Pro Full 8" Suspension 4 Stroke Friction Drive

Jul 18, 2018
Hello, I am a Mechanical Machine Designer, BMX and Mountain Bike rider, I have been a Professional Machine Designer for 30 years.

Mathematics and Drive Design Calculations are my strong point.

I needed a strong bike with good suspension and brakes that could take me to visit my 90 year old Mother in a retirement village which is a 30 mile or 50 km ride, which I do once a week.

As a fan of the Shell Eco Marathons and the fastest bicycles in the world like the record set by Sam Wittingham just pedaling 133 km/h I decided to put my 30 years of Machine Design Experience to good use and design the Ultimate Friction Drive for a Bicycle so I can travel long distances economically and get physically fit at the same time.

I have had the bike for eight years its a Kona Stab Deluxe, I have done more than 1200 Miles or 2000 km using the friction drive and I still have the original tires on the bike Maxis Hookworms for road use.

Bike Drive Specifications:

Mounts onto the seat post with two U-Bolts in 10 minutes
A modular spring loaded swing arm unit that any one can easily install.
Suspension travel up to 10 inches or 250 mm
Tire wear: 8 years 50% still to go
Fuel Consumption: 140 mpg or 1.68 L/100 km
Engine: 35cc Four stroke Honda
Fuel Tank Size: 0.16 US gallon or 0.63 Liters
Engine Weight: 7.2 lbs or 3.3 kg
Engine Power: 1.3 hp or 1 kW or 1000 Watts
Engine torque: 1.18 ft-lb or 1.6 Nm or 0.163 kg at 1 meter
Range per Tank: 23 miles or 38 km
Speed: 22 Mph or 35 km/h @ 7000 rpm engine revs to 10 000 rpm
Material used for drive chassis: 304 Stainless Steel
Drive weight excluding engine: 7 lbs or 3.2 kg.
Drive bearings dynamic loading is 1474 lbs or 670 kg each so friction drive slippage can be completely eliminated via increasing spring loading.
Stainless Steel Drive shaft has a unique shape that complements grip and does not wear the tire down even in the rain.

Bicycle Pedal Sprockets: Front 52 teeth rear 11 teeth

I have ridden the bike extensively for long distances over a period of years to perfect it before presenting it to the public so that its solid and reliable, the design is currently on Revision 5 and I am now finally satisfied with its hill climbing capabilities as I live on top of a small mountain at 5760 ft and my Mother lives next to a river 4720 ft so after riding 25 miles I get to do a hill climb of 1040 ft.

This is what has evolved this drive into a finely tuned compromise between speed and torque. I am now able to go home in top gear with the 52 and 11 tooth sprockets in use and I am able to go up the mountain on the side with the lowest gradient at full speed.

I live so far away from Europe and America that I am considering selling the manufacturing drawing packs and laser cut files as I am snookered by distance shipping costs are around $500 USD so if people want to buy the design outright and manufacture them then you welcome to contact me.

For those who dont want to manufacture them but still want one.
I am manufacturing the drives locally for $300 for those who are willing to pay the high shipping fee, sorry for the shipping fee, it may be less for Europe I based that $500 on the further est distance from my location so it most likely will be less than that.

They not cheap but the quality is as as high as possible made of 304 stainless steel which should last for generations.

My Kona bike currently looks like this but I designed it to fit on any bicycle.

The last photo shows the drives elevated so you can just ride the bike without the drive if you run out of fuel.

You welcome to contact through this forum me if you interested.


Last edited:
Jul 18, 2018
Howdy and welcome, Cat Man.

Dig your design and great lookin' MB!
Thank you for your kind comment Dan : )

I have built several electric and petrol powered bikes and I have gathered a lot of information about the pros and cons of all of them, so if any one wants to ask any questions they most welcome as it will save builders a lot of time and money as I have already "payed my school fees" and I will happily share the information to help others so that that they can go straight to the best drive without having to spend the time and the money finding out the hard way like I had to.

Here is a vid on the first electric bike I built from first principals just to see if I could actually get it to work at all and it did work quite well as a test bed, the chain coming off the front wheel drive sprocket was a bit dangerous though at full speed but it proved a point that could be useful for others.

I managed to "cheat" quite nicely by using a rear wheel in the front and by using the handle bar neck stem for chain tension and alignment so that I could do the test with the least amount of work, notice the acceleration head flick at 0:20 - lol - enjoy the vid.