Problem with chain bicycle lock combination no longer working, possibly tampered with. URGENT

Don't use that combination. Really. It is unnecessary as it duplicates a straighter chainline combination and it's also possible that your rear derailleur can't **** up all the slack chain when using small gears front and back.


Read this:

http://www.active.com/mountainbiking/Articles/_Cross_chaining___a_real_don_t_for_a_properly_functioning_bike.htm

http://www.sheldonbrown.com/gears.html

Google "bicycle shifting technique", for example:
http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/
You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible.
Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency.
To demonstrate this for yourself, put the bike in the same combination of gears you're having a problem with. Get behind the bike and look straight along the top of the chain. As you can see the line of the chain is a mild zig-zag where it is parallel to the bike at each gear but needs to angle across the drivetrain in between. On some bikes the chain might even come in contact with the next larger chainring when used this way.
The big-big combo uses up all available chain length and the rear derailleur will be pulled toward the front of the bike, sometimes so far that it is in danger of being snapped off.
THERE IS NO UPSIDE TO CROSS-CHAINING.
As you can see, the rear derailleur is probably not long enough to **** up all the slack this gear combination creates. There are other combinations that would yield the equivalent gear ratio without either stressing the drivetrain or dropping the chain.
The basics of shifting are these:
1) The big ring and right side of the cassette in back are for speed.
2) The small ring and the left side of the cassette are for high torque, lower speed
Ancient bike wisdom for beginners: If your legs ache, shift down. If your lungs ache, shift up.

Google "bicycle shifting technique", for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chain line is as close to straight as possible.

Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency.

To demonstrate this for yourself, put the bike in the same combination of gears you

Google "bicycle shifting technique", for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible.

Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency.

To demonstrate this for yourself, put the bike in the same combination of gears you

Google bicycle shifting technique, for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible.

Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency.

To demonstrate this for yourself, put the bike in the same combination of gears you

Google "bicycle shifting technique", for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible.

Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency.

To demonstrate this for yourself, put the bike in the same combination of gears you

The simple nature in which you state the problem reveals a novice level of bicycle gear understanding.

If you feel up to it, start here for tools and techniques regarding the hardware...

http://www.parktool.com/blog/repair-help/categories/derailleur-systems

Google bicycle shifting technique for operational advice, for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible.

Excess sideways stress on the chain will wear it out prematurely and decrease its normal efficiency. To demonstrate this for yourself, put the bike in the same combination of gears you

Go to masterlock.com and they should have your answer. You can recover you combination etc, so I am sure that they can help you

If you learn to shift correctly this won't happen..

Google bicycle shifting technique, for example:

http://coachlevi.com/cycling/complete-beginner-guide-to-bicycle-gears-shifting/

You should NEVER run cross-chained (big-big or small-small). The drive train performs best when the chainline is as close to straight as possible. Excess sideways stress on the chain will wear it out prematurely and increase its normal efficiency.

To demonstrate this for yourself, put the bike in the same combination of gears you're having a problem with. Get behind the bike and look staright along the top of the chain. As you can see the line of the chain is a mild zig-zag where it is parallel to the bike at each gear but needs to angle across the drivetrain in between. On some bikes the chain might even come in contact with the next larger chainring when used this way.


If you can shift to the big-big combination without snapping the rear derailleur off, you're lucky. The big-big combo uses up all available chain length and the rear derailleur will be pulled toward the front of the bike, sometimes so far that it is in danger of being snapped off.

THERE IS NO UPSIDE TO CROSS-CHAINING.

As you can see, the rear derailleur is not long enough to **** up all the slack this gear combination creates. There are other combinations that would yield the equivalent gear ratio without either stressing the drivetrain or dropping the chain.

The basics of shifting are these:
1) The big ring and right side of the cassette in back are for speed.
2) The small ring and the left side of the cassette are for high torque, lower speed

If you have a bicycle with a deraleur system (chain with a lot of different-sized sprockets in the rear), is is possibly because the sprockets are worn combined with a slightly stretched (worn) chain. The best solution is to replace the offending sprockets (they are always the smaller ones) and the chain. You should be on your way. (Before doing ANY of that, however, MAKE SURE that your gears are adjusted properly. A deraleur that is trying to stay between gears will cause just this same symptom.)