Please help with my first kit

[Ima Schwinner]

First off, I'd like to preface this question by saying that I have searched out and read every thread I could find regarding rack mounted engine kits.

While I look forward to someday building a motorized Ratrod, I don't currently have the time to tackle a project like that. For my first MAB I'm looking for longevity, and MPG. I'm willing to use either a 2-stroke or 4, depending on which one gives me the best MPG with my final setup. I'm considering both the GEBE and Staton kits, and since both kits might require the rear wheel to be re-laced, I think the Staton's approach looks more solid. My concern however, is that the Staton gearbox and chain will consume too much energy from a small motor like the Robin-Subaru.

I live at 3400ft, and most of the places I'd like to ride will gain another 500 to 1000ft elevation. Will that create carb tuning concerns with the Tanaka or Kawasaki 2-strokes? Would going with a larger 2-stroke actually improve my fuel economy over the smaller Robin? I read in a previous post that 2-strokes give their best economy by running at 80+% of their max RPMs, so would the smaller 33cc Tanaka give better economy than the 40-43cc engines using the Staton gearbox? Will a larger engine allow me to the bike up a little for lower RPMs, and does that then equate to better fuel economy?

My hometown is small enough that I can easily bicycle from one end to the other in a few minutes w/o an engine, and I only live one mile from work. I want a MAB for toodeling through the countryside and into the mountains. Once outside the city limits, I'm not overly concerned with the sound level of whatever motor I choose. Obviously quieter is better, but for ME, I'll get the warmest, fuzziest feelings by achieving the best MPG average.

I will probably start with a mountain bike frame (a 20yr old 26" Schwinn) but for longer trips, I'd ultimately like to find/build a cruiser. I used to own dual-sport motorcycles, and loved the freedom of riding anywhere my little heart desired. I'd like to replicate that feeling (within reason) with a motorized bicycle. I'd really appreciate some specific feedback regarding what motors, gears, and mileage you all are getting out there in bicycle land. Thanks a bunch.
I.S.

[Bikeguy Joe]

I'm bumping this one .....I think you fell through the cracks!

[Ilikeabikea]

I read this one but I'm only familiar with center frame mount two strokes. I live at 3200 ft. and don't have any trouble with my two stroke. Of course I'm sure it would run much better at sea level......................

[Dave31]

Don't know much about the Gebe or Staton

On my Chinese 2-stroke I get between 120-135mpg...depending on how hard I ride it. I live at I think 2400 and ride up to 9,000 and have no problems.

[Ima Schwinner]

Thanks guys. They're popular kits and engines, so I know there are folks out there with good experience and knowledge to help answer my questions. I just need to lure them to my thread.

[Dave31]

Originally Posted by Ima Schwinner

Thanks guys. They're popular kits and engines, so I know there are folks out there with good experience and knowledge to help answer my questions. I just need to lure them to my thread.

Yes...there is a few here with that set up...they are just not here right now.

[Spunout]

hi.
all my bikes are/have been 2-strokes. always good with the power.
i installed a Dax Titan 4-stroke rack-mount 50cc, on my Dad's bike over the weekend.
i must say i am fairly impressed with the amount of torque achieved.

i read somewhere that guys are having to buy a new kevlar belt for the GEBE's every 500 miles.

[bamabikeguy]

Originally Posted by Spunout

i read somewhere that guys are having to buy a new kevlar belt for the GEBE's every 500 miles.

I have at least 4,000 miles on my latest belt, not one fray....and even though I carry a few extras for my customers, replacing is a rarity.

The trick is the getting the rear wheel ready for heavy duty usage from the beginning, so you don't fiddle around later and get mal-adjusted.

I think the guys who have belt problems are the ones running over 40cc, who let a friend jump in the saddle...if you are going to go "big engine", there is NO jumping on the throttle, like you can on the smaller engine, you have to go easier on the acceleration. I was guilty, the victim AND the criminal, climbing up a long steep incline on one of the five 40cc Tanaka test engines in 2006, and when I had to peddle 15 miles home, the engine was in a box for return the next Monday. Too much engine, imo.

I tell my customers if they want to switch to a 40cc, it is better to learn on the 33cc, then trade up, since the frame-mounted setup is already there.

Simply bolting on the "40" in the future would be simple, and I'll buy back the "33" from them in a NY minute.

Set it up right, the efficiency is over 90%, and letting Chubby Uncle Frank or his Wild Child Norbert jump on your bike, take it for a spin, is THE biggest danger to a belt.

You will get adjusted pretty rapidly to the sound of the engine and the pressure on the throttle, but it is hard to communicate to somebody taking a demo ride. If you did get a GEBE/Tanaka 33, I'd say start with the #12 tooth normal gear, and switch over to the #11 hill gear when you go into really hilly territory, it only takes a few minutes.

I live at 3400ft, and most of the places I'd like to ride will gain another 500 to 1000ft elevation. Will that create carb tuning concerns with the Tanaka or Kawasaki 2-strokes? Would going with a larger 2-stroke actually improve my fuel economy over the smaller Robin? I read in a previous post that 2-strokes give their best economy by running at 80+% of their max RPMs, so would the smaller 33cc Tanaka give better economy than the 40-43cc engines using the Staton gearbox? Will a larger engine allow me to the bike up a little for lower RPMs, and does that then equate to better fuel economy?

I am just now learning the effects of "ethanol", and hopefully will arrive at my solution in the Appalachian foothills around here, but our elevation is in the 1,000+ range. In the "ethanol" thread I just found out yesterday 33 Tanakas carbs are pre-set (such low maintainance, I haven't had to worry about those kinds of things before Chevron switched blends 2 weeks ago)

But all engines are basically set for these type altitudes, 1,000 and below, because that takes care of the majority of usages. (and I was using the smallest 25cc on the Denver trip, loaded down for bear).

I remember reading a post from an engineer in some mountain country of a simple "adjustment" to the intake, iirc it involve a touch of solder and a smaller diameter drill bit.

But on my Denver run, I felt the altitude effect in reverse.

The Tanaka 33 has a chrome cylinder sleeve, will take a thousand miles to really reach full potential. However, the first 3-4 tankfuls are all important using the "break in" procedures.

What would be the ULTIMATE advise might be if there was a lower (under 2,000 feet), straightaway type terrain within a few miles of you, where you could spend one single day doing that break-in, a 6-8 hour leisurely ride, varying the speeds, stopping for 10-20 minute breaks.

In that way, you would know, in your bones, what optimum felt like, and when you returned to the high elevation, figure out if that narrowing the jet is worth it or not.

What is your daily commute or usage going to be?

I use 4 strokes for folks doing city riding, less than 20 miles, but 2 stroke is better for WOT longer distances and people wanting to spend a lot of time in the rural areas.

[bamabikeguy]

I'm considering both the GEBE and Staton kits, and since both kits might require the rear wheel to be re-laced

Simplest works best, forget relacing.

Wheelmaster makes a steel 12 gauge wheel, order it at a bikeshop, $35-38.

Pyramid or equiv. Industrial tube $10 (esp.on rear), Tuffy Tire Liners $14 a pair.

Extra layers over the rubber gasket covering the spoke-ends (I use electric tape) and a few zip ties on the spoke intersections and you are ready for action, regardless which system you choose.

[graucho]

I have to agree with bamabikeguy about the belts. I have 1850 mi and my belt looks new.
I have a video of both of my GEBE belt drive and Staton friction system. Its kind of dorky, but I shot it with my hand camera. The RobinSubaru 35 are not that loud, the camera amplified the sound X=2. The video shows a close up of the mounting areas. My elevation is at 1000 ft. Ive heard the RobinSubaru 35 has automatic timing which may help with elevation? Maybe someone has info on this?
http://www.youtube.com/watch?v=0UZT91Dma-E