The biggest bag we recommand using is the 35 L but not everyone will be comfortable to ride with that much weight on the front wheel. The main reason why we don't recommand large bags in front is safety. It is harder to maneuver the bike. Also, you'll need to validate that you have enough clearance from the bag to the ground to make sure it doesn't rub on the road while you turn and that your feet do not touch the bag. * If you choose to use a 35 L, pack the heavy weight at the bottom of the bag.