New GT2-150 frame 53cc 10G 3-speed shifter

Discussion in 'Photos & Bicycle Builds' started by KCvale, Dec 3, 2015.

  1. KCvale

    KCvale Motorized Bicycle Vendor

    I am all giddy to build on this new GT2 frame.

    A couple of us builders worked with Don Grube last year for upgrades to the GT2 gas tank frame and we got what we wanted.

    [​IMG]

    150mm rear horizontal drop out (hence GT2-150) bicycle engine frame designed for use with 2 stroke and 4 stroke engines.
    Good with heavy duty disc brake axle for single or multi speed sprockets.

    Compatible with coaster, caliper and disc brakes, and can accommodate up to 3" wide tires with enlarged 100mm wide front drop out area.

    The real key changes here are:
    The wider frame at the seat post to accommodate 3" wide tires.
    The old style would only take 2 1/4"

    And the the open rear horizontal drop outs with adjustable left side disc brake caliper mounts as well as a right side derailleur mount so you can get the left chain tight without a Tensioner on the right for internal shifters.
    That means you can use a really good axle tug on the right side with a 3-speed hub to keep it in place.

    Like the original GT2's it also has V-brake bosses, chain guard mounts, and both upper an lower cable routing gussets, and a nice big bottom bracket hole that can take both 3-piece and 1-piece cranks.

    This was all in an effort to build a 53cc 4-stroke internal geared fat tire shifter with my 10G to make a bike like this...

    [​IMG]

    But without the peanut tank...

    Same Kenda 24x3" Flame tires which are actually 26" tall, and an internal 3-speed disc hub.

    This is a scratch customer build so he calls the shots.
    He wants a disc brake Spinger for the look so it's getting this.
    FORK SPRINGER 26 SUNLT DLX 300xTDLSx28.6x30 DISC BK

    [​IMG]

    Everything should be here Monday.
    1st up is what to powder coat the frame and my mounting parts with.

    My pretty close powder coat outfit has to send the frame out to bathed and striped of the coating to clean bare AL, but even then $150 to do the whole frame and my parts from their stock pallet.

    The pallet on the left is stock.

    [​IMG]

    I am kind of digging the textured pallet on the right in the middle, you need to open the whole image, the copper/black one.

    http://glendalepowdercoating.com/fig/colors/PowderBrochure (Large).jpg

    I got another frame for myself too so I'll see, this a custom customer build so it's up to him, with maybe just a little nudging from me ;-}

    The hard part is the wheels.
    The Kenda Flames are under $25, finding 24" matched wheel sets with a disc front and 3-speed disc rear has to be custom.

    For this one I bought a Fito Modena GT just for the the wheels and brakes, fenders and seat.
    I still have to swap the rear hub out!

    I want to get wheel sets made in volume (like 10-20 a month) to cut everyone's cost to have the cool fat tire 3-speed wheels to build any type engine or even electric shifter you want with the frame/wheel set combo.

    I suppose I best see my what local bike shop can do as the one thing I don't dink with is lacing wheels.
    Anyway, all fun stuff and the pics will start coming next week.
     

  2. KCvale

    KCvale Motorized Bicycle Vendor

    Just some catch up...

    The Monarch dual spring twin fork fit like a glove on the frame.
    Unfortunately The Fito Modena's 1" headset wouldn't fit the 1 1/8" steerer tube so I had to get a bigger one.

    To decide engine placement I have a SBP 4-stroke base temped in the frame.

    [​IMG]

    [​IMG]

    That allowed me to use some easy to cut sheet metal to make a template for the 10G long shaft base.

    [​IMG]

    I have the steel version made now and mounted combo goes in for powder coating Monday.
    Then it's time to move the rest of the Fito's parts over.
     
  3. KCvale

    KCvale Motorized Bicycle Vendor

    Here is the steel base temped in place.

    [​IMG]

    [​IMG]

    The unusual shape allows a solid 3 point frame mount using the 2-stroke pedestal.

    All the torque force is straight down right above the pedal chainring between the two vertical mounts.

    [​IMG]

    [​IMG]

    With the engine offset slightly to the right, it allows a straight left side crank arm to clear the 10G and still allow the right side output sprocket and chain to clear the base.

    With the engine mounted forward and to the right with fixed mounting holes it will still work the stock HS can exhaust or any other exhaust, and unlike most bases, no adjustments needed and no issues with the choke, throttle cable, petcock or gas line.

    I am really liking this frame with my system and already working on the design for next years frames incorporating the design right on the frame direct ;-}
     
  4. KCvale

    KCvale Motorized Bicycle Vendor

    Busy week.

    Those darn pesky new customers that want a new bike in time for CostMuch (My new term for Christmas) keep taking time away from this build.

    I finally have the drop in solution for a 10G build on the GT2A-150 frame.

    [​IMG]

    Since the frame is always the same, so is the base.
    Everything just plays so nice together!

    The carrier bearing is right where it's needs to be for a perfect chain line to the sprocket with a tight new chain, to an easy to adjust fixed mount tensioner for when you get chain stretch.

    Then is was strip it all back down.

    [​IMG]

    I dropped it off early this morning for powder coating before I could get good pics, but that's OK, I will take all kinds of pics when it comes back before I build the bike back up.
     
  5. MacZulu

    MacZulu Member

    nice clean work as usual KC
     
  6. KCvale

    KCvale Motorized Bicycle Vendor

    Thanks MacZulu,
    The Sturmey Archer SX-RK3 Internal 3-speed disc brake hub finally got here.
    It's up to the bike shop to get it laced in today.

    Time is getting short, the customer is flying in and renting a truck to take it back home on the Jan 2nd.
     
  7. KCvale

    KCvale Motorized Bicycle Vendor

    OK, not sure what all the fuss was about putting disc caliper on the right side mount for a Monarch duel fork Spinger was all about, it bolted right on with a 160mm rotor.

    [​IMG]

    And the new SA SK-RX3 3-speed disc hub went in the Fitos 24" wheel just dandy too.

    [​IMG]

    Just waiting for the frame to come back from coating now.
     
  8. johnsteve

    johnsteve Member

    why did you lace the wheel the way you did? It looks a bit off to me.

    Also, looking at some other builds on this webstite, I have noticed that many people like the 26 inch wheel in front and the 24 inch wheel in the rear. What is the reason for this?
     
  9. Vapourtrail

    Vapourtrail New Member

    your right johnsteve that wheel isn't laced properly

    the spoke on the left of the valve should be on the other side of the hub flange
     
  10. KCvale

    KCvale Motorized Bicycle Vendor

    I don't lace wheels, I have my local bike shop do.
    That wheel had coaster brake hub, I had him put in the 3-speed, I assume it looks odd because he reused the spokes and the hubs were different sizes.

    The wheels are both 24" with 26" tall tires.

    I picked up the frame yesterday and made some progress.

    [​IMG]

    Plenty more to do still, but it's on its wheels.
     
  11. KCvale

    KCvale Motorized Bicycle Vendor

    Done and out the door.

    Note that some pics were before I added the last stuff..

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Here is the final handle bar layout.

    [​IMG]

    From left to right on the bars:

    Leather covered foam grip.
    3-speed shifter.
    Rear disc brake lever.
    1200 lumen 7.4V LI CREE T6 3-function LED headlight.
    Digital Tach/Hour Meter.
    Analog Speedometer/Odometer.
    Front disc brake lever.
    Leather covered foam twist throttle w/ kill button grip.

    Love it? sure did ;-}
     
    Doug Foster and KenM like this.
  12. johnsteve

    johnsteve Member

    Id like to ask why you used the Sturmy Archer instead of the Nuvinchi hub? Nice build BTW. Might have to ask you about a new build in the future if you dont minkd
     
  13. KCvale

    KCvale Motorized Bicycle Vendor

    You mean besides the fact that they suck for motorized bikes?
    Sorry, bad taste in my mouth from an excited then disappointed early adopter of CVP's for MB's.
    We built six, 3 failed.

    Don't get me wrong here here, Fallbrook Technologies was awesome to me back in 2011 when the first CVP hubs came out, heck they even gave me a free $300 Developers Kit hub, their newest tcomputer controlled automatic shifting version as I was active on their developers website to try it with an engine for free, and just launching their campaign for CVP bicycles with the help of the Cadillac Fleetwood bicycle.

    [​IMG]

    In short..
    They can't handle a gas engine because of pulsing power.
    They can't shift under constant power.
    And you just don't need unlimited shift points even with a small gas engine.

    I actually found my left wrist getting tired from the constant turn of darn shifter.
    Granted you can keep power at it's peak better, but you can't even go from low to high with one turn, you have to let go and start again as the shifter spins almost all the around from low to high.

    Perhaps they have improved the design since then, but even now they still say a gas engine voids the warranty.
    Need some middle gears for hills of faster acceleration?
    An internal geared 5-speed should handle it better than any CVP unless they made some vast improvement.

    Again, I'm not saying they may not be better these days, I just won't trying one any time soon unless Fallbrook gives me another oneto try with gas for free.
     
    Last edited: Jan 6, 2016
    johnsteve likes this.
  14. johnsteve

    johnsteve Member

    Thats really good to know, because I was thinking about buying one. It does look sweet in therory, but maybe the reality is different. Looks like a Strumey Archer is in my future. Just not sure which one I want to buy with disc brakes
     
  15. KCvale

    KCvale Motorized Bicycle Vendor

    If you want more gear look at 5-speed internal, I am actually for something like that form my next build and their be a Nexus that will work, don't know yet, to swamped with builds to research it.
    If you do, pass on the info please.
     
Loading...