125mm to 153mm
Price $129 to $1??
Depending on chainring options
Prices shown good as of 11/18/2017
Prices include: Shortened Arms, Chainrings & All Bolts
Outstate MN residents add 6.875% sales tax.
Metro residents add 7.775% sales tax
About the FSA Alpha Drive 10 Speed Double Cranksets
With ISIS Spindle Interface
Outer 36t chainrings are 7075 Alluminum Alloy. Inner 22t is heat threated steel
Double rings are spaced for 10 speed indexed shifting and work with 10 or 11 speed chain.
Available with 10/11 speed FSA 22/32/44 Triple Alloy rings for $189
Also available with 23/33/42 Rotor Q-Rings for $399
If you need a similar crank, but shorter than 125mm, I can shorten the square taper SRAM S600 to 85mm.
ISIS 113 mm will give a 48 mm
For Fat Bikes I have 148mm FSA Platinum ISIS BBs to fit 100mm threaded shells for $52.Q factor; 170mm with a 113mm BB spindle. Great ankle clearance.
Bolt Circle Diameter (BCD) The outer rings are 104mm BCD, inner is 64mm.
"Safely" is a relative term. Modern cranks hopefully have a margin of safety to allow for the occasional 280 lb mountain biker. The Alpha Drives are pretty beefy wherever I put the new pedal hole.
Unless you are a smaller rider, or on a recumbent, Knee Saver type pedal extenders should not be used with these cranks.
10 speed Mountain Double w/Guard $129 - ISIS BB22t inner ring is heat treated chrome moly steel
The teeth of the 36 and 22t "Double" chainrings are cleverly offset outboard. So you get a proper "Double" chainline on triple crankarms.
36t outer ring is 7075 Alloy
The stock guard it lightweight plastic. Good for keeping the chain from coming off or keeping your pants out of the chainring. But for a proper BASH guard see the option below
Race Face Narrow-Wide Chainrings
These rings keep the chain from coming off, without retention systems.
Alpha Drive with 30t Chainring (150mm Shown)In order to fit a 30t ring on a 104mm Bolt Circle, the female part of the chainring bolt is machined as part of the chainring, adding to material and machining cost.
$165 for 32 or 34t or $179 for 30t
Available in Black, Blue, Red, Lime Green, Orange & Purple
30t get black steel chainring bolts. For chrome add $6
Race Face rings are CNC machined from ultra hard 7075 aluminum.
These rings need 9, 10 or 11 speed chain for the chain retention to function properly. You can run 9 spd, chain on 8 spd. cassettes.
If you want the 30t Race Face ring, I recommend 2mm Wheels Mfg. spacers be installed between the frame and the flange on the right side of the BB to optimize the chainline. I can provide these for $2.
Two Chainrings & Rugged
10mm Thick Polycarbonate Bashguards
are lighter & tougher than alloy guards.
Gravity guard with 22-36 rings. $175
A bit spendy because I have to use extra long female nuts from one set of chainring bolts and oversized head male bolts from another set