The rack on a mountain bike is a valuable part when choosing what bike to buy or just upgrading your current racks. Most all off-road bikes come with either two or three chain rings as part of the racks. You will find that most all of these bikes on the market come with three chain rings as part of the racks.
Racks that come with three chain rings most likely come as 22, 32 and 44 teeth with the ring with the least amount of teeth closest to the bike frame and the ring with the most amount of teeth near the rack arm. On the other hand, someone who rides a mountain with the intent of racing and therefore owns a cross country bike, will most likely buy a double bike racks rather than a triple. With a double rack there is a lot less shifting and therefore you can put more focus on the race. You can either buy this type of crank set as a 42/30 or as a 40/28.
For someone who is looking to race off road and is tooling to save as much weight as they can while still being able to have enough gear ratio’s, then a double chain ring is a great way to go.
A lot of guys that I ride with from time to time have a triple on their bikes and therefore have plenty of gear ratio’s to choose from.
I competed in a race this past summer and my bike came standard with a triple and with parts of the course that I had to use my small ring and then shift to my big ring each time on the flat areas made for a lot more shifting than I wanted to. But for someone who needs a lot of different gear ratios for different types of terrain, then a triple bike rack would definitely be the way to go!
No matter what kind of bike rack you have on your bike, be sure that when you’re chain is not in too much of a diagonal meaning that if you are in your big chain ring, you shouldn’t be in your biggest couple of cogs. Also, when in your small chain ring, you shouldn’t be in your smallest couple of cogs.
Hitch Bike Rack 