NX in NU?

Timothy Hunter /

I have a NU50M with a big bore kit in it. Would swapping a NX bottom end/transmission give be some higher gearing? Would it be higher than the malossi race gears?

Re: NX in NU?

I got a lot more gearing by replacing the transmission gears and relacing the rear wheel with a spare front wheel rim and spokes.

The NX was the predecessor to the urban, don’t know what difference there is in the transmission- they look pretty similar.

Re: NX in NU?

Timothy Hunter /

That's why I want to swap the transmission. The NX has much smaller tires, but the same 30mph top speed. I know the NX and NU share the same motor that's different than the rest of the Expresses. I guess I just go get the NX. If the swap doesn't work out, I can just fix it and sell it.

Re: NX in NU?

Re: NX in NU?

Timothy Hunter /

Yeah the extra idler is what I believe gives it the much higher ratio. The input and final drive shafts look the same, so it might be possible to swap transmissions.

Re: NX in NU?

Jack Rutherford /

You are dealing with a much smaller belt on the nx so that would kill your top end. Then going from a 10” to 14” rear tire will kill acceleration assuming you can mount an nu50 rear on to that engine transmission given the hub and the shorter transmission.

Re: NX in NU?

Terbo Speghetti /

You can just run a 14" wheel on an nx, I've done it. Gearing was one tooth higher than the malossi gears of the last guy I talked to is right.

Can't run the electric start unless you've got a really low profile tire tho.

Re: NX in NU?

Terbo Speghetti /

Also the nx is shorter, so your Urban will look funny and maybe handle kinda weird.

Best bet is to do all this on an old express tube frame. Less likely to twist anyhow

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