has anyone mounted a 47cc tanaka???



I am looking at the 47cc tanaka motor I see gebe has pulled the 40cc purefire kit you can still get he motor from other sources and get the kit from them, has any one used the 40cc purefire? what are your thoughts? do these motors and this mounting system vibrate much? my cousin has the chinese 70cc vibrates alot and I would like the full suspension that this system allows.
Give me the pros and cons. do you notice the 15lbs over the back tire as far as balance goes? Bama looks like you are the godfather of this thread what made you pick the gebe over the chinese 70-80cc units thanks for the input. I am looking into the 47cc units I live in a mountainous region and dont want to pedal up hills at all. total weight for bike and rider 260-265 thanks for any insight. Sly

Ps. you can click on thes enginges and see the dyno for torque and HP pretty big difference



Good early morning sly.

It would seem bamabikeguy aka Paul is on another of his 200 mile a day road trips. :cool:

I do believe the 47R is a more highly tuned version of the 47 so it may not have the low rpm torque and strong mid-range of the ol' regular 47.
I am lead to believe, by my research, that the 47 series lacks the multi-position carb that the 40 has, this multi-position type of carb has some real advantages for our application...I think. The 47 just might test the service life of the belt but I really don't know.

Since you indicate going with a belt drive, I will encourage you to call Dennis at gebe. Read my post on this page. I am 60 and plan to be pulling a trailer by next year, maybe sooner and will be working hills with an 11 tooth on a Robin/Subaru 35cc. According to Dennis and Julia the only time I might need to pedal is on steeper grades over 6k' ellivation.


Hello Pete thanks for the reply... the regular 47 motor is capable of running in any direction the 47R I need to check on. When you look at the gebe website he alludes to the fact that his system might not be strong enough for the 40cc I think that is why he pulled the motor I have an email sent to them asking if the mount and ring could take it and have not heard back yet. I will post what they say I really like this system but think they are content to use smaller less powerful engines and call them "assist" because they are not enginerrd heavy enough for a motor that can really move you along undar all circumstances. which really stinks because I want the power of the 70cc but not the headaches involved.

this is from the gebe website under the tanaka 40cc...and I think It's why the motor is no longer available I really wish they would get this system more heavy duty for the bigger motors

"You will want to be sure your bicycle can take the punishment this engine can dish out.
Because of the extreme low-end torque of this engine, we have been working with suppliers for an even heavier duty drive (HTD or High Torque Design gears, belts and drive rings) and wheels (36 spoke, 4 cross Wheelsmith spokes, Triple V rim).

Pete have you recieved your robbins yet? let me know what you think sure would be nice to have a little more punch... robbins is 1.6 HP tanaka 47cc is 2.3hp a big difference in power, looks like they need to step up to the plate and get some heavier duty gear for the big boys.


Preface: I am not posting to sell or promote anything. What I have to say is based on my research that lead to my decision to go GEBE given my age and needs.

My sarcastic answer to you sly would be to just tell you to buy a motorcycle. A Kawi 250 Ninja if you are < 140# or a Suzi GS 500 if you are larger. Done! Remember we are talking bicycles here and by law should not go over 30mph. If you need hill climbing ability it can be done safely with gearing, rather than unsafely with horsepower.

I just got off the phone with Julia at GEBE. I ordered the R/S 35 and will be getting all three drive gears, 11, 12 & 13. She wanted to know why in the world I wanted an 11. Truth is I've had two bad motorcycle accidents in the distant past and my legs really suffer at times because of it. I want to make the grade with sore legs at 6k' while pulling a 70# gross weight trailer. Oh! she says, that'll do'er. GOOD! I say. Done! So even if I never need the 11, it will be with me. I ordered a spare belt that will be installed and very securely and neatly stored in such away that it can be installed in minuets. Just in case. Belts are good for > 6000++ miles if properly installed and not subject it sever shock loads off road, ingesting rocks between belt and sheave, or loaded beyond two HP.

So yes the Tanaka 40 is at the drive belt's limit. I could make it live a very long time because I posess mechanical sympathy. ( the only reason Ferrari was so successful early on was because their driver Juan Manuel Fangio had mechanical sympathy ).

The Tanaka 32 will pull the largest gear they have...the 14 and produce about 34mph. So with the 12 on there you should be able to climb walls.
I went with the R/S 35 because it is supposed to have better low end torque and I do not want to mix gas at this time. Plus my mountain bike does steer quickly and I am uncofortable on it doing down hills at 35+mph as a pedal bike.

The GEBE system offers a clean, quiet, vibration free, non-lube throwing, low maintainnce drive system. The Robin Subaru and Tanaka engines are state of the art motors that are EPA tierII and CARB II certed. And yes they are awaiting the newly certed Tanaka 40s.
I like having the engine/heat away from the pedals that my fat body needs to use. I like the fact that the motor uses forced air cooling because it will live longer, produce good power during slow going on very hot days with long climbs. I don't need to see my nekkid engine on this real world touring power assited bicycle.

Read my thread on Tanaka 32 vs Robin 35. I almost changed my mind again today. The 32 is small and the muffler is easily modded with an extension for more quiet.

The drive belts long service life will be dependent on pedaling the bike up to atleast 6mph before applying power. Both Dennis and Julia have said this to me over the phone.

Best of safe fun and luck no matter what your decision.


Keep us posted SLY-- I'm in the same boat!!!

I have the same question as you Sly, but I already have a Tanaka 47cc Type R mounted on my bike with a Dimension Edge kit. I get lousy grab & a lot of slipping, but that was the case even with my 43cc Mitsubishi. I also want to know if the GEBE can take it. I don't mind changing belts every couple months as I am already changing my bald rear tire once a month at least. The Type R is red hot by the way, I just need a way to get the power to the pavement. Let me know what you figure out-- I am definitely interested.


DeadBleedRed glad to have you here, you would probably know the answer to the earlier question can that 47R motor be mounted at any angle? like the 40 and 32? also how is the clutch engagement work with that motor come on low and easy or fast and hard? does it run pretty smooth or have alot of vibration? would you buy it again or go with the 40 purefire? I think you could be the pioneer here. Boldly go where no man has gone before. From what I have read that 47R has alot of power and torque they use them in the racing circuit for goped type scooters how loud is it?

I have not heard back from gebe about my questions on these motors sounds like Ol Pete has it pretty dialed in on the belt limits and I see your other post on the wheels, it will take a very strong wheel. I just wonder how the ring will hold up. Sounds like the weak link here is the wheel and belt, I think If you could get this to work with that 47R motor It would be the envy of everyone on this board (meaning our chinese 70cc brethren) a more reliable motor with full suspension. I will say that asthetically they have us beat. let me know If you hear anything before me maybe they are really buisy.

2 Questions for Ol' Pete the Wheel you are talking about are they From gebe? or someone else? and the little reserve tank on the goped do you have a link to that item Thanks. Sly


sly said:
sounds like Ol Pete has it pretty dialed in on the belt limits.

2 Questions for Ol' Pete the Wheel you are talking about are they From gebe? or someone else? and the little reserve tank on the goped do you have a link to that item Thanks. Sly

I have been a good to very good master diesel mechanic all my life. I raced outboards as a child, rode dirt bikes for years, restored several cars and motorcycles, now this little hobby.
Point is...I know how to ask questions, then listen to the answer, then ask an intelligent follow up question that generally gets me close to the truth.
I find truck drivers, car owners and motorcycle riders will all tell on themselves given the right questions, then listening. I talked to Julia and she told me the truth. Riding rough shod with the Tanaka 40 will kill belts quickly. Like I said, mechanical sympathy.
When guys put Corvair engines in VW busses, first gear would explode if they tried to drag race. Just get it rolling in first then roll on the power in second. Do that and all was OK. OH! Change gear oil every 10k miles. Simple!

Answer #1- The rims are made by Velocity in OZ. They are a pretty good mid-range wheel, abit heavy for the pedal bike crowd. The owner of Velocity OZ has a brother State-Side, that has a bicycle business, part of that operation is hand building Velocity wheel sets. Each wheel has the builder's bench mark etched into it. This indicates pride.
Do a search for tandem bicycle wheels. Find 12 gauge spoked wheels in a 4 cross pattern. Then post the cost.

Answer #2- http://www.sdminimotorsports.com/site/707069/product/Tank 1
It does have a filter inside the tank, just as the small stock tank. I may locate this tank between the engine and seat post, that way changing the drive sprocket for hills or highway will not be impeaded. Cost with shipping(USPS Priority) & CA tax was $44.

NOTE: What goes fast must stop fast. Have good brakes. :cool:


Have you considered this type of gear over chain drive. The gear boxes run an oil bath and the 1/2" wide gears are all ball bearing supported.
It will add weight, maybe some gear whine, maybe a touch of vibration but the lube throwing chain won't break with the 47R's power...If one used a proper chain not a derailer chain.
I have no idea if a 47 will fit-up but a Robin will.
A Tanaka's expansion chamber will most likely NOT clear the gear box.

I saw a very used bike with this type of rackmount on it today but it has a 25cc Honda for power. If I can buy it for <$125 it might find a new home. It has the CA moped plate already. The 300# former owner said it bounced him too much at 25mph. :D



Page through this sly and you will see the 47 & 47R. That's the gear box on the Honda I am talking about. I might have been mistaken in the pic I posted. Not positive it's the same gear box.


The pic above is the Staton gear box as the outside chain type. They do offer it with the chain inside the case so the engine is a little better centered on the bike.
When you look at the pics you will note the engine offset is further to the right of the bike with the outside chain.

These guys use this same gear box on powered wheel barrows that tote 1000#. Hahahaha!! You could prolly put 20HP on that box and rip spokes out by their nipples! Hahaha! *takes deep breath* Hahahaha!

Look how heavy duty the mounting hardware is...KRIPES!
Gear box and mounting hardware must weigh...What?.. 35~40# vs the GEBE at asbout 15#. I must see what the shipping weight is.

My real complaint about this system is weight and complex mounting/adjusting system. I wish now I had picked up the back of that bike. I have to see it again next Saturday. Mmmm.
Oh! Pictar. :eek: :D


The gearbox has a lifetime warranty buddy.

There ya go. Gear it for 70mph with a fully kitted 47R screaming away. Weeeee! What are those blue lights in my mirror?