I had a back box bolted onto a Renntec, until i slowed down one day approaching a 6' 6" and it snapped in half and the whole thing overtook me!They're supposedly only designed for 5kg of weight, which is a joke to be honest, bearing in mind it's made of metal?
I found one which was £75 or offers. Took a punt with £50 and it was accepted.
You have to remember that these bikes have a 187kg weight limit as well, that includes any extra luggage, which all sounds okay, until you get a lump like me that weighs 100kg alone, then the weight of the luggage, so that only allows me to have midgets or the very slim variety as passengers, which is easier for me i s'pose!
I made my own using an old Renntec that I had lying around. It's easier than it looks! Unfortunately I didn't take any photo's before I sold the bike, but I used 1" square steel bolted to the handrail mounts, and then welded the rack onto this. I then bolted my backbox onto it from there. I carted my work gear using it for a couple of years on the fazer, and the kitbag stands 2 1/2 feet high, and weighs about 30kg!!! I stood it up on end (pillion seat) and bungeed it to the top box. Never let me down and was steady as a rock. The box was always loaded with kit, and the handling was a little slow, but still steady. Word of advice when buying a box. Buy a good quality one, and don't go too big! My cheap 30 litre one I bought with the quick release mechanism decided to 'quick release' on its own once at 40mph. after buying my wifes b'day present present from Anne Summers