Bicycle Mechanics - Deralleur help

I'm trying down-hilling/free-ride, but my bikes stock derailleur is terrible. it is soft and allows the chain to bounce and slap to easily. does anyone know of a way to stiffen a derailleur? if not, what is a good derailleur to buy. please, no jokes and "rude replies. ive already had enough of this in the past day.

thanks

It all depends on what you are running, cranks? Gearing? Chain slap is generally pretty normal (to some extent) and generally a derailleur isn't going to fix that unless I'm misreading your post. Is your chain too long? Is your rear derailleur picking up enough slack?

Have you tried adjusting the tension screw on the rear Derailure ? Just a thought.

I'd agree with johnknappcc above. Check your chain for length, and your derailleur cable for proper tension. It should - the cable - be taut while in the resting position - small cog in rear, small chainring up front.

If you could post a photo of your rear-derailleur with the chain in both the small-small setting above, and another of it in the large-large position, this could help us come up with a more certain diagnosis.

If you've checked your chain length, cable tension, and adjusted your b-tension screw, it may just be that your derailleur springs are worn out or crappy to begin with. Just dealt with this on my old 400lx shimano rd.

didn't they used to make something like an 'idler pulley' on a tanbem for downhill bikes? it went on the chainstay and kept extra tension on the chain