How do I choose a good mountainbike

Question

I am a kid that wants to start riding a MTB, but I do not have a lot of money to buy a expensive bike. I have about R 10 000 South African Rand. (600 dollars) how do I buy a bike that can be used to ramp (jumps) and so on where and what should I look for and so on.

I want to be able to teach myself a new skills but don't have a lot to work with.

I want to be able to jumps and I really want to buy the best bike for the best price because I can only buy once. I had a old bike that just broke and I have decided to buy a new one. I like to watch mountain biking on YouTube (Seth's bike hacks and so on) and want to be able to ride for a team at my school if it comes down so really need a good bike for a good price but I don't know how to get or choose one.

Answer 1

How do I choose a good mountain bike?

Summary
Everything on a bicycle is important.

The most important part of a bicycle is the frame.
The best bike for the money will have:

1. The best quality of frame construction you can afford. Frame quality includes the quality of materials and craftsmanship. Generally, the quality of the components increases as the quality of the frame increases (there are exceptions to this, it can't be taken for granted)
2. The correct geometry to fit you correctly and support your riding style. There are a variety of geometries to choose from no matter what your price range.

Selecting the correct geometry to support your riding style is a matter of situation (where and how you ride) and opinion that can only be developed by saddle time on a variety of bikes on different terrains. That being said, it is possible to generally describe riding characteristic trade-offs for different frame geometries. Understanding the characteristics can help riders make informed decisions.

At a high level the best frame geometry is finding the right balance between nimble handling and stability for your specific needs / preference.

Details
Here is a picture of some of the key factors in mountain bike frame geometry.

I have taken the lettered list from Jamie Darlow and have elaborated on the descriptions integrating comments from his article.
A – Head angle - the angle between the ground and the head tube. Generally the more vertical the head angel the more nimble and less stable the ride.
B – Seat angle - angle of the seat tube relative to the ground. This determines where the seat is in relation to the pedals which effects pedaling efficiency and weight distribution between the wheels.
C – Bottom bracket height - distance from the ground to the center of the bottom bracket. Effects your center of gravity and pedal clearance.
D – Chainstay length - distance from the center of the bottom bracket to the center of the rear wheel. Effects weight distribution between the wheels and wheelbase.
E – Front Center- distance between the center of the front axle to the middle of the bottom bracket. This number is influenced by
F – Wheelbase - distance between the wheels. As a general rule longer wheelbase is more stable and less nimble. Shorter wheelbase is more nimble and less stable.
G – Down tube - distance from the middle of the bottom bracket to the center of the bottom of the head tube
H – Top tube - distance between the top center of the head tube and the seatpost
I – Reach - distance between the top center of the head tube and the verticle line that runs through the center of the bottom bracket. This number helps with sizing a bike correctly.

Frame part diagram

Better bike makers will publish frame geometry specifications for their bikes.

Frame construction is a complicated topic full of technical details and passionate opinions. The information provided should provide a beginning point for more research.

An example of an area for further research is the effect different frame materials - aluminum/steel/carbon/titanium have on riding characteristics.

Answer 2

Comfort. That's the single most important measure of a bike and a rider's compatibility.

If you have a bike frame that is too big or small, too long or short, it will exhibit as aches and pains from riding. You won't want to ride a bike that hurts.

How to measure "comfort" ? You as the rider have to get on the bike and try it out. Being younger, you can probably adapt yourself more than a less-flexible rider (ie older person.)

Normally, a moment on the bike can be enough to categorically say "no I don't like this" A short ride around a carpark or around the block might give you some ideas. A proper ride would be 30-60 minutes, and involve some road, and short climb and short descent, and some turns and low-speed manoevers. If you're looking to stunt the bike, then ideally you want to try some jumps and so on.

Few new-bike sellers will let you go for a long cruise though, so one solution is to look out for demo-days. Locally a brand might tour with a trailer full of new model bikes for test rides, Giant do this annually. Downside, they're generally the very top models and demoing electric MTBs and so on, which will be outside your budget.

If buying second-hand, a seller who is a rider may come with you for a test ride. That can be an awesome way to find new riding partners too.

Given your age, you are still growing so any bike that fits now, may not fit as well in a couple years, so consider resale value. That means don't strip the decals and don't give it a rubbish paint job. If you do, take photos of it before making changes.

The technical specs of your bike don't really matter. As long as it is safe, and goes and stops as expected, the number of gears and teeth and angles don't make a lot of difference other than "this bike feels different to that bike" so you have to ride them to compare.

Good luck with your searching.