You want to make sure basic frame is well built, and my opinion, built to last. We hear a lot about frame fatigue these days. Frame fatigue is normally going to happen around weld joints. After a lot of riding and/or shock to these weld joints they can weaken and become less stable.
If you think this is the case for your cycle you may want to have it checked out by a good mechanic. One way to lessen this problem is to make sure you purchase high quality frames and components (sprockets, brakes, rims, etc.). It seems, however, these days that you get what you pay for.

The other factor to look at is. In other words; what are your intentions for your cycle? Are you commuting short or long distances? Do you plan on riding daily or occasionally? Do you like to go at or a moderate pace or do you “have a need for speed”?
Do you like 2-wheels, 3-wheels or 4-wheels under you? Would you like underseat steering or a more conventional handlebar style steering?



What is your comfort level in riding?
It really comes down to:
* quality craftsmanship
* use you intend for your cycle
* style of cycle you like
* level of comfort you desire
For more information on frame welding visit http://www.bikeschool.com/