AnkleWork

Didn't you post earlier:
Some people don't realize how obvious their jive is.

ThermionicScott 

I've never liked rubber as a rim strip. It shifts around and it isn't strong enough for high pressure on double-walled rims. Even on single-walled rims I'd rather use Velox or tubeless tape. What rims are you using?

Do you live in some remote area that doesn't have mail service? You could have ordered Velox or any number of products that would have solved your problems perfectly by now.

trailangel

Adipe, you are making this way too complicated. You say you cut the rim tape.... I think you probably cut a plastic rim strip and the sharp edge worked your tube and cut into it.
This may happen when cutting a tube to use as a rim strip as well. May not happen right away, but might chaff on the tube and make a hole.
Use Stan's Tubeless tape, Kapton packing tape (available anywhere), cloth tape, or correct size rim strip. Gorilla tape or gaffer tape could work as well.
Don't try to re-invent the wheel.

79pmooney

I am confused as to how the rim tape makes any difference at all in shock absorption when riding. With the tire inflated, the bead is up on the shoulder of the rim (most modern rims have shoulders)and furthier lifted above that shoulder by tire pressure. There is no mechanical connection between that rim strip and any force, just the impacting of air. I'd expect tire choice, size and construction and air pressure choice to be the vast majority of the factors affecting ride comfort.

As for sizing the 26" innertube as a rim strip, why not just cut it too wide, measure the width, put it on and measure the stretched width. calculate the ratio unstretched width ot stretched width. Calculate the unstretched width you need to get the desired stretched width. Cut again.

You talk about more resistance to accidental damage to the wheel as a need for very high spoke tension, Now this is just my experience - the very tightly spoked wheels I have owned were much more prone to "potato-shipping" when bumped than wheels built with lower spoke tensions. Also that lower tensioned wheels could be straightened (sometimes) after potato-chipping but highly tensioned wheels were ruined as the rim would take a permanent bend.

Ben

adipe

ghost punctures, crap being able to enter inside the tire because it is not very well sealed at the interface with the rim.
and i cut the tape because it was already irregular and it could not work.

the rim in under higher compression than what is written in the books.
i have my reasons to choose so, the wheel is solid and i will not have it otherwise. it just needs a bit thicker tape than usual.
the most available solution is what i asked about... if maybe... maybe... anybody knows better if it has proven to work or opinion about it - maybe better than a standard rim tape... or not.

i did not ask for opinions of people like you but from people in the know.
in the meantime i managed to explain perhaps all the reasons, i was not interested to show myself being wise but i had no choice but do so after being ridiculed by amateurs in mechanics. i was in no mood to explain the details today, i rather wanted to have answers for my question and not offtopic.

the tape being cut is not something i could ever regret because it was already irregular and the tire was not straight at all on the rim to begin with because of that.

this bike i had worked to bring back to life after the former owner(s) had it's wheels in such a shape you would not imagine.
and the last owner was not cheap. the LBS situation around here is horrendous. i know better about wheels than most guys around here, including you.

read again what is bold above and see about what is happening with the friction between all kinds of surfaces, especially when small dust goes in. the wheel needs a tighter interface.
the tubes they sell around here could be as old as 10 years and nobody takes blame for selling bad stuff.

i'm trying to help myself and people who might read this thread, those who would have one or more of the problems i had and am about to fix. don't address me saying there is nothing to "re-invent".
in fact i am not inventing anything, i am just discovering what others already know but have not written as to me having luck finding by google etc.

did you know that crap can enter the tire and that tubeless is dangerous in sand because of that?
did you know that WTB recommends for tubeless tape of such width that climbs up on the sidewalls? they don't explain all the why's.
"WTB recommends using tape that is 5mm wider than your inner rim width."

i am not making it complicated, i am trying to reduce towards zero what you would think to be impossible: abrasive crap going in the tire when riding. it's the cause of the higher frequencies of (ghost) punctures in winter.

Atlas Shrugged

``ghost punctures, crap being able to enter inside the tire because it is not very well sealed at the interface with the rim.
and i cut the tape because it was already irregular and it could not work.``

Perhaps loosen the tension on the spokes after the tire is mounted which would in your words increase the rim diameter thus preventing ghost punctures.

adipe

it may be just a hard to perceive dampening when large shocks or heavy cornering.
the tire interface to the rim would not be on a rigid urethane layer - 2.5-5GPa.

the butyl is much less rigid than that. you can search out the matter (as low as 0.001 – 0.002).
https://downloadfiles.grantadesign.c..._Materials.pdf

but the most important benefit is a tighter interface so that craps would enter in a much lower pace so that ghost punctures would be less frequent.
i was just pointing out that i cannot assess the difference in compliance, dampening, just something to see about later.

usually they make rim tape as thin as possible with relatively rigid urethane so that you can mount tires easily.

the tire beat does not stay fixed on the sidewall of the rim but travels and therefore a more compressible and thicker layer of tape can have a dampening effect.

adipe

i do not want that.
you are being offtopic and i already asked from the get go not to be asked here to explain why i am very happy with the tension i chose to have before doing the work myself.

could you please go your way and maybe never bother me again?...

trailangel

What a Richard

Atlas Shrugged

How about place a bead of silicone caulking compound around the interface where the tire meets the rim to prevent ghost punctures.

shelbyfv

The reason for this is that modern rim tape is very slick and helps the tire bead slide up onto the shelf of the rim. If the rim does not have a shelf, tape only needs to be wide enough to cover the spoke holes with a margin to allow for movement.

ThermionicScott 

There is an even simpler explanation for this: inner rim width is measured at the bead hooks and the rim bed is wider than that. With classic high-pressure clincher rims, the difference was around 5-6mm, newer rims tend to have a bit less. So there isn't some big mystery or conspiracy involved in recommending a rim tape that is wider than the specified rim width.

3alarmer 

kapton tape...measure your space, buy the right width, and apply two layers, one right over the first one.

3alarmer 

ThermionicScott 

Also, this theory about "ghost punctures" is totally bogus. Outside grit does not migrate past the sidewall and bead of an inflated tire. Any grit you find inside the tire and rim was from failing to clean everything properly before mounting the tire.

terrymorse 

More unscientific fantasies. The tire bead/rim interface is held in place with several atmospheres of pressure, obviously no solid material will pass through.

AnkleWork

Didn't you write earlier:

What a difficult life to struggle with so many unique problems. And your interpersonal skills are not getting you closer to solutions. HTH

TimothyH

It sounds like the OP is trying to use a butyl tube as rim tape to compensate for a slightly smaller than normal bead seat diameter. I don't think that will work.

A smaller than normal bead seat diameter would explain the statement above, especially if conditions are dirty and/or wet.

Again, I don't think what the OP proposes will work but it is worth a try if tubes are readily available and free.

If it doesn't work and the OP is unwilling to use a rim built with a standard bead seat diameter then there is nothing useful anyone here could possibly add.


-Tim

squirtdad

repeat simple solution: Velox tape

the idea that a butyl tube used as a liner is compressible in any meaningful/practical manner is wishful thinking

TimothyH

I think the OP will simply need a properly sized rim.

Rim tape of any kind is not the fix here.


-Tim-

adipe

i won't quote as to reply to someone specific. only one here - thanks, shelbyfv - had a positive take to the enterprise and finally understood the details i mentioned in the first post. i forgot to mention from the beginning that i'm on a low budget so i can't be bothered with tubeless tape which would have been thin and also not removable for cleaning up the rim properly from time to time. the wheel is made as strong as possible and only if the electric motor hub is somehow damaged and beyond repair will the spokes be slacked and that will be with tools so that the rim will go to make another wheel it such a case. it's a disc wheel so having no braking surface this wheel is virtually guaranteed to work for decades provided chemicals do not mess up by contributing to stress corrosion cracking. that's why i want the tape to be easily taken off, to be able clean the rim in the space tension through flexural stress has any rim vulnerable, regardless of the tension the spokes have, uniform or not, high average or not. so i see no reason to have the rim under a lower compression. you want the rim to have a proper compression so that the radial deflection is low under load and the spokes never go slack. having 250mm spokes of the heaviest kind from the KTM factory i had to set a high tension and the advantage of having spokes less vulnerable to hits (vandalism, rocks hitting them etc.) is not a thing to be disregarded. if i had thinner spokes, at least on the NDS i would have set a lower tension.

the rim is clearly a modern 29er rim - 622 bead diameter. so the only particularity to this wheel is the higher compression and therefore the higher strain, the diameter being more than 1mm shorter. a normal tape would not sufficed and the tire is a Conti Race King which - i have to tell people around here - lets in mud easily for the sake of easier than normal fitting, even for tension of the spokes as the books say (120kgf but most people measure that with the tire uninflated and that is usually for a 32h rim).

so, if anyone tells me to let the spokes looser for the sake of having a less shorter diameter/circumference of the rim is clearly not in the know about wheels. and if anyone says such a high tension is to be avoided either doesn't know crap about my needs/environment or doesn't know crap about mechanics or is lazy to figure out that you can have the cake and eat it too if you achieved the right spoke tension variance with the right low radial runout (0.1mm total) for the average DS tension you have set as an optimum.

a good advice i would have considered would have been about the maximum width of the extra butyl layer - about the same as the external rim width i guess, i forgot to measure the final adjustment. but YMMV (if somehow you find yourself needing to do so with a high tension wheel with many spokes) because the channel where you insert the nipples can be lower for some and higher for others.

so... here's the final update - i guess:

the rim is the "Oval" brand and it's a really nice rim that would have had a just about right diameter for usual tires. it certainly can withstand 150kgf DS tension in the 36h set if it withstood more than 180kgf (forgot to measure when i did the straightening) with the tire at about 3.8 bar (55 psi).

the rim tape was not fitted correctly before i bought the bike - having the wheels messed up i bought it kinda cheap and i knew i can fix them properly and do a better job than KTM did at the factory both at choosing the components, including the same Alpine set of spokes for both flanges, and at wheelbuilding. the guys there have no clue about bicycle wheels. i had to work for a front 32h wheel having DT Rev spokes, DT Prolock nipples with flat/low spot wheel that had the tension just a bit higher than 70kgf average both sides (no disc). i cursed them for choosing Prolock nipples and i replaced them with brass nipples i carefully lubed to achieve just a tad under 120kgf average tension with low radial runout and low spoke tension variance. (slightly offtopic, just to show that i'm used to see people not having a clue about what makes a wheel both strong to impacts and safe/durable in the long run).

so, the provided rim tape had no use as it was before except to be cut narrower than what the width was. the width was not good enough when originally fitted and so it had messed up and i either would have had it replaced with a much more thicker one or just add the wide butyl layer i just added tonight. which is nice and ensures the pressured tube does not rub against a rigid tape. nor does the tire move around, forcing the tube to rub against a normal rigid or slightly abrasive tape (cloth).

the cut portion of the 26" inner tube makes the wheel just 50 grams heavier, i don't give a crap about that, it's totally worth it; anyway, the total weight of the bike is way over 20kg. a thicker rim tape as needed would have added some weight anyway. the butyl layer not only ensures a tight fit but also a relative ease getting the tire on the rim and would impose 1-2 tire levers only when getting off which i never do on the road because i don't want to carry pump, levers, patches or extra tubes but i'd rather have some Marathon Mondial or some tire liner with a larger than 2" tire in the rear and a 1.6" Dureme front that is puncture resistant. it's an electric bike you do not use more than 20 miles in one day.

i had the surprise to find the cut portion tube to be under any tension (not a really tight fit) so i made sure it does not get narrower than the rim seat so tht it climbs just so a tiny bit of space remains to the rim hook;

the work was tedious but i'm glad i did it;
the hard part was cutting it patiently with scissors, without having extra tools to make sure the width stays the same;
i mounted the tire using just my hands, no levers required, that's because...
butyl is compressible and so...
the interface between the tire and the rim is better sealed now against crap coming in.
ghost punctures, several ghost factors involved. ghost busters! i do not like to be under sod's law.

the wheel is now with a inner tube that had a puncture repaired and unfortunately i only figured out that the patch is best applied after you take the plastic cover off from it by bending it several times and using something to cut the plastic thin tape in the center and carefully getting it off and then apply the patch in such a manner as to stretch it properly to take the best shape and have smooth transitions. any curvature on a patched tube is to be smoothed out and that is not possible with the plastic tape still on; also the drying up of the solvent is faster this way.
i thought to point this puncture repairing tip as not many people figure this out on their own easily and it's a very useful thing to do. i read about this just now, right before mounting the tire, after so many years..
Patching a tire

so, the wheel is now under a light pressure now and will be let to dry up completely
i'll make the test ride tomorrow i guess.

adipe

a final comment do explain away what most people (still) do not get:

if the tire bead is just a bit higher than the rim seat then:
1. the tire more easily skids on the rim and forces the tube rub against the rim tape - hello, ghost punctures;
2. crap more readily comes inside the wheel through gaps that occur when riding (shocks, etc);
3. the tire does not stay rightly centered.

if you choose to benefit from a high tensioned wheel or if the tire mounts very easy and then does not stay stable or if you just are having ghost punctures then you have to increase the thickness of the tape, regardless of the material.

ThermionicScott 

Sounds like you've got it all figured out. Good luck.

3alarmer 

...I'm not sure what that linked post says, but you leave the plastic film on the patch. Even when you put the patched tube back in the tyre, the plastic stays in place. The simplest tool for burnishing the patch is something like this one, but most people don't have them. With patience, you can do a similar job with the patch and tube on a flat, firm surface using a coin with a serrate edge, going back and forth in a couple of directions. It's usually called a "stitching" tool, and you see them used now by people repairing punctures in tubeless car tyres using an internal patch.




I know you're on a budget, but if you really, really hate to remove the wheel and repair a flat, given the minimal cost for new tubes online at places like Ribble and Wiggle, it makes very little sense for you to put a patched tube back in there. Even with the best technique, a certain percentage of patches fail. I have excellent technique, and I still have a faiure rate of maybe 20% over time.

terrymorse 

More imaginings with no basis in reality. None of these is true of a seated and pressurized tire:

1. there is no movement between tire and rim or tube and rim
2. at no time do gaps form between the tire and rim to let in debris
3. a tire does not wander around on the rim after it is pressurized