Help me decide which setup to go with!!

Discussion in 'Rack Mounted Engines' started by wesb1023, Feb 24, 2012.

  1. wesb1023

    wesb1023 New Member

    Hi, its been a while since I have posted up here. I sold my bike with a gx35 and bmp friction drive awhile ago and haven't been up here since. With gas prices rising, I have decided to plan another build. This time I want it to be more practical for longer trips. I don't have a problem with pedaling a bit here and there but I just want something that I don't have to worry about a damp road slowing me down. I am more than likely gonna get a staton chain drive setup. Which engine and which kit is my problem now. I want to stick with the Honda gx35 or the Honda gxh50 for engines. So lets start with the gx35, with a staton fixed gear drive, what would be the best ratios to go with? I weight 210 lbs and want to ride as fast as possible, as my commute will be 30 miles one way. Would a nuvinci kit be good with this engine? Worth the extra money? I would love to know top speeds with this engine and the nuvinci kit. My other dilemma is whether to go with the gxh50 instead of the gx35. I just don't want to break the bank if you know what i mean. Any input would be greatly helpful! Thanks in advance!
     

  2. wesb1023

    wesb1023 New Member

    ok, I have done some more searching and have answered some of my own questions. I kind of want to get this purchase right the first time if you know what I mean. I am leaning more towards the station outside gearbox, with the gxh50. I don't mind pedaling, but i think the extra power would be useful for maintaining speed up a hill.
     
  3. loquin

    loquin Active Member

    That, or a Nuvinci CVT hub, with a 33/35cc engine. (You'll have to get the engine separate from the kit, if you're going Staton and want a Honda, as Honda has come down against using their engines on a bicycle application. :( )

    The Nuvinci and a 35cc engine can be 'geared' low enough to go up a very steep slope. And, still get the great mileage.

    It's not cheap. But, you'll get 50 MPG (or more) better mileage than with a fixed gear gxh50 setup, and it's close to the same price. (the GXH50 has to have an adapter and a special clutch to use Staton's gearbox, and that jacks up the price considerably.)
     
    Last edited: Feb 27, 2012
  4. wesb1023

    wesb1023 New Member

    Thanks for the reply Lou, I saw all the extra parts on the staton website and was pretty upset. The nuvinci/gx35 combo would be cheaper than the fixed gear gxh50 kit, engines included. I dont know, I am really having a hard time making up my mind. I have read and read until I am blue in the face, and still change my mind on which setup to get every day!!! The only thing I didnt like about my BMP/gx35 kit was the lack of power climbing slight hills, it would get up the hill just pretty slow, on the flats I was grinning from ear to ear. Pretty sure it would be the same way with the nuvinci/gx35 kit minus not having to pedal at all. I am now questioning my first thought of the chain drive all together. I thought that even if I had a chain drive bike, I am gonna steer clear of driving in the rain if possible. The staton friction drive/gxh50 is whats on my mind today......who knows about tomorrow!?!? I just keep thinking of all the moving parts on the chain drive setups.... and the lack there of on the friction drives. Plus I wanted more power for my fat butt with the gx35 before, pretty sure I would be wanting more still with that engine even with the chain drive, or are the chain drives just that much better? Sorry I know I am like a chatter box, and I over analyze EVERYTHING!!! Thanks again!!
     
  5. loquin

    loquin Active Member

    If you've got rain to contend with, (at least on a regular basis) all the extra torque of the GXH50 is going to spin the spindle against the wet tire...

    Most of the feedback I've seen on FD versus equivalent chain drives, is the power is about the same. (FD has extra 'rolling friction' caused by spindle deflecting the tire., Chain drive is very efficient from sprocket to sprocket; losses in gearbox are about the same as rolling friction of friction drive)

    However, Staton's chain drive (including his Nuvinci drive) has a freewheel, so you can coast downhill, and not be pushing the motor.

    A CVT allows you to maximize the power output from the engine; so you'll definitely be able to go uphill faster than you would with a fixed ratio of the same engine. Peak power output of the 35cc Honda/RS engines are about 5500 RPM, with Max RPM pushing 8000 RPM. The CVT allows you to keep the engine RPMs in the middle the peak output band when hill climbing or when on the flat.

    I have the same issue with my FD Mitsubishi (which has a max power RPM which is much closer to the MAX RPM) on hills. What happens is that, as the engine slows down when climbing, being a fixed ratio, the engine RPM goes down as well. As the engine RPM slips out of the max power RPM, power output gets less, causing speed to drop even more, causing speed to drop, causing RPM to slip further away from max power band ... and so on.

    With the CVT, you just slip the ratio (equivalent to shifting to a lower gear) up a bit, and you can keep the motor at max power - you'll end up going a lot faster up the hill than you could with a fixed ratio drive.

    I would like a Nuvinci system; even though I haven't owned one. I can tell you this; the folks who have the Nuvinci are very happy with it...

    Take a look at the Nuvinci threads in the CVT forum... In particular, take a look at the discussion in sparky's Nuvinci poll to see what the folks who actually own a Nuvinci say about it.

    The other point that the folks who own a Nuvinci bring up, is that they're able to run their engines at a lower RPM when cruising, which can't help but improve engine longevity and mileage.

    Now, you don't get anything for free. There is a loss in POTENTIAL top end, as a Nuvinci is somewhat less efficient than a fixed gear system. But, a fixed gear system is virtually never geared for maximum top end. It is a compromise gear ratio, that gives you acceptable performance at lower speeds, with (on Staton 'standard' systems) max RPM at about 30 MPH.

    This means that at 30 MPH, on a fixed gear system your engine is screaming, and max torque output (at 5500 RPM) occurs at about 21 MPH.

    HOWEVER

    According to calcs using bikepower, a 180 pound rider, on a 50 pound bike/drive, could just about maintain 21MPH with 1.4 HP on a 6 percent slope (6 feet rise over 100 feet horizontal run,) with a 75 percent efficient drive.

    If the slope is anything steeper than this (which is the max recommended slope for freeways,) then a 35cc motor is going to bog down. And, you because your power output is in a relatively narrow power band, you're going to not be able to handle a much steeper slope.

    But, with a CVT, you can raise the ratio at will. Say that the slope goes to 10%. You would just raise the ratio until you maintain a speed at 5500 RPM and keep cruising. According to bikepower, that would be between 15 and 16 MPH for the same power output as 21MPH at 6%.

    The one accessory I think you would really want to have on a Nuvinci system would be a Tach.
     
    Last edited: Feb 28, 2012
  6. wesb1023

    wesb1023 New Member

    I am interested in the nuvinci, I have been from the beginning. I searched for the NC motored bike laws and this is what I found......

    North Carolina Moped Laws
    Moped Defintion
    vehicle with two or three wheels with a motor of no more than 50 cubic centimeters of piston displacement and no external shifting device. Legally, a moped's top speed cannot exceed 30 mph on a level surface. Although some mopeds on the market have top speeds higher than the 30 mph limit, they are illegal for use in North Carolina. If a moped does not fit the above requirements, it must be registered as a motorcycle under North Carolina Law.

    So.... would the nuvinci be legal in NC?????? Is it an EXTERNAL shifting device?? It could probably be easily concealed to any "PIGS" in my community...LOL Just because it doesnt have any "visable" gears.
     
  7. wesb1023

    wesb1023 New Member

    Ok, I made my choice. Man!!! I just dropped some money!!! I just ordered the staton outside drive fixed gear kit & a gxh50 engine and adapters. I decided to go ahead and bite the bullet because I plan on this being alternate transportation this summer....not just for fun! This is what I had in mind to begin with, but part of me was trying to talk the other part of me out of spending this much money!! I will have to post up some pics when I get it together. Anyone know around about how long the wait time is when you order from staton?
     
  8. loquin

    loquin Active Member

    I've never had to wait more than a week to 10 days. If he's waiting on parts to get in to complete a batch of the kits that you have ordered, it might take a bit longer.
     
  9. shawnshank

    shawnshank Member

    Why not go with the Tanaka GEBE belt drive kit? It's lighter, gets better mpg (close to 100 mpg), doesn't slip in the rain (toothed belt), it's super fast...mine tops out around 35 mph, handles hills easily and is very reliable. All I have to do is pedal briefly when I start from a dead stop (and when I say briefly I mean about 4 rotations of the crank) and as long as I keep moving I don't have to pedal again. It whips over small hills and on average hills I don't have to pedal at all but I do because I like to stay at top speed. On the steepest of hills I get up to full speed before I hit the base of the hill and I use the highest gear on my bike and start pedaling to help get over but it's so fast and easy I don't even break a sweat. The torque is incredible. I've seen videos of the one you are looking at and I find them slow to come up to speed and have a lower top end than the gebe. I have had the 40cc kit for about 4 years now and I have never had a problem with it except for when I've modified it from its original setup :banghead:
     
  10. wesb1023

    wesb1023 New Member

    Well, its a little too late for that now, I am almost finished with the build. I rode it for the first time friday....what a blast!!!! I still have a few odds and ends to button up, but I will post some pics when I'm done.
     
  11. shawnshank

    shawnshank Member

    Oh I guess I missed that part of the post...sorry haha!!
    What are you getting for a top speed do you know?
     
  12. spokedjoke

    spokedjoke Member

    Wow almost my Exact situation!! im also about to drop big coin on a Tanaka GEBE kit or a honda gxh 50 with Staton, only problem is Now that i got the cash I cant find the PF4000 Gebe kit, only the 33? cc and the Robin EH035 is O.O.S. and staton raised the EHO35 engine almost $100!! Im wondering Where you found the gxh 50, cant find one ANYWHERE!
     
  13. shawnshank

    shawnshank Member

    After re-reading this post today I went on staton-inc.com and saw that they have the tanaka 40cc engine for sale. You can get the engine from them and get the engine mounting kit from GEBE if you like the belt drive / rack mount better. I'm pretty sure that mounting kit from GEBE includes the clutch converter you'd need...just tell them what size clutch when you order it. At $719.00 total...it's not a bad deal at all. If you do decide to go with the GEBE consider buying the heavy duty rim on their site. At $124.00 is well worth the peace of mind you get when you're buzzing around at 35+ mph.

    http://www.staton-inc.com/store/products/Tanaka_Pure_Fire_PF_4000_39_8_cc_2_2_hp_ENGINE_ONLY-249-11.html

    http://www.bikeengines.com/mountonly.htm


     
  14. wesb1023

    wesb1023 New Member

    I got my gxh50 from smallenginewarehouse.com. They were sold out when I checked one day, and the next they had 8 so I went ahead and got one. Anyway, I really like this setup but it's pretty heavy. The staton gearbox is alot heavier than I thought it was gonna be. But riding it, I can't tell how much weight is back there, just wind in my face!! I went with the 16.07 to 1 gear box with 16 tooth sprockets. I got it toped out at almost 36mph. But I have not even put 5 miles on it yet, and have knobby tires and all. I also don't know how fast this engine should turn, the website says 7k, but I have also heard somewhere it should turn 8k rpm. I maxed it out around 7250 rpm so far. I would love to tighten that governor spring a bit if I knew it wouldn't hurt anything!
     
  15. darwin

    darwin Well-Known Member

    Wes if thats a new honda I wouldn't be maxing it out till at least 250 miles on the clock.
     
  16. wesb1023

    wesb1023 New Member

    I will try to take it easy for the first little bit!!! One of the things that has been taking me so long is I did not like the exhaust coming out the front. I bent and welded a pipe on the muffler, so now the exhaust is in the rear. I covered the exhaust pipe with header wrap so it wouldnt burn me if I touched it. Looks pretty cool I guess, I will get some pics up soon.
     
  17. wesb1023

    wesb1023 New Member

    Ok, here it is. I still lack a few things but I guess its far enough along to show it off a bit!!! What do you guys think??

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  18. shawnshank

    shawnshank Member

    I love the look of it...it's nice and clean. What a beast too. I'm surprised you're getting that kind of top end with all that weight and the knobbie tires. Do you know how much the bike weighs? How much do you weigh? I'm just curious to know if I'd get the same top end if I built one with the same engine. I wonder if there is a frame mount that would work with that?

    I'm sure you'll get years of reliable use out of it. Those segmented engine straps with the bolt half way would make me a bit nervous though. I know that on mine (I have the GEBE kit) the vibration caused the bolt that attached the engine strap to the frame to sheer off while I was riding. Just be careful and check all those bolts each time you ride to make sure they are tight. if you can build in a little back up in case one of those bolts snap.
     
  19. wesb1023

    wesb1023 New Member

    Im not sure what the bike weighs, its heavy though. I weigh 210 lbs. I really dont even have to pedal at all either, I could just hit the gas n go but I have been pedaling just to keep my clutch cool.
     
  20. dchevygod

    dchevygod Member

    Looks great but I suggest taking off that stock tank and putting a HT tank on the frame tube so the engine looks a bit smaller and the weight would be better distributed. A question too what kind of throttle are you using?
     
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