Kapusta

Another Tales From The Coop episode.

Sounds like some Patch Training is in order.

rumrunn6

& remember, if you know exactly what & where the puncture is, you don't have to remove the wheel & tire. just get 1 side of the tire bead off & sneak the deflated tube out in that area, patch it & then slip the tube back in, be sure it's straight etc, get the tire bead back on & inflate.

I tried this one time w/ a MTB tire & it worked more easily than I expected

prj71

You still running 23-25mm tires?! Don't know anyone running 110 psi these days.

I've used them successfully on my 32mm tires which don't get pumped up beyond 80 psi.

prj71

Have not had that happen yet. Once you stick the patch on it gets sandwiched between tire and tube. Not sure how it would leak.

rsbob 

Why do I patch tubes? Because they are there.

Stopped using self adhesive patches long ago after too many leaks.

jadmt

perhaps low pressure isn’t enough to keep it sealed.

cyccommute 

Better title: I Don’t Believe It Because Nothing of Value Ever Comes from A Co-op. (Note the proper use of co-op. It’s not a chicken coop)

You seemed to have missed the whole “patching was good with Rema and bad without” thing.

Racing Dan

In my experience it amounts to fear mongering claiming only Rema will do. I've bee patching for decades with many different patch kits and always had good, lasting results. The trick is to know how to properly glue the patch, not picking a certain brand. Imo, every kit will work if you know and even Rema will fail if you don't. - Stay away from the preglued quick patches tho. Get the vulcanizing type with orange contact patch.

Im sure in the COOP you've seen a lot of bad patch jobs, - and I bet you a dollar they were all either preglued or failed from inadequate technique.

Btw.. it really isn't hard. Just remember abrading the tube before applying the glue, then let the glue dry for 5 minuets and only the press on the patch. - It will fuse to the tube, instantly.

VegasJen

I guess that is the big difference. I tend to patch tubes immediately after I get home. But I can see how you way makes sense if you're going to wait and do several patches at once. As of right now, I'm only carrying a single spare tube. I don't carry any of the emergency patches because my earlier experience was not favorable. But that was with the cheap ones. I will look up the better ones mentioned in this thread and buy a few to keep in my tool kits.
This is why I use a Dremel for my repairs. A Dremel with a sanding wheel can take those casting seams down smooth and provide a flat surface for your patch to bond. That is key to an effective repair. I tend to cut my patches to about the size of a standard postage stamp so that I have at least 1/4" in any direction from the puncture. This has worked well for me.

SurferRosa

.

urbanknight

I think the point was you're probably not doing it correctly if that many other brands fail on you. I've had leaks, but only because I messed something up. Perhaps your beloved Rema patches are easier to do correctly or are more tolerant of a sloppy job.

daviddavieboy

I don't mean to be argumentative but if these REMA patches do a good job with less effort wouldn't that make them a bit better than a patch kit where a person needs to be fastidious in their workmanship ? I only had good luck with Velox patch kits and those Park scabs hardly ever worked even to get me home. - yet some people really like them. On the side of the road I would want the easiest, most reliable system to get me going again in the shortest amount of time but I am funny that way.

urbanknight

Absolutely. If they do work better, then they would in fact be a better choice just as cyccommute claims. Just wondering why they had such trouble getting all the other brands to work properly.

bruce19

What are tubes"

Trakhak

From what cyccommute has said, it seems likely that the failures with other brands come down to the fact that Rema patches become (in effect) welded to the tube whereas other patches are merely glued on. (There may be other brands that have comparable chemistry, but whether that's the case is unclear.)

Glue can work, obviously, but co-op clients who are inexperienced at patching tubes and/or impatient to finish the job probably manage to screw up the patching procedure more easily with other patch kits.

jadmt

https://sdb.rema-tiptop.de/files/AU_..._VULC_0029.pdf

https://www.parktool.com/assets/doc/...t/VP-1_SDS.pdf

any chemists or chemical engineers amongst the group? I was going to suggest the sniff test and taste test but decided against it lol..Park glue made in Taiwan Rema in Germany. who takes their patching more seriously......
on certain areas I can see how possibly the rema patch with its serrated edges might not lift but to be honest I have used park without fail and the patches appear identical other than the edges. If one is into fashion the Rema can be found in all black without the orange edges....

daviddavieboy

I am curious as well. I have a friend that ran a co op and know the volume of repairs like this they did. I don’t know what their failure rate was but everybody seemed mostly happy.

pdlamb

The most interesting thing I saw reading the Rema "sheet" was that, apparently, the Rema glue polymerizes in place, as does the (more traditional?) Park glue's heptene. Note that the hoo-hah about vulcanization may apply to the glue to patch interface (OK, good thing), but there's nothing that jumps out at me that would indicate there's any significant vulcanization taking place between the glue and the butyl rubber (after all, that rubber is mostly a long chain alkane that was cross-linked through vulcanization during the tube manufacturing process). I think the best analogy would be a pancake (Rema patch) soaked in maple syrup (Rema glue) and then slapped up against a plate (the tube). One side of the glue is going to stick to the patch, perhaps better than some other glue or patch would stick. The other side, after polymerization is complete, should work just about as well as any other glue to stick to the butyl tube. That is, I suspect the difference between the different components polymerizing, presumably around mechanical roughness in the prepared butyl tube surface, is insignificant.

Interestingly, one of the components (cyclohexylethylamineamine) is darn close to a nylon precurson. Should we call Rema a nylon cement instead of a rubber glue?

Now a few caveats:

1. The MSDS isn't intended to give the reader information about how the material is supposed to work; it's just a list of what's in the package and what hazards are associated with it.

2. I'd expect the details of how it's supposed to work are proprietary, and quite likely covered by patents, as Rema has changed the composition of their glue within the last 17 years. So another chemist may come up with different speculations on the details of chemical mechanisms.

3. Because polymerization may continue after the 5 minutes' "drying" time, a cyclist would be well advised to avoid putting a freshly patched tube back on the wheel -- to the extent possible. I know through experience, when you run out of tubes, patch and ride beats walking; but it's not ideal.

cyccommute 

Address this in post 90. Look under my signature line…“Mad bike riding scientist”… under my name. I’m a chemist with many years of reading and interpreting safety data sheets. There are lots and lots and lots of patches that “look” identical. Often the point is to “look” like the Rema. But you can’t see the difference. Even I as a chemist can’t see the difference. I could develop an elaborate separation scheme and run tests but I don’t have access to that kind of equipment anymore and I doubt that my employer would have looked kindly upon me spending several thousand dollars of chemicals, equipment time, and my time doing that kind of analysis since it’s not what they paid me to do.

On the other hand, I’ve spent many years of looking into this and trusting the research and development of others. That’s fair in science, by the way. Not too many scientist are going to remain as scientists if they lie to everyone.

cyccommute 

I assure you that I know how to patch a tube…see above about the number of patches per tube I will run. The reason I use, and suggest, Rema is because I’ve done a lot of research on what cold vulcanizing is (and isn’t) and on what goes into the Rema patch system that makes it superior. I stay away from preglued patches for the same reasons that others stay away from them…because they tend to fail. I stay away from anything other the Rema for exactly the same reason.

We patch tubes to resell them. For a very long time, we used Rema patches and Rema vulcanizing fluid in the large cans. There were always some failures due to poor technique. That’s inevitable in a volunteer organization. Then some of the paid staff decided to save money by going to Clark patches. Failures of the patch increased significantly. I estimate the failure went from 1 in 100 to 1 in 10 or 20. The only variable that changed was the patches.

Let the glue dry completely. It could be 5 minutes. It could be 10 minutes. It could be 6 weeks…forgot about a patch job several times. I’ll agree that the patch will adhere to the tube instantly. But there is a difference between adherence and fusing. The fusing part happens much later and, without the promoters in the Rema system, it may not happen at all.

cyccommute 

I don’t experience patch failures. I know how to prep the tube, how to dry the vulcanizing fluid, how to handle the patch, etc. I also know that if I want the job be long lasting, I use Rema because nothing else is worth my time and effort. I tend to use the proper tool for the job because using the improper tool just makes for more work.

The issue with the patch jobs tend to be that the patch just peels off. After a few hours, a Rema patched tube can be inflated to test for leaks or if the tube gets another flat…I tell my students when I teach tube patching not to inflate even Rema’s immediately after patching since that will tend to peel the patch up. But these tubes often sit in a bin for days to weeks to months. As soon as the tube is filled with the cheap patches, the edges pull up. Rema patched tubes just don’t do that.

I haven’t found any patch kit that has the chemistry that Rema does. Most all of them are simply rubber cement and even say that. Park says that it is “vulcanizing fluid” but from what I’ve read on the SDS, it has the same ingredients as other rubber cements. Even if the Park does have the chemistry, you shouldn’t mix patch kit components since the chemistry from one maker to the next is probably different.

prj71

Lots of silly discussion about patches and chemicals. LOL. Just wow.

When I did use glue patches whatever Walmart sold worked just fine.

tomato coupe

You can't conclude from this that Rema is the only brand of patch that works.

prj71

I conclude over complication of something simple as a patch. Leave it to BF.

urbanknight

These two comments do not agree with each other. If a patch peels, it failed. With the exception of the few patches I have botched, none of my "vulcanized" (glued) patches have ever peeled, not even after over a decade and with multiple patches all over. The patch lays so flat that I couldn't pick an edge with my fingernail if I tried. But I digress, Rema may well still be a better, easier to use product. It's just that the other patches aren't as bad as you make them seem.