davester

I think the main downside is that many people don't read instructions or otherwise learn the proper technique so fail to sand the tube or allow the glue to dry before applying the patch, resulting in failed patches. Patching is relatively simple but is not idiot-proof. This results in failures. Those of us who are instruction-follower types can patch away until there's more patch than original tube left with no negative consequences.

Johno59

Six

jpdemers

A dozen patches means I've saved $100.
ETA: less the cost of the patch kits, but still...

I carry a spare tube in case the flat is unfixable, or (less likely) I'm in a rush to get somewhere, but generally will put on a patch. It takes only a few extra minutes.

jpdemers

Hey, I have a frame pump on my bike, and . . . oh. Never mind.

mgopack42 

my patches never seem to hold for long, so once to get home then toss!

stephr1

My preference is pristine. It's always nice to know that the odds of having any leaks is near, or equal to, 0. Having said that, depending on the condition of the tube in general, I usually toss a tube when I have to patch it a 4th time. And, if I catch a thorn or some such right near the edge of a previous patch and I can't be sure it'll be really sealed after the new patch, I won't take that chance and I'll toss right then.

BTW - riding a mtn bike with 26x1.95 tires.

zowie

I don't have a number-of-patches limit. Practically, I think the most has been 3, maybe 4, before the tube starts getting dry, the valve gets damaged, or it gets unpatch-able damage and I toss it for one of those reason.

ThermionicScott 

I'd rather spend my time patching tubes than at work making the extra money.

To answer the OP, I don't have a set number of patches that I'll allow on a tube. I'll pitch a tube if the valve fails, the extremely rare occasion a patch job leaks (which is hard to recover from), or I guess if the tube becomes heavier than desirable due to the number of patches.

I consider a well-patched tube every bit as trustworthy as a brand-new tube, perhaps even more. Brand-new tubes can have defects you might not know about until you're out on the road. (Are you "virgin tubes only" guys testing your new tubes after you buy them? )

jays35

I have several tubes that have 3+ patches. I save the tubes(s) that have punctures and take them to my local tire shop. They will repair them for $1 a patch. I have never had a patch fail.

daoswald

Zero.

Given the choice, I never put patches on my tubes. First flat on a ride? Replace the tube but keep it in the saddle bag as a spare for the duration of that ride, only.

Second and third flat? Apply a stick-on patch to whichever of the tubes is less damaged (the one that got the first flat, or the one that got the second flat). Back at home, toss the ones that have had temporary stick-on patches applied, add a fresh one as backup in my saddle bag, and if necessary, reorder some replacements.

I know it's probably irrational. It's just not worth bothering with them.

KraneXL

But what of structural integrity and balance?

Chr0m0ly 

Not until they start to overlap.

Bill in VA

This. Easier to carry a spare and quicker to get going again.

Kahsyrbag

I don't think there is too many patches for my older brother, when patches failed him one time he used rtv(silicone usually used for gaskets) and metal window screen, the screen was visible because a quarter inch of it stuck out from under the tread.

Moe Zhoost

I don't think I've had a tube with more than five patches, but some of them are going strong after 30 years. Main reason for taking them out of service is a leak at the valve stem.

I find it curious that some folks don't want to spend the time putting a patch on, when it's likely that they spend more time acquiring a new tube. I usually buy a bunch at a time, but it is difficult to source the right size tube, at a reasonable cost, with the right length stem (I prefer shorter stems).

prj71

Some peoples time are worth more to them than money. Putting on patch takes more time than just changing a tube.

Order online. Ebay, Amazon or one of the online bike parts retailers. Piece of cake finding the right size tube and stem length at a reasonable cost. Never have to leave the comfort of your chair and it shows up at the house in a nice little box. Less time than running to the bike shop to buy one which more than likely doesn't have it in stock.

Moe Zhoost

To the first: The 10 minutes it takes to patch a tube is easily used up in time wasted responding to this thread. I'm loath to admit how much time I spend on BF. If you spend the time saved on something worthwhile (like picking up trash on a local MUP) I'll give you a pass. Oh, by the way, I am part of a group that picks up trash on our community trails and it's not uncommon to find discarded tubes and CO2 inflators.

To the second: Yes, if you're willing to buy any brand, weight, and any stem length perhaps e-shopping is quick. Try shopping for a quality brand with a 35mm presta stem.

Think globally. Discarding something that can be easily fixed is a practice becoming less and less sustainable.

KraneXL

It sounds so simple when you put it that way. On the other hand, some things can be repaired, some cannot. I learned that the hard way. When it comes to the functional part of a machine, a repair can sometimes greatly effect its balance and the way it operates. Those changes won't likely matter much on a cruiser, but can be more noticeable on a racing bike or at high pressure.

Anyway, I couldn't agree more on re-purposing inorganic materials. I still have my grocery bags from over a year ago, and rubber is easily recycled. As to the trash clean up, good for you. I participate on my own when I can but rarely as a group. However, it occurs to me it might be a better idea to lobby for more trash receptacles at least at the entrance and exit of the path, trail, MUP, etc.

In LA, the homeless encampments have turned the bike paths into extended city dumps. The trails are strewn with trash that literally goes on for miles. Trying to clean up those areas would be a full-time job. The city does it once every couple of months, but mostly only on or next to the roadways.

non-fixie 

Useful discussion. Excellent thread, @davester.

davester

First of all, many (perhaps most) of us carry a spare tube (or two) so patches are typically reserved for our second or third flat of the ride (flats come in threes, you know!) after we've already used up our spare tube(s), so the time issue isn't relevant.

Secondly, it is not always true that patching takes longer than changing a tube. If you can see from the outside where the puncture is (i.e. a nail, staple or goatshead thorn sticking out of the tire), it is often quicker and easier to just pull off a few inches of tire bead, pull only the punctured area of the tube out and patch without completely demounting the tire bead and removing the tube. Also, this method focuses you on where the puncture-cause breached the tire so that you can remove/fix it. In contrast, if you yank the tube and then throw a new one in without figuring out exactly where the puncture was, you may have another flat a short distance down the road since the offending sharp object may still be in the tire (I've definitely had this happen, both to myself and fellow riders).

Lemond1985

Zero patches for this tube. I had a slow pinhole leak that would take a couple days to notice. Put the tube underwater, found the leak, roughed up the area, and put on some glue. Before putting the patch on, I wanted to confirm the exact spot where the hole was, so I put some air in the tube (maybe 10 lbs) and looked for the telltale bubble in the glue.

Could not find the bubble, so I rubbed fresh some glue over the old glue, and BAM! the tube explodes. Never seen that one before.

martl

There is no quality/safety lost by using a (properly) patched tube. none. At all.
But there is an often overlooked benefit in patching (apart from the obvious ones). They keep track for you about where on the wheel the punkture happened. What you thought was a random event or the fault of an innocent little gap or crack in the tire, might actually have been a slightly dislocated rim ribbon, or an undetected sharp bit on the rim itself. The patching track record will reveal that

prj71

Don't seem to have a trash problem on any of my local trails. Either paved trails around the city or the off-road trails through the woods. Seems most have the mindset of "pack it in, pack it out"

Does it have to be 35 or will 40-42 work just fine?

I guess. Maybe. My time is worth more to me though so there's that.

zowie

It saves time if you patch a few tubes at once. I get a few flats a year and patch them all at once during the winter. Then I have my supply of spares for the next year.

Salamandrine 

While that is true, it should also be noted that there are some poor quality patch kits on the market these days. BITD anyone serious about cycling used Rema Tip Top patches, and they never failed. Before then there were the burn on type I guess, but that is before my time.

Also, there are some modern tubes, namely Michelin, that cannot be patched. I don't know if this is because of the type of synthetic rubber that they are using or the mold release agent, but nothing will stick to them.