Rat Rods, friction drive moped kit.


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3:31 PM
May 11, 2020
---- Rat Rodz Friction drive ----

An easy way to convert most available standard bicycles, such as a cruiser, hybrid, mountain, road, trike, etc.
Turning an existing bicycle into a fully functional moped is only a couple bolts away for a Rat Rod kit.

----- Direct Drive -----
Simple to operate, simply pull the clutch lever in, pull start, and pedal off! Release the clutch lever to engage the drive spindle.
Adjustable clutch spring tension!


-- Add an ADA centrifugal clutch --

Kit is also available to install and allows the engine to idle at a stop with out having to use the clutch lever raise the engine off the tire.

Uses standard Zenoah 2 stroke hobby engines (22.5cc-34.5cc, or higher cc) resulting in an easy to start, run and maintain.

Paired with a Racing dynamics 1.5L gas tank, the result is a moped with reliability, distance, and presents a clean and light alternative to other moped kits.

Corundum coated spindles. Performs just like a velosolex type!
Steel option available as well!

Return program for used corrundum spindles, new, $25 .
I'll refurbish the spindle for $5!


Requires no to a minimal amount of modifications to install.

If caliper brakes are used, one will need to be removed at the front to accommodate the universal mount.
Some however can be used with an brake adapter.

V brakes and other caliper less brake sets can be used in conjunction with the universal brake adapter


Sizes from 1" - 2.5" and larger
Rim sizes 16-20 (modifications maybe needed, I haven't gotten to mount on this yet) 24,26,27,29

Like most vehicles, a reliable and quality engine is paired with the importance of quality tires.

Why I choose Zenoah
CY engines and rovan are cheaper alternatives, but you do get what you pay for. Zenoah is high quality and certainly worth the money.

Friction drive simplicity, both in operation and design.
zenoah reliability, no centrifugal clutch (unless desired) for less parts to wear, keeping you on the road.

What I offer:

Direct Drive M1 (seen with g2d99)
  1. Handles tire width up to 2.125"
  2. 3rd bearing supported
  3. 1.5L gas tank, Racing Dynamics
  4. Clutch lever and thumb throttle included, options for twist throttle available.
  5. All hardware included, these are ready to bolt on.
  6. Corundum or steel drive spindles available.

  • Complete w/ 23cc g2d99 engine, $370
  • Complete "hot rat" style w/23cc engine, after market carburetor, highflow muffler and airfilter. $410
  • Complete w/ 29cc Rovan engine, $410
  • Complete with G290rc Zenoah engine $470


Centrifugal Clutch M2 (add $90)
  1. centrifugal clutch, and accepting tire width of 2.25
  2. Uses 3rd bearing support
  3. 1.5L gas tank
  4. Corundum or steel drive spindles available.
  5. Includes fittings and extra fuel line
Inquire about engine options, recommended 29cc or larger.

  1. Fits widths up to 3.25 inches.
  2. 3rd bearing support, depending on desired width
  3. Ships with no fuel tank, no 3rd bearing buy later or fashion up your own
  4. Engine is bolted on w/ spindle. Just add fuel source.
  5. Can use centrifugal clutch aswell
G2d99 - 23cc, Spindle.
Rovan - 29cc, Spindle.
Zenoah - 29cc, Spindle.

Buy your own parts kit;
Frame, Struts, clutch and lever and custom tailored throttle cable. Just need, engine, spindle and gas tank of some sorts. Centrifugal clutch set up or direct drive available. M1-M2 $160
M3 $170

I can do custom colors, but nothing to an exact match. But cherry red, daisy yellow, pink. I can do some very close matches. Black is standard, clear coated.

Get unfinished aluminium and steel parts and I'll knock $15 off the price of any kit.

If interested, contact me via email.

We can discuss the bike, and its intended use to help build a kit to fit right and send you on the road.


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I will be updating this thread with more pictures. I needed to get some of the build in its entire complete form, but I was in a rush that day and now we have 18" of snow in the forecast! No riding till the weekend! Any questions please feel free to ask.
Wow thats an incredibly well designed kit! Like the third bearing! I had a 24cc Zenoah in a gasser model heli.
Ran like a Rolex and made good power for its displacement. Cant imagine a better engine for your kit. Im impressed!
It took trial and error to get there, lot of shop time!
Making something practical, simple, but with some serious features.

I love the clutch design, and it uses steel bushings press into the aluminum to protect it and make it last longer on the pivots, using marine grade grease the maintenance is like once a year at the most.

I also updated the post, for those who like centrifugal clutch setups, this can also run those ADA no problem. No getting off the bike to raise or lower your engine. You can still just engage the clutch lever.
Roughly, what kind of top speeds can one expect, without pedal assist? For comparison sake.
And I'm a little fuzzy, does $210 kit include the engine? Or no? I'm presuming not incl.
I must say, I'm quite impressed with the elegant simplicity of your kit. Easy on. Easy off. Easy to switch to another frame. I like it.
Top speed is variable. Spindle, engine size, and weight of rider are all factors, throw in wind speed and it's a whole game.

Top speed I have e hit is 32 with an .825 spindle. No wind, 160lbs, plus 60 for the bike.

Changing over isn't super quick. It's no quick release system, but less than an hour and you can be switched.
Top speed is variable. Spindle, engine size, and weight of rider are all factors, throw in wind speed and it's a whole game.

Top speed I have e hit is 32 with an .825 spindle. No wind, 155lbs, plus 40 for the bike.

Changing over isn't super quick. It's no quick release system, but less than an hour and you can be switched.
Hour? That's quick. My V mounted bikes, because they have to be so stable to maintain the chain line, are always pretty much a permanent part of the bike.
And I'm amazed at 30 mph from <35cc. You can do all the convoluted gearing/Jack shaft/cvt crap in the world. Bottom line is always HP. Gonna look into these little motors a bit more. Thanks for the info
Nice setup, can it be installed on the rear? Above pic shows way too much pressure on the tire if the tire isn't low on pressure. Only about 1/4in is needed for optimal grip. This design may need more than the usual kits we are used to.
This kit can be mounted on the rear tire, which may require extension mounting hardware to make it work. These kits CANNOT be swapped back and forth, front and back.

I really recommend a zenoah engine as the power plant, the cheaper clone engines are CHEAP and will be a headache.

Swapping bike to bike can take less than an hour, a few times of dissembling makes quick work. Everything is practice.

I'll have more info later today or tomorrow