Specialty bicycle retailers nationwide between May 2011 and September 2011 for between $550 and $1,100.
The bolt that secures the seat saddle clamp to the seat post can break posing a fall hazard.
Consumers should stop riding the bicycles immediately and contact an authorized Trek dealer for a free replacement bolt.
For additional information, contact Trek at 800-373-4594 between 8:00 a.m. and 6:00 p.m. CT Monday through Friday or visit the company's website at www.trekbikes.com
Trek has received four reports of incidents with one injury involving a broken tooth and lip injury.