Here is the Bates seat mounted on Steve's Panhead. You can't tell if this photo was taken before or after the seat was repaired.
eBay is full of custom motorcycle parts. Some are out there in your face, while others are hidden in obscurity at the bottom of a milk crate full of junk...just like at the swap meet. One section of parts that receive a lot of attention is the selection of custom seats; specifically Bates solo seats. Bates seats have been bringing sky-high prices for a few years now and there is no end in sight. A Bates seat adds ambiance to the period-built bike.
Now, not every Bates seat you find is going to be N.O.S. (new old stock). Some seats have been used and even abused, but if the sticker is on the bottom of the seat pan then you can be pretty sure it's a Bates, so it's worth fixing if damaged. The two most common problems with Bates seats are torn or ripped seat covers, which can be fixed by a competent person and a good sewing machine most times. The second most common problem is a broken mounting bolt. There are two 5/16-inch carriage bolts that slide in the mounting channel that is welded to the bottom of the seat pan, these two sliding carriage bolts are for mounting a pivot joint. The other half of the pivot is welded or bolted on the frame of the bike. We've seen a lot of the carriage bolts that are rusted or broken when the seat's owner wanted to change mounts. So was the case with this particular Bates seat belonging to our friend, Steve Uhl. One of the mounting bolts had twisted off when Steve wanted to change mounts, this situation could easily have ruined the seat and its value. However, there is a way to fix the problem. Steve removed the seat cover screws and the foam padding, and then carefully cut an opening in the seat pan, removed the broken bolt, and slid a new bolt in its place. The flap in the seat pan was folded back in place and welded shut, all without hurting the original Bates sticker on the bottom of the seat pan. The whole operation took a couple of hours, and with the seat mounted back on Steve's Panhead you would never know it required any fixing at all.
Parts:
5/16x2-inch carriage boltLocal hardware store
MSRP $.15
Steve removed the cover and foam and put the seat pan on the bench, where he used the cut-off wheel in the die grinder to make three small cuts in the forward, tapered section of the seat pan. | 
Bates seat pans are made from some thick sheetmetal, and when you bend them into a shape, the metal strengthens even more. This is why Steve used a screwdriver to help the cut flap up out of the way. | 
The flap allows the head of the broken carriage bolt to be removed and the new bolt inserted into the mounting channel. |
With the new bolt in place, Steve folded or pushed the flap back into place and spot-welded the corners of the flap with a TIG-welder. | 
Welding a small section of the flap at a time to prevent warping, and more importantly, to keep from burning the original Bates sticker, Steve finished the welding over 20 minutes or so, and then used compressed air to help cool the seat pan. | 
Here is the seat pan from the bottom, with the new carriage bolt in place. Yes, it's a little long, but Steve trimmed it to length with the cut off wheel. Notice the Bates sticker is intact and unharmed. |
To dress the welds, Steve used a four-inch, right-angle grinder and a 60-grit flap wheel to finish off the weld. You have to be just as careful with the four-inch grinder and the flap wheel so you don't generate too much heat and damage the sticker. | 
Back in service. You have to look very closely to find where the repair was performed, and chances are you never get to see the underside of the seat, anyway. | |