Is front wheel traction getting you down? Does your neck feel like it’s filled with nails post-ride? If so, it’s time to think about your handlebar height. We experiment to find the perfect MTB bar height for you.
Handlebar height is perhaps not the sexiest of topics. Back-in-the-day we all rode on 680 mm flat bars and, even the easiest descents were terrifying. Then came wider riser bars and, like Neanderthal man, we all raised up out of our crouched riding position and discovered that comfort and control were not mutually exclusive. However, year on year, fork travel increased and our bikes grew. Now, the front end of a modern long travel 29er towers higher than ever before. So much so, that bar manufacturer Renthal have just released a new, ‘Flat’, version of their popular FatBar Lite for those looking to go lower at the front. So is lower better again? We hit the trails to find out.
What is Stack and Reach – understanding the terminology
Before we delve into bar height, it’s important to understand some terminology, namely Stack and Reach. Stack is the vertical distance measured from the centre of the frames bottom bracket to the centre of the top of the head tube (where the fork steerer enters the frame). Reach is the horizontal distance from the centre of the bottom bracket to the centre of the top of the head tube. Reach has nothing to do with the position of the seat and grips as many people think.
Riser bars vs Spacers
First, it’s time to dispel a common misconception. Adding 40 mm of spacers under the bar is NOT the same as adding a 40 mm riser bar. For example, if you change from a flat bar to a 40 mm riser bar (assuming the backsweep and width remain the same) the contact point with your hands moves vertically upwards 40 mm. When you add spacers under the stem, however, you change the position of the stem on the steerer tube which is at an angle. For example, if your bike has a 65 degree head angle, a quick trigonometry equation shows that for every 10 mm of spacers you add, the stem moves 9.06 mm upwards, but importantly 4.22 mm rearwards. Adding 40 mm of spacers, in this case, would move the grips 36.24 mm upwards but also 16.88 mm backwards in relation to the head tube. Riser bars make no change to the grip position in the horizontal plane in relationship with the head tube, adding or removing spacers changes the bars horizontal position as well as the vertical plane.
Finding the correct MTB bar height for you.
Now we understand the terminology and differences between making adjustments with riser bars and headset spacers. In order to see how the bar height and position influences ride feel we headed to the Innerleithen trails with a brace of FatBar Lite flat and riser bars from Renthal for a day of back to back testing. Throughout a day we hot-swapped between 0, 20 and 40 mm rise, all cut to 760 mm wide. To ensure proper testing, no other changes were made to set up and bar rotation and backsweep within the stem was identical. Test bikes were a RAAW Madonna and a Pole Evolink with a stack and reach of 639 and 475 mm and 639 and 510 mm respectively.
Low MTB bar height – Flat Bar
Fitting a flat bar to our test bikes was instantly noticeable to our testers. Your bodyweight is pulled low and to the front, and the connection to the front wheel feels a lot more direct. Steering is very precise at low speeds, and you can feel the traction of the front tire through turns. On flow trails and flatter trails the bike darts through corners with precision and does not understeer.
However, when riding very steep terrain, the low front end pulls your weight far forward in a very aggressive position which requires more strength and energy, we found our arms and hands getting fatigued faster. The high loading on the front wheel also means it feels a little overloaded and is harder to unweight over holes and compressions. We also found it hard to drive with the legs as the low bars moved the weight forward and onto to our arms.
Advantages of a low MTB bar height
- More weight on the front wheel for precise cornering
- Easier to feel traction from the front tyre
- Less understeer in corners
Negatives of a low MTB bar height
- Overloaded front wheel hangs-up into holes
- The body is pulled into a physical position on steeper terrain
- Hard to push with legs as weight is biased towards the front
- Uncomfortable position if you’re not flexible
High MTB bar height – Riser Bar
At the other end of the spectrum, when we swapped to a 40 mm riser bar the changes were instantly noticeable. The riding position is more open with the head and chest higher for a more comfortable ride. On steeper trails we found we were more centralised on the bike, with the weight spread more between the legs and arms, feeling less fatigue. The front wheel was well weighted in corners on steep trails, but we found we could still unweight the wheel over obstacles.
However, on flat trails and slow speed corners, we did not feel as connected to the front wheel and we had to actively ride further forward on the bike for maximum control. In flat turns we had to ride more dynamically, pulling our weight over the bars by stretching our legs to weight the front wheel and avoid understeering.
Advantages of a high MTB bar height
- Improved control down steeper tracks
- Improved vision down the trail
- More comfortable position
- You can lift the wheel when descending
Negatives of a high MTB bar height
- Rider needs to be more dynamic to keep weight over the front wheel
- Steering feels less sharp on flatter tracks
The debrief, what is the perfect MTB bar height?
First a disclaimer. Your body position on your bike is heavily influenced by suspension setup, so make sure you have your fork and shock set correctly before optimising bar height. Mountain biking is not the same as road cycling, the position is more dynamic and as such, there is no ‘recommended’ ideal bar height. Bar height, like suspension setup, is highly subjective and depends on your own personal physiology, height, bike choice and the chosen terrain. However, the properties of extreme bar heights of ‘very low’ and ‘very high’ are easily observable and will help you find the optimum bar height for you. Running a low front end gives huge front end grip on flatter trails, but is a physically more demanding position on steeper trails. Running a higher bar gives more control and comfort on steeper terrain and a more relaxed head up position on mellow terrain. However, negatives include loss of traction on steep climbs and less weight over the front wheel on flatter trails. You cannot carry separate bars for climbs and descents, well you could but your riding buddies would soon stop inviting you to rides, so what is the ideal compromise?
Reasons to go lower
If you feel that you are lacking front end grip in the corners, and the front wheel feels light and understeers in flat turns, dropping the bar height a little will provide more grip.
Reasons to go higher
If you find on steep trails that you are suffering a lot from arm fatigue and the front wheel feels heavy and hard to lift over obstacles raising the bar height will provide more control.
There is no magic bullet number, seek and you shall find
In conclusion, while there is no ‘magic bullet’ fix we recommend experimenting with your bar height, the easiest way is by adjusting the headset spacers under and above the stem. Next time you ride your home trails, try going up or down 1 cm (depending on your chosen issues as described above) and see if there is an improvement. For an all-round bike for fun, up and down the trails, we recommend finding a position as high as you can while retaining enough weight on the front wheel in flat corners. After experimentation, once you have found a good height if you want to retain the reach of your bike you can fit the corresponding riser bar to the number of spacers you have added.
Words & Photos: Trev Worsey