Is biking a good exercise for dvt patients?

Yes, after .....: A couple of weeks to optimize your anticoagulation treatment and have the thrombus "mature", and assuming your doctor is ok with it given your specific circumstances. Remember to be even more careful about trauma - being anticoagulated means your blood does not clot as fast as it normally would. Always wear a helmet and appropriate clothing including shoes when biking.

Generally: But swimming, anything with flat or legs elevated may be somewhat better.Dependent legs may be congested and swell.

Exercise is good: As dr. Wright said, swimming might be better but biking is ok too, especially if you have a recumbent bicycle. Like dr. Accurso said, don't forget your helmet. As long as you are properly anticoagulated and you have the ok of your doctor, nearly any exercise is ok although mixed martial arts isn't a great idea. Don't forget that you need to wear a compression stocking for two years after a dvt.