Motor Upgrade

[InsanityOvrload]

Well I can unfortunately confirm that the same motor used as a drop in upgrade for the RadRunner Plus (since both the expand and the plus have the cord coming out of the opposite side of the motor compared to the rest of the RadPower models) does not work for the RadExpand 5. It drops in and fits just like the stock motor, however unlike when you do it on the RadRunner Plus there is a bit of wiggle room inside the housing on the Expand 5.

The motor will work at first and seem fine, however while riding it can potentially cause the planetary gears to slide down the shaft and expose the key if the motor slides around inside the housing. Without the key in the planetary gears it'll shoot out of the the shaft and bounce around inside the motor while running and could, like mine did, lodge itself into the nylon gears completely destroying them. It looks like this happens because they made the location the planetary gears rest lower in the housing on the expand than on the housing in the RadRunner Plus which lets the motor sit lower in the housing and causes a gap at the top where normally it'd be flush. The stock motor of the Expand is also too tall to fit into the housing of the Plus; this should confirm that they made the motor longer inside the housing for some reason.

I originally thought I had a faulty motor and received a second one and had the the same thing happen again and then received a third motor. After realizing the problem I put a couple washers on the shaft between the top of the motor and the lid of the housing to make sure it didn't slide up or down the shaft. This worked for a month or two until a week or so ago when the bike motor just suddenly stopped rotating. Turns out the washers wore out a bit and allowed the motor to move up the shaft just enough for the key to come out and lodge itself into the nylon gears like the first two.

I've since swapped back to the stock motor and have had no issues, but I'm locked back to 22 mph top speed rather than the 35 mph I was getting.

Anyone have any ideas or is a motor upgrade on the expand just not possible due to that weird gap between the upgraded motor and the lid?

[Eric7]

Thanks for the information.  But I am not sure what you are talking about.

Which motor drop in are you referring to? Is this something like a motor advertised as a "true 750 watt" motor?  I assume 3rd party and not from Rad?

Or is this something from Rad?

[pnwetc]

Thanks for the information.  But I am not sure what you are talking about.

Which motor drop in are you referring to? Is this something like a motor advertised as a "true 750 watt" motor?  I assume 3rd party and not from Rad?

Or is this something from Rad?

Not OP, but this is probably a reference to the 1000w Bafang from Eunorau that some folks have successfully installed in their Radrunner Plus. This is distinct from the "true 750w motor" some have installed on other Rad bikes, most notably because the connection cord comes out the opposite end (as is true of the stock motor in the RR+ and the RadExpand 5).

[InsanityOvrload]

Thanks for the information.  But I am not sure what you are talking about.

Which motor drop in are you referring to? Is this something like a motor advertised as a "true 750 watt" motor?  I assume 3rd party and not from Rad?

Or is this something from Rad?

Not OP, but this is probably a reference to the 1000w Bafang from Eunorau that some folks have successfully installed in their Radrunner Plus. This is distinct from the "true 750w motor" some have installed on other Rad bikes, most notably because the connection cord comes out the opposite end (as is true of the stock motor in the RR+ and the RadExpand 5).

Yes; that motor is exactly the device I am referring to. Its a common upgrade for the Plus model and I was hoping it would also work for the Expand, but no luck.

I'm thinking I might just go all the way and lace the 1000w motor into the current rear wheel. Since the problem is that the internals of the housing for the two motors are different if I just unlace the stock housing and lace the 1000w motor in it should all work fine. Both the Expand stock housing and the 1000w housing are the same size externally after all.

[Eric7]

Not OP, but this is probably a reference to the 1000w Bafang from Eunorau that some folks have successfully installed in their Radrunner Plus. This is distinct from the "true 750w motor" some have installed on other Rad bikes, most notably because the connection cord comes out the opposite end (as is true of the stock motor in the RR+ and the RadExpand 5).

Thank you all for the clarification.

This is something I had not appreciated.  The Rad Expand and the Rad Mini ST2 do not have interchangeable rear wheels. In fact, the wheels are very different.  One has the electrical cord come out on one side and the other has it coming out the other side.  Now I look more carefully I see the differences.

Thanks again.