XTR M9050 Di2

I was recently asked, on a respected mountain bike forum, “what is the point of Di2 for a 1 x 11 set up?”. This is a good question so I thought I would answer it here:

The pay off with XTR Di2, on a 1 x 11 set up, is that the shifting is simply incredible. It is smoother and more precise than the mechanical XX1 it replaced and less finiky to set up. The shifts are stronger and quicker than either mechanical XTR or XX1. The shifts are clean and precise every time with no effort or delay at the shifter, especially climbing whilst pedalling. I am anticipating that this additional smoothness in the drive train is going to equate to greater longevity of parts. Finally there is none of the almost micro-precision with the B-tension screw that seemed to be required with the XX1 derailleur.

Use the best you can afford

The drive train is the heart of the propulsion for one’s bicycle and quite an expensive part of the bike. Gains in efficiency here have to contribute to lower overall expense and more enjoyment when riding. It is always nice to know that a component or set of components is just going to work perfectly and not have to worry about it at all during a ride. I have always believed (after snapping a chain during a cross country race many many years ago) that the drive train is subject to a lot of strain, from our pedalling, from the elements and from the constant battering that riding off road delivers. Clutch rear derailleurs have helped in this area but I have always believed that this is an area that strongest and lightest are worth the effort (and money).

As a simple example; the XTR HG-900 11 speed chain (240 grams average) is 30 grams lighter than its ‘little’ brother, the XT HG701 11 speed chain (270 grams average).  That does not sound like much but it equates to an increase in weight of 12.5%. That is weight that is being shaken up and down, however many times per minute, as it runs over, around and through the expensive parts of the drive train. Simple physics means that mass and velocity contribute to force and more force means more wear and tear. Marginal gains perhaps but a 12.5% improvement in weight for a relatively low cost is one that I will always take.

Shifting Effort

I know that this next point sounds like a load of rubbish but I did not even realise how hard the right thumb worked nor how long it was away from the grip until I installed XTR Di2.Amazing but probably something that Shimano’s notoriously obsessive R&D engineers did think about.

Complexity

I was hesitant to install it, even though I had obviously made the decision to buy it, as I imagined that it was going to be complicated to set up. It sat in my workshop for several weeks before I took the plunge. Other than realising that e-tubes mean none of the limitations imposed by mechanical cable routing (the need to for smooth curves), so I could revise my preconceptions and almost do what ever I liked, and that most recent (2-5 years old) mountain bike frame designs were not conceieved to accomodate Di2, the set up was one of the simplest I have ever installed on a bicycle.

It is about small gains, I have to admit that, but as I ride 200+ days per year and spend about six hours on my bike for somewhere between 100 and 120 days per summer season it is all going to add up for me.

Of interest, it took almost five weeks of constant riding (125-150 km of trail riding per week) to use the first 20% of the battery: Shimano XTR Di2 1 x 11 setup

Is It Worth the Investment?

So the short answer is that it is just the best shifting experience I have ever had on a bicycle. I can only imagine that the gains are even more appreciable when racing or with a 2 x 11 set up.