So my 12 year old DS went out on Dunday about 11am on a bike ride with his friend, then playing out in the streets with kids from 8 to about 14. When he came in at about 8pm he had what look like burns on the inside edge of both thumbs. He couldn't give me an answer about how he got them after a lot of questioning he decided they were off gripping the handle bars of his bike but I'm sceptical this is the case. Who would grip the handle bars so tight to give themselves friction burns. Surely you would stop before they got as bad as these are if you hands were getting rubbed from the handlebars? I'm suspicious because his explanation when he came up with one sounds unlikely but at the same time I cant think what dodgy thing he could have been doing to get them. Any ideas?