Lighten Up - Cranks
Feb 23, 2011
article & images by Nick Salazar
There are but three contact points on any bike: the bars, the saddle, and the pedals. All three are ripe areas for weight savings, as we've already explored at the front end. For this installment of the Lighten Up series, we're headed South. Between the cranks, chainrings, and pedals, we've got a lot of grams to shed. So let's get started.
Our crank of choice for this build is the Lightning SL Carbon. It's a lightweight crank that's very heavy on features. For a really detailed analysis of the various light crank options, definitely have a look at the Fairwheel Bikes Crank Shootout. They did a fantastic job of analyzing them all, so we don't need to reinvent the wheel there.
The Lightning SL crank is the perfect balance of what we were looking for. It's one of the lightest cranks out there, bested only by the THM Clavicula and the AX Morpheus. But it overtakes both of those cranks in three areas. First, it features a nice narrow Q-factor, which is arguably better aerodynamically, and is preferable ergonomically for many riders. Second, it has an interchangeale spider, meaning you can swap the cranks from compact to standard without buying a new crank. That spider is also Quarq compatible, so adding power is an easy option, and results in the lightest powermeter crank available anywhere. Finally, this beauty is available in any size from 160mm to 190mm, making it the most usable of any light crank out there. And it is plenty stiff to boot. If the crank looks familiar, that's because you may have seen its progeny before. Specialized bikes loved the Lightning design so much, they bought the patent for it, and currently manufacture it themselves as their S-Works crankset, spec'ing it on their highest-end rides.
We paired it with an exotic set of Fibre-Lyte chainrings that weigh just 80g for the pair. The choice was obvious, both from a weight perspective, and also an aesthetic one. The 3k weave on the Fibre-Lyte chainrings matches that on the Lightning crank arms. Plus, these are among the stiffest rings out there (Quarq reports that they calibrate very well on a powermeter setup), and their only drawback, other than their price, is the extra care that must be taken not to shift under load. To be fair, it's never a good idea to shift under load.But doing to excessively can lead to a chipped chainring tooth. Moreover, they won't last you quite as long as steel rings, but I've gotten several thousand miles out of each set of Fibre-Lyte rings I have ordered, and I always come back for more. They're just too awesome. The final weight for this system, including the crank arms, spider, chainrings, and the bottom bracket, weighs in at astounding 544 grams. That's several HUNDRED grams lighter than a Dura-Ace system.
To finish off these wonderful cranks, we set them up with some very rare, exotic, and insanely light pedals. Look in the "Related Articles" section below to read about them.
Lightning SL Crank
Easily our favorite crank out there. We can't wait for the BB90 version.
Lovely rings, but must be used with care