Are there any types of bicycles that are not allowed to be used in triathlons. I was about to bid on a TT bike and then thought, that it might not be allowed in a tri, what about softrides? suspension bikes, etc?
I would look closely at a time trial bike. The set up of the bike if I recall correctly is not the same as a tri specific bike. I could be wrong, but it wouldn't hurt you to research it. Soft rides are legal and I think that there were several at Kona.
Unless you race the ITU circuit tehy are all pretty much OK. As far as I know you can't use softride and similar in ITU. But they may have changed the rules since I last checked.
I probably didn't make myself clear on my response. I didn't mean that a TT bike might be considered illegal. The bike itself is usually set up a for road riders with its geometry which favors the muscles they have built from riding. A tri-specific bike is set up with a geometry that helps a triathlete by letting them use the muscles built up from running.
After I read my post I didn't feel that I was really clear on that and didn't want to mislead anyone.