I moved to Colorado... time for a shifter!

Discussion in 'Rack Mounted Engines' started by dchevygod, Apr 2, 2014.

  1. dchevygod

    dchevygod Member

    I have an axle mounted LSD G43 on my current bike. IMG_20131205_225950_969.jpg

    I have a Flowsystem tuned pipe for this motor but can't mount it, where the motor is positioned it would be hanging off the left side considerably. I can just see myself smacking a pedestrian with it or something else and snapping the pipe/mounts or even the topend!
    This is my motor on a GSR goped BTW.
    If I move the motor to a rack I can have some new pipe mount tabs welded on and use it "fingers crossed" the topend has to be flipped to mount the pipe on a goped. I've since put it back to stock because my trans reverses rotation and the air filter/exhaust would've been backwards

    My concept is this, fabricate a beefy rear rack for engine mounting. Find a splined #41 6t sprocket to fit my 5:1 trans and drive the 7spd cluster off engine power with the biggest best quality chain that's going to fit the derailer. The derailer may work as is, or may need repositioning IDK yet this is all in the planning stages.

    My rear rim is a dual drive so the pedal power will be moved to LSD in a single speed, "geared high so I can pedal assist at higher speeds" as it is I can't assist past 15-18 mph. That doesn't suit my needs, I have had this single speed setup up to 50 mph "5:1 trans-11t pinion-44t drive and 4+hp" on a straight flat run.

    Even if I leave my bike single speed I want higher pedal gearing. I guess my best bet is to increase the crank sprocket size instead of changing gear clusters?

    If I do build the shifter I'll use a 16t on the left side drive hub and a bit smaller crank sprocket than I would have setup as a single speed? I'll have to get it together to test some gearing options and see what works best for me.

  2. dchevygod

    dchevygod Member

    Any recommendations?
  3. dchevygod

    dchevygod Member

    I'll never use a China girl motor. Sorry, but I just don't use kits. If I were to center mount a motor and use a shift kit it would be a CY460R on a four stroke center mount plate, on an occ or wcc chopper bike.

    I read constantly about how those China girls are just junk until they are rebuilt almost from the ground up, the cdi is weak, the bearings are poor quality, the transfers are restricted, casting is of poor quality and almost all the head gaskets leak from the factory or shortly after beginning to break in.

    Also I'm not fond of how the sbp shift kit has a freewheel crank, exposed jackshafts and all the different length chains. It seems a bit dangerous to have a buzz saw spinning right next to my ankle!

    I'm glad you can haul your trailers with ease, I know the ht's coupled with a shift kit make for a decent bike. But just like a mini 4stroke huasheng I'll never buy Chinese junk again, one too many bad experiences.

    I always design my concepts to use existing proven reliable parts, goped motors are awesome for reliability and in stock form, more powerfull than a ht or China girl pound for pound. The aftermarket is vast and the engines are readily available since Gopeds have been around for awhile.

    Not to mention the cc limit on MB's here in the states is less than 49cc, I beat two tickets because I could prove my engine was no bigger than 49cc, 29cc in fact and not with a sticker! And the center mount looks more like a motorcycle bringing unwanted attention from the fuzz. I already go too fast I want it to look mostly like a bike.
  4. dchevygod

    dchevygod Member

    Of all the ht's I've worked on I have yet to really be impressed by them. Fun? yes, cool? kinda, reliable? not in my experience. I can't leave a motor stock its not in my nature! And those engines start fragging when they are modified to produce good power.

    If it won't handle 10,000+ RPM with a stock Bottom end I won't use it. These start coming apart at just over 8500 RPM " dyno tested a stock 66cc " then ported the top end, used an msd ignition from a goped and used a pumper carb for another test, just before it hit 9000 RPM "loaded" the needle bearing fragged, snapped the con rod and broke the piston into pieces. Only 20 min of run time? Tuned real rich to prevent a lean seize and it fragged the bottom end real fast, count me out!

    To each there own though if it works for you use them. I bet you never revv it really high because of the shift kit so yours should last.
  5. dchevygod

    dchevygod Member

  6. Fabian

    Fabian Well-Known Member

    Crikey, i am sorry about posting incorrectly. I should have looked more carefully.

    Let me delete my posts.
  7. Fabian

    Fabian Well-Known Member

    posts deleted
  8. dchevygod

    dchevygod Member

    Not trying to be mean I thank you for your input Fabian, I'm just a weird dude that doesn't like conforming to the norm. I haven't seen a rack mounted shifter so I thought I'd be the test dummy LOL.

    Sorry I didn't mean to offend you, truce?
  9. Fabian

    Fabian Well-Known Member

    In no way have i find your comments "mean", because you are just exploring a different method for powering a bicycle.
    Although i prefer the technical aspects of a centre mount design; being more closely related to motorcycle design by having the engine at the more preferable centre of mass, it isn't the "only" method to achieve reliable transportation.

    I just checked in to see what was happening by clicking on the "new posts" tab at the left hand top corner of the forum page.
    It was my error that i didn't check the location of the thread.

    No harm done, and no offence taken.

  10. dchevygod

    dchevygod Member

    The real reason I want to mount the motor to a rack is the use of my Flowsystem. Well I could just make another gebe style custom and boom. I'll dig up the first revv vid of this pipe from the previous owner. Its unexplainable.
  11. dchevygod

    dchevygod Member

    This is the first motor this pipe I have was on.
    It hits insanely powerfully on three different bands

    This one is my motor right after I installed the Flowsystem on my buddies GSR40. I traded a stock Chung yang 4.2hp 460r for the Zenoah G43 and pipe. I had just put a new ported top end for him "flipped for the pipe install" I love this motor&pipe combo!

    The other motor is not ported with an old school pipe I don't even remember the name
    Last edited by a moderator: Dec 15, 2015
  12. Fabian

    Fabian Well-Known Member

    Impressive pipe work.
    dchevygod likes this.
  13. darwin

    darwin Well-Known Member

    Dcchevy buy ya a tuba then when riding you can blow your horn too, for the exhaust I mean.
  14. dchevygod

    dchevygod Member

    I know its kinda obnoxious! But really the videos don't do the symphony justice! These pipes are made for 3 different motors "G43,CY460R & G62 conversions" by a goped engine building ledgend "Eric Hill" that owns and operates Flowsystems.

    There is no other pipe that sounds and performs this good. That's my opinion but there are several that share it. I do believe in the old adage "loud pipes save lives!"

    Darwin do you want a pic of me playing the Flowsystem?
    I did play the trumpet, and do have to admit I did blow my own horn when I picked it up LOL. It sounds like a dijerydu, if I spelled that right?
  15. cpuaid

    cpuaid Member

    it's insane what people in the goped / powerboard scenes can do with a small 2-stroke engine. many of the small engines i acquired for my motorized bikes came off from them. powerful and super reliable.
  16. dchevygod

    dchevygod Member

    I concur. Also very easy to upgrade/port. The small clutches kinda suck with as much power the RC motors can make. I have a GSR 29 ported and piped, long story short 54mm clutches don't last long while racing/spirited riding, if geared for speed. 45mph, 8:68 gearing on a 10" pneumatic dot rated tire. If you haven't ridden a fast GSR your missing out!