Chain Often Came of Your Bicycle?

Sometimes customers come to the shop asking us to help install their chain which had fallen off their bicycle. That can be fixed by adding a master link or rivet.



If the components on your drivetrain are worn out, it would be best to change them if you are installing a new chain, especially, if it is an expensive one. This is because each time you ride and change gears, any worn out parts on the drivetrain, such as, the freewheel/cassette or chainrings or derailleur wheels will pull and rub against the new chain. Your new chain will be damaged and you will have to change it sooner than it should.

If the mechanic informed you that the cassette needs to be changed too, it is possible that the teeth on the cogs of your cassette are damaged. If you do not change it, the chain will keep skipping over the top of the cog and fall off. Ask the mechanic to show you where the damage is. If you cannot see any wear, or burrs or bents on the teeth, you can always send your bicycle to another shop for a second opinion.

The following are some questions a good mechanic should ask you before re-installing your chain:

1) Is it a new chain? New chains for bicycles are always longer than needed. A chain that is too long will slack and fall off the bicycle. We can use the old chain, if it is still on the bicycle, to determine its required length. However, if there is a slack in the old chain, it is possible that it has worn out, in which case, we will have to determine the correct length required for the new chain.

1b) If it is a new chain, did you get the right chain for your bicycle? There are differences in chains for single speed and geared bicycles. Bicycles running on higher speed need the narrower chain which is more expensive. The cheaper single speed chain installed on a geared bicycle can cause it to fall off the chainring due to its width and thickness.

2) Did you fell off your bicycle while cycling? If you did, we will have to check if any components on your drivetrain have been damaged or need adjustment. Your new chain will be damaged if there are bents in the chainring teeth or on teeth of cogs on your cassette.

3) Did the chain come off only when you change your gear? That will mean either the chain is worn out and need to be changed or that the gears need to be set. Chain wear or dirt on it will affect the efficiency of your gears. If that is the case, just putting the worn out chain back on will not help as the chain will fall off again when you shift your gears.

Before the mechanic put your chain back on, he will have to check it for bents or stiff links. The chain will have to be cleaned first if it is clogged with dirt. Once installed, the chain should be lubricated together with the components on your drivetrain.

When should I change my gears?

You do not have to zoom down a slope when descending if you put more resistance on the pedals by using the "higher" or "harder" gears.  The lower gears are easy gears are for ascending hills.

Shift down to a lower gear = Ride uphill = ride on lower gears to climb uphill with less effort.

You are cycling on low gear when

1) your chain is on cog of smallest chainring = gear 1
2) your chain is on cog of biggest sprocket at the rear = gear 1

Shift up to a higher gear = Ride downhill = add resistance on the pedals and to reduce cadence (in your own term, heaviest).

You are cycling on highest gear of your bike when
1) your chain is on cog of largest chainring at the front = gear 3
2) chain on cog of smallest sprocket = gear 8 = you are running on 24 speed

This diagram of cogs on a chainring and freewheel of a 24 speed bike gives you an idea on which cog your chain is sitting on when you change your gears.

What this video if you would like a clearer picture of how your chain moves on the chainrings and cogs when you change your gears.

Is BMX good for long rides?

Is BMX good for long rides?  That depends on the number of teeth on your chainring.

If you are buying a BMX for doing tricks, you would want to buy one with lesser number of teeth on it. This is so that you can start to ride off faster after doing your twists and turns. However, if you like to go a longer distance, if that is what you mean by long rides, choose one installed with larger number of teeth on chainrings, eg one with 48 teeth.

This is a GT BMX 43T (teeth) chainring. You should be able to find BMX with 28T (teeth) right up to 48T (teeth) chainring.



A BMX with larger wheel size instead of the common 20” will also help you cover more distance. You can calculate your gear ratio and how far you can go each revolution by knowing your wheel size, the number of teeth on your chainring and on your rear sprocket.

There is a table posted at link to article BMX Madness Gear Ratio and Sizing Charts which shows the distance you can cover based on the above information.  I have also extracted from the site to show you how that is calculated:

“For example, if your front sprocket is a 45 tooth, and your rear sprocket is a 16 tooth, then your gear ratio would be 2.8125 (45 divided by 16 = 2.8125). You then take that number (in this case 2.8125) and multiply it by 20 (the diameter of a BMX wheel). 2.8125 x 20 = 56.25 (the gear size). You can apply this simple formula to cruisers (BMX bikes with 24" wheels) by multiplying the gear ratio by 24 instead of 20.”

If "long rides" means ride for a longer period, you have to note that most BMX are made of steel to handle the stress of load during jumps from a height so it is a heavier bike to ride. Make sure that you choose a frame size that is suitable for your height. If the bike is too small, you are more likely to stand up to pedal, each time you want to relieve the fatigue on your legs. That will damage your pedals more quickly than they should.