I post this note to the group every year. Please double check your
bike. There are no excuses for most of these failures.

When doing long rides, it is important to have a well-maintained
bike. A mechanical failure 100 miles away from your starting location
can be a big problem. The best approach is preventive maintenance.

Here is a list of things to check on your bike.

Tires.

Make sure there are no thin spots in the tread. Tires with large
nicks and slashes should be replaced. Check the side walls for signs
of age or cracking. If you tires lose a lot of air overnight, replace
the tubes. Remember, you will be out on the bike for 14 or more
hours. You don't want to have to use a bike frame or mini pump after
10 hours on the ride. If your tires have boots in them, please
replace the tire before the double. By the way, US currency makes a
great boot if you ever get stuck, but you should always use the
largest denomination bill you have, that way you have an incentive to
remove it.

Rims.

Check your rims for cracks around spoke holes. If you find any
cracks, replace the rim. Also, true the wheels and take them out on
at least one ride before the double to make sure they are right.

Shifting and brake cables.

Make sure they are not frayed where they meet the shifters or levers.
This is always where they break. You may have to remove the cable to
check it.

Bottom bracket.

Try pushing the cranks toward and way from the frame (not round and
round like you pedal). Any play may indicate a bottom bracket
problem.

Headset.

With the bike on solid ground, hold the front brake as hard as you
can. Now push the bike forward and back. If you hear any clicking
noises, or feel any play (but not frame flex), then you have a loose
headset.

Chain.

Look for bad links. Check any master links you may have in the chain.
Periodic chain noise (a noise once for every revolution of the chain,
but not for every turn of the crank) indicates you have a bad link. A
good way to check for a bad link is to run the chain backwards and
look for any irregularities as the chain goes through the rear
derailer.

Attachments.

Make sure all water bottle cages are secure and the cages hold the
bottles securely. Check any packs and make sure they are secure.

Pedals.

Check for play and proper lubrication.

Handle bars.

Make sure the handle bars are secure and in the right position. Face
the front of the bike. Straddle the front wheel between your legs and
grip it tight with your feet and thighs. Try turning the handle bars
left and right. Tighten if loose. Make sure the front of the
handlebars have not been pushed too far down. The tops of the brake
hoods should be close to the tops of the bars if the bike is level.

I have seen all these failures occur on club rides. There is no
excuse for most of them. The most serious failure required an
ambulance ride to the hospital and a resulted in a broken collar
bone. All these problems can be prevented with 15 minutes of
inspection. Do it now and then again on the Saturday before the ride.
Better safe then sorry. Mechanical failures take all the fun out of
cycling. Don't let it happen to you.