Your brother-in-law is encountering pinch flats. http://www.sheldonbrown.com/flats.html
These happen when the tube gets compressed between the rim and the surface, and causes two "snake bite" holes. Pinch flats can happen to anyone on any bike, and are prevented by: 1) raising the air pressure in the tube and/or 2) avoiding big, abrupt impacts. In your brother-in-law's situation, he is overloading the rear tire for whatever pressure he's running. If he has skinny tires (like a road bike), he may have to inflate his rear to the maximum pressure on the sidewall when he adds a load to his bike. Wider tires require lower pressure, so he could also help this situation by changing the rear tire for a wider size, if possible. I pinched and flatted my rear tube this Sunday because I tried to hop a curb. I didn't get the rear wheel high enough and it impacted directly on the curb edge. PSSSSHHH. I carry a spare tube so I swapped it and rode on, then I patched the two holes later at home. When I'm further from home, I'll often swap the tube and then patch the bad one right there on the side of the road. On Wed, Nov 18, 2015 at 9:21 AM, LeahFoy <[email protected]> wrote: > My sister and her husband commute to work in downtown Pittsburgh. Her > husband rides a Specialized of some sort, and has racks and baskets. He has > popped his rear tire a few times now, and was told by the LBS that because > of all the weight on the rack and over that rear tire (he is an attorney > and carries two laptops and a heavy leather bag), he should be careful and > stand up over bumps or risk blowing the tire out. My sister was telling me > about this phenomenon and was advising me to do the same. I asked her if > his rack screws into the frame, and it does. > > I don't understand this. I have zero (read: ZERO) mechanical understanding > of bicycles, but I've never stood up over bumps (granted, I'm 5'6" and 130, > my BIL is a sturdy 6 feet, 230) and I've never worried about popping my > tire. > > Do I need to worry about my back tire? If not, what is it about Riv's > racks and/or frames that insulates us from the same issue? > Thanks! > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/rbw-owners-bunch. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
