Shaving grams from a hardy gravity bike to make it feel better on climbs and off the ground isn’t a simple venture, nor is it a cheap one. Apart from the unending cash outlay, the trickiest part is deciding which components can afford a diminished diet. Never the tires or brakes, likely not the wheels, and the frame weight is fairly set. What about the cranks: How much do you want to bash carbon fiber into rocks vs. aluminum?
The LG1 Race Carbon Cranks from e*thirteen have a reputation and robust build that made me think twice about carbon cranks on my recent all-mountain hardtail build. If World Cup DH racers trust them, surely I can too. The brand’s engineers had a tall task to reduce weight without removing the safety and reliability characteristics in these massive spinners, and at $399 (available at JensonUSA and Amazon) consumers are paying a premium for their hard work. A set of LG1 Carbon cranks weigh roughly 475g with a 32t chainring, tipping the scale below Shimano’s feathery XTR offering.
The cranks, chainring, and bottom bracket are all sold separately so you can select the precise measurements for your needs. The crank arms come in 160, 165, 170, and 175mm lengths, and e*thirteen claims to be the only brand offering DH cranks in a 160mm length to suit extra-low bottom brackets. Ultralight aluminum crank spindles can be had in 73 or 83mm widths to fit trail/enduro or DH bikes, and chainrings come in either a non-Boost, Boost, or Superboost option with between 30 and 38 teeth.
I went for a fairly standard 170mm crank arm, bolted to a 73mm spindle with a Boost 32t chainring. Mounting up the LG1 Race cranks is as easy as any other set. The spindle is attached to the non-drive side crank arm to make it easier to install and remove the cranks without removing the chain guide and/or bash guard. Simply tighten the chainring with the lockring and provided tool, then grease the spindle and slide it through, finally tightening the 8mm hex bolt to spec. Any remaining space can be filled by the bearing-preload ring on the non-drive side. With the recommended number of BB spacers installed I didn’t need to move the preload ring whatsoever. Everything fit precisely.
LG1 Race cranks will work with most bottom bracket standards, and thankfully my personal bike has a BSA threaded bearing holster that’s easy to service and swap. The external BB comes in 73, 83, and 100mm (fat bike) spindle widths, and 30 or 24mm diameters, for $36.95.
The large, sealed bearings that spin on the 30mm spindle are still feeling smooth and clean after a long summer of riding, and they should keep rolling well through the abusive winter months. For folks who prefer to clean and re-grease their BB bearings a few times before replacing the cups, the large seals on either side should make that maintenance relatively painless.
Rubber boots at the pedal end and clear adhesive protection on the sides are welcome measures toward keeping the LG1 Race arms looking good. I typically rub the paint or polish off my cranks in a few rides, but this set still looks great after a load of pedaling and there are no chips in the carbon tips. On the strength front, e*thirteen says that the LG1 crank arms have “World-Cup DH-rated layup and construction, compacted carbon fiber, with additional 3k added to the front and rear faces of the crank for impact resistance.”
I’ve pounded these carbon arms into a number of static objects, and I’m convinced that I can’t break them. A set of cranks that’s tough enough for DH and light enough for XC seems worth the extra cash if you have it. I wouldn’t have thought cranks were a safe place to save weight, but the LG1 Race set has done so while maintaining all of the power-transferring stiffness a rider could want.
The outer edge of the crank arms has a shape that agrees well with my ankles, which isn’t something I can say for every set. The smooth surface hasn’t bothered my splay-footed stance, and I haven’t had any issues with my forward ankle banging on the crank arm while riding rugged descents as it does with some other crank shapes.
The replaceable rubber boots on the LG1 Race are far thicker and seemingly more effective than any of the others I have tried, and they don’t slide off as soon as they hit a stone. It’s an unnerving feeling to step on the pedal after clipping out in a turn to find that the crank booty has slipped off and became lodged between your foot and the pedal. Fortunately, these protectors stay put.
I did have an issue with the 32t SL Guidering when it first arrived. The Shimano 12-speed chain wouldn’t wrap all of the way onto the teeth, rendering the chainring unusable. I tried to ride with it and the chain fell off every five-feet or so. I let e*thirteen know about the issue and they found a problem with a few chainrings from one batch that weren’t pairing well with Shimano chains. They immediately sent a new ring that has worked great since.
For the sake of “science,” I filed down the teeth of that first ring with a Dremel tool by quarter millimeter increments until the chain connected correctly. It’s always nice to know how to fix problems, and even better to know that the company has a great customer service team to take care of any issues.
Thanks to E*thirteen for providing the LG1 Carbon cranks for testing.