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Tight tires, grind down tight rim to decrease diameter?

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Tight tires, grind down tight rim to decrease diameter?

Old 12-05-19, 12:43 PM
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previously noted, but still good tire jack

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Old 12-05-19, 11:31 PM
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Originally Posted by Snikerdoodlz
I'm using Schwalbe Marathon road tires. Those tires are already tighter than usual, so the combination was brutal. I used to use Maxxis Gypsies, which were still unreasonable.

People are saying to guide the bead into the central depression. Does it not do that automatically when you pull on it when flipping tire levers?
Yes and no. As above, thicker tires and sidewalls are harder to keep pushed into the center well. With a lighter standard bicycle tire it's easy to get the beads to stay there. The heavier tire just requires more effort to maintain the slack in the bead that's needed to pull it over the rim's wall.

If you watch them change car tires at a auto shop you'll see that the principal is the same- they just have big hydraulic machines to do the prying and lifting of the bead.
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Old 12-06-19, 02:38 AM
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The trick I use is to put the bead in the center channel as suggested but then to do the last difficult bit at 90 degrees from the stem, not 180. This way the opposite side sit entirely in the channel. Tires that I couldn't otherwise get on have slipped right on this way.
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Old 12-06-19, 05:29 AM
  #29  
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Originally Posted by Jeff Wills
Yes and no. As above, thicker tires and sidewalls are harder to keep pushed into the center well. With a lighter standard bicycle tire it's easy to get the beads to stay there. The heavier tire just requires more effort to maintain the slack in the bead that's needed to pull it over the rim's wall.
.
This is my understanding, that the strap/toe clips force a really stiff sidewall tire down and into the depression a and holds it in place.
I've seen some continental touring plus tires that are like this, very stiff sidewalls, throw in a certain rim combo and its been a real bugger.
decades ago I had some specialized city nimbus something tires that were like this also.
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Old 12-08-19, 10:01 PM
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Originally Posted by Snikerdoodlz
I'm using Schwalbe Marathon road tires. Those tires are already tighter than usual, so the combination was brutal. I used to use Maxxis Gypsies, which were still unreasonable.

People are saying to guide the bead into the central depression. Does it not do that automatically when you pull on it when flipping tire levers?
Which Schwalbe Marathon, and what size? They come in several models and widths.

26x2.00 is a wide rim so your tire choices are limited.
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Old 12-08-19, 10:49 PM
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Originally Posted by WizardOfBoz
Second, there is no way to do the grinding with sufficient precision, without removing the rim and mounting it on a lathe face plate. Precision metal cutting requires tools and jigs and fixtures that are exceptionally rigid and a spoked bike wheel doesn't qualify.

So, I suspect that you'd end up with an aesthetically unsatisfactory wheel with really uneven grinding marks that would break prematurely.


If one trued the wheel, very true, say 1/4mm wobble/hop, then one might be able to use the wheel as a lathe of sorts. And, build a jig to do the work.

Where to take the material off? In the bead seat, or the valley between bead seats, and it severely reduces the strength of the wheel, and a E-Bike wheel at that!!!

One could grind off the hooks. It might help with mounting slightly, but risk blowouts. Or, the hooks may also contribute strength to the sides of the rims.

Aestetics won't be an issue as the grinding would be mostly hidden.

Anyway, I agree that this is a very bad idea, and one needs to further diagnose the problem/solution.
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Old 12-08-19, 11:11 PM
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Originally Posted by dsbrantjr
If your rim has a thick cloth tape such as Velox, you could try a thinner tape such as Continental Easy Tape or a layer of filament-reinforced packing tape or Kapton tape. The thinner tape should make tire mounting easier by allowing you to get the bead deeper into the center of the rim channel.
Yes, the shape of the rim above, it appears to be a standard rim, without the new tubeless shelf that causes so many people problems.

I'd also look at the tape.

Another option are veloplugs. On occasion, I've gone over the veloplugs with a thin layer of tape like electrical tape (or stronger tape).



The veloplugs provide the strength, and the tape keeps them from moving, and keeps the tube inside.
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Old 12-08-19, 11:26 PM
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Originally Posted by CliffordK
If one trued the wheel, very true, say 1/4mm wobble/hop, then one might be able to use the wheel as a lathe of sorts. And, build a jig to do the work.
I grew up working in a machine shop. Modern metalworking doctrine is that you use an extremely rigid machine to cut metal, with a rigid fixture holding the workpiece. Else you get chatter, grabbing and gouging, the workpiece breaking, or (worse of all) the workpiece or parts of it flying off the lathe and killing someone. Thus, you'd use a lathe with the rim fastened to a faceplate. Given the rim diameter, you'd need a pretty massive lathe (a 30" swing). The pic below is a 42 inch lathe with a propeller mounted to the faceplate.

A spoked wheel has a very high strength to weight ratio, but is not nearly as rigid as a faceplate that is 2 inches thick and made of heat-treated tool steel. For one thing, transmitting adequate power from a hub to the wheel rim would likely break spokes. A bike hub has superb strength for handling a cyclist's weight, but bike bearings don't really come anywhere near the rigidity of that lathe spindle which are gonna have perhaps 6 inch id, tapered roller bearings in double sets fore and aft.

Not saying it couldn't be done with some clever McGyvering and by suspending normal rules of safety and risk avoidance. But we agree:

Originally Posted by CliffordK
Anyway, I agree that this is a very bad idea, and one needs to further diagnose the problem/solution.
Your advice is IMHO golden and is really what the OP should be doing. Observe, think, and test different methods of solving the problem before getting out the angle grinder, I always say.


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Old 12-09-19, 05:34 AM
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Originally Posted by WizardOfBoz
I grew up working in a machine shop. Modern metalworking doctrine is that you use an extremely rigid machine to cut metal, with a rigid fixture holding the workpiece. Else you get chatter, grabbing and gouging, the workpiece breaking, or (worse of all) the workpiece or parts of it flying off the lathe and killing someone. Thus, you'd use a lathe with the rim fastened to a faceplate. Given the rim diameter, you'd need a pretty massive lathe (a 30" swing). The pic below is a 42 inch lathe with a propeller mounted to the faceplate.

A spoked wheel has a very high strength to weight ratio, but is not nearly as rigid as a faceplate that is 2 inches thick and made of heat-treated tool steel. For one thing, transmitting adequate power from a hub to the wheel rim would likely break spokes. A bike hub has superb strength for handling a cyclist's weight, but bike bearings don't really come anywhere near the rigidity of that lathe spindle which are gonna have perhaps 6 inch id, tapered roller bearings in double sets fore and aft.

Not saying it couldn't be done with some clever McGyvering and by suspending normal rules of safety and risk avoidance. But we agree:



Your advice is IMHO golden and is really what the OP should be doing. Observe, think, and test different methods of solving the problem before getting out the angle grinder, I always say.


If you have a 42" lathe (horizontal or vertical), then one should be able to chuck up the fully built wheel, although the rim will still have to run straight (no taco).

If using a fixed cutter, then yes, "rigid". But, one could likely break some of the rules if using a rotary cutter (grinder) (noting, of course, potential issues with grinding aluminum).

I have no doubt it would be possible to do with a cheap apparatus if one was slow and cautious. But it still wouldn't be my choice of remedies.
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Old 12-09-19, 05:49 AM
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If you are at home and have the time, leave the tire in the sun for an hour or so to make it more pliable...you may have to wear gloves as they can get quite hot. After mounting/dismounting a couple of times, it should become easier. That said, get the tools mentioned above and pay attention to centering the sidewalls when mounting (also mentioned above). Tools and technique. Cheers!
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Old 12-09-19, 08:51 AM
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Originally Posted by CliffordK
If you have a 42" lathe (horizontal or vertical), then one should be able to chuck up the fully built wheel, although the rim will still have to run straight (no taco).
If using a fixed cutter, then yes, "rigid". But, one could likely break some of the rules if using a rotary cutter (grinder) (noting, of course, potential issues with grinding aluminum).
I have no doubt it would be possible to do with a cheap apparatus if one was slow and cautious. But it still wouldn't be my choice of remedies.
I think we are in violent... agreement. Yes, setting up the wheel to be true on a faceplate would not be my idea of a good time. I agree with your idea of fixturing. perhaps true the wheel really well, put it in a truing stand-like apparatus, and use a block of Teflon(R) to buttress the portion of the rim that you are grinding with a Dremel or an old tool post grinder. But before I ever got to that, I'd buy a new rim!

But in my experience, if something doesn't work that should work then I'm not using the proper technique or tool. The suggestions above (soapy water to lube the tire and rim, get the tire bead in the center of the well in the rim) allowed me to go from "I can't mount this d**m tire! It's too tight! It's a bad design poorly implemented!" to "Gee, that wasn't so hard".
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Old 12-09-19, 09:41 AM
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Originally Posted by CliffordK;21238469
Another option are [url=https://veloplug.com/en/
veloplugs.[/url] On occasion, I've gone over the veloplugs with a thin layer of tape like electrical tape (or stronger tape).
Velo Plugs take up more space than two wraps of 1 mil Kapton, and you don't want to reduce clearance even farther.
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Old 12-09-19, 03:39 PM
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Originally Posted by Snikerdoodlz
I know that it's a problem with the rim itself since I've put my exact same tires on another rim with much less effort..
To be clear, the problem is this tire with this rim. And assuming that they're compatible at all, the answer is to stretch the tire. Lots of good ways to do this but what I do is (with no tube installed) get the tire on as far as you can and work the tire lever around the remaining bead and lock it onto a spoke and let it sit for a while, then move the unseated bit around and repeat. Once you can get the whole tire on without a tube inside, then take it off, install the tube, reinstall the tire and don't use a lever.

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Old 12-09-19, 04:42 PM
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^ Some people may be so conditioned to use tire levers during every install/removal that it may not occur to them to try without. But I think you learn valuable insights when attempting to guide the beads over the rim while keeping the slack in the bottom of the well, all by hand. Even if you do go back to using levers.

I'm firmly convinced that some people make the job way harder than it needs to be, by using levers for brute force and not understanding how slack works.
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Old 12-09-19, 05:02 PM
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If you can get one side of the tire on without the tube, then you can get the second side on with the tube.

Also beware of getting the tube pinched between the tire beads and the rim (which effectively makes the rim larger).

I'm not a big fan of the thornproof tubes, but they may be harder to trap than the regular tubes.
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Old 12-14-19, 03:16 PM
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Originally Posted by Drew Eckhardt
Velo Plugs take up more space than two wraps of 1 mil Kapton, and you don't want to reduce clearance even farther.
Yup. Velocity even notes the following.
"Tight tolerances require the use of a low profile rim tape like Velotape to avoid tire installation issues. Veloplugs are not recommended on A23 or A23 OC rims."
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Old 12-14-19, 03:19 PM
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Originally Posted by squirtdad
previously noted, but still good tire jack

I have one of those, but since I switched to Schwalbe tire levers, I've never used it.

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Old 12-14-19, 04:47 PM
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Yup, those are a smart design!
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