An internationally known bicycle designer died while riding on RAGBRAI Monday. Sixty-three-year-old Tom Teesdale of West Branch built custom frames for bicycles. University of Iowa professor Steve McGuire taught design classes with Teesdale.

“Students just loved his teaching and to this day I’m not sure that they realized how important and famous this person who was working with them was,” McGuire told Radio Iowa this afternoon.

McGuire said a cyclist who got a Teesdale bike frame was like a violinist who got a Stradivarius.

“He knew how to match the geometry of a bicycle to a person in such a way that when a person got on a bike — a bike that he built — they felt like they were really riding a bike for the first time,” McGuire said.

Some of Teesdale’s innovations are now standard components of mountain bike frames. A bicycle Teesdale built is in the Mountain Bike Hall of Fame in Europe and there’s one in the U.S. Mountain Bike Hall of Fame, too.

“Tom had a level of craftsmanship that some people would actually put in the category of national treasure,” McGuire said.

McGuire now builds bicycles, too, after learning the craft from Teesdale. McGuire has gone through about 23 Teesdale bike frames over the years and four remain in his garage, ready for a ride.

“About 15 years ago he actually built a tandem recumbent bike for my son, myself and my wife to ride. Our adult son has cerebral palsy,” McGuire said. “And this great frame builder, known internationally, built many of the special frame bikes that are used every year now in Iowa Special Olympics.”

McGuire spent time on the phone today, talking with friends and admirers of Teesdale.

“It’s been a really sad day, (with) tears, but I have to say that he went out in a wonderful way. He was riding a bicycle that he made for a trip that he took with his daughter on RAGBRAI,” McGuire told Radio Iowa. “You know, I can’t think of anything more fitting.”

RAGBRAI officials say Teesdale suffered from a medical condition while riding his bicycle near Graettinger on Monday and he was pronounced dead at a local hospital. Teesdale began building bike frames in 1976. His business is called TET Cycles and the company’s website says he has built “thousands” of custom bikes during his career.