2025 Ultimate Guide to Bike Bolts, Studs, and Fasteners
If you've ever stripped a bolt mid-ride or wrestled with a seized rotor screw, you already know how critical good fasteners are to a bike's performance, safety, and longevity. As a longtime rider and self-confessed bike nerd, I've spent years upgrading, snapping, and eventually upgrading again — and I’ve learned the hard way that not all bolts are created equal. This 2025 guide is for anyone who wants to understand their bike’s bolts inside and out, whether you're wrenching in your garage or building up a dream titanium rig.
1. Stem Clamp Bolts
These bolts secure the stem to your fork steerer tube. Most use 4mm or 5mm hex heads.
- Torque: 5–6 Nm
- Common Issues: Over-torquing on carbon steerers — use a torque wrench.
- Upgrade Tip: Go titanium if you ride in wet weather; steel stem bolts are prone to rust.
2. Handlebar Faceplate Bolts
Hold your bars onto the stem via a faceplate. Usually four bolts.
- Torque: 5–6 Nm
- Visual Tip: Tighten evenly in a cross pattern.
3. Top Cap Bolt (Preload Bolt)
Used to preload the headset before stem bolts are tightened.
- Torque: Just snug — this isn't a clamping bolt.
- Pro Tip: Replace if stripped; it doesn’t need to be titanium.
4. Seatpost Clamp Bolt
Keeps your seatpost from slipping. Inline or collar-style clamps are common.
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Torque: 4–7 Nm
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Material Tip: For riders looking for durability and corrosion resistance, especially in wet or muddy environments, upgrading to titanium saddle clamp bolts is a smart choice. These bolts reduce weight, resist rust, and maintain consistent clamping force, helping your saddle stay securely in place ride after ride.
5. Saddle Rail Clamp Bolts
These bolts attach your saddle rails to the seatpost clamp. Proper torque is essential to avoid damage, especially on carbon rails.
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Torque: 10–12 Nm
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Upgrade Tip: Many cyclists prefer titanium saddle clamp bolts for their combination of lightness and corrosion resistance. Using these bolts is especially beneficial if you ride frequently in wet conditions or want to upgrade your bike with premium components.
6. Crank Arm Bolts
Hold your crank arms to the bottom bracket spindle. Big torque here.
- Torque: 35–50 Nm
- Threadlocker: Highly recommended.
- Upgrade Tip: Titanium saves weight and resists seizing over time.
7. Chainring Bolts
Attach the chainring(s) to your crank spider.
- Torque: 8–12 Nm
- Common Problem: Chainring bolt spin — use a chainring nut tool.
8. Pedal Axle Bolts
Thread your pedals into the crank arms.
- Torque: 35–40 Nm
- Maintenance: Use anti-seize or grease. These often get stuck.
9. Rear Derailleur Mounting Bolt
Attaches the derailleur to the derailleur hanger.
- Torque: 8–10 Nm
- Tip: Check alignment; a bent hanger can strip threads.
10. Front Derailleur Clamp Bolt
Secures the front derailleur to the seat tube.
- Torque: 5–7 Nm
- Note: Clean contact surfaces help alignment.
11. Brake Caliper Mounting Bolts
Bolts your disc brake calipers to the frame or fork.
- Torque: 6–8 Nm
- Risk Area: These bolts see mud, water, and heat. Titanium here is a solid upgrade.
12. Disc Rotor Bolts
Attach the rotor to the hub. Usually T25 Torx.
- Torque: 4–6 Nm
- Loctite: Blue threadlocker helps prevent loosening.
13. Bottle Cage Bolts
Hold bottle cages in place. Usually M5 bolts.
- Torque: 2–4 Nm
- Quick Fix: Replace rusty stock bolts with colorful anodized titanium.
14. Fender and Rack Mount Bolts
Use frame-mounted studs to attach racks or fenders.
- Torque: 4–6 Nm
- Material Note: Stainless or titanium preferred to avoid seizing.
15. Wheel Axle Bolts or Skewers
Secure your wheels to the frame. Bolt-on or quick release.
- Torque: Bolt-on: 20–30 Nm
- Safety Tip: Always check before every ride.
16. Thru-Axle Bolts
Common on modern disc bikes.
- Torque: Usually printed on the axle (10–15 Nm)
- Tip: Keep threads clean and lightly greased.
17. Suspension Linkage Bolts
If you ride full-suspension, these bolts matter.
- Torque: Varies greatly
- Important: Use manufacturer torque specs.
18. Derailleur Hanger Bolt
Attaches hanger to dropout.
- Torque: 3–5 Nm
- Why It Matters: Keeps shifting crisp and alignment proper.
19. Cable Pinch Bolts
Found on derailleurs and brakes.
- Torque: 4–6 Nm
- Pro Tip: Don’t over-tighten and fray the cable.
Why Titanium?
For wet, muddy, or coastal environments, titanium fasteners are nearly immune to corrosion. I’ve had steel bottle cage bolts seize inside an aluminum frame — had to drill them out. Titanium fixes that.
Other advantages:
- Lighter weight (great for climbing bikes)
- No rust, ever
- Long-term torque stability
Want a deeper dive into why titanium is ideal for bikes? Check out our detailed post: Why Titanium Alloy Bolts Are the Top Choice for Road and Mountain Bikes.
Target upgrades: brake calipers, rotor bolts, crank bolts, saddle clamps — anywhere that gets dirty or sees a lot of torque. brake calipers, rotor bolts, crank bolts, saddle clamps — anywhere that gets dirty or sees a lot of torque.
Tools You’ll Need
- Allen keys (metric, ball-end preferred)
- Torx wrenches (especially T25)
- Torque wrench (must-have for carbon bikes)
- Threadlocker (blue Loctite)
- Anti-seize compound (for metal-to-metal contact)
Final Tips for Bolt Longevity
- Check torque regularly — especially stem and brake bolts.
- Don’t overtighten — invest in a torque wrench.
- Grease or Loctite as needed — read your manufacturer’s specs.
- Upgrade vulnerable bolts to titanium — especially those exposed to water, sweat, or mud.
Bike bolts may be tiny, but they hold your whole ride together. Treat them right, and they’ll keep you rolling smooth and safe. Ride on.