KEEP IN MIND that this quad is evolving from my upright bike and recumbent tadpole camping trips through the 5 deserts of the American Basin and Range Geographic Province…


The quad could handle this ride on a day trip, the trike couldn’t.


Moving base camps entails loads over 500 pounds gross up 15% grades on rutted loose surfaces.

KISS (keep it simple) is number 1 guide, which can’t always be kept.

Negative – Suspensions are vulnerable.

Negative -Tadpole conversion only amplifies the torqe weakness of a center beam with a rear wheel fork.

So its a flexible ladder frame.  A bonus is that the center is open for mid-drive components … gets the extreme low gearing.

I require  fat versatile tires.  The next set will be selected from Mod Trial 406’s.  I would like to try larger wheels like Trials 559 (Two Sixers) or MTB 622 (Two Niners) but won’t until the next frame version, an extra $2000 shows up, and a time machine that stops my aging at  its current 72.

AND a 6 Gear Inch drive-train (yes that number is six)

The Schlumpf Mountain Drive with dual 27T/53T rings paired with an ICE Capreo 9T/46Tcassette on 60-406 Big Apple wheels did produce 6GI to 120GI.  The 6GI is just about right for those loaded soft hills.  The 120GI is for safety keeping a bit of tension in the chain on potentially runaway down hills.

WITH A FATAL FLAW:  Remember those hills … speed is 2mph going to 1mph… the chain is barely moving and has half its maximum tension … a down shift is needed for  steeper incline … to shift it is ABSOLUTELY necessary to release the chain tension or skip, snap, crackle, pop without shifting…so its done … nothing driving the rig up … BUT gravity continues  to drag the rig down … so quickly the rig almost stops … forward progress ceases without the shift…and you are on a steep slope hoping the braking will hold…..

Some other means of shifting NEEDED. Internal Geared Hubs do NOT have the required tolerance for these levels of input torque.


Front dual ring 29T/53T or Schlumpf Speed Drive.

Mid Nuvinci N360 16T In / 16T Out  from Disk rotor holes.

Rear is a fabricated two gear sequential shifter integrated with a quasi-positraction differential.



LINK 2 Two Speed Gearbox.wmv

Ladder Frame

Self  suspension,

3 inch twist for wheels climbing obstructions (larger wheels would enable more)

6 inch absolute clearance (no hanging derailleurs).

Clear center space for drive-train.

Sliding utility mounting rail to rail eg seat, mid-drive, racks.

Shorter crank boom.

Four Wheels distributes load over 4 tires

better float over soft ground /or/    allows a heavier load.

tires wear longer better riding stability and balance

eg. side slope tilt goes to 35° from 25° of tadpole.

Two Tracks straddles mid-obstructions rumble strips humps between two-track trails and roads

Positraction Differential <loose surface, snow / ice> both wheels powered. Only 1 wheel needs traction for drive power.

Steering is maneuverable less yaw and roll ? little brake steer (Bryan Ball)

Lifting front-end enables easy moving on Rear Freewheels.

Lifting front-end so quad is on Rear Freewheels enables vertical parking <garage>

Suited to a wide range of riding contexts (How its ridden, where its ridden) Off-pavement riding is enabled Road touring is enabled

Fixing flats, changing tires is easy for all cantilevered open wheels Convenient large behind the seat storage platform (watch for Fargo’s floorboard) Center rear trailer hitch. AND takes the options / accessories of tadpoles etc.

Terrain Convertible.  How easy it is to change wheels sets; roading to camping to snow or sand (now that FAT wheels have arrived).  No need to change drives … this one covers all.

Why not QUAD Wider turning circle (fixed, fall 2011) Drive / Chain line more complex (fixed, spring 2012) Can’t Z-turn through narrow passages (doors, gates) (v2 will be narrower) A weight increase. More parts, especially field unrepairable and one-of-a-kind.parts. Harder to pack for shipment (fixed with couplers, fall 2012) Fenders (¿ in the desert?)(¿loose hand carting?) NO fenders are best, (fall 2012 )

Quote: from a BROL thread
Higher angle side slope stability Frame has 3″ flex twist when climbing / descending obstructions. trike would roll over. High clearance over and two track straddling of obstructions No middle drive wheel which is ineffective in ruts and cavities Four tire float, 2 track not 3, and positraction through sand beds Simpler mid drive installation for extremely low gearing / smooth spinning uphill Adjusted seat higher and upright for power stroked cadence More tire traction and positraction on sloped “slickrock”I started with a tadpole not taking kindly to desert primitives. Not to my liking as so much of the deserts attractions are out of the way and I couldn’t get there. Although a quad was a thought while considering a trike … none were available. This quad evolved over several years of tripping … still none were available. The restrictions of the tadpole were gnawing at me. The light-bulb was Ashley coming up with the tadpole conversion…Except this one is a dedicated ladder frame.Each difference might not be absolutely critical, some are. On a minute by minute, incident by incident basis, the enabling features, even if small, get the quad over section the trike just couldn’t. Some places the quad doesn’t make it … pushing / carrying is hurtful, even more than the trike. Some places the trikes maneuverability is prime.

Why not a Tadpole? Why not a Delta?


4 thoughts on “Quad-ing

  1. Hi Tyquad,

    I tried the Slickrock Trail a couple times this past fall on my semi-fat tired Villager tadpole. It has 2.5″ Creepy Crawlers on 19″ trials rims and 9 GI.

    Both times were a fail. It wasn’t due to excess off-camber (you can usually find a circuitous route to stay upright on wide open slickrock) by rather by the route being VERY steep in places. As you are well aware, fat tires on slickrock offer unlimited traction and I could climb to the point where the front tires lost their attachment to the earth! The frontend became weightless.

    It is a totally unnerving experience to be stuck unable to proceed forward and being literally out of control trying to back down, the wheels just locked up and skidded to where they wanted to go.

    I found a more suitable slickrock trail out at Moab Brands, the Circle-O Trail.

    I love riding on slickrock and will continue looking for suitable rides for a tadpole.


    • Hi Alan
      I can hardly wait to ride Slickrock.
      Indicators show 5 minute – 30% grades … that’s why 6 Gear Inches and 2 wheel drive … so with my maximum 5 minute power … I can pedal with at least some cadence … over the steepest … without stopping.
      Stopping dead when you can’t go up, don’t want to go down, can’t brake enough to stop sliding, can’t hand wheel, can’t get off, don’t dare try sideways … is one of my nightmares.
      So I invented this, though have never made one.
      A hinged spike clamped forward and underneath the front boom. The back facing free end has a release. In the no-choice stop, release the spike. Its sharp end drops to the ground. Roll back a bit to set the spike. An emergency anti-back-roll brake.

  2. What can you tell me about getting the lowest possible GI from my Catrike quad?
    It was just delivered 3 days ago and was shipped with road gears I can barely push the pedals on flat ground.
    So far I have learned to change the sprocket right side nuvinci 380 from the 16t to a 22t my quad has the Schlumpf HSD, Nuvinici 380 and 26″ 4.8″ tires so what can I do with the left side and rear sprockets? I read in one of your articles about a 6GI that would be great for me.

    • Hi Jesse … nice buy, enjoy.
      Could we work out how you balance with the quad rig and the roads you will ride?
      Knowing your strength capacity would be good.
      Do you have a current FTP? (feel free to ignore this line)
      How about gender, age, height, weight, and waist around the belly button? … points to a decent estimate of your capacity.
      Send the location of a hill you don’t like because its really hard. eg Google map coordinates or just the town with cross roads at the beginning and end?
      What is the ring’s tooth count on the Schlumpf HSD?
      What sprocket did Utah install on the non-drive side of the N380 and the sprocket driving the rear axle differential?

      Lets see the possibilities with the existing components and some variations with changes.

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