POWER - Grubee Skyhawk GTA5 66CC Angle Fire Slant Head

About the same as all the other versions of the HT.
Somewhere between 2-3hp.
If you run a lot of hills, you might need a larger rear sprocket but your cruising speeds will suffer. The stock 44 tooth is a good compromise for most folks.
Most people just help on hills by pedaling.

Most people use the SBP or homemade jackshaft. Homemade is the only "cheap" way.
Use the search box as there are FAR too many threads on jackshafts for me to pick through.

One of my favorite DIY jackshaft assemblies: http://motorbicycling.com/showthread.php?t=12284

...obv some alteration may be needed to suit & check the full & related threads, the concept has evolved a bit since '09

BarelyAWake said:

One of my favorite DIY jackshaft assemblies: http://motorbicycling.com/showthread.php?t=12284

...obv some alteration may be needed to suit & check the full & related threads, the concept has evolved a bit since '09

Click to expand...

The single biggest part cost in a $200 SBP shift kit is the $80 HD freewheel, and then the BB cartridge, sprockets and crank arms that attach to it.

You still have to Do It Yourself, it's just a box full of the best parts that work well together, at least they have for me.

As far as the mountain bike and your 300# frame a bit more info is required for a proper assessment but one thing is for sure, you'll want to loose those knobby tires and get some street tires.

KCvale said:

The single biggest part cost in a $200 SBP shift kit is the $80 HD freewheel, and then the BB cartridge, sprockets and crank arms that attach to it.

You still have to Do It Yourself, it's just a box full of the best parts that work well together, at least they have for me...

Click to expand...

While still a nice option for those without any fabrication ability - I've gone through my fair share of those "$80 HD freewheels", the kit's freewheel crankset is not only the most expensive part, it's eliminated by the above DIY method.

It & similar DIY versions are essentially just two pillow block bearings, a length of keyed shaft, two shaft sprockets & lock collars... best of all, no more then a "BMX" style freewheel cog & shaft adapter. Total expenditure for the components is likely around $60. All parts can be found at any good hardware store except the BMX freewheel & adapter ofc, these "custom" bits are easy to find however;

BMX freewheel: http://www.amazon.com/Odyssey-13t-BMX-Freewheel-Threaded/dp/B000VT3ZCU $20

Adapter: http://www.staton-inc.com/store/pro..._sprockets_1_10_wide_2_set_screws-986-25.html $11


Not only are the BMX freewheels inexpensive & commonplace, you needn't replace the crankset & pedal assembly, reducing complexity & cost both

Pic from Russell's example;


Quick clip of another version on my trike: http://youtu.be/U10xLqTekOw

The low cost is the only reason I could afford to build my OCC as a jackshafted shifter build. Been lusting after the SBP kit for a decade but no way am I spending double the cost of an entire kit. Simply too expensive for me.
But using the freewheel on the jackshaft totally removes the single most expensive and unreliable part: The crank freewheel assembly.

With the addition of a 5speed cassette, I can duplicate the SBP advantages without the expensive custom front freewheel. This does, however place a premium on proper derailleur adjustment and chain maintenance, but I can do that for free.

All these parts are standard BMX stuff except the freewheel adapter which is easy to find and FAR cheaper than even the chinese version of the pedalcrank freewheel.
I'm looking at using this style mount/jackshaft on regular frames to get a shifter bike without the expense, but that's for later on.