A suspicious fire has heavily damaged the SOS Vélo not-for-profit bicycle repair store in Montreal's Hochelaga-Maisonneuve neighbourhood early Tuesday morning.

The fire began in a trailer at the back of the building that was being used for storage, but quickly spread to the roof of the main repair shop.

Firefighters needed about an hour to put out the fire and nobody was injured.

Montreal police are now investigating and said clues found at the scene suggest the fire was intentionally set.

A 51-year-old man was arrested near the scene and will be questioned today by police. 

The general manager of SOS Vélo, Guy LaRocque,​ said the fire damaged the equipment used to sandblast and repaint the frames.

There is also large hole in the roof at the back of the building.

SOS Vélo fire damage

The fire at SOS Vélo burned a large hole in the roof of the workshop. (Elias Abboud)

LaRocque said the store will likely be closed for a couple of days while damage is assessed and the building is cleaned up.

LaRocque said repairs to the equipment and building could cost more than $100,000.

Founded in 1995, SOS Vélo is a not-for-profit group that builds and re-sells bicycles to help adults re-integrate into the workplace.

"Today, we're going to close the shop tell the people that are in training that they don't work but we're going to pay them anyway so they can continue to have money for living," said LaRocque.

The organization only hires candidates aged between 18-55 and who didn’t complete high school.