Friction Drive VS Chain... which one is better?

If you want a rear rack mount look into the Sytems offered by That's Dax and Golden Eagle. The Eagle system uses a belt via a wheel belt sheave, whereas Dax uses a friction drive.

Both systems have a lot of positive comments on this site and either should work well.

Considering the price of the GEBE [Golden Eagle] it is important to note the use of HIGH QUALITY AMERICAN parts & labor is the reason. We totally understand American parts & labor, as we also keep Americans working in producing the EZM kit and Q-Matic drive. Most often, "you get what you pay for".

As far as gas mileage is concerned, the drive system plays an important role, but also consider 2-stroke vs 4 stroke. The 49 CC 4-stroke is known to get as high as 185 MPG, and no messy oil to purchase, mix, or store. Often when considering mileage, the 2-stroke numbers don't include the cost of the oil, and the oil will increase the MPG cost.

Hope this information is helpful.

Have fun,

I have 7MBs, 4 FD, 1 Chain, and 2 all belt. The belt and the FDs are the quietest drive wise, I like the chain the least. Of my 4 FDs 2 are front drive and 2 are rear. The rears are slightly quieter. All that said, the most pleasant to use for extended rides are the FDs. They are not the fastest however. Most FDs run in the lower 20s. I have one that will criuse at 25, the rest are right around 20-21. The real advantage to the FD is simplicity. Pretty much if the engine runs it gonna get you there, also just about zero maintainence. FDs arent for everyone, but if you are happy in the low 20s speed wise(there are faster ones, but its a trade off) and like simplicity Fds are cool.

FD with a 1 1/4 roller and a 50cc motor will scoot alot faster than low 20s, 1 3/8 or 1 1/2 will get well into the high 30s even 40mph.

What rpm are you basing this on? According to one of the mulitude of gear calcs out there, a 1.25" roller hits 20.8@ 7K rpm. I am turning a 2" roller on my 2.5hp Lifan 4800 yeilding a 28mph top. You would have to turn a 1.5@ 9K to acheive 40mph. Doable I guess with the right engine. Short lived for the common 49cc 4stroke.

My calc has a 1.25" spindle @ 7Krpm = 26mph, the 1" is 20.8mph @ 7K.

I am depending on the accuaracy of the calc I picked up from the another forum. I generally figure these on a calculator using the overall ratio between the circum. of the roller and the tire, guess maybe I should go back to that method.

The reason my name is GEJoe is that my first motor was a Golden Eagle I purchased in 2005. That said, if you buy one, be prepared for broken spokes and carry a spare belt. Change the spokes to 12 gauge if you can and enlarge the spoke holes on the drive ring slightly. And be prepared to pedal vigorously up hills. I just recently tried friction drive. I have Armadillo tires and they always have a lot of black crumbs at the end of the ride and smell like burnt rubber, regardless of the drive roller tension. Maybe Kenda slicks would be better. Got caught in the rain the other day and drove home 2 miles afterward. Took a while to clean up the bike from all the debris that the drive roller slung everywhere. Fortunately I am converting the setup over to chain drive next. Then I can say I have had experience with all drive setups.

cannonball2 said:

I am depending on the accuaracy of the calc I picked up from the another forum. I generally figure these on a calculator using the overall ratio between the circum. of the roller and the tire, guess maybe I should go back to that method.

Click to expand...

For a friction drive the size of the wheel is irrelevant. Since the friction drive roller's surface is moving (or at least is suppose too) at the same speed as your tire's surface and your tires surface is moving at the same speed at which your moving forward.... then the the roller will be moving at the same speed at 30 mph no matter what size your tire is.

That is why friction drive is so nice for things like BMX bikes and other bikes with smaller tires.

If your engine's crank is directly attached to the drive roller then the equation to figure out rpm is:

Circumference = Diameter * Pi
Miles Per Hour * Minutes Per Hour / Inches Per Mile / Circumference = Revolutions per Minute.

You convert miles per hour to miles per minute
then you convert miles per minute to inches per minute
Then you divide that by the inches of circumference which gets you revolutions per minute.

so:
mph * 60 / 63360 / (diameter * 3.14) = rpm

If you write all that down and simplify it then you end up with something simple to plug into a calculator:

mph * 336.15 / Diameter = rpm

sooo...

26 * 336.15 / 1.25 = 6991.92

28 mph with 1.25 gets you about 7k.

But moving the numbers around gets you different equations...
if:
rpm = mph * 336.15 / diameter
then:
diameter = mph * 336.15 / rpm
and even:
mph = rpm * diameter / 336.15

So if your engine goes up to 9K rpm and you want to be able to go 40...
40 * 336.15 / 9000 = 1.5 inches

more or less. It's not exact. But it is close enough.

For 7K rpm with different diameter rollers...
1 inch @ 7k = 21mph
1.25 = 26
1.5 = 30
1.75 = 36
2 = 42

More or less.

Thanks for the info I am aware if the tire size being out of the equation I was referring to the relationship of tire to roller to interpert the overall reduction. The reduction on my 26" bike is basically 14:1 which is know to be a good hill climb ratio. Given the engine rpm, I can figure the top speed, with this ratio. I am more interested in some ways in the ratio, not the top speed.

Sorry guys, I went back and looked at my scribbles and I had entered a 1.0" roller yeilding 20.6. The calc I used agrees on the 1.25. Also I looked at my original ratio calcs and my ratio is more like 13.1:1, using a 2" roller and a tire that measures about 26.25 actual.

miamiRiding said:

First test drive last night Recieved my Staton Inc Friction Drive w the Subaru 35cc kit Friday and installed it that night, just a one modification to allow the back tire to spin under the u-bracket and I was good to go.

bought some synthetic oil and started her up for the first time saturday night... she started w just two pulls and runs quiet and great... wife and kids had a blast riding it too

saw a police speed control radar in my neighborhood and the temptation to test it was too much anyways it "clocked" me at 29mph not bad for barely full throttle (since I still need to break it in)

big thanks for the earlier suggestions... i am very happy w my kit/engine

Click to expand...

The S/R engine is on the small side but IMO that's a plus in a rack mount, makes the easer to dismount. Every thread I've read from S/R owners indicate a satisfied customer as the quality as well as the noise level are excellent. Staton, IMO, makes the most durable drive units on the market (I own 3 FD & 1 CD) and he stands behind his product. You've made a wise choice.

miamiRiding said:

First test drive last night Recieved my Staton Inc Friction Drive w the Subaru 35cc kit Friday and installed it that night, just a one modification to allow the back tire to spin under the u-bracket and I was good to go.

bought some synthetic oil and started her up for the first time saturday night... she started w just two pulls and runs quiet and great... wife and kids had a blast riding it too

saw a police speed control radar in my neighborhood and the temptation to test it was too much anyways it "clocked" me at 29mph not bad for barely full throttle (since I still need to break it in)

big thanks for the earlier suggestions... i am very happy w my kit/engine

Click to expand...

Good to hear it's working out, mine's on order, should arrive Tues / Weds. What size roller did you go with? I ordered a 1" as I'm heavier than most and want the ability to go up a hill once in a while.

miamiRiding said:

First test drive last night Recieved my Staton Inc Friction Drive w the Subaru 35cc kit Friday and installed it that night, just a one modification to allow the back tire to spin under the u-bracket and I was good to go.

bought some synthetic oil and started her up for the first time saturday night... she started w just two pulls and runs quiet and great... wife and kids had a blast riding it too

saw a police speed control radar in my neighborhood and the temptation to test it was too much anyways it "clocked" me at 29mph not bad for barely full throttle (since I still need to break it in)

big thanks for the earlier suggestions... i am very happy w my kit/engine

Click to expand...

Synthetic oil is not good for break in. It eliminates too much fricton, keeping the rings from seating quickly and well.

Yeah, level is good.