The overpasses above the East Tamar Highway were packed and there were nearly as many pillion passengers taking photos of the crowd as there were crowd members taking photos of the passing parade.

And there was plenty to see and hear - the first bikes roared under Invermay's Mayne Street overpass just after 9.30am and the "tail-end Charlie" followed 21 minutes later.

Police led the bikes along the East Tamar Highway, Turners Beach Road, Bridport Road, Batman Bridge and through Deviot and Gravelly Beach back to Launceston.

At least, they led some of the bikes - the parade had stretched out to such an extent by the time it had reached the Batman Bridge that people thought it was all over.

But about five minutes later more bikes came through and, with no one to guide them along the road to Deviot, continued on the West Tamar Highway and Exeter.

Phil and Wendy Emanuel and their daughter Rebbecca, of Sidmouth, were among 20-30 people at the Batman Bridge- Deviot Road intersection waving to the passing two-wheeled parade.

"We wouldn't have missed it for quids - it's just a shame that something like this doesn't happen two or three times a year," Mr Emanuel said.

Charlie Palmer, of Harley- Davidson in Sydney, flew to Tasmania with daughter Indiana, 9, but his partner Barbara Mallon rode all the way, taking two days.

Indiana said that she had been to "heaps" of HOG rallies.

"The furthest I've gone on the bike is Canberra and it would have been nice to come to Tasmania on the bike instead of flying," she said.

Ms Mallon said that she had been on many Thunder Runs, but yesterday's was "definitely the best ever".

"It was awesome to see so many people waving and cheering," she said.