I had the occasion of testing the new Sram XX1 transmission at Eurobike. I rode a few laps, with ascents and descents on a track conceived by the people at Sram, in order to fully understand how the new drive train works in every situation.
One thing is sure: the concept of one single 32 tooth chainring connected to 11 sprockets cassette (10-42 teeth) seems to flawlessly work, even without a chain guide. The chain does not drop, regardless you’re shifting gears while descending or passing over stones and roots. I simply couldn’t drop the chain, and nor the riders in Megavalanche could. However, it seems that there are a few voices pretending that under extremely difficult conditions, a chain guide is needed.
Actually, it is enough to study the chainring teeth for a moment to understand how the system works and why the chain maintains its position. It moves from one extreme to the other, thanks to a design which is very similar to a cross. The cassette is no wider than 10 sprockets one, Sram managing to pull this trick, by giving up the cassette mounting ring, which was taking up supplementary space. As a result, the smallest sprocket is now responsible for binding the cassette to the hub. The chain is significantly narrower than one used for 2 x 10 transmissions.
Shifting is very fast, as the derailleur’s spring is hard and immediately reacts as you actuate the levers. XX1 derailleur belongs to the Type 2 generation which is to say that it reduces chain slap, and, thanks to a small button installed on its body, you can block the cage. Thus, removing the back wheel has never been easier. The cage is carbon made, same as the shifter’s levers and the crank arms.
This system has obvious benefits. Small weight is the supreme reason and the numerous configurations you can choose from are also to be considered. The chainring can easily be replaced, as you can install one with fewer teeth, in case you want to take part in a XC race. Or, for that Enduro contest waiting for you during the next week, you can mount a chainring with more teeth. Everything is just fine, except price, as you might have already supposed. 1,299 euro may be a bit too much for your new drive train. But, those in search for performance and simplicity, regardless of budget size may find in Sram XX1 a partner for the long run.
Total weight: 1.5 kg, out of which:
Crank: 650 grams
Derailleur: 220 grams
Sprockets: 260 grams
Right shifter: 110 grams
Chain: approximately 250 grams
Compared to a complet Sram XX drive train, the new Sram XX1 is 140 grams lighter and is slightly cheaper than separately buying all XX’s components individually. It is also simpler to use, because you will only have to replace the sprockets. Last, but not least, shifting is quicker.
In conclusion, I can recommend this transmission for all kinds of bikes, from XC to All Mountain, hardtail or full suspension. I can’t wait for its price to go down as time passes, and I have to admit that the 42 toot sprocket is simply huge. It is the biggest sprocket I have ever seen in my whole life.