspension fork with caliper mounts I can adapt and nice upgrade wheels with rotors.

I don't think I'll have to go there but there is a path and it's not very expensive, probably less than $150 with hydraulic disk brakes unless you want brake switches.

That will start to make the value proposition look a lot worse but like I said, I don't think I'll have to go there.

I think I figured out my battery construction.

I'm going to use 3/4" aluminum half round covered with heat shrink to fill in the gaps from the egg crate stacking, glue each cell to its spacers so there is no movement, wrap the exterior with heavy tape and then a layer of thin padding. At the top I'm going to use large chunks of nickel lattice designed for square layout 18650s and in between the nickel I'm going to add hand cut insulating material, then the top is going to be sprayed with plasti-dip to encapsulate it without blocking the cell vents because the insulator will prevent the plasti-dip from getting down in the cells much. I'll do that top and bottom with a full sheet of insulator over the top (and bottom) with more thin foam and heat shrink covering the exterior.

That thing should turn out solid.

The BMS wires evidently use a JST-XH connector. I will get a crimper and terminals so I can trim my wires to length, add new terminals and then put them in to the connector body so it won't have any excess spaghetti.

I'm going to get a Meanwell HLG-240H-54A LED power supply for my battery charger. I might mount it next to my motor controller so it goes with the scooter.

I will probably turn the voltage limit down to 51-52V so that I can use that battery cycle sweet spot between 3.9V and 3.5V where cycles dont degrade battery capacity as quickly.

I think I'm going to take the sprockets off my motors to verify the mounting so that I'll be ready to order my new sprocket.

If I get my mechanicals together this week, I'll be able to start on the battery next week but I'll be waiting on heat shrink to arrive before i can button it up. Hopefully it will be done some time in may.

If i had started on this in mid March, i wouldn't be rushing and would probably already be done.

I got the sprockets off. The armature shafts are reverse threaded by the way.

It looks like the old motor has the same shaft diameter but it doesn't, it has a sleeve spacer. The shaft is a single D cut to keep the sprocket from rotating relative to the shaft. The new motor has a double D cut shaft and at first glance it looks like the single D sprocket might be able to fit over the double D shaft but it doesn't.

At least I can measure the new motor shaft to be sure I'm ordering the correct sprocket.

So I ordered a charger for the battery.

For the spot welder, I need lipos so I bought a few and a charger with a 24Vdc power supply.

While i was shopping, i bought a portable thermostatic soldering iron that can run off that 24V power supply or a small 6s lipo i bought. I also bought a hot glue gun that runs off a 3s pack too. Just a little portable tool kit.

I have ordered everything that i will need soon and i have tried to order as much as possible from USA retailers so that shipping won't be messed up.

My critical path looks like the egg crate cell holders i ordered. I couldn't find a USA source so i tried to find a Hong Kong source with expedited shipping. I'm not sure if that is going to work out.

The stuff I haven't ordered yet is not needed for testing but I'll look to see what might have to be ordered from overseas and try to get those on the way so they dont create additional delays.

I'm going to make a list of tasks also.

My wheels are nice cast aluminum but they are tarnished pretty heavily. I will probably Scotchbright them and paint them.

The plastics are ok but I think I'm going to try a bit of body work and a vinyl wrap.

I might paint the handlebars too. The chrome isn't great so it probably won't clean up as well as a nice coat of paint. If I do that, I'll probably get the fork legs too.

A few spots of the frame need a little paint to cover up cracks and exposed metal. I might strip everything down and paint it, maybe even replace the headset while it is apart but that might be too much.

New tires and tubes are on the list.

Probably a spare chain, maybe a new tensioner.

A thumb throttle is probably more ergonomic than the half grip twist type.

A step down voltage converter and good lights might eventually make the list.

I think I have decided on a 13 tooth sprocket.

I found a gear ratio calculator and theoretically that gives about a 27 mph top speed at 4,500 rpm but I'm not sure if that is a no load RPM rating. Hopefully it will be able to do a low power cruise around 19 mph at 500 watts which is what another calculator suggests (on flat land and a high estimate of the cargo load).

That should be perfect for cruising side streets and avoiding traffic. Using about half a charge between 40-90% battery capacity, that gives an easy 19-20 miles of range and if I need to go farther, up to around 40 miles if I top up the charge and run the battery low.

The battery charger is about 200 watts so if I plug in for 2.5 hours, my battery is going to be full when I leave for a possible 40 mile round trip without stressing the battery much.

I was watching a video showing the same motor/controller in a mobility scooter and saw a feature that I forgot it had, three speed operation. With a pretty simple switch, I can limit the speed. I'm not sure if that limits rpm or controller current but it will be interesting to see how that will change speed and range.

I came up with a theme for the wrap.

I want something highly visible and interesting so that people pay attention to it instead of ignore it on the street and cause an accident.

First idea was a color shift wrap but there are no colors I'm in love with.

Then I saw a Tron style vehicle wrap with blue reflective tape.

I think what I'm going to do is use a dark color shift wrap with blue reflective accents to make my
Pocket Mod in to a Light Cycle.

Very geeky and unique enough that no one could steal it without having very obvious stolen goods or removing the wrap and having an ugly scooter with obvious signs of body work.

In the end, I think the sight of an adult on a Pocket Mod is unusual but on a Light Cycle, it's just eccentric. It's not necessarily better but people will judge it in different ways.

Here is a picture of the wrap I'm thinking of:



Here is a picture kind of like the effect I'm thinking of:



Maybe I'll add some cheap underglow as part of the lighting.

I got my nickel strip.

Batteries are supposed to arrive by tonight but I bet UPS will screw it up and they won't arrive until Monday. The real gating issue is spacers from China. I am also waiting on lipos for the spot welder but they are coming from a US warehouse so it probably won't create a delay.

I found a chart with current ratings for different nickel strip sizes.

My 7mm by 0.2mm is supposed to be acceptable for 9.6 amps and my series connections will be essentially three strips so 28.8 amps is ok and 6.4 amps per strip is good for a 19.2 amps with no worry at all.

My controller will draw 33 amps max so not great for my nickel if I push it really hard.

I think what I'm going to do is cut my nickel long, spot weld it and then fold the excess back upon itself with plenty of spot welds to parallel the connection. In an ideal world that would put my connections at 5.5 amps per strip, so under the maximum of the good range.

This would make my battery the weakest link, ideally I would keep current draw under 5 amps per cell but full output would be about 8.25 amps per cell, ok but a little outside the happy place for discharge with my M50T (I think) cells. Luckily I intend to have some nuance with the throttle so I'm not worried about occasional short term discharge peaks because 90%+ my battery will be well inside it's happy place.

One more question answered. I kind of wish they would make custom slotted nickel specifically for my egg crate pack of 21700s with no big squares cut out of it. That would allow a very good connection without any doubling of the strip. The slots would be mostly so I could have some reference to align the spot welds but also to make welding easier. The 4p 18650 nickel is my best option failing that so no second guessing.

I got my batteries and aluminum half round. The batteries are the LG M50T cells.

Weighing by hand, I think my bare cells weigh a bit less than the old 24V lead acid batteries. After adding nickel, spacers, insulation and padding it will probably weigh a bit more.

The motor and controller are a few pounds heavier too.

By the time I'm done it will probably weigh 5-10lbs more, very acceptable.

If I can believe my tracking info, I'll get some heat shrink and my thumb throttle today. The heat shrink is to insulate and increase the size of my 3/4" half round. Which will fill in the gaps on my egg crate style battery pack. With my revised stacking plan I only need two half round spacers. When I wrap the exterior, all of the batteries are going to be locked in. The small amount of hot glue holding it to that point will become redundant.

I hope the throttle is a reasonable piece. I want to maintain a solid grip on my handlebars and use the dexterity of my thumb to control speed. I got the type that pivots perpendicular to the bars rather than coaxial. I think that will be more natural and ergonomic.

(Edit) the tracking was correct, I have my throttle and heat shrink.

Probably the best approach to this project right here. No mid drive, a hub would do nicely. Especially with the disc brakes. Only thing missing is the fork replacement.

https://www.amazon.com/Electric-Conversion-Scooter-Accessories-Brushless/dp/B07TTP9Z8H