Rear brake mount instructions
Your Sturdy frame has an interchangeable rear brake mount, made in two versions: one for a 140 mm rotor and one for a 160 mm rotor. Both come with the frame. To change rotor size, fit the matching mount. This page shows how to tell the two apart and how to swap them. For the brake caliper and rotor themselves, follow your brake maker’s instructions.
Before you start
Important
Brakes are safety critical. If you are not confident doing this work, have it done by a qualified bicycle mechanic.
Always fit the mount that matches your rotor size.
Don’t squeeze the brake lever while the caliper is off the bike.
Before riding, check the rear brake works properly.
Tools and torque settings
- Torque wrench covering 6–8 Nm
- T30 Torx bit (mount bolts)
- The tools your brake caliper needs
- Anti-seize
| Fastener | Tool | Torque |
|---|---|---|
| Mount bolts ×2 (M6 × 12 countersunk) | T30 Torx | 6–8 Nm |
| Caliper bolts | See your brake maker | Your brake maker’s figure |
Which mount do you have?
Both mounts come with your frame. Each is engraved with the rotor size it takes: 140 or 160. You can also tell them apart by their shape:
- 140 mm mount: longer and lower.
- 160 mm mount: shorter and taller.
Both mounts fit the same two holes in the chainstay, with the same two bolts.
Swapping the brake mount
- Wheel out. Take the rear wheel out: see our rear wheel instructions.
- Caliper off. Undo the caliper bolts and lift the caliper off the mount, leaving the hose connected.
- Old mount off. Undo the two mount bolts from the outside of the chainstay with a T30 key, and take the mount off the inside of the chainstay.
- Clean. Clean the chainstay face and the bolt threads.
- New mount. Hold the new mount against the inside of the chainstay. Put anti-seize on the two bolts and fit them from the outside.
- Tighten. Tighten both bolts to 6–8 Nm with a T30 key.
- Caliper and rotor. Fit the matching rotor to the wheel, then fit the caliper to the mount and align it, following your brake maker’s instructions.
- Wheel in and check. Refit the wheel. Check the brake works and the rotor doesn’t rub. If you fitted new pads or a new rotor, bed them in following your brake maker’s instructions before riding.
Labelled drawing: brake mount and bolts
Looking after it
- Check the mount bolts are at 6–8 Nm whenever you work on the rear brake.
- Put fresh anti-seize on the threads whenever you take them apart.
Questions? Contact us.
Warranty
Everything we make is guaranteed for the lifetime of the original owner against defects in design, materials and workmanship. If a part we made fails because of a defect, we will repair or replace it.
Parts we buy in, including brake calipers and rotors, are covered by their makers’ warranties.
Fasteners and wear parts: bolts, nuts, washers and threads wear in normal use. They are covered against defects in materials and workmanship, but not against wear, thread damage or galling. Replacements are available: contact us.
Not covered:
- crash or impact damage
- damage from fitting or use that doesn’t follow these instructions
- modified parts
- normal wear and cosmetic marks
To make a claim, contact us with your order number (your order confirmation email is your proof of purchase) and photos of the problem. Stop riding a part you think is damaged.
This guarantee is given by Sturdy Cycles Ltd, The Old Tannery, Lower Keyford, Frome, BA11 4AR, United Kingdom. It applies worldwide to products bought from us or an authorised dealer. It is in addition to your legal rights as a consumer and does not affect them. See also our terms of service.
Revision history
| Rev | Date | Change |
|---|---|---|
| A | October 2026 | First issue |
This page is document SC-IP-FR-003 revision A. The PDF version has the same content.