Looking at updating the pipes on my 2002 VFR. I remember someone saying that some pipes will not fit under Honda saddlebag frames. Can you tell me which brands do work? Also, for 2-Up riding, how important is it to upgrade the rear shock? mine has 19K on it.
As I recall, the 02' models had the underseat exhaust. If you do a google image search for "2002 Honda VFR 800 (insert brand here) exhaust" you should get an idea for how much clearance there will be. As a rule manufacturer's generally don't like to make pipes larger than stock, they will almost always be smaller than stock due to the increased chances for fit issues if they are larger. I'm no expert, but from what I have learned, upgrading the shock isn't so critical, its the spring rate that you need to worry about. Generally speaking, changing out springs is relatively cheap. You could also swap out the shock while you're at it, but I think springs, both front and rear are likely a better investment. If you're worried about the bike being way too stiff when flying solo, I've seen variable rate springs from a variety of suppliers on the market. I would check out race tech's website and use the spring rate calculator for both solo weight and 2 up weight to see what range a set of variable rate springs need to fall within.
Well to follow what Sammich and TNRabbit said, most aftermarket pipes should be fine and as far as suspension, seek out Jamie for advice and/or service. Since I use my '09 for work, touring and 2 up riding, I went with a used OEM ABS model VFR rear shock (remote preload adjuster) so that I can easily adjust the preload with whatever weight I will be carrying. However, before I installed it, I sent it to Jamie for rebuild. I gave him my base weight, anticipated maximum weight and the general riding I would be doing and he rebuilt it to support my needs. I also had him supply new valving, springs and shims for my forks, which I installed. Great ROI if you ask me.
