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patching a tube question

1371 Views 30 Replies 9 Participants Last post by  Lombard
novice here …

should a tube patch be applied with the tube inflated a few psi, or completely deflated ? or it doesn't matter ?
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put on some new to market tpu tubes

not interested in fractions of watts, or fractions of lower rolling resistance they say are afforded by the material. that data didn't really attract me to the tubes in the first place.

i do endurance loops for 20-40 miles and the landscapes i ride around have a lot of grades. no where near flat. long-ish rides, unavoidable debris on some roads … need something that is more puncture resistant than butyl

with my outgoing tubes standard butyl up front thorn resistant butyl out back - did fine on most of my rides. maybe with tpu might notice an improvement, will see.

the main selling point for me - tpu is really tough compared to butyl. i took a .7 mechanical pencil tip to some sample material used as a rubber band for the tubes … would not pierce it and the material didnt even show a mark where i applied pressure. the same test on a butyl sample and the wall was pierced.

side benefit of the swap is that the ride weight is lower by 1 to 1-1/4 pounds which doesn't hurt anything.

in context here, my choice is to pay a little more per tube and wind up on the side of the road with a flat less often or not at all. so it’s worth the extra cost in that regard and if they ever do puncture, they can be patched.
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side benefit of the swap is that the ride weight is lower by 1 to 1-1/4 pounds which doesn't hurt anything.
ounces maybe?
ounces maybe?
Pounds.... Because he was using massive thorn resistant tubes. If he switched to decent butyl tubes like Conti Race Lights, he'd have also saved 600g (1.3 lb)


the bontrager thorn resistant tube i use is 380 grams. can feel how thick it is when riding, almost solid like a rock.
but its on there because i did not find any tpu stuff available in stores and wanted to get rolling the same day i got the puncture. wasn't stocking any spares either.
ounces maybe?
about 1 lb. of lost weight:

old tubes: 130g+380g
new tubes: 60g+60g

kept the butyl spare, but will pickup another tpu to replace it.

ride-wise, feels like no tubes are there. pressure monitoring over the course of 2 days and real time during rides, very stable.
gotcha. i guess i didn't realize how heavy those old tubes were!
gotcha. i guess i didn't realize how heavy those old tubes were!
the lighter one is standard bontrager road
the heavier one is thorn resistant bontrager road
the lighter one is standard bontrager road
the heavier one is thorn resistant bontrager road
Thorn resistant tubes are in a different category all together. I use these in my mountain bikes. For those of you who have never seen the size of the box these come in, let's just say I would noy want to carry a spare one of these with me.
they are bulky and heavy
they are bulky and heavy
Exactly my point. But when I ride a mountain bike in the woods, there are many opportunities for punctures. I've rather have the extra weight. And although I use these bulky tubes in my tires, the spare I carry is a standard butyl tube.
Exactly my point. But when I ride a mountain bike in the woods, there are many opportunities for punctures. I've rather have the extra weight. And although I use these bulky tubes in my tires, the spare I carry is a standard butyl tube.
Lombard, it took you a while to see the light with di2. It’s now time for you to embrace tubeless (for MTBing). 😎
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Lombard, it took you a while to see the light with di2. It’s now time for you to embrace tubeless (for MTBing). 😎
Hey, I am slow to embrace new technology. 😉 And I don't use a mountain bike enough to justify new wheels and tires.
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