Student-Contributed Wiki

Student-Contributed Wiki

An awesome student from our education program made this wiki. It is not managed by iFixit staff.

Mongoose 20'' BMX Troubleshooting

The device is a Mongoose BMX bicycle with 20'' tires. The production year was between 2005 and 2010.

Tire will not stay inflated ¶ 

Bicycle tire will not hold air even though you've been inflating it.

Inner tube is leaking air ¶ 

Although patching a tube may be possible, it is ideal to just replace it.

Tire has a tear in it ¶ 

It is possible for the tube to be working probably while the tire is still flat. This would only happen if the tire was damaged. You would have to replace the tire to fix this.

Pedals do not make the bike move ¶ 

Your bike can roll, but the pedals are what is making it move.

The chain fell off ¶ 

Sometimes the chain can fall off, or come off of the sprocket. This is an easy fix that only requires putting the chain back on the sprocket and possibly needing to tighten the chain.

The chain broke ¶ 

If the chain is broken you may need to replace it. You can avoid replacing the whole chain if only a link or two are damaged, but you'll need extra links.

Handle bars are squeaky ¶ 

While riding the bike your handle bars make a lot of noise and squeak while turning and maneuvering.

Faulty ball bearings ¶ 

Sometimes the ball bearings just get old and rusty and no longer allow turning with minimal friction. If oiling the ball bearings does not solve the problem then they will need to be replaced.

Headset is dry ¶ 

In other words, the headset and the fork have no oil between them and the metal on metal is making the squeaking noise. You will need to remove these two parts and oil the fork where the headset overlaps it.

Seat moves freely ¶ 

The seat either moves up and down or rotates forward and backward easily.

Loose bolts ¶ 

Sometimes this problem is fixed simply by tightening some loose screws.

Broken seat clamp ¶ 

If the seat clamp is broken then it probably needs to be replaced. The seat clamp is not easily repaired.

0 Comments

Add Comment

View Statistics:

Past 24 Hours: 1

Past 7 Days: 3

Past 30 Days: 10

All Time: 311