4 geometry terms to know for your mountain bike suspension setup
A mountain bike suspension setup can be complicated, especially when you do not have Know-How or experience. The basic Know-How for a mountain bike suspension setup are geometry terms. These terms help you to understand how your bike geometry affects your riding.
1) How reach influences your mountain bike suspension setup
The reach measurement of a bike will indicate how leaned forward a rider will be. Some riders may want to try a frame sized up or down depending on their preferred fit. A longer reach may provide more stability, while a shorter reach gives a bike a snappier feel.
- Longer reach for more stability
- Shorter reach for more maneuverability
Reach is maybe the most important measurement to indicate if a bike is a good fit to you and therefore very important for your mountain bike suspension setup.
One important factor you have to keep in mind is that if you make your head tube taller your reach is getting smaller. That’s because the head angle is not vertical – so, the longer the head tube, the further back the top of it becomes, and so the shorter the reach measurement. But this is not the case if you use headset spacers.
One easy way to measure reach when you do your mountain bike suspension setup is to put the front of the bike against a wall, and then you measure the distance from the wall to the bottom bracket and to the top of the head tube. Then you subtract the the second measurement from the first and here we go, you have your reach.
A bike’s chainstays are the lower part of the rear triangle with a horizontal connection to the rear wheel. Concerning playfulness the chainstay is very important. A bike with shorter chainstay will wheelie and manual better than a bike with longer stays.
Cornering is also improved with short chainstays due to a shortened wheelbase. But watch out, if the chainstay is too short, you loose stability. Chainstay length should be chosen carefully in order to achieve the right balance.
- Longer chainstay – it is easier to do manuals and lift front wheel
- Shorter chainstay – helps with weight distribution. You do not have to lean forward that much in corners to have more weight on front tire and therefore have balanced weight between rear and front part
3) Bottom-bracket height and your mountain bike suspension setup
The higher the bottom-bracket height, the higher the center of mass of the rider, and so the bike tends to pitch when faced with bumps, hard braking or steep gradients. In this sense, a lower bottom bracket improves stability.
Moreover a higher bottom-bracket height helps you to ride over big rocks and other obstacles without getting stuck. Also tree trunks are often a problem for riders and often the reason the bike gets stuck and the rider flies over the bars. So bottom-bracket height is very important when doing a mountain bike suspension setup.
General tip: Go as low as you can without affecting pedaling efficiency and clearance
On the other hand the lower the bottom bracket the center of mass of the rider is lower. This has some advantages, like agility is higher especially when turning. Therefore bikes with lower bottom-bracket heights are generally easier to move in and out of turns.
4) Head angle
Head tube angle also influences your mountain bike suspension setup. It is the measurement in degrees at which the head tube points towards the ground. Bikes typically have head tube angles ranging from 63 to 72 degrees. So how the bike handles is directly influenced by the head angle degree.
Cross-country or enduro bikes benefit more from steeper angles, while a full-on downhill bike will have a slacker angle.
Head angles affect bike handling in a few key ways. Here are the basic effects of the head angle:
Steeper head angle increases steering speed, nimbleness and twitchyness
Watch out in your mountain bike suspension : Flat head angle increases stability
The head angle also affects the steering response directly.
So, the slacker the head angle, the less the bike steers when you move your handlebar. So a steeper the head angle makes the steering response faster.
Also an important fact is that slacker bikes are less good at dealing with flat landings and this is also the reason why many bikes have longer fork travel than rear travel.
So we hope you could learn something about setting up your mountain bike. Do not forget to try out our mobile app SAGLY. In the app you can learn more about your mountain bike settings and how to improve them. Happy Riding!