Bonthrone Ltd. of 917 Fulham Road was founded in the 1970s by David Bonthrone who opened a shop in Kingston upon Thames.
The joint administrators are Brendan Guilfoyle and Chris White accountants at The P & A Partnership of London.
Guilfoyle said: "Trading in recent years has been difficult due to ever increasing competition. Regretfully the directors have decided they can no longer provide financial support to the company."
The shop premises in the Fulham Road have closed but David Smith at Charterfields has been instructed by the
administrators to find a purchaser for the business and assets.
The sale will include the Bonthrone B2C website, http://www.bonthronebikes.com This website is described by Bonthrone Ltd. as "one of the UK's biggest online bike stores with 18,000 bicyle products available serving cyclists all over the UK and Europe."
Warning signs that something was afoot at Bonthrone started appearing at the end of May.
On contributor to the BikeBiz.com trade-only forum said: "Just had a customer tell me they ordered [from Bonthronebikes.com] two weeks ago, was told order on way, and now can't get them to answer the phone."