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Shift Kit?

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  #1  
Old 08-29-2009, 05:11 PM
bugoutbike bugoutbike is offline
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Default Shift Kit?

HI All,
I was browsing the forums and read this in one post.If you are going to get a shift kit .


Get the heavy duty freewheel not the standard one.
Lots more complicated .
I use s shift kit based bicycle and would not go back to a plain non shifted kit.


So what is a shift kit and free wheel clutch. I understand the terms but have not seen either yet. Does someone make these in kit form? Thanks for any help.
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Old 08-29-2009, 05:24 PM
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Pablo Pablo is offline
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Default Re: Shift Kit?

Quote:
Originally Posted by bugoutbike View Post
HI All,
I was browsing the forums and read this in one post.If you are going to get a shift kit .


Get the heavy duty freewheel not the standard one.
Lots more complicated .
I use s shift kit based bicycle and would not go back to a plain non shifted kit.


So what is a shift kit and free wheel clutch. I understand the terms but have not seen either yet. Does someone make these in kit form? Thanks for any help.
Sick Bike Parts LLC - Performance Parts for Your Motorized Bicycle

Sick Bike Parts LLC - Shift Kits

1) I would say if you have any engine mods, ride hard, etc get the HD Freewheel.
2) It's more moving parts for sure, but not complicated.
3) I am the same way. Bolt on sprocket? Yechhh......
4) See the links above for kits. We designed the thing and first to the market, we've sold over 1000 now, no huge problems. Just some folks have blown out the low cost Dicta FW, so we designed and have a HD FW now.
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Old 08-30-2009, 12:53 AM
bugoutbike bugoutbike is offline
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Default Re: Shift Kit?

Thanks Pablo. That is on very cool and thought out kit! I wonder why they just didnt make the China engines with a Right drive instead of the left? This is indeed one of the best mods Ive seen.
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Old 08-31-2009, 03:44 AM
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Default Re: Shift Kit?

I have one, starting your bike takes a little getting use to. Shifting gears is great esp. if you have any hills in your area. I use to top out at 35 with the motor screaming. Now I can do a honest 40mph with the motor rpms up but not screaming. To start mine I took Pablo's advice. With the bike in the lowest gear get pedaling along clutch pulled. Then let the clutch out with the right pedal a little forward of straight up. Stand up and give it a hard push like a motorcycle kick start only going forward. Takes a little practice but it works great. For some reason (I'm guessing cause of the much more solid motor mounting) it took almost all the vibration out of my bike too.
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Old 09-01-2009, 11:04 PM
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Default Re: Shift Kit?

I will agree with Pablo and Junster. I put a jackshaft kit on my mountain bike, taking my time over the span of a few days. I like it so much more than a fixed gear ratio. I find that running on flat road in 5th gear is relaxing. At wide open throttle, engine speed stays around 4800 rpm on flat roads. In the 5200 rpm range in lower gears, my engine and frame starts resonating, vibrating really bad. I am at thin-air 6200 feet, and have hit 33 mph at wide open throttle. I weigh 245 lbs; I bet I could get 40+ mph if I had less wind resistance. My longest day ride has been 138 miles; half of it into heavy headwind. I still managed 100 mpg. After 375 miles, I checked the jackshaft for chain stretch, cleaning and lubing. Have not made a single gear adjustment since my first test ride. First smart move heads-up: Position the jackshaft frame so you can remove the clutch gear cover. You will see why if you ever have to make a clutch gear adjustment. Second smart move: Purchase a good MOTORCYCLE helmet and a bright yellow riding jacket. Make traffic see you! Make sure the police note that you are NOT exceeding the speed limit!

Enough for now,
MikeJ
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Old 09-02-2009, 01:42 AM
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Default Re: Shift Kit?

I'm not exactly sure how my neighbor did it but he managed to get the chain wrapped twice around the bottom bracket on what used to be my Mamba. Took me a little while to get it unwrapped. Stock freewheel held up. Rear derailleur needed a little twisting back into shape.

I adjusted derailleur to just barely make it into 1st, He may have gone over the top of the gears and into the spokes.

Totally agree with MikeJ on doing the harder setup so you can get the clutch cover off. I also use snaps instead of screws for the rear half of the clutch cover (craft store or leatherworking supply) so you can check on the jackshaft sprocket easily.

Right now I am trying to figure out how to have a stock bike chain guard and the shift kit. I have a little time while breaking in a new engine.

Oh yeah, don't let a shift kit be your first build, too many things may go wrong and you just get all confused. Then there is the added joy when you switch over to the shift kit and you get all the torque and speed possible. I'm not saying you can't do it just that it does make it a bit more complex.
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Old 09-02-2009, 10:46 AM
bugoutbike bugoutbike is offline
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Default Re: Shift Kit?

Thanks for the info. I had to pretty much custom fit everything to get the engine to fit into the tiny frame on this mountain bike. See my build thread. Next build will have all the goodies oh and a real mountain bike.

http://motorbicycling.com/f3/skyhawk...h-10736-3.html

Last edited by bugoutbike; 09-02-2009 at 10:50 AM.
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Old 09-09-2009, 10:11 AM
Fabian Fabian is offline
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Default Re: Shift Kit?

Just to add my experiences:

I've had some serious problems after installing the shift kit, but the problems were not related to the shift kit.
In truth, the shift kit is a lovely piece of engineering and after you've ridden with gears, you'll never be able to go back - JUST GET THE ""DELUX"" KIT with the heavy duty freewheel bearing, big air filter, high grade bolts and engine cylinder stud kit bolts and high grade fuel cutoff valve.

Ok,

Only going from my experiences, you only have to do two (ok maybe 4) very low cost or even zero cost modifications to make the final drive chain (your bicycle chain that operates the rear cassette or cluster absolutely reliable and it's far better explained in pictures than words.
In the initial stages, i had no end of problems stabilising the final drive pushbike chain from the 36 tooth sprocket to the rear cassette on the rear wheel.
It resulted in 3 broken rear derailleurs, 5 or 6 damaged rear wheels and a few broken rear derailleur cables.

The diagnosis was that even with a jump guard or suicide guard, the chain was somehow; unbelievabley still jumping off the 36 tooth chainwheel and mostly pulling it's way through the jump guard, destroying the chain on the bottom bracket or to a lesser extent, jumping inbetween the 36 tooth and 44 tooth chainwheel and catching on the spacer nuts.

The solution to perfect reliability was initially costly because nescessity is the mother of all invention.

Just take your large and small chain tensioner idler wheels from the Chinese Bicycle kit and set them up as i have done and you will have no problems at all with the chain jumping off the 36 tooth chainwheel and even if it does, it will be a harmless situation where you only have to reattach the chain onto the 36 tooth chainwheel - a 2 second job if it even happens.

The other modifications are (photos attached):

taking a damaged rear derailleur (the one that smashed it's way into your rear wheel) and hacksaw off a derailleur leg; attaching it to a piece of 3mm aluminium to prop up the slack side of the primary drive chain that is powered by the 10 tooth engine sprocket.
This will stop the chain cutting into the aluminium of the engine casting at low engine rpm's.
This modification is not nescessary if you constantly keep an eye on the chain stretch and replace chain at the 0.5% wear rate.
I find it's just peace of mind.

The other mod is to take one of the thick rubber rings that sandwich onto the rear spokes in the original Chinese engine kit and sand it down smooth so it can be attached/glued with silicon onto the bottom bracket side of the 36 tooth chainwheel.
Now you take any piece of thin plate (in my case 2mm MDF/plywood) and cut out a ring that can be glued onto the rubber drive washer you've glued to the chainwheel.
If the chain does throw onto the bottom bracket side, it harmlessly slips on the rubber drive washer and you not only get to ride home under engine power but you also have a perfectly usable and undamaged chain.

If wanting to spend the money on a proper professionally designed system there are a few good options such as the ROOX Rollercoaster or Chain Pimp device.
Personally, i like the spring loaded Roox Rollercoaster modified with a set of encaptulating top rollers from the Chain Pimp - the most perfect solution.

One other thing and it's another low to zero cost option:
Replace the chain tensioning pushrod with a high tensile rod (standard rod bends when engine load pulls downward on the pushrod); replace one of the upper 1/4 inch nuts on the pushrod and find or buy a single 5/8 bolt.
Cut the head off and drill the appropriate sized hole so it can be tapped with a 1/4 inch tap.
Take this newly created wide headed nut and use it to push directly on the bent lower metal tab of the shift kit mounting plate.
The wider nut will not allow the bent metal tab to bend as the engine forces down on it.
You can only do up the jackshaft mounting U-bolts to a limited pressure before they start to crush the thin walled tubing of aluminium bicycle frames.
The engine will always want to try and slide down the seat post tube - this is a saftey issue and i will cover my modification to the U-bolts to prevent a much more secure mounting face with less pressure and more adhesion and easier adjustability.

These modifications are actually quite easy and simple taking no more than about an hour of your time and potentially will save you quite a bit of money that you can invest in the Delux Shift Kit and optional accessories.

Fabian
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  #9  
Old 09-09-2009, 10:13 AM
Fabian Fabian is offline
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Default Re: Shift Kit?

And the other photos
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Old 09-09-2009, 10:15 AM
Fabian Fabian is offline
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Default Re: Shift Kit?

and the last of them
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