Front runs lower to improve steering traction on technical terrain.
⚠ These are starting points based on Schwalbe and Maxxis MTB pressure guides. Final pressure depends on terrain, riding conditions, and personal preference. Always check tyre sidewall for maximum rated pressure.
MTB tyres run 18–40 PSI compared to 80–120 PSI for road bikes. Lower pressure allows the tyre to conform to rocks, roots, and uneven terrain — increasing the contact patch and improving traction. It also absorbs small impacts, reducing rider fatigue. Road tyres run high pressure to minimise rolling resistance on smooth surfaces.
The trade-off: too low and the tyre rolls sluggishly, loses cornering precision, and risks burping off the rim (tubeless) or pinch flats (tubed). Too high and traction and comfort are reduced on rough terrain.
Why tubeless allows lower pressure
Without an inner tube, there is no risk of a pinch flat — where the tube is pinched between the tyre and rim on a sharp impact. This allows tubeless riders to run 2–5 PSI lower than tubed setups, improving traction and comfort without the puncture risk.
The minimum tubeless pressure is approximately 18 PSI. Below this, the tyre can burp — momentarily unseat from the rim, releasing sealant and air. Tubeless-ready rims and tyres have a tighter bead lock to resist burping.
Why front pressure is lower than rear
On a mountain bike, approximately 40% of total weight is on the front wheel and 60% on the rear. The front tyre runs 2–4 PSI lower than the rear for two reasons: less weight means less pressure needed to support the load, and lower front pressure improves steering traction and confidence on technical terrain.
Descending, even more weight shifts to the rear. Many riders drop front pressure further when riding steep or technical descents.
Frequently asked questions
What PSI should I run for trail riding on tubeless tyres?
For trail riding on tubeless, most riders run 24–28 PSI rear and 22–26 PSI front. The exact value depends on your total weight (rider + bike). A 75 kg rider on a 14 kg bike (89 kg total) should start around 26 PSI rear and 24 PSI front on a 2.4" tyre, then fine-tune by feel.
Can I run MTB tyres at road bike pressures?
No. MTB tyres are designed for 18–40 PSI. Running at road bike pressures (80+ PSI) will cause a very harsh ride, reduce traction dramatically, and risk damaging the tyre carcass or rim. Always check the maximum PSI printed on the tyre sidewall.
How does tyre width affect pressure?
Wider tyres have more air volume, so less pressure achieves the same effective spring rate. A 2.6" tyre needs 1–2 PSI less than a 2.4" tyre for the same feel. This is why e-MTBs with 2.6"+ tyres often run lower pressures despite the heavier bike weight.
What is the minimum safe pressure for tubeless?
18 PSI is the generally accepted minimum for tubeless mountain bike tyres. Below this, the tyre may burp — momentarily unseat from the rim and release air. Some riders run lower on specific rims and tyres, but this requires experience and knowledge of your specific setup.
What is a pinch flat and how do I avoid it?
A pinch flat occurs when the inner tube is pinched between the tyre and rim during a sharp impact — creating two small holes, known as a snakebite puncture. It is caused by insufficient tyre pressure. Tubeless setups eliminate pinch flats. With inner tubes, maintain at least 22 PSI to avoid them on trail terrain.
Should I change pressure for wet conditions?
Many riders drop 1–2 PSI in wet conditions to increase the contact patch and improve traction on slippery roots and rocks. Conversely, muddy conditions sometimes benefit from slightly higher pressure to prevent the tyre from loading up with mud. Experiment to find what works.
How does e-MTB weight affect tyre pressure?
E-MTBs are typically 6–10 kg heavier than non-assisted bikes. This extra weight requires higher tyre pressure — usually 3–5 PSI more than an equivalent non-assisted setup. Include the full e-bike weight in the bike weight input for an accurate starting pressure.
How do I know if my pressure is too low?
Signs of too low pressure: the tyre feels sluggish and slow to respond in corners, the sidewall visibly bulges during hard cornering, you experience burping (sudden loss of air without a puncture), or the rim hits rocks and roots through the tyre. Add 2 PSI at a time until the handling feels precise without losing traction.