Many questions, wanna make a purchase!

Discussion in 'Motorized Bicycle General Discussion' started by ProDigit, Mar 27, 2013.

  1. ProDigit

    ProDigit New Member

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    Hi all!
    I've been browsing this forum for a while now, and using the search engine got a little disillusioned that lots of older search results pop up (2008, 2009 threads), but nothing more relevant (is like finding a needle in a hay stack).

    I'm looking to purchase a bike and an engine kit in the direct future (like preferably yesterday), but I want to do a little more research, before possibly ending up disillusioned, or paying a lot more because certain parts don't fit.

    Let me introduce myself:
    I'm 6'3" tall, and 170LBS.
    I live in South Florida, Miami, where the weather is hot, and there are almost no hills.
    I would love to get a bike that would go ~40MPH(faster is a bonus), and has great gas mileage nearing 150MPG (if that be possible); all while keeping a budget. It will mainly be for a fun ride, to discover the neighborhood.

    For the bike:
    I found Walmart sells bikes below $200 USD, which is good enough for me. I want to make this a cheap but good project.

    I was contemplating between buying a $200 32in wheeled cruiser bike from Walmart, because they sit me comfortable; or one with no less than 29in wheels, depending on how it fits the engine.

    The 2 bikes I had in mind:
    http://www.walmart.com/ip/32-Genesis-Men-s-Beach-Cruiser-Bike-White/20658229
    OR
    http://www.walmart.com/ip/Genesis-Onyx-29-Cruiser-Bicycle/16203481


    About the engine:
    I most definitely would prefer the 66/80cc version over the stock 49cc version, as I need the extra torque to reach higher speeds.
    I'm not so concerned about acceleration too much (it is important, but less important to me, as I would accelerate with pedals from a dead stop.
    First pedals, then engine and pedals, until a cruising speed has been reached of at least 20MPH, and then go from 20MPH up in speed only using the engine.
    I live in the suburbs, with a lot of 35-40MPH roads, with little stop lights
    Of course, I wouldn't want the engine to take forever to get there neither!


    From my knowledge with scooters and mopeds:
    Though 2 different beasts, I know that a 3.3 BHP gets speeds of upto 50MPH, and a 2.7-3BHP gets speeds of upto 40MPH; while a 2BHP usually gets speeds of upto 30MPH, and a 1BHP gets speeds of upto 25MPH.
    This engine has 2.7BHP, so speeds of upto ~40MPH would be really nice.

    I presume gearing it to go 50MPH will not be possible (over geared).

    Since I want to get a bike with 29-32in wheels, I assume my top speed with the stock 44T sprocket will be higher, according to the FMLA (formula):
    Speed High = Speed Low x Large tire dia / small tire Dia, or:
    32MPH * 32in / 26in = 40MPH;
    So, if a 26in wheeled bike goes 32 MPH, a 32in wheeled bike should go 40MPH (neglecting the added wind and friction resistance)
    It would be the same as if I had equipped the 26 in wheeled bike with a ~36T rear sprocket.


    So my questions to you guys would be:
    1- How does a 26" bike ride with a 36T sprocket (on a flat ground with someone on it that's less than 170LBS) (does it take long to accel? ; what's the top speed and top RPM? )?
    2- Are there any differences in the engine kits out there, save for 49 vs 66, or black vs silver? (I probably will be buying from eee-bay)
    3- Are the Ebaay kits any good?
    4- Should I buy a black engine, because I fear that those cheap chinese exhausts will rust like crazy!?
    5- How can I know which bike fits the 9 screw sprocket (when buying online)?
    and lastly:
    Do you have a recommended bike and engine kit for me, aside from the ones found on evil bay, and Wall mart?


    Thanks guys!
     
  2. Toadmund

    Toadmund New Member

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    Well, OK, you want to go 40mph.

    I'll tell you about my bike, 66cc ,My mods consist of, polished head dome, notched cylinder skirt, wide intake pipe, ported exhaust and trimmed gaskets also trimmed gaskets in transfer ports.
    I use Echo powerblend 2 stroke oil (I have Opti2 I haven't tried yet)

    Ehh.. what else....
    44 tooth sprocket.

    On a flat I hit 58kmh or 36mph, but on a slight 2Degree slope up to 63kmh or 39mph or with a 70kmh wind behind me ;)

    I am keeping my 44 tooth as I live in a hilly area, but if you went down in teeth and with a 29" wheel you should be able to hit those speeds (my guess) But you'll have less torque.

    And believe me pal, those speeds are scary on a bicycle! You'll be happy even if you don't reach 40mph.

    I'm 6'2' and 170+- lbs
     
  3. ProDigit

    ProDigit New Member

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    Thanks!

    I have a 50cc scooter, and regularly go over 45MPH. (motorcycle too, and what is scary is going over 100MPH).

    I do agree, that anything over 35-40MPH just feels less comfortable, as in "should there ever be a frontal accident, it will be catastrophic"-kinda like.
    However once you get used to the faster speed, it's less scary.

    I mainly want it to go 40+MPH, so that I my avg cruising speed does not have to be at WOT, as most of my cruising will be done between 30 and 35MPH.

    I think of just keeping the 66cc engine stock, perhaps put a performance exhaust, if I find any, and look if there's something I can do to the intake or not.
    For MPG reasons, once the break in is over, I will run the bike lean; and compensate by putting Premium gasoline from BP (which is higher performing than any other brand out there), and get a high ratio oil mixture (like between 60 and 100:1). I think that will increase my speed the most.

    But other than that, just finding the right sprocket, which is not too slow in acceleration, yet gives great top speed.

    I'm a little worried if I get a bicycle which the sprocket does not fit on...

    I'm also worried that if I do buy a single speed bike, that I'd either have power to accelerate with pedals, but at cruising speed won't be able to aid the engine (due to the high speed); or have power to aid the engine at high speeds, but not have the power to accelerate quick enough from a red light with the pedals.

    For that I've been reading up on 3-speed beach cruisers, however I heard the transmissions get pretty hot running at such high speeds.
    It would be nice if someone could confirm this, or if it's just a rumor.

    Thanks!
     
  4. Wild Bill

    Wild Bill New Member

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    Prodigit, Im new at this also and like you I am hoping for around 40 mph top speed and cruise around 30 mph. So far with just 2 hop ups, carb and SBP pipe I am at just up to 35.8 mph top speed after playing with the jetting.

    I have just got a Puch high compression head and Jaguar cdi that I havent put on yet, the head should give me more torque and the ignition has an advance curve that should help top end so with those 2 mods I am thinking I will be around 38-40 mph top speed but we will see.

    You got to remember that you cant hold the top speed for long and have the engine hang together for too long.

    Also you may want to consider the SBP shift kit, it helps get up to speed and going up hills though you say its pretty flat where you are.

    Also if you are gonna go that fast on a bicycle on city steets you neeeeed very good brakes! If you go with rim brakes you need v-brakes imo. But I would say really drum or disc brakes are the way to go. I have disc front and rear and in traffic they can be a life saver or at least a bike saver!
     
    #4 Wild Bill, Mar 27, 2013
    Last edited: Mar 27, 2013
  5. 2door

    2door Moderator
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    Prodigit,

    Gear high. I know the terrain where you live well and hills are non existant. A well tuned 2stroke with a 36 or even a 32 tooth rear sprocket should be able to provide your 35/40 desires. You also have the added advantage of sea level tuning. That can be significant where horsepower is concerned. You'll need to pedal assist from dead stops but from there the engine should provide enough power for you.

    One thing to remember and it was mentioned above by Wild Bill, brakes, brakes, brakes.
    It is a bicycle, not a factory designed or built motorcycle. It has bicycle wheels, bearings and bike brakes. Before you get too involved with attaining high speed, make sure you can stop the thing. I'm a disc brake fan and user but drum brakes get good reviews too as well as quality rim brakes with the right pads. Rear wheel coaster brakes are fine as long as the front has good brakes. Rear coaster and front disc works well together.

    As to your sprocket question. The 9 hole sprockets are designed to fit a wheel with 36 spokes. Some members have adapted them to a 32 spoke rim but it isn't recommended.

    Not sure what you mean about "transmission" not holding up. Are you talking about the rear hub? If so, the hub isn't in play with engine power. Only if you install a so called "shift kit" will the rear hub be subjected to engine power. Otherwise only the bearings are under any stress and that's not a concern if they're well lubricated.

    Good luck and let us know how you're doing on your project.

    tom
     
  6. biknut

    biknut Active Member

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    Just be advised, no matter how you do it, dependable 40mph riding with cost about $1000. Key word, dependable.

    All my 80s will do 40 mph, but stock Walmart parts only last about 100 miles at that speed. Expect to do a lot of upgrading in the first year.
     
  7. chainmaker

    chainmaker New Member

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    Brakes, brakes, brakes, and like Bikenut said, key word dependable.
     
  8. ProDigit

    ProDigit New Member

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    Thanks for the advise!

    I feel like I've learned a lot from this forum!
    Indeed, I agree with the disc brakes. I just wonder if they are easy to install on a beach cruiser's front wheel.
    Since I have a beach cruiser, it probably has a rear pedal brake, I probably can only install one front disc brake system.
    I'll scout Ebay for some answers on that!

    I had one concern, that, I saw one passing by today, and man, those things are loud!
    Almost as if he was riding without a muffler.
    If they are that loud, perhaps drilling in the pot to get a better exhaust flow is not such a good idea.

    Are there mufflers that are silent for these bikes?
     
  9. ProDigit

    ProDigit New Member

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    100 miles?
    I think that may be a little exaggerated...

    If anything, the engine does aid in the braking process (engine braking).
    The bike's wheels (29in) will rotate about just as fast at 40MPH, as a 24in wheeled bike does at 33MPH, or a 20in wheeled bike at 27MPH.

    I may want to equip the axis with some thick grease (perhaps lithium grease).
     
  10. Toadmund

    Toadmund New Member

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    I lube my bearings with slick 50 motor oil engine treatment.
    Go Teflon!
    I dilute about 50/50 or sometimes 2 parts paint thinner and 1 part slick 50, so when I oil my chain the paint thinner evaporates leaving a nice thin film on it.

    Never have problems with my bearings, they never seem to wear out.
     
  11. chainmaker

    chainmaker New Member

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    If you have a coaster hub you would need to change the hub for disc brakes. Venice motorbikes sells a rear adapter for calipers if you go that route. As far as noise goes I ran an expansion chamber with a Briggs muffler and it wasnt so bad.
     
  12. d_gizzle

    d_gizzle New Member

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    Man,I'm glad I left Florida! Apparently Jeb Bush wasn't the problem.
     
  13. ProDigit

    ProDigit New Member

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    I always say I wanna buy, but then some things show up, and I notice, I have to spend more in research.
    Initially I was fine with buying a $89 bike from walmart, and add a $150 kit on it, but seemingly there's a lot more that goes on, and by careful research I can filter out some disappointments I may have in the future for being so cheap!

    So the bicycle I'd love to have, must have shocks like a mountain bike, must have a front disc brake, must have a comfy saddle like a beach cruiser, and must host the 66cc engine kit with ease; and on top of that, it must be cheap enough for me (and my wife) to still consider it an affordable hobby.
    For instance, my 50cc scoot costed me $800, delivered to the door. It does 50MPH on a good day.
    I have no complaints on it, it works perfectly fine.

    I'd like not to spend too much, so preferably stay under $400 ($150 for the kit, 250 for the bike or something).
    I don't care if it lasts long or not, just as long as I can have a few months of riding pleasure out of it, and learn, perhaps in the future I can upgrade to better material.
     
  14. biknut

    biknut Active Member

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    If you keep your speed down to something like 20 mph, a walmart bike would last a while longer. You have to take into consideration it was designed with about 10-15 mph top speed in mind.

    When you start going 40 mph, everything has to be heavy duty bicycle quality. Not much on a $100 Walmart bicycle can be considered heavy duty.

    Another thing you might want to look into is legality. In Florida a china girl style motor bicycle should be considered legal, but it seems like the state authorities have some kind of vendetta out for them.
     
  15. Wild Bill

    Wild Bill New Member

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    Prodigit, you can do these on the cheap and still have a good bike but it more depends on the person doing it. You seem to be doing it right by researching things first and all it takes is a fair amount of mechanical aptitude which you seem to have covered also.

    As for a front disc, you need a fork that has disc mounts and a front wheel/hub with disc mounts also. Both fork and wheel can be found cheap.

    If you want a full suspension bike they can be hard to find on the cheap, theres a couple of GT LTS bikes like mine on ebay, one is a buy it now at $300 complete bike but its been there a while so he may take less if offered. Theres a better one that has a starting bid of $250 complete bike. The $300 one has a rear elastomer suspension instead of a shock, not quite as good as a shock. Theres a thread on the forum on compatable frames for these things in the mountain bike section, and a few build threads.

    But a full suspension bike isnt that big of a deal on the street, just a good suspension fork, lower air pressure in the rear tire and a soft seat will be fine.
     
    #15 Wild Bill, Mar 27, 2013
    Last edited: Mar 27, 2013
  16. noah.w

    noah.w New Member

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    I Agree with you tom, i got my bike going last night with a 32 tooth rear sprocket i hit about 36 not broken in yet, cant wait to get it broken in and see how she really goes. And as people have said before 40 MPH on a Walmart pedal bike is scary, be careful and check and grease your bearings
     
  17. chainmaker

    chainmaker New Member

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  18. ProDigit

    ProDigit New Member

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    I find it strange that on a 66cc engine, your top speed is only 40MPH!
    The numbers just don't add up...

    while on a 4 stroke scooter with 50cc you can get at least 40MPH.
    The 2 stroke scoots (with variator) sometimes reach 60MPH.
    Makes me question if the 66cc is really a 66cc, or a 33cc 2 stroke (2x stroke from a 4 stroke, thus compared to a 66cc 4 stroke)?

    This makes me believe most people haven't optimized their bikes yet.
    If the 2 stroke 49cc can get to 45MPH, with 29-32in wheels, and a 32T sprocket, I'd probably go with that one!

    Again, being able to go 45 doesn't mean I'll go 45. It just means I'll be riding 28-32MPH more comfortably (on lower RPM's).
     
    #18 ProDigit, Mar 28, 2013
    Last edited: Mar 28, 2013
  19. d_gizzle

    d_gizzle New Member

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    I didn't know bicycles were made for over 20mph? So if I buy a bike from a bike shop I can just ride it? Bearings and everything else self lube or something? If frames and components are different but you telling me that the Nirve Street King was built for high speed? The Jesse James bikes? ANY bicycle manufactured as solely a bicycle? Kinda like the chain isn't strong enough on a pedal bike,so where are the factory bikes with 415 chain? Felt is about the only brand that appears to be making bike frames for the motorized bicycle community.
     
    #19 d_gizzle, Mar 28, 2013
    Last edited: Mar 28, 2013
  20. noah.w

    noah.w New Member

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    The thing is the 50cc runs smoother and higher RPM and is easy to get high speeds out of, the 66cc is a larger piston and runs a little rougher, but has a little more low end to it. I have a 32 tooth sprocket on mine and not broken in it scoots along great and at realitivly low RPM
     

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