Park Tool Patch Kits
Observing an inner tube discarded on a road fills us with revulsion. It's not only the littering, but the discarding of what is almost certainly a perfectly repairable tube. Some people might think they're too rich or busy to repair a tube. Super. Then take it home and then give it away to a broke bike rider. You can toss whatever on the ground in a European ProTour race and it will likely be treated as manna; even if a rider takes a dump on the road during the Tour you can bet someone will figure a way to take it home and make it the centerpiece of a shrine. If you're riding and racing in the U.S., littering just makes you a bum.
But the bigger thing is to patch the tube. You should be saving that tube in case you flat again on your ride. In preparation for that occurrence, you should have a sticker-style (aka pre-glued) patch or few in your bag. And you should have a traditional vulcanizing patch kit at home. We tested both. For the sticker patches, we went with the Park GP-2. For the vulcanizing, we went with the Park VP-1. If you haven't patched a tube before, instructions are are here.
The Park Tool GP-2 is, to us, the standard by which sticker patches are measured. They weren't the first to market with these patches, but they've dominated with this simple kit. Maybe it's because of their bike shop reach, maybe it's because of 3M helping devise the sticker, but we've been using these for what must be a decade or so. There are six 24mm square patches and a piece of sandpaper in the 31mm by 31mm by 7.5mm box. The kit complete weighs 4g.
They work just like stickers and will work just as well on latex tubes as they do on butyl. If you're in a real rush, you just find the hole, peel the backing off the sticker, press it down on the hole, shove the tube back in the tire, and go. If you have a few more moments, you should take out the included sandpaper and roughen the area around the hole a bit. You use the sandpaper not to increase adhesion but to clean off the tube. It's an easy way to make sure there are no substances that will make it harder for the sticker to stick.
One thing you absolutely shouldn't do is inflate the tube without putting it in the tire first. We learned this tip from Calvin Jones, the Park Tool guru. He explains the reasoning as such, "It's more like a tourniquet" than a glued patch. Since the patch is not permanently affixed to the tube, the tire works to create downward pressure on the tube and that pressure helps the sticker adhere to the tube.
Jones told us that people have reported going years on a tube with a sticker patch. Our experience is quite different. We've never had a stickered tube last more than a month without giving way.
We had been saving flatted tubes for this review. We took two tubes that had holes in them, and shoved them inside our Vittoria Corsa CX 700x25mm tires.
The patches lasted a few days before all the air leaked out. Taking a look at them afterwards, the leaks were probably the result of two classic problems that afflict sticker patches. Problem one is that the tube was a 20mm tube in a 25mm tire. The more the tube has to stretch, the more ripping pressure is being put on the tube before the tire holds the patch in place. The second problem is that one of the tubes had a hole next to one of those super-thin seams you typically see on tubes. Having the hole in that position meant the sticker was on top of a seam resulting in the sticker not lying perfectly flat on the tube and the seam probably functioned as an escape route for the air.
We switched to 23mm tires and re-patched. The tubes lasted longer, though one went flat after sitting in a warm car. And this is classic problem number three for sticker patches. While the car interior wasn't the 120-degrees Fahrenheit it needs to be to loosen the bonds of the adhesive, it was pretty warm and that was enough to take the sticker, which was probably on the edge of not holding, over.
That the stickers held for a few days on this test is plenty for us. All we really want them to do is work until we get home.
When it's time for a permanent tube repair, you need a vulcanizing patch kit, the VP of Park's VP-1. This is the classic patch kit you've seen in many forms. "Vulcanizing is a process that turns rubber into a more durable material.
There are six patches, four round, each about 26mm in diameter, two oval, roughly 26mm by 335mm, of the variety with the Orange sub layer and Black top layer, along with sandpaper, and glue (more properly "vulcanizing fluid").
In our younger days, we were good friends with this sort of patch kit. Flat tires were a common occurrence for us then, so we mastered the art of gluing. We once went crazy and patched one tube 20 times. That was a bad idea, but we got it out of our system.
Even with our experience, we realized that we didn't know everything about patching. In our conversation with Park's Jones, we confirmed a number of things we've heard disagreements on. First of all, the orange side goes against the tube. The orange rubber has high sulphur content to improve adhesion, so you want that side against the tube. The patch is designed to have a tapered edge, so it is thinnest on the orange edges and thickest on the black section. The sandpaper is to clean the tube; you can use alcohol if you have it and have the time. You should wait until the glue is dry before applying the patch. Leave the plastic film that covers the patch on the patch after the patch is stuck to the tube. This is to make sure the patch doesn't adhere to the tire. We've cut large patches in half in the past. While this can work, the abrupt edge might be felt through the tire.
We generally wait until we have four or more tubes to patch and then sit down and do them all at once. So long as you have the room to store old tubes, this makes repair simple and it goes by relatively fast.
The Park patches and vulcanizing fluid work exactly the same as similar patch kits. We cut apart the two sets of two round patches so that we could keep the plastic backing on the patches. They group them together because it's cheaper to produce that way. As with all of such kits, we find we run out of patches about by the time we're about halfway through the glue. This could mean they send too much glue, but we'd prefer more patches.
Patching tubes isn't sexy or exciting; it's boring. But if you ride, it needs to get done. Have a sticker-type kit in your saddlebag and a vulcanizing type in your toolbox at home. If you're missing either from your life, order them now.