I made a bike stand from a ¾” pipe clamp, pipe and a wheeled metal drawer. Works pretty good, just the drawer is cheap and rickety. My problem is, how do you keep the handle bars straight and solid to work on? I tried bungie cords, works ok, but slips to easy. Should I put an extension on the stand to tie the bars too?

Is any special tools needed to tear down wheels hubs to replace bearings, replace the cassette or to take apart the bottom bracket?

Thanx for your help.

The Park HBH-2 "handlebar holder tool" works well:

Hubs (assuming loose bearing hubs) will require cone wrenches to properly service.
Cassette will require a lock ring tool and a wrench (torque wrench to get the lock ring torqued back on properly is helpful).
Bottom bracket varies by type. You may need a crank puller to remove the crankset as well as tools specific for your BB.

OP:
You will also need a chainwhip to keep the cassette from turning when using a cassette lockring tool.

Front hubs typically need a 13mm cone wrench for the bearing cone and a regular 17mm wrench for the locknut
Rear hubs typically need a 15mm cone wrench for the bearing cone and a regular 17mm wrench for the locknut
***this can vary depending on manufacturer/make/model of hub***

If you have an adjustable cup and cone type bottom bracket then you will need a compatible hook spanner for the adjustable cup lockring, a pin spanner to hold the adjustable cup in position when tightening and loosening the lockring, and a fixed cup wrench if you desire to remove the fixed cup wrench.

If you have a cassette type bottom bracket you will need a specific tool that is compatible with the bottom bracket type you have.

There are also specific tools for different models of external bearing bottom brackets.

If you your bottom bracket/cranks are square taper type or a variation of octalink (splined spindle/hole) you will need a crank arm extractor (and usually a 14mm socket to remove the crank bolt).

The type of tools you need really depends on what parts you have on your bike.

I think anyone who works on bikes would benefit from having the following non-bike specific tools:
2.5/3/4/5/6/8mm allen keys
8/9/10/15/17mm combination wrenches
1 inch combination wrench or 8inch adjustable wrench
needle nose pliers
diagonal cutters
#1 and #2 philips head screw driver
flat head screw driver
socket wrench with 14mm socket (6 point and thin wall preferably)

After the above general tool recommendation anything I could recommend would be to handle a specific repair or installation/removal situation.

-j