Recently, I got an e-mail from one of the frequent posters on the GWRRA message boards regarding premature rear brake wear on the GL1500. Gordon Seykora claimed that the GL1500’s left saddlebag could become deformed when badly overstuffed —deformed enough to foul the brake caliper and result in unevenly worn brake pads.
I wrote him back. “Those bags are pretty rigid,” I said. “That just can’t happen!”
“Oh, yeah,” said he, “I’ve personally seen it happen on two GL1500s, the last one being a 2000 model! The guy had to soften the bag with a heat gun and massage the bag till there was adequate clearance.”
So we took a look for ourselves. The accompanying picture was taken from directly underneath a ’99 GL1500SE. What appears to be the upper edge of the caliper in this picture is actually the rearmost bottom edge. The brake pad that’s visible is the outboard pad. As the pads wear, the piston attempts to push this pad closer to the rotor against which it is resting. When this pad can move no further, additional piston movement occurs as the entire caliper assembly slides to the left (as viewed here), causing the pad on the other side of the rotor to also come into firm contact. The thickness of the brake friction material (clearly visible in the photo) approximates the space required between saddlebag and caliper body to accommodate this left-sliding action during the life of the brake pads. The space available, at least on this example, appears to be just barely adequate.
Now here’s the rub. Should the caliper body come into contact with the saddlebag, the caliper would no longer be able to move laterally. The results would be reduced braking effectiveness with rapid wear of the outboard brake pad, and no additional wear on the inboard pad. If the condition isn’t spotted in time, the outboard pad may wear down to the metal backing plate and seriously damage the brake rotor.
After closely examining the inside of the left saddlebags on two ’99 GL1500s, it seems to me that the area in question should be adequately protected from contact with the bag’s contents by the presence of the tool kit and owners manual (if they haven’t been removed). Even so, I really don’t think that pressure on the inside of the bag would cause it to deform, even at high ambient temperatures, unless the plastic had been softened through exposure to some chemical. I don’t know for certain, but I suppose it’s possible that grease or brake cleaner could soften the plastic. After all, I haven’t seen the two bikes that Gordon describes, and I’ve learned to never say never. It’s just that with so many Wingers cramming their saddlebags to the bursting point on a regular basis, wouldn’t a problem of saddlebags becoming deformed by heat and internal pressure have become evident and been addressed a long time ago?
I suspect that something else may be going on here. Yes, it’s entirely possible that some late model GL1500s’ saddlebags were inconsistent in shape when manufactured. It’s also possible that the saddlebag frames on these bikes were either improperly mounted or had been tweaked in a parking lot tip-over.
There may be other possibilities, but for our purposes, aren’t they really immaterial? The key point here is to make GL1500 owners aware of the minimal clearance that exists between these two points, even in the absence of damage or poor adjustment, so that you’ll hopefully keep an eye out for trouble. Thank you, Gordon Seykora, for bringing this to our attention.
