I have an old Steinmark leather jacket that I bought when I was in the navy. It is super heavy duty, and it weighs quite a bit. Well I recently got back into riding but the jacket is a little snug,(not saying I'm not in shape or anything like that) it's a known fact leather elves decrease sizes over time.( damn those elves) is there any way to make the jacket maybe stretch or add a size or two. The jacket has a lot of miles and memories on it.thanks. Keith

Leather can be stretched a bit, but I am not sure if you can get more than maybe one size. I have stretched gloves and boots before. Use a leather softener/conditioner like mink oil. You would need to wrap it around some kind of form that you can make tighter and tighter each day for a few days, re-coating with mink oil as it dries.

I know the feeling my first leather jacket stretched to the point of opening at the seams. Now i'm more then a few sizes larger than then. One other option would be to find a tailor or one that deals in leather and have them insert a panel to increase the size. The reason I say that is when I purchased my present one (made here in the US) they made mention if i should go up a size or two they could insert a new panel so this would be the last leather jacket I would ever need.

Good luck I know how a good jacket can be.

Chaz has it right. Leather can be stretched (look at the knees of your chaps after a ride) but only some. It is, after all, the hide of an animal.Once it is tanned, the ability to stretch is limited by the cellular structure.
The best way to increase the size of a leather jacket is to have an insert or two sewn in by a professional. A split is harder to fix. So, either retire it... or have it 'expanded' to fit. Also, the leather may be too old to subject it to any real expansion.
Hope this helps & let us know what happens...
Edge

Well I guess you could get a good buddy who is bigger than you oil HIM down, ask him to wear the jacket then oil down the JACKET with mink oil, and send him on a day ride.
I know you were being serious