55mm Bolt & Screw for Flex & Suspension: Fit Guide

By Micro Kickboard | Published: 2026-11-03

Category: How-to Guides

Learn how to replace the 55mm bolt and screw on your Flex rear wheel or Suspension folding block, with step-by-step checks to avoid common mistakes.

Quick answer

The 55mm bolt and screw (part 1321) is a direct replacement for the Flex rear wheel and Suspension folding block. Match the part to the location, use the correct tools, and tighten gradually to avoid damaging the threads.

Why the 55mm length matters for Flex and Suspension

A bolt that is too short may not engage enough threads, while one that is too long can protrude and interfere with moving parts. The 55mm length is specified for these two locations, so using the correct part reduces the risk of loosening or damage. If you are unsure about a different location, consult your scooter manual or contact support rather than guessing.

When to replace rather than re-tighten

If the bolt shows visible bending, stripped threads, or deep corrosion, replacement is safer than re-tightening. A bolt that repeatedly comes loose may indicate worn threads in the frame or folding block, which should be inspected before installing a new bolt.

Step-by-step replacement

Identify the correct location: Confirm whether the bolt is for the Flex rear wheel or the Suspension folding block. Check your scooter model and the old bolt's length (55mm) before ordering. Mixing up locations can lead to ordering the wrong part.
Gather the right tools: Use the correct size hex key or screwdriver for the bolt head. A poor-fitting tool can strip the head, making removal difficult. Test the tool fit on the bolt head before applying force.
Remove the old bolt: Support the scooter so the wheel or folding block does not shift. Turn counterclockwise to loosen. If the bolt is stuck, apply penetrating oil and wait before trying again. Forcing a stuck bolt can damage the frame threads.
Clean the threads: Wipe the bolt hole and the new bolt with a clean cloth to remove dirt or old threadlocker. Inspect the internal threads for damage. Debris can cause false tightening and loosen the bolt later.
Install the new 55mm bolt: Hand-thread the bolt first to avoid cross-threading. If it binds, back it out and try again. Once seated, tighten gradually in a star pattern if multiple bolts are involved. Cross-threading is the most common installation mistake.
Tighten to the correct torque: If you have a torque wrench, use the value in your scooter manual. Without one, tighten firmly but do not over-tighten; stop when the bolt feels snug and the part is secure. Over-tightening can crush bearings or strip threads.
Check function and re-check tension: Spin the wheel or fold the mechanism to ensure smooth movement. After a short ride, re-check the bolt tension as new parts can settle. A quick re-check after the first use prevents loosening.

Product facts

Parts: 55mm Bolt & Screw for Flex & Suspension - Part 1321: This 55mm bolt and screw is a replacement part for Micro Kickboard scooters, used on the Flex rear wheel and the Suspension folding block. It is designed for these two specific locations, so you can replace the worn bolt without modifying other components.
Parts: 55mm Bolt & Screw for Flex & Suspension - Part 1321