As others have mentioned, it's important to get back on the bike as soon as possible, but be that as it may, perhaps by showing him just how much fun you're having riding your bike, will encourage him to start riding again. My youngest sister home-schooled her 4 children, and when I asked her how she taught her kids to read, she said she didn't, the kids taught themselves, all she did was to encourage them. I asked her how she did that, and her reply was that being an avid reader and keeping a book-list, she would review her books after she read them. The kids asked her what she was doing, and she explained to them, and having seen how much fun she was having, it wasn't long before the kids were all keeping book-lists, and two of the girls even started their own magazine (they were about 8 or 9, but the seeds had been planted, and had germinated). Encouragement is the key! Don't rush it, but it's OK to be excited about it - the enthusiasm will rub off! Good Luck! HTH -
- Wil