Updrive Conversion

The conversion is not hard it’s just a little time consuming and awkward to do. It will test your patience

Please note that the following is for informational purposes only. It is what we did to convert our ELF to the newer Updrive 3-chain system because our NuVinci axle broke when it was on the Rear Wheel. We assume no responsibility for any installations to correct the NuVinci Axle breaking problem. 

The Updrive is a 3 chain system. It is the current standard on all newer ELFs. In the updrive system the motor and geared hub (NuVinci CVT) are mounted under the seat. This up drive system has 3 bolt on cogs. They are available online and made by Surly or Problem Solvers.

The rear Wheel Hub, 22t Freewheel, Spacers, 12mm Bolt and Nut were purchased from Bikeman.com. We’d like to thank Bikeman for his guidance and the prompt shipping of the parts that we needed.

Two additional ELF “Sliders” are needed to make this conversion. They can be purchased new from Organic Transit. Many times you can find used Elf parts for sale from the classified section of Anyone Can Bike. Always check there first.

Motor Chain

The motor connects to the right side of the rear wheel with a 3/32″ chain. The rear wheel has a 22 tooth ACS Crossfire freewheel on it. The cog on the motor is an 18 tooth bolt on cog. What kind of chain is it?

Geared Hub Chain

The mid drive geared hub (NuVinci) is connected to the left side of the rear wheel with a 3/32″ chain. The rear wheel has a 20 tooth bolt on cog and a spacer to keep the chain away from the rotor of the disc brake. The chain is goes to an 18 tooth bolt on cog on the left side of the NuVinci. There is a spacer between the cog and the NuVinci.


Inorder to use the motor from the rear wheel hub setup it will need to have the cog removed and placed on the other side or have the motor reverse directions. The motor and chain drive will be on the opposite side from where it currently is and spinning the opposite direction. We happened to have another motor and just placed the new cog on it instead.

Pedal chain

The right side of the NuVinci has an 18 tooth threaded cog with a 3/32″ chain that goes to the pedal chain ring.

Parts list:

Assuming the NuVinci still has its 18t freewheel Cog, remove the Bolted on Freewheel. Ours was a 27t DICTA.

2 additional Sliders for the NuVinci to be mounted onto the main frame – Organic Transit or Used from Anyone Can Bike Classifieds

1-Surly Single Cassette Cog 3/32”22t freewheel for the right side rear wheel- Bikeman.com

1-Surly Single-Speed Kit, Spacers and Lockring- Bikeman.com

1Single Speed 20t Bolt on Cog for the left side rear wheel – Problem Solvers

1- Booster Conversion Kits – Problem Solvers

1- Single Speed 18t Bolt on Cog for the right side of the Motor (remove and discard the old screw-on Cog) – –Problem Solvers 

1-18t Bolt on Cog for the left side of the NuVinci

1-12 x 142 TA 36-hole cassette Hub – Bikeman.com

1-12mm x 190mm Bolt- Bikeman.com

1-Bumax 88 M12 stainless nut- Bikeman.com

1-set M12 shim washers – Bikeman.com

1-additional Chain tensioner – Organic Transit or Used at Anyone Can Bike Classified

4-sets of bike chainsWhat about my chain?

Organic Transit made an Updrive Kit at one time. This shows the parts for it including Motor and NuVinci. This kit is no longer sold by Organic Transit.

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Photo courtesy of M Eakin


Remove the seat.

Disconnect and remove the Disk Brake, Wheel Slider, Body Mount Sliders (You will need to suspend and support the body when you remove the sliders), Wheel Tensioner, Cross member Bracket and Motor Slider.

Remove the Tray. It will have to be shortened and put back.

The pair of sliders that mount the new rear wheel and 12mm bolt will probably need to be drill out and enlarge to accomodate the new 12mm bolt.

Then install the new Slider for NuVinci, then Body Mount Sliders, the Motor Slider with Chain Tensioner attached, the Cross member Bracket and finally the Wheel Slider.

Cut the Battery Tray to the size you need at the back end and replace the tray.

Re do spacing on Disk Brake Mount for proper alignment

Mount the Second Chain Tensioner for the Pedal Ring to NuVinci at the Tray.

Our Diagram for the Updrive

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12 x 142 TA 36 hole Cassette Hub

(Note, we had a bike shop drill out the hub and wheel then relace it with 13 gauge spokes. We hope this will add more strength to the rear wheel.)

Our Up Drive Conversion 3-Chain ImagesMessages Image(2021161964).png

Tray Cut for Up Drive. The Tray needs to be  Shortened to accommodate the NuVinci

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Overall NuVinci, Motor and Rear Wheel

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Close up of NuVinci mounted ahead of the Motor

Brackets and NuVinci and Motor mounts

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Right side of  Rear Wheel with Freewheel       Left side of Rear Wheel

This is not a difficult modification, but it is time consuming. The uniqueness of the ELF makes the modification awkward and tests ones creativity to the limits at time, but the outcome is amazing. Our ELF “Shelby” runs better, faster, and has far less problems or repairs after this conversion.