Truvativ Hammerschmidt

 

The Truvativ Hammerschmidt crank is by no means cheap, with a £649.99 rrp for the AM crank. However, used cranks in refurbished/unused condition are going for under £200, making it a serious contender in comparison to other double chainsets.
Personally, I have the 'AM' crank, although the only difference between the AM and FR cranksets is the gear ratio, with AM typically on 22t and the FR crank on 24. The system, on paper, is a stroke of genius; allowing you two potential gears up front without the possibility of dropping the chain. Instead of a front derailleur shifting over two cogs, the cranks are internally geared, making it a completely unique product. Admittedly, a weight penalty is paid. However, the crank does eliminate the need for expensive and weighty chainguides, the risk of dropping the chain, and problems with fettling a front derailleur in one (relatively simple) product.
Setting up the Hammerschmidt is a doddle, simply fix it up to the ISCG mounts and bottom bracket like you would with any crank/chainguide combination. Unbelievable though it seems, setting up the gears took virtually no adjustment; with two very obvious settings it's easy to see whether it is functioning correctly or not.
On the trails the cranks are perfect. The choice of only 175mm or 170mm arms may pose a problem for those of us who like a lot of clearance, but I never had an issue with striking rocks or other obstacles. The shifting is absolutely seamless, and I have yet to find another product which shifts this quickly and effectively with just a soft touch on the lever. It's worth noting that shifting could be left until the last moment when climbing, and it still shifted just as effectively under strain. This, in my experience, is not possible with traditional double chainsets. There is a minor amount of noise and resistance, although I found this negligible, particularly when the trail got rough and fast.
So, a verdict. On the one hand, I had two gears on a downhill/freeride bike, turning it into an all round product which couldn't have been achived without purchasing a whole new bike. The chain doesn't ever drop, and the crank is simple to fit and maintain. On the other hand, it's weighty, resistant and (on the four bolts) prone to breaking - a problem emphasised by the fact that (should only one of these bolts break) you are expected to spend £120 on a whole replacement section. And no, this is not the sort of bolt you can make up yourself, or that the local bike shop will have on the off-chance. Therefore, I'm torn. On my enduro/freeride build it's totally indispensable, and there isn't another product out there which could do the job. However, for the expense and weight conscious, a classic double with a tight chain (or single ring with chainguide) may well be the obvious alternative.