Build question on 29er

[sourbeer]

im getting ready to do a build and would like to use an Electra moto 3. It has 29" wheels but disk brakes on front and rear. I realize I will need to remove rear disk to mount the drive sprocket to wheel. It also has a 3 speed hub. Is there any reason I couldn't use this for a 2 stroke build. Space in the frame for motor, frame tube size ?

My son and I are doing these together and I want to build a sweet bike.

The other choice I had was a felt burner but it has coaster brakes only. Was a lot cheaper though.

 

[sparky]

I haven't been here in a while.

But if I really loved my son, I would get him a belt drive kit with a Japanese engine... and more than likely a 4-stroke. Well, if it was his first... I'd probly get him a 2-stroke and then I could get him a 4-stroke motor and let him adapt it later on.

 

[crassius]

hard to tell from pic. but that looks like a 32 spoke wheel - makes sprocket mounting harder

 

[sourbeer]

hard to tell from pic. but that looks like a 32 spoke wheel - makes sprocket mounting harder

Specs indicate 32 spokes. Is that a deal breaker ?

 

[HumanPerson]

Hub adapter? Several vendors sell them. I'm really not sure who to mention but a search for hub adapters should point you in the right direction.

 

[FurryOnTheInside]

http://custommotoredbicycles.com/sprockets_for_disc_brake_hubs_universal_disc_sprocket_adapter

 

[sourbeer]

Looked at adapters and they seem to be a good option. How will I know what spacer I need? Measure hole spacing on the actual disc brake? Or are there some standard sizes for discs?

 

[FurryOnTheInside]

Looked at adapters and they seem to be a good option. How will I know what spacer I need? Measure hole spacing on the actual disc brake? Or are there some standard sizes for discs?

You have a 135mm O.L.D. hub? Or some other size?
The usual position of the rotor mount face (I checked two 135mm multi-speed cassette hubs) is 52.5mm left of the bike's centre line.
(Measure your hub width and figure out your rotor mount position to be sure)

You have a Grubee or generic non-Grubee 2 stroke?
The Grubee or generic non-Grubee drive sprocket has its inner face at 35mm left of the bike's centre line.
(You should double check, I measured only my generic non-Grubee)

The kit sprocket is usually attached to the spokes and can be run with dish in or dish out to achieve a decent alignment. The adapter at the top of that linked page allows you to space the sprocket (nine hole, or three hole MB sprockets) with washers/spacers on the sprockets's fixing bolts. You shouldn't need any other products from that page as far as I can imagine. You may have to open the centre hole in the kit sprocket so it can pass over the rotor mount (and clear the spokes!). You surely need longer rotor bolts due to the thickness of the adapter.

 

[sourbeer]

Wow thanks for all of the help. Would I have an option of a jack shaft setup on the right side that would allow me to utilize the 3 speeds along with keeping my rear brake?

The kit i am looking at currently is grubee gt5a 66cc skyhawk from a local vendor.

 

[FurryOnTheInside]

Wow thanks for all of the help. Would I have an option of a jack shaft setup on the right side that would allow me to utilize the 3 speeds along with keeping my rear brake?

The kit i am looking at currently is grubee gt5a 66cc skyhawk from a local vendor.

Yes the Sick Bike Parts Shift Kit is well liked by forum members. Cheap copies of the early versions are not so well liked.
You won't need the Ultra heavy duty (UHD) freewheel so that will save some expense, you probably want the HD for reliability. The UHD is for derailleur gears and costs a wee bit more which is why I'm bothering looking at rotor mount sprocket adapters.

Will your planetary gear hub take the torque? idk. Ask @KCvale about your specific hub as he builds lots of internal 3-speed bikes. Certainly worth having gears if you can do it IMHO.

(You can (probably) still have the rear disc brake and a left side fixed gear motor drive, if you want to wait until later on to get your SBP shift kit.)