Top 5 best mountainbike transmission (derailleurs, crankes, shifters) 2021
Whenever it comes to buying a transmission for mountain bikes, I recommend those who want to try to rely as much as possible on homogeneity: this means that you buy a derailleur from a range, it would be ideal to pair it with a shifter and a casette from the same range, for maximum performance. All transmission systems are made to work harmoniously together, hence the recommendation.
A more expensive transmission means increased performance, ie higher speed in changing gears, a greater sense of precision, various options for the derailleur that reduce the noise that can occur on high bumps, higher ergonomics and of course, lower overall weight.
Transmissions are still among the most expensive components for bicycles (purchased as a set), and as a rule, the most expensive are also the lightest and most efficient, some using materials such as carbon to save tens of grams. Some transmissions are very close in performance or weight, but the purchase decision must be made either based on the ratios offered by the sprockets (or their number of teeth) and the ergonomics of the lever. Valid for both Shimano and Sram transmissions, both will need a cassette adapter or a new rear wheel hub where you will install the sprockets. Let’s see what we have on today’s menu.
1.Shimano XTR M9100
Shimano XTR has always been the absolute top of the range among enthusiasts, although Sram comes with lighter products at the top of the range. As a general rule, XTR transmissions are slightly cheaper but more durable, and most components are made of aluminum and not carbon. This means greater impact resistance and because some components are heavier, they will be even more durable. The new Shimano XTR is offered in the 1×12 or 2×12 version, so with one or two chainrings, the first variant being dedicated to those who have stronger legs, and the 2nd, to those who want more ratios either because they do not have enough power to support a 1×12 transmission, either because they participate in long marathons and want more gear ratios on the mountain. In any case, the new XTR shines in all respects, being my favorite of 2020.
Weight: 1,515 grams
Price: 1,360 euros
2.Sram X01 Eagle Carbon
Sram on the other hand proposes with the new Sram X01 with 12 sprockets a bling-bling range, which looks very good in terms of design and includes carbon arms for the gear but also a carbon patina for the gearbox. It is only 5 grams lighter than the Shimano XTR and costs about 25 euros more than its Japanese competitor. The difference between X0 and XTR is made in terms of the number of sprocket teeth (XTR being more advantageous for the ratio between the sprockets), the 2-way release lever that the XTR range has and the Shadow Plus design of the XTR derailleur. In any case, it works flawlessly and could easily win the beauty contest between the 5 broadcasts presented here.
Weight: 1,510 grams
Price: 1,385 euros
3.Shimano SLX M7100
For those who do not have budgets so large as to purchase the top ranges of Shimano XTR or Sram X01, there is Shimano SLX. Now available with 12 sprockets, this range borrows the radical design we find on the top XTR line, but is more sweetened in places. Also, the materials used are different, but the functionality is impeccable. The total weight is about 300 grams higher than in the case of the top products, but the price is 5 times lower, so anyone who wishes for the best cost vs. performance, will find in Shimano SLX a real ally.
Weight: 1,885 grams
Price: 310 euros
4.Shimano Deore M6100
But by far the new Shimano Deore is the most attractive option when it comes to the budget, because it does almost everything the top ranges do, but with a significantly lower price, of 250 euros. It is worth mentioning that the SLX costs only 60 euros more and the weight saving is about 300 grams. Otherwise, Deore also offers 12 sprockets but also some slightly heavier components due to the materials used. You will feel small differences in the speed of changing gears and in the shifter, where the materials are not necessarily the greatest. Otherwise, you can handle it perfectly on any mountain trail.
Weight: 2,110 grams
Price: 250 euros
Sram’s budget proposal is called SX or NX, but the two ranges have not proven to be the most reliable, so the next option I can propose is GX. It has exclusively one chainring and 12 sprockets, a total weight of 1,821 grams, so lighter than Shimano SLX, but a higher purchase price, of 460 euros. Of course, this price may be lower, depending on from which online store you buy. But don’t forget that all Sram casettes will need a special adapter for your hub, as in the case of Shimano, which cannot be installed on conventional 8, 9, 10 or 11 speed hubs. It has a robust design, built mainly of aluminum, and the change gears are very accurate.
Weight: 1,821 grams
Price: 460 euros