Axiom Big Drop Crank Review

So it was time to upgrade my cranks. No longer feeling confident on my Truvativ's, and being disenchanted with the whole ISIS fiasco, I wanted something that was proven, strong, guaranteed and was not square taper. I got three out of four.

The Axiom Big Drop MTB Crank is basically a BMX crank with a special MTB specific bottom bracket. It looked strong, came with a lifetime guarantee and was definitely not square taper. The whole system is based on a 19 mm cro-mo axle with 36 splines at each end. On each end is a polished tubular cro-mo crank arm. The drive side crank arm has a replaceable 4 bolt spider. Toothed bashguard and two rings 32 and 22 teeth are included.

The thing that really sold me on this crankset was the bottom bracket. It consisted of aluminum cups with large cartridge bearings on the inside. One bearing on the left side and two bearings on the drive side. All spacers and hardware are included with the set, however providing instructions is apparently not a priority for Norco as there were none.

With the help of a BMX friend installation went without a hitch. Tolerances were tight and I could fine tune my crank clearance on both sides of the bike. The whole system is amazingly adjustable. Probably the most difficult part of the installation was trying to line up the two cranks straight when there are 36 positioning options to choose from.

Next it was time to ride the cranks. Increased stiffness was noticeable immediately. I thought my Truvativ's were stiff, but they are butter compared to these. What is noticeable now is frame flex. Manufacturing of these cranks is done in Taiwan and they did a great job of lining things up. Each crank arm consists of three pieces welded together. Welds were good, but more importantly there was no indication that any of the alignment was off. Pedaling had a perfectly flat feel. Because of the increased stiffness felt with these cranks my confidence improved when doing drop offs. Rear wheel maneuvers also seemed a bit easier as there was a better platform to stand on.

The bashguard is a toothed affair and has reduced diameter allowing for better ground clearance but we will see if the chain gets nicked when hitting things at an angle. Bearing quality is good so far. If it is not, the bearings are of a common size so upgrades won't be too difficult.

I have not had too much experience with Axiom products in the past, (Only a titanium stem from about four years ago.) however I am impressed so far with this crank system. If you are tired of your ISIS cranks being crap, give these a try. I look at all the abuse that some BMXers give to their cranks, and am glad that I am now on a similar splined system with the added benefits of increased stiffness and adjustability.

We will keep you updated on long-term bearing quality.



--Aorr.