'Sick Bike Parts Shift Kit - is it worth the cost?'
They are to me.
I am on my 40th shifting build today, the previous 39 are here.
The key part of a shift kit is the bottom bracket freewheel bearing.
This is the expensive crucial part that isolates a sprocket pair from your pedal crank axle so when the engine or motor is turning the sprocket pair your pedals don't beat your legs off.
This bearing is THE crucial part, and they are not all the same.
The $20 FWB is for light use.
OK for a <500W electric or stock 48cc 2-stroke, maybe even a stock 49cc 4-stroke but I don't take the chance.
Even a stock 66cc 2-stroke will rip this bearing to shreds in short order and they don't fail pretty.
The $80 freewheel is the quality item
From the SBP page.
- - -
"Heavy duty front freewheel made exclusively for Sick Bike Parts by White Industries.
HD freewheel required if you use a slant head or other high compression head, also it is highly recommended for hard riding or larger riders.
Center hole thread is 1.37 x 24 tpi, 5 bolt pattern diameter is 2.63 inches.
Leaders in the industry for hiqh quality bicycle components. Not only are these freewheels durable but are also serviceable.
Made in the U.S.A. Six month replacement warranty"
That is your $60 difference in kit prices and a price I am happy to pay for something designed of this use and will hold up.
*Hat's off to the SBP for this custom bearing, and now I guess a super HD FWB is in the works for really high performance engines.
As for internal hubs for shifters I love them!
Just a fat chain straight to a single sprocket on the back wheel.
The Nexus 3-speed's have held up to everything I have managed to throw at them without failing, and I have thrown a lot.
There ARE a few downsides to a shifter as well.
They are pain in the butt to assemble.
Adjusting your left side chain tension requires disassembly.
Unless you make a tensioner, right side chain adjustment requires moving the engine mount.
As mentioned above you have no bike momentum to help you start the engine when you drop the clutch, you have to kick start the engine with your pedals and you have no back-pedal coaster brake use if equipped that way like a Nexus, you need an alternative brake.
And finally there is the 'jump stop' strategic placement on the seat post if you are using derailleur gears to keep the chain from flying off inside the sprocket when you are in 1st gear.
So are gears worth the hassle?
Like I said, they are to me.
And a 3-speed is just right for most shifting builds.
People power benefits from a lot of close gear ranges, engines don't need it.
It's your direct drives power and speed in 2nd gear, but it has a torquey low end in 1st and an overdrive speed gear in 3rd.
Hope that helps.