Flying off drops, sending jumps, clattering through rock gardens, ripping turns and charging climbs is brilliant fun, but it’s really hard on your bike. It doesn’t take long for a little issue to become a big problem if you don’t get it sorted out properly and professionally straight away. Here’s our guide to the six most common health problems your mountain bike is likely to have, how to identify them and how to put things right.
1. Broken brakes
- If your brakes are not stopping you properly, then you definitely need to stop riding and get your bike booked in for a checkover.
- If your hydraulic brakes are pulling too close to the bar for comfort then they probably need a ‘bleed’ to remove air from the system.
- If there’s lots of noise but you’re not stopping, you might have worn your brake pads out so they will need replacing.
- Sticky pistons in levers or calipers can make disc brakes drag after you’ve pulled them. They can be serviced at home, but if you're unsure, head to your local bike shop.
- Rusty cables will ruin the feel of mechanical disc brakes and rim brakes, so fit a new inner cable.
2. Grinding gears
- If your chain is grinding and clicking rather than sitting quietly in gear then your ‘indexing’ might need adjusting to get your transmission back on track.
- It might be your gear hanger that's bent though, so double check that's straight before messing with your mech.
- If the chain is lined up fine but keeps slipping and skipping on the cogs then something – or everything is worn. If you’re lucky, a fresh chain might solve things, but if you’ve left it too long and worn the parts too badly, then you might need a new chainring and cassette (rear cogs) as well.
3. Loose bits
- If you’ve tightened your wheel axles and there’s still a clunk or a wobble when you pick up your bike or give it a wiggle, then it’s probably a bearing somewhere that’s loose or just plain dead.
- Suspension pivot bearings will clunk if you lift the bike up a little. Put your finger on each one in turn to feel which are loose and if they can’t be tightened, then it’s time to replace. Don’t leave things like this either or that little bit of wobble will soon ruin your frame – forever!
- Crank, pedal or wheel bearings can feel stiff to turn, wobble sideways or just sound ‘dry’ or ‘hollow’. If they’re not silky smooth and quiet though it’s time for a service and probably some replacement parts.
- If there’s stiffness or a wobble in your steering then it’s your headset bearings having a headache. Sometimes that can be solved with a simple top cap tension adjustment but otherwise, get it serviced/swapped before you crack your frame.
4. Dead suspension
- If you actually read the instructions for your suspension you’d see many brands suggest servicing every 10-20 hours of riding. I don’t know anyone but pro racers who do that though, so your springy bits are probably suffering more than you realize.
- If it feels like you left the lockout on over bumps then your seals are probably dry and your lubricating oil is dirty. Self-servicing this stuff is actually pretty easy if you’ve got the right tools and lots of patience, but keeping everything clean and going slow is crucial. As always with tool time if you're not 100 percent confident then get it checked in with a pro.
- Bouncing around like a rubber ball? Sounds like your rebound damper has lost control. Wrist-breaking spikes on sudden impacts? That’s your compression damper or bushings feeling unwell. Either way, it’s time to book in with a suspension specialist for a check and refresh.
5. Droopy dropper
- Don’t forget that your dropper post is a just sliding tube with a simple seal to stop water and grit getting in. So if the post is sticky or glitchy, then just a quick unscrew, wipe down and relube can work wonders if you follow the instructions carefully.
- Moving the post can also cause issues with cable tension, so give your control lines a wiggle to check there’s not an easy fix there.
- The RockShox Reverb is famous for getting a bit soggy at the top of the stroke if it gets a bubble in its hydraulics. There’s an easy invert and button press trick that you can Google to buy yourself some time, but get a proper bleed done to sort it properly.
- Wired dropper posts can also bounce if they get a cartridge issue but they tend to have more issues with their control cables.
- Sometimes the cable can get unhooked from the operating mechanism at the base of the post – which is easy to solve.
- Another common issue is that the cable has got crushed or bent enough to stop running smoothly, which is an easy or awkward fix – depending on the way it routes through the frame.
- Sometimes the post can be pushed too far down in the frame and the mechanism itself snaps though which is only fixable if you can find spares.
6. Wobbly wheels
- A few years ago, bending wheels, ruining rims and snapping spokes was a monthly occurrence or more if you were riding hard. Thankfully, wheels are far tougher than now so they’re the last on our health check list. Disc brakes mean you can run wheels with a small wobble or dent that would have been impossible to tolerate with rim brakes.
- Serious alloy rim dings need carefully bending back into shape to keep tubeless tires safe when cornering.
- Any leaks in a carbon rim could mean a crack that’s ticking like a time bomb ready to explode at the next serious slam.
- Loose, bent or snapped spokes also need replacing or re-tensioning as soon as possible before the surviving spokes get overstressed and the whole wheel collapses.
