Looks like this is my next project: Razor RSF650

My main concern would be whether any of those motors have fans in them. Maybe you can ask them. I've never seen a fan before on an MY1020 style motor in all my research. I can tell you for sure my motor would be a steaming puddle of chinese copper by now if it didn't have one.

Also be sure it's the same length. There exist motors with the same diameter and appearance but roughly an inch longer.

Chain tensioner mod

What I did was removed the two bearings used as rollers from the tensioner and dug through my bin of miscellaneous cooling hoses from various vehicles I've disassembled. Found a hose with a slightly smaller inside diameter than the bearings, pushed them in and trimmed to length. It's a tough hose, definitely not of the sort you'd find at a home improvement store. You can use a zip tie or something similar to hold the tensioner up if you find it slaps when going over bumps. Helps keep the chain on track.

Also I'm curious if you're RSF has the same manufacturing defect that I've found on both RSF's I've worked on.

Appears the jig they used to position the motor mount tabs is out of spec for MY1020 style motors. This causes the one bolt on the drive side to pull the end casing out by a couple millimeters. It's obvious just by eye. This tweaks the bearing on this side and cannot be good for it. You can see I've used an M6 washer and an actual motor mount shim to take up the space.

Edit: Just checked electricscooterparts again. Those 60v motors have the same kv as the mophorns we were discussing. It's running faster because the voltage is higher. However they have different end caps designs. The same as the Unite motors. It'd be worth checking if they're made by Unite. If so I'd stay away from those.

For science and stuff. Unite MY1020 650W stock Razor RSF650 motor






Couple thousand miles on it. Still has a good amount of brush life left. That's about the best I can say about it.

Inductonaut said:

Edit: Just checked electricscooterparts again. Those 60v motors have the same kv as the mophorns we were discussing. It's running faster because the voltage is higher. However they have different end caps designs. The same as the Unite motors. It'd be worth checking if they're made by Unite. If so I'd stay away from those.

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Good info! I asked them if they were same motor but they said they were different. But makes sense the 60V is faster because of higher voltage. If you ask me, that's messed up that they would do that. If it's the same motor, then just say so.

Great pics and also tip about the tensioner mod with the hose.

I cant take pics of my RSF650 because I don't have one yet. But soon, and I will be able to see what you are talking about how the motor mount needs a shim since it's not true.

Signed up for both credit cards today on Amazon.com and got two gift cards, one for $100 and the other for $60. Got instant approval.

Ordered the following:
1) Razor RSF650 - https://www.amazon.com/Razor-RSF650...ld=1&keywords=razor+650&qid=1575045847&sr=8-2
2) Mophorn 60V 2000w electric motor - https://www.amazon.com/gp/product/B07ZS8NTL9/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
3) X-PRO 270mm Rear Gas Shock Absorber - https://www.amazon.com/gp/product/B00NK9Z7ZG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1.

Total: $533 !!!!!!!!!!!

I will post pics of the internals of the motor once I received and when I get the chance!!! I'm really hoping when I crack it open, that it has the fan blade insert for cooling.

Good deal! Good luck on the motor purchase.

Regarding the shock, the eyelets are much heavier duty than stock and need a small amount of filing or sanding just to the flatten them a little bit top and bottom and then it's a direct replacement. When you get it you'll see what I mean. I just did a quick pass or two with a belt sander but any method will work. Really didn't need much.

Also keep an eye out for bolts and fasteners that might loosen up over the course of a few rides. There didn't seem to be much rhyme or reason for which got loctite and which didn't. Footpegs and kickstand on mine began to loosen on their own.

Small details but it'll keep your bike good and solid.

New 14 tooth motor sprocket is due in tomorrow. Also picked up a "link and a half" master link to try getting chain length spot on for regen braking. Will update.

1) How about the chain? Is the #25H enough or is something tougher recommened? I will be running a big 72V lithium ion battery and probably a Sabvoton 72150 controller.

2) I thought I read somewhere the front bearings sometimes give out because the factory tightens the front wheel too tight in the fork. Your experiences?

3) With your current setup, what is the range for your bike?

I'm anticipating this is going to be the most fun out of all my bikes.

Preliminary results with the 14 tooth sprocket 47.0mph Closing in on 3x stock speed. :lol:

I think I can squeeze another mph or two out. Went out in the rain and wind with a not quite fully charged battery at 73v. Also wearing my motocross gear just in case. Happy to report it ran smooth and stable. In better weather I'll be able to go for a tighter tucked riding position and without the bulky gear. Hit the boost switch a little late at 30mph and ran out of straight. Next run boosting at 15-20mph might be better timing.

It's been a few weeks with my #25H chain and I gotta say I haven't noticed any stretch so far. Seems to be working very well. It's a cheap chain so worth trying I'd say.

Yeah the bearings needed replacing within the first 1000 miles on both RSFs I've worked on. When you replace them just do front and back. Over tightening actually shouldn't be the problem because there is a steel axle sleeve inside the hub to sandwich the inner bearing race properly. My opinion is they're just rather cheap chinese bearings. It's a known issue like you said. We tightened our axles pretty darn tight without effecting the resistance of the bearings.

I've got a lightweight pack only 5ah. Running the tight course I have it'll actually run for 40-50 minutes no problem. Cruising at speed range is more like 5-6 miles. I'm using 5ah lipos because they're going to be used as building blocks for a much larger battery for my full size dirt bike.

Your setup should be a beast. Looking forward to seeing how you have it setup and hearing the results!

Two thumbs up: Thanks for the updates. The bike is stable at that speed?
With your initial testing of the 14 tooth sprocket, do you think you are going to stay with it or go for a different one?

All of the tips are priceless!!! Much appreciated.

1) Red loctite
2) Upgrade Motor
3) Spray motor with Insulating paint
4) Shim motor at mount to be true
5) Rear Shock - XP pro
6) Rear Shock mod for fit
7) Wheel bearings
8 ) Tension w/ rubber hose
9) Welding freewheel sprocket
10) Keep front fork
11) #25H chain upgrade with "link and a half master link"
12) Upgrade to controller w/ more amps
13) All weather tires
14) Different sprockets for different ratios - 11 tooth - 1:7.27, 14 tooth - 1:5.71 allowing the rear wheel to spin much faster.
15) Wear safety gear

rockstar195 said:

The bike is stable at that speed?

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Just a reminder that stability can be not so much in the eyes but in the hands and seat of the be-sitter. I find shocked forks and that better rear shock combined with those fair sized wheels promising, but it's still a smallish bike. And don't forget those hydraulic brakes, maybe from a 110cc Chinese dirtbike,

rockstar195 said:

With your initial testing of the 14 tooth sprocket, do you think you are going to stay with it or go for a different one?

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WIth the 2000w motor try out the 11t first, it's an improvement over the 650w but still not incredibly muscular. I think you'll be happier getting to cruising speed quickly than with having a higher top speed you reach slowly. There's still something upward double the RPM potential with just the motor swap.

Dauntless said:

rockstar195 said:

The bike is stable at that speed?

Click to expand...

Just a reminder that stability can be not so much in the eyes but in the hands and seat of the be-sitter. I find shocked forks and that better rear shock combined with those fair sized wheels promising, but it's still a smallish bike. And don't forget those hydraulic brakes, maybe from a 110cc Chinese dirtbike,

rockstar195 said:

With your initial testing of the 14 tooth sprocket, do you think you are going to stay with it or go for a different one?

Click to expand...

WIth the 2000w motor try out the 11t first, it's an improvement over the 650w but still not incredibly muscular. I think you'll be happier getting to cruising speed quickly than with having a higher top speed you reach slowly. There's still something upward double the RPM potential with just the motor swap.

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I too am questioning about having the rigid RSF650 fork vs the MX650 "shocked" fork. Not all the roads and streets that I ride on are smooth pavement. Sometimes I have to ride on the sidewalk and other uneven surfaces. Not until I get and ride my RSF650 will I be able to tell for sure, but since I tinker alot, I'll probably end up getting the MX650 fork to see the difference. Maybe someone else out there can throw their 2 cents in about this topic.


The following was found at the bottom of the thread of this webpage: https://www.pocketbikeplanet.com/118-electric-pocketbikes/101146-rsf650-upgrades.html

"If you want to upgrade the RSF650 front fork, go with the Razor MX650 replacement forks (found a used one on eBay). This will fit directly to the bike itself without any modification. HOWEVER, you will need to replace the brake disc from the MX650 which also bolts directly on in place of the RSF650 disc. THEN, you'll have to adjust (bend) the caliper bracket to allow for the RSF650 stock tire increased width from the MX650 stock tire. Just be careful how much or how little you bend it away from the hub, spacing is crucial. I learned the hard way by pounding and readjusting it a lot before i got it in the right position in relationship to the mounted caliper and tire hub. Be aware that the RSF650 tire is going to be a tight fit in the MX650 front fork but it will roll freely without any binding. Forget about using any front fender though. I upgraded to 1600W and 48V and it takes off if you're not very aware of your throttle control as you roll it on. The added front suspension (and decent rear suspension) to the RSF650 is awesome, along with the added power. I also added a larger rear sprocket for more torque...which this thing has plenty of now. I'm just under 200lbs and I can get up to 30mph on this bike now (on level ground). I'm still anxious to get this off-road (as was my original plan for the upgrades)."

A lot of good points Dauntless. :thumb: Definitely a small bike for those speeds. I wouldn't recommend trying to commute like that. More of a thrill seeking thing... I also have a lot of saddle time on this bike. Found many of its limits at low speeds as I gradually upgraded it.

By stable I mean speed wobbles did not set in nor were there any vibrations from the tires. I felt confident in going faster.

One thing to remember about this bike is its somewhat unconventional geometry with the giant swing arm pivoting just in front of the seat. It means the whole bike pivots in the center making the shock work front and back to a degree. You feel the bumps in the bars but the front wheel tends to maintain contact rather than bouncing like a rigid frame. The dampened shock improved the feel from the front. Reminds me of the early monoshock dirt bikes with centralized shock absorbers.

Anything 40mph and under the MX650 forks are probably fine. For sidewalk riding it'd definitely improve comfort. The guy that did that mod was barely reaching 30mph and I agree, it'll work great at that speed.

The 14 tooth is less punchy but it works fine. At 15kw it picks up speed alright it just doesn't try to throw you off the back as hard when you hit the boost switch. :lol:

That said this is an experiment to see how fast I can get this motor to go. Unless you want more speed there isn't really any reason to sacrifice torque for rpm that you won't use. I'll probably reduce it later for more wheelie action.

With the higher voltage pack you'll be running (mine is 66v nominal) you might find you can reach 40mph with your sabvoton and a 9 tooth. Now that would be an impressive little bike.

Wanted to see just how much power could be squeezed into this bike. Unfortunately I think the fairing would need modification to fit a Sevcon size 6. :lol: Maybe a size 2 or 4 would fit.


Width is fine it's just a few inches too long.

I don't have much to say in regards to the last post, but for the pivot point (circled in orange - see pic below), does that have a bearing that needs to be upgraded? Or does it have to be greased?

Seems like a plastic bushing. I haven't taken it apart yet but I have wondered about it also. I've printed bushings like that before so I can replace it but it might be worth checking if it's actually greased or not. Hasn't seem to have worn much if any yet.

If you plan on using the original power switch be sure to wire in a precharge circuit to limit inrush current. I have mine operating through a stainless steel momentary switch that fits perfectly into the hollowed out charging port.

Without precharging the contacts of the switch will weld half open. I encountered this when I upgraded from 12s lipo to 18s. The higher voltage required longer precharging of about 20-30 seconds compared to 15 seconds. I was able to force the switch back but integrated led light flickered and eventually stopped working after that.

It could also be wired without a momentary switch with just a resistor across the contacts but I decided against this because I liked the idea of being able to quickly cut all power if needed.

:thumb: When I get my bike, I'll check it out (pivot and switch). If it is a plastic bushing, maybe it can be upgraded to a performance bushing like the ones offered by Energy Suspension.

Very good on the explanation on how the suspension behaves on this platform.

As far as the Sevcon, looks like a beast of a controller - will have to look it up. Makes me want to put off ordering my second Sabvoton 72150 until I can get measurements and will be positive it will fit. This will be first time I'll be working with a motor like this..... it gets fun at around 80A? The Sabvoton I have now has a max of 350A for phase amps, and a max of 150A for battery.

I might try at least one time to see how it does as a commuter.

Like these pity they not uk bound
Dualtron ultra hubs would drop straight on this loads on aliexpress, with a 20s batterys feeding around 50amps battery to 2 controller 100amp battery max giving around 7.5kw max power with out having a melt down straight away, you be taking an adult to 70mph top end no probs long as they under the 200lbs mark the frames max design weight.

The bushing can be swapped to a oil impregnated bronze type if it's failing fast straight swap get the dimensions.

Ianhill said:

You be taking an adult to 70mph top end no probs long

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70 MPH ?!?! Now thats crazy!

Im still deciding if I will be going with a Sabovoton 72150 or with a smaller cheaper controller. Can anybody suggest one? The sabvoton may be overkill for this.

I took one of those 1600w motors to 4.4kw with a sunwin trapizwave controller on a electric scooter so plenty of drag and it topped out at 48mph I done that for a full discharge covered 14 miles in 20 mins or so and used about a kw hour the motor was toasty but still fine for how much of a kicking it had took key is to key the rpm up to stop a melt down at that power level I was getting close on 8krpm at 16s 58amp if I remember correct.

Nice!

Makes me wanna go with the Sabvoton. Or something like a Sabvoton.

Received the X-PRO 270mm Rear Gas Shock Absorber today. MUCH bigger than the DNM RCP3 rear shock that's on my Enduro EEB. Still waiting on the motor and bike.

Inductonaut said:

Kv of the 48v 1800w version: 4500rpm/48v=93.75kv

Kv of the 60v 2000w version 5600rpm/60v=93.33kv

If the rpm specs are true it's likely the same winding in the same casing. Maybe you could get one, crack it open and find out for us!

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Received the motor today and cracked it open.

View attachment 3

BY1020? This is from Unite?

It's a Mophorn, bought from Amazon.com.
Looks exactly like Inductonaut's 48v 1800w motor on page 1, and it probably is - they are just advertising it under different running specs.

Here:
https://www.amazon.com/gp/product/B07ZS8NTL9/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Seen that rotor type on aliexpress the old type I had with single piece magnets but I never had one come off even at 8krpm.

If you really won't to give the motor a world of pain wrap the rotor with a thin layer of fibreglass sheet or even better carbon fibre to help keep the rotor in one piece to push it close to 9krpm and encapsulate the end turns with a thermal transfer compound to stop the end turns melting and then wrap the motor with a copper pipe heat jacket and flow water around to to take the heat away from the stator could properly take it over 5kw specially if you get a temp reading from the windings to monitor potential meltdowns on the run.

Ianhill said:

Seen that rotor type on aliexpress the old type I had with single piece magnets but I never had one come off even at 8krpm.

If you really won't to give the motor a world of pain wrap the rotor with a thin layer of fibreglass sheet or even better carbon fibre to help keep the rotor in one piece to push it close to 9krpm and encapsulate the end turns with a thermal transfer compound to stop the end turns melting and then wrap the motor with a copper pipe heat jacket and flow water around to to take the heat away from the stator could properly take it over 5kw specially if you get a temp reading from the windings to monitor potential meltdowns on the run.

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Those are some crazy hot rodding tips that I've never heard of. You really should get one of these bikes and find a way to get it shipped over there somehow. I'm not trying to test the limits of the hardware, just trying to have a fun high performance bike that will last.

Here are my latest modding pics to the motor: