Home built full suspension custom frame pics!

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StevenMain

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Jul 18, 2016
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I know, Ill need some more flight hours for those though lol..

I also want to paint her up when finished and add some mudguards and maybe pitbike plastics
 
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cannonball2

cannonball2

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Oct 28, 2010
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Kinda hard to tell from the pic, but looks like the idler is on the wrong side of the chain run. If its spring loaded or flexes under high loading then the chain will try to pull it inward and out of alignment under high power. I have run idlers occasionally on the wrong side when its the only way but wasn't dealing with the power your engine makes.

Just an observation.
 
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StevenMain

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That's a good observation. It is indeed on the wrong side but it was the most expedient thing I could come up with and I do believe it might work. It has a nice little groove I cut in it which keeps the chain in line entering the motor. The chain has been flopping off the pedal mainly so another something is needed. If seen chain drive systems with tensioners on the slack side and with tensioners on both sides... never on the drive side only like I have atm you're right.
 
KCvale

KCvale

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Feb 28, 2010
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With derailleur gears you want a jump-stop attached.

It normally goes on the seat post, but what it does is guide the chain onto the drive sprocket when you are using the big inner sprockets on the rear wheel.





There is not much you can do for small outer sprockets and it makes the chain jump in between the 2 front sprockets which really sucks as it get caught on the sprocket bolt ends. TIP, and you have you front sprocket assembly together, grind off the remaining bolt off down to the nut so the chain don't get caught.

This is why I much prefer a single sprocket internal shifter.
 
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StevenMain

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Thanks for the reply KC but it's actually not the deraileur chain I have been having trouble with. It's the engine to crank short chain. I'm going to build a new tensioner or idler on the correct side of the chain and see how that goes.
 
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StevenMain

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I just spent a few hours riding, and finally beating the piss out of my bike... and forgetting it only has a single front brake hahahaha. Anyway seems all is good except for breaking the ****ty sram PC1 chain. I think a KMC 410H is all I need. It's 20% thicker on the side plates.. I didn't have one derailment in a few hours. Just broke chain 4 times. The clutch slips a bit in gears higher than 3rd so I'm going to put the ceramic pads in when I get a chance too. I'm having a blast on this bike. The power and speed are amazing.
 
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StevenMain

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Cannonball, I just saw your Sturmey Hub transmission. I LOVE it.. you only need 3 speeds anyway! I need to look into it more for a new build!
 
cannonball2

cannonball2

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Oct 28, 2010
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I have done so many builds that I tend to purge details over time. Basically you need the hub and two sprockets. The inner one is the modded one. In the link I give the (sketchy) details. As I remember the inner sprocket is from an SA 7\8 speed hub. Its bigger diameter just fit over the inner shoulder of the SX3. The inner sprocket is drilled to fit the spoke holes and held in place by#10 allen screws and nuts. Plenty strong with the # used. That's pretty much it. The rest is what ever it takes to make it fit what ever you are doing. Frame clearance on the left is most critical. This frame was a $99 Walmart fixie dropped to 26" MTB wheels. The rear wheel is offset by design to the right, this really helped it work out.

Unlike most IGHs the SX winds up in 1:1 in high. Plan your overall(fixed by the sprocket #s) ratio as high as you think the engine will pull it. The other two gears are lower. I guessed wrong the first time as the engine will pull a higher ratio at speed. Try to find a hub with the thumb shifter. The bar end it came with sucked!

The advantage of this hub is its locked(no freewheel). You can pedal start it and you have engine braking. You can even gear it down like an M/C. Also like most IGHs if you come to a stop in the wrong gear just shift it, it doesnt have to be moving like a derailleur shifter. This bike rides and sounds like a M/C reminds me of a Harley Hummer I rode when I was a kid.

This is a very simple complicated build!

http://motorbicycling.com/showpost.php?p=600133&postcount=24
 
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StevenMain

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I absolutely love it. It think it looks much cleaner and more robust than any SBP shift kit. Also may cost less lol... in the mean time I've got my build humming about pretty good. Chain tension is key, too little I derail, to tight the chain breaks side plates. Just run and it's hours of fun lol. I ordered pit bike plastics to make certain I get pulled over by every single cop lol...
 
KCvale

KCvale

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Feb 28, 2010
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StevenMain said:
Cannonball, I just saw your Sturmey Hub transmission. I LOVE it.. you only need 3 speeds anyway! I need to look into it more for a new build!
Click to expand...
Important note regarding IG hubs, look at their braking options!
For example a coaster brake IGH is useless on a shifter, you can't back-pedal, but there are band and disc brake hubs that work well.

Though for most 66cc 2-stroke uses 3-speeds work great though I'm not keen on 3rd being 1-1 opposed to 2nd, I like 3rd being overdrive ;-}

When you are playing with smaller power like a 49cc 4-stroke I like a 5-speed or even a NuVinci 360.
I had a 50% failure rate with NuVinci a few years back but this new version is holding up.
 
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StevenMain

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Today is my first day off work since actually getting bike going. .. I went on a 5 minute ride. Hadn't really ripped on it it... damn ring broke and gouged my cylinder... replacement on the way. I de boogered the piston ring land and epoxied the gouge on the jug, will borrow a set of rings from a friends new motor. Frustrating these china motors are. I've busted two set of rings now. Only failure I've had on this motor in 2,000 miles though since I built it.
 
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StevenMain

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The gouge left from the ring breaking up was deep, probably as deep as a ring is thick, and equally as wide. The piston AND rings were merely 2 months old.

I ordered a new top end, no idea why the premature ring failure since the first one last me close to 1500 miles...

Anywho I used JB weld on the gouge and threw it in the oven at 200 for 20 minutes.. Thats enough time to allow it to set, by the time it is cool to the touch I sanded it smooth with a dremel sanding roll.

I realize how half-ass this sounds but I really wanted to ride today and stretch her out. Ran 22 miles without any trouble. This is the second time I've had to epoxy a jug, and the first time it last me several months until I decided to try a new port design and retired the jug.. JB weld is more than sufficient for this task and holds up wonderfully. There is no loss in performance with the epoxy.

Took the bike up to 38 mph halfway into 4th when I remembered again I only have front brakes and backed off. Ive had 41.5 on a 44 tooth out of this motor, I'm hoping I can claw my way to 50.... When I have disk brakes on both wheels hahaha.
 
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