40 MPH Club

Discussion in 'Motorized Bicycle General Discussion' started by massdrive, Aug 10, 2014.

  1. Nopedaling

    Nopedaling New Member

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    My speedo's are spot on and I have also was Stopped by an officer for going 40 in a 25mph zone downtown Atlanta.. My motor is also from rose326a on ebay
    as well.. She has the goods! xct2
     
  2. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    Prolly cuz yer an old phart like me and you know what we are capable of doing? Well I'm not that old, I won't be 57 for two more weeks.....still a kid at 56yrs. old :D

    Anyway, after I broke the exhaust port off my last Tanaka 47R I started running super high revving GoPed 46cc engines on my scoot. Next thing ya know was hitting 52mph on a fully tricked out CY46 Trevor Simpson engine on my BladeZ. On 10"tires standing 6" off the ground going 52mph.......it's a little more than exhilarating, it's down right scary FAST!

    It is fun to go fast sometimes but you should always know what the consequences are if you get outta control and how badly you could be hurt or killed. Just thought I'd share this cuz I didn't make it this long in life riding like an idiot like some people might think.....I do know better and it's from experience. And when I say 40mph......I can back that up

    And congrats massdrive (^), hope we can get together and ride someday!

    scotto-
     
  3. thatsdax

    thatsdax Member

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    ok. Installed a 36T Hit 35mph.. I just do not have the power to go any faster on this bike with this build at this altitude. . I will look into some engine mods and try again. Also. I may consider a Different bike. The current bike is a Diamond back Mountain bike, heavy with knobs which hurts a lot.. I may try a Fixe with 700c. Will let y'all know what happens... Enjoy the ride...
     
  4. thatsdax

    thatsdax Member

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    Ok.. Put on a Chrome Banana and it upped me 1mph !! So.. The Chrome Banana is better than a worked Chromie !! Cool.. I had thought it would be better since it allows for expansion right off the exhaust manifold, where the Chromie has the Chrome conduit all the way to the chrome canister which is restrictive until it gets to the canister and then allows for some expansion.. But.. The big boost came when I ramped the piston !! The bike then hit 38mph !!! Wow !! Keep in mind this is a new piston and ring set that has only 2 miles on it. I still have a good cross hatch in the cylinder so it will break in eventually and make more power.. I may pull the piston and ramp another millimeter off it at the exchange ports.. The theory is that when something is done and good happens.. Do more of it.. Right ? lol .. I think this is a good excuse to buy that Fixe and install one on it.. This is fun.. In aggregate.. The biggest improvements have been, up the BMEP to 118, RT Carb and Chrome Banana, and Ramp the piston.. Those 4 things have increased my power by 4 times over stock and stock settings... Note: the Chrome Banana I am using is the version with out the extra muffler at the tip.. So.. This pipe is louder, but not objectionable . Enjoy the ride..
     

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    #24 thatsdax, Aug 12, 2014
    Last edited: Aug 12, 2014
  5. thom

    thom New Member

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    hi,

    i reached 59mph on gps with my setup + 36 tooth rear sprocket. And i can tell that i did not reach the max top speed, there was still power but i had not the equipement protection to reach more than this :p


    [​IMG]
     
  6. thatsdax

    thatsdax Member

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    We are 6000 feet high. racers equate us at 9000 feet due to lack of humidity.. So.. We are way way down on power here.. What is your altitude? Also , I have no valves as I can see you are running Reed Valves. I have no intake or exhaust valves... I do have a 10hp 48cc Liquid cooled 2 stroke version with reed valves.. But that is for future use and I know that engine should break the 50mph barrier even here at my altitude.. But for now. I am running my standard Port valving motor.. I will not valve it...
     
    #26 thatsdax, Aug 13, 2014
    Last edited: Aug 13, 2014
  7. KCvale

    KCvale Well-Known Member

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    Ohh for crying out loud...
    Don't measure in KPH and quote your speed in MPH...

    [​IMG]

    36MPH is respectable for direct drive, good for you!
     
  8. thom

    thom New Member

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    i said 59mph... this mean 96km/h



    look at my video; with 56 tooth in sand;
    https://www.youtube.com/watch?v=HOK9DsKZ_KQ
     
  9. thatsdax

    thatsdax Member

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    I can see he is running a Reed Valve motor.. It is possible to approach and even exceed 100kmph with 50cc reed valve 2 stroke motors.. It is very very hard to do at my high altitdude. Rule of thumb is 3-5 percent loss of power for every 1000 feet. Depends on Pressure density.. In my case.. I am trying to find the requirements at my location to enter the 40mph club. I am very close now as I was able to hit 39mph yesterday with the build seen in the pictures..

    And yes.. I did go out last night and buy me a Fixe at Wally World for 99 bucks !! It is a great deal.. This fixe is made by Kent which is a good name brand but bottom end Kent for sure. Brakes are ok, Frame is steel, Spokes and front hub are lower quality. Everything else on the bike seems top shelf.. It looks well enough to handle 40-50mph. If I were going for 50-60 mph, I would get a Mazi , Condor, or Pinarello road bike made for speeds such a those.. But.. I only want to break 40mph for now. I am going to do another build similar to the one on the Diamondback. The only Change I will make is to do a 3/4 Ramp on the piston instead of a 1/2 ramp. Everything else I will make the same.. The difference will be the bike, and increase the ramp to 3/4. I will then test and see.. Wish me luck !! pics coming
     
    #29 thatsdax, Aug 13, 2014
    Last edited: Aug 13, 2014
  10. FFV8

    FFV8 New Member

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    Guys look closer, thom's bike is not a China Girl.

    i would call it a "China Case" - that is basically a racing Moped engine stuffed in there. Moped reed valve cylinder (not a ching chong 3 port with bad timing) parked on top of the Moped crank with about 4mm more stroke. He is at 78cc's or so. Yes, it will spin to 13,000 rpm I would love to see the dyno sheet.

    How about some actual specs on the engine thom?
     
  11. stinkfoot

    stinkfoot New Member

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    I hit 40 miles per hour when my exhaust baffle fell off. The bike runs GREAT! Sounds like a motocross dirtbike!
     
  12. thom

    thom New Member

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    closer pic: [​IMG]


    The spec of this cylinder matched with the exhaust should be arround 16-18hp peak at 10.000rpm. I adjusted the squish 0.50mm (0.020inch), i removed about 0.005 inch from the head, and made a little bit of magic inside the port. I beleive it should be arround the 18hp.

    dyno of similar setup with same cylinder are about 10whp (a lot of loss due to the belt of the scooter) [​IMG]
     
  13. knightscape

    knightscape Member

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    Don't let me rain on the parade, but Kent isn't the same manufacturer it used to be. A few years ago, some of the mass producing companies out of china started buying up a lot of the "old names" of cycling; Dawes, Windsor, Kent, Motobecane, etc. They share none of the lineage of those former companies' design, engineering, etc. At this point those bikes are just as good as all the other bikes rolling out of several of the massive producers over there, alot like the HT or Huasheng engines. That is to say they are just fine for most purposes. And don't get me wrong, I actually have a Kent tandem that my wife and I ride together, it's cheap and awesome, but it's not really a Kent anymore, if you take my meaning.
     
  14. Lightning Boy

    Lightning Boy New Member

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    My second DIY project, the 66cc chainsaw bike (FD)- has only been up to 32 mph so far, but I'm sure it can go faster. Haven't been brave enough yet to push it farther. I can't say I feel safe at those speeds on a 20" BMX. I usually cruise under 30mph, but I normally run out of courage before that thing runs out of throttle.
     
  15. thatsdax

    thatsdax Member

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    Ok.. I built another 38mm Stroker motor. 3/4 ramp, Slant plug head, Modified Chromey Exhaust and RT HP Carb. Install on the Fixe went well.. I love the Steel Frames.. I was able to use the Fixed Sprocket on the left side to simply bolt on my 36T. I did it old school as the holes in the 36T matched up perfectly with the Sprocket that came on the bike !! So..For those of you that do not like the Sandwich, this setup is for you !! I love the overall install and the bike. I was not able to use the Chrome Banana expansion chamber as there was nothing I could to to keep it off my font tire since the forks on this bike are pretty much straight. So.. I had to go with the Modified Chromee. Also. I did not intake port match.. And so..With that.. I have been able to hit 36mph so far on this bike.. Disappointing? humm.. Maybe a little.. But 36 is fast and I love the bike.. Too bad it is sooo tough to bend and make the Chrome Banana fit as it really does add power.. I will port match the intake and see where that takes me... Anyway.. Enjoy the pics.. Enjoy the ride.. :)

    O yes.. I removed and replaced the Rear Wheel reflector to the same position as the valve stem. This balanced the wheel... Weird.. Eh ?
     

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    #35 thatsdax, Aug 15, 2014
    Last edited: Aug 16, 2014
  16. CranbrookKid

    CranbrookKid New Member

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    Hey thom, you should make a build thread of your bike. The idea of a china motor/moped hybrid is intriguing to say the least.
     
  17. rogergendron1

    rogergendron1 New Member

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    FINALY !!!!!!!

    YOU JUST INADVERTANTLY GAVE ME SOME INFO I WAS LOOKING FOR ABOUT OPTI 2 !!!!

    i was wondering how well it would hold up under sustained high rpm driving, as it turns out that with 26in wheels and a 36t rear and you going 43mph your motor should have been turning around 8,000 to 8,500 rpms for quite a few min !

    i would love to see this done at 40 with a 44t rear but over 8,000 rpms is what i was after when looking into opti 2 for race driving and it would apear you put it right up there..

    how well did the bike stay at the proper operating temp ? did it over heat ?
    and have you taken off the head and looked into the jug for scoring ???

    i would like to know whaT YOU THINK ABOUT THE PERFORMANCE OPTI 2 OFFERS AT High rpms from your experiance so far and what mix ratio were you useing ?
     
  18. massdrive

    massdrive New Member

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    As I said I only ran that speed for a short distance, about 100 yards. So I was running at WAT for only a few seconds. Also weather conditions were unusually ideal. Here in Vegas the air is extremely dry maybe 10% humidity on any given day, for instance today we only reached 6%. Last Sunday morning the ski was overcast the temperature was only in the 80's and there were thunderstorms surrounding the valley. The humidity was a whopping 40% lol and no wind. Rare conditions here in Las Vegas. I had a freshly cleaned air filter, a fresh spark plug gapped at .035". I inflated the tires to the maximum 65 psi, and I mixed the fuel just a little lean. Normally I mix precisely 2 ounces of Opti2 in 1.5 gals. of premium gas. That's a little less then 100:1. On this day I mixed the fuel a little lean because of the weather conditions I wanted to do a speed test. I mixed 1.8 ounces in 1.5 gals of gas. That's a little more than 100:1.
    So in answer to your question the bike did not over heat and I road another 5 miles to get home cruising at 30 to 35 mph. About 150 miles ago I checked the piston and cylinder and all I found was a little carbonization on the piston, fare less then normal.
    All I can say is that I was hesitant to use Opti2, but after running close to 600 miles with it I am sold on the stuff. I don't have any hard stats, but my engine is noticeably smoother, quieter, revs a little higher, and is more powerful, I picked up 3 mph immediately after switching to Opti2. I don't have a temp gage, but it seems to run a little cooler too.
    I hope this answers your questions...
     
  19. mrfubs

    mrfubs New Member

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    hey tom! im gonna share your videos so everyone can see what a difference that jug makes. hey what size jets are you running to feed that thing btw?


    https://www.youtube.com/watch?v=HOK9DsKZ_KQ&index=6&list=LLcBEG4q7OB8MQRdyqUSIgWw

    alright so a interesting fact at 13000 rpm guessing the piston and goods weigh 109 grams and the stroke is 1.61 inches along with a 4.33 inch connecting rod all on assumptions

    Effect of Rod/Stroke on TDC and BDC inertia force:
    Your Upward Inertia Force at TDC is 1,101.29 pounds.
    Your Downward Inertia Force at BDC is 756.00 pounds.

    i my self have reached my new top speed of 50mph on the dot according to my phone gps. youll see it under the zero says MAX
    Screenshot_2014-08-13-22-23-241.jpg
    CAM002021.jpg
     
    #39 mrfubs, Aug 15, 2014
    Last edited: Aug 15, 2014
  20. thom

    thom New Member

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    jet #130, carb is a stage-6 edition but in fact its a kehein pwk 21mm with power jet.
     

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