All Maintenance Tasks · Monthly
Check Bolt Torque
Almost nothing on a bike comes loose all at once. A stem bolt gives up a fraction of a turn a week until the bar moves in your hands on a bump, and the ride where that happens is chosen at random. The opposite error is just as expensive: overtightening crushes a carbon bar, strips an aluminum thread, or cracks a seatpost clamp that then costs more than the tool would have.
Interval
Monthly
Once a month, or after roughly 200 miles
Time on the job
15 minutes
Once you have done it a few times.
You or a shop
Some practice
The stop signs further down are the real answer.
Applies toRoadMTBHybridE-bikeKids
How often, really
Monthly is right for a bike ridden regularly. Anything you have just installed or adjusted gets checked again after the first ride and again a week later, because that is when hardware settles. Rough surfaces, a rack with weight on it, or a bike that gets loaded on and off a car rack all pull this interval in closer.
The interval on this page is Monthly. Once a month, or after roughly 200 miles.
What you need
- A torque wrench that covers the low range, roughly 2 to 14 newton-meters
- Hex and Torx bits to fit the bolts on your bike
- The manufacturer documentation for your stem, seatpost, bars and cranks
- Assembly paste, if your manufacturer specifies it for a carbon clamping surface
Doing the job
Find the numbers before you find the wrench
Torque figures belong to the part, not to the bike, and there is no universal table worth trusting. Most stems, seatpost clamps and brake levers have the figure printed right on them next to the bolt. If a part has no marking, look it up in that manufacturer documentation. If you cannot find a published figure for the exact part, that is the moment to ask a shop rather than to estimate.
Understand what the number means
Torque is measured in newton-meters or inch-pounds and describes how hard the bolt is being stretched, not how tight it feels. A five newton-meter bolt and an eight newton-meter bolt feel nearly identical by hand, which is exactly why a torque wrench exists. Small bolts on light parts live in a range where a strong wrist is genuinely dangerous to them.
Treat carbon and aluminum as different materials
Aluminum parts generally tolerate being a little over the mark; carbon does not, and it fails suddenly rather than gradually. Carbon clamping surfaces are also often specified with a friction paste, which raises grip without raising clamping force. Never carry a figure across from an aluminum part to a carbon one, and never assume a carbon part uses the same paste-free assembly as a metal one. Where the manufacturer has not published a figure for your exact part, do not pick one.
Work through the bolts in a fixed order
Do the same loop every time so nothing gets skipped: stem faceplate, stem steerer bolts, seatpost clamp, saddle rails, brake lever clamps, shifter clamps, brake caliper mounting bolts, rack and fender hardware, bottle cage, then crank and pedal interfaces. Pedals thread into the crank in opposite directions, and the left one is a left-hand thread.
Tighten in a pattern, not one bolt at a time
On any part held by more than one bolt, such as a stem faceplate or a four-bolt saddle clamp, bring the bolts up gradually and alternately rather than running one bolt home first. On a stem faceplate this keeps the gap even top and bottom, which is what the design expects.
Confirm the bar and the saddle do not move
With the front wheel gripped between your knees, try to twist the handlebar. Stand over the bike and try to twist the saddle by hand. Neither should move. If either moves and the bolt is already at its published figure, the problem is not the bolt: it is a worn clamp, a missing paste, or a part that has been damaged.
Stop and take it to a shop
If any of this shows up while you work on check bolt torque, put the bike down and let a mechanic look at it. None of these are things to ride out and see how it goes.
- A bolt keeps loosening after being tightened to the published figure, or it turns without ever feeling like it is tightening. That is a stripped thread or a damaged part, and adding force makes it worse.
- Any crack, crease, star-shaped mark, soft spot or paint line at a carbon clamping area, on the steerer, bar, seatpost or frame. Stop riding the bike and have the part inspected.
- A creak or click from the bar, stem, seatpost or bottom bracket that comes back after the hardware is at its correct figure. Something is moving that should not be, and finding it is worth a shop visit.
- You cannot find a published torque figure for the exact part in your hands. Ask the manufacturer or a shop rather than guessing, because the guess is only ever wrong in the expensive direction.
Where this usually goes wrong
- Using a long hex key for leverage on a small bolt. The extra leverage is precisely what strips the thread or crushes the part.
- Trusting a generic torque chart found online for a specific carbon component. Charts describe averages, and carbon parts fail at the specific number the manufacturer publishes.
- Checking bolt torque once after a new build and never again, when the first few weeks are exactly when hardware settles and needs another look.