Personally, I feel that the long-distance cost performance of 24-speed cars is relatively high. First, it is cheap, and second, it is convenient to maintain. Even if the chain is broken, it can be replaced at will. Of course, many technologies are scattered in 13 and 14, and the ACERA suite has reached 27 speeds.
If you must buy a 30-speed, the SLX M675 kit is good, reaching the professional level, and the speed, accuracy and appearance of the kit have been greatly improved compared with Alivio. I am using this set myself, and it may not meet the standard. I feel no different from my friend's XT. Compared with my previous Alivio M430, I feel very different. Although M6 15 sets are also decentralized by SLx technology, there is still a certain gap between the speed change feeling and Slx, and the price difference is not very big. SLX is cost-effective.
For frames, it is recommended to use steel frames for long distances. Choose between carbon and aluminum, and definitely choose aluminum: 1. Carbon frame is expensive, easy to be damaged when falling off the car, and difficult to maintain; 2. As far as the distance is concerned, the carbon frame is not conducive to the installation of shelves. The key to choosing a long-distance frame is to choose a frame that can be stretched. If the height is between two sizes of frames, choose the larger one.
Remember, remember that the choice of buying frames is not so competitive. The geometry of the frame has a great influence on the comfort of long-distance riding. My current XTC FR+675 large set +XT wheelset is not as comfortable as the cottage brand I spent 800 yuan on long-distance cycling.
Coach is not expensive. Many people buy used cars when they enter Tibet, such as 2 1 speed, but they don't want them when they enter. There are also many precedents for people riding long distances and damaging the grass of good cars.