Rims too tight -- sandpaper them down?
 

I have some new rims that are super tight with my preferred tires. I'm very experienced, and still broke two tire levers getting them on there (which I ultimately did). The tires aren't tight on any of my other wheels. I think it's the tubeless-ready idea biting me in the ass. Manufacturers are deliberately making them tight by adding a tiny amount to the circumference of the rim. But I'll *never* get those things on out on a ride! It doesn't matter what tricks there are in the shop to mount a tire if you're screwed from the get go on a ride in the middle of nowhere. I have to be able to get the thing mounted in seconds not hours.

My question: Has anybody ever sanded down the outside of the rim? Wet/dry sandpaper, 100 grit will take them right down, then 600 grit to smooth them. Aluminum is soft, WC wet/dry sandpaper is hard, this will work very quickly. People regularly sand out ding marks and such. But I've never heard of anybody sanding down a rim to improve tubeful tire fit in "tubeless-ready" rims.

Has anybody ever tried it?

Please do *not* reply to this thread with other advice for getting tires onto the rim, I'm asking a very specific question. I know *all* the tricks already thank you. This is maybe a new one.

Cheers,

Jon.

No.

I would not, as I do not have a way to warrant that they have been sanded evenly, and without compromising the integrity of the rim or its balance; but, since you know *all* the tricks already, maybe you could enlighten us with your experience?

You broke levers.... (plural)

I'll honor your request not to give "tricks"

Barry

It would be interesting to measure the actual diameters of rims that are tough mounts vs easy mounts.

That kind of accuracy at home would be tough. Few of us have calipers that open wide enough and with jaws deep enough to span a rim and clear the hub. With a tape measure, you are bending around the hub and probably spokes. But a non-digital approach would be to nail two (say 4") pieces of 2x4 to a wall or tabletop 13 1/3" apart. Drive two nail vertically so a rim touches them. Now a tight rim will be a push to get through and a small one will show a paper width of space. (You do need to check that your rim is actually round first. A tiny bit of hop will show bigger than what we need to measure to establish tire mounting ease. And that hop doesn't change the circumference; the only dimension that really matters for tires.)

I'll leave this to someone else. My Vittoria tires mount easily on my non-tubeless ready Open Pros and when those rims expire, I'm going back to tubulars.

BAD idea. Maybe a Kool stop bead jack is needed. Soapy water can help too. Oops, sorry. You know all the tricks. I have no such problem with my fulcrum racing 3 wheels.

Yeah, you just don't know all the tricks. Or you are poorly skilled at executing them.

I've yet to find a tire and rim that levers are necessary. Sometimes they are helpful and quicker, but never necessary.

Kool stop tire bead jack, but you know this.

I just can't get them on with just my hands and thumb pressure, maybe I'm not doing it correctly, but no matter how I press/compress/squeeze tire, I can't push last bit over the rim with my thumbs.

If you don't want to wait for answers, a similar question was posed in 2019 and you can read those responses. I believe you will not find any competent person agreeing to remove rim material. WARNING: Tricks may appear in the following thread.
https://www.bikeforums.net/bicycle-m...-diameter.html

And there have been bad tire rim combinations going back decades; way before tubeless.

My only suggestion, while not a trick, is to first see if you can mount the same tire from another bike that you have ridden for a while. It may still not work. But I have found that after a tire has been mounted and ridden for a while it does become easier to remove/mount. I imagine some will disagree, but stuffing a 2.1 WTB Velociraptor into a sub 14mm wide Matrix Mt Titan rim has taught me differently.

John

I thought I knew all the tricks too, until some really tight tire/rim combinations kicked my butt.

I was afraid with some of these I’d never be able to fix a puncture on the road.

Here’s something I’ve learned: after being pressurized and ridden a little, they loosen up. With some tires, although the first time going on can be super tough, subsequent mount/dismounting is MUCH easier. They stretch and soften just a little. Edit: just noticed I restated the same thing as the previous comment. Glad to see others validate my findings.

To answer your question, no, I would not recommend sanding or filing your rims.

nope no sand.... no guarantee of eveness, which in a tensioned wheel can lead to uneven stress and pre mature failure

Get a tire jack Kool stop, VAR etc since clearly you do not know all the tricks :)

This. I used to run new Contis on wheels with Velocity rims for a while before trying to mount them on Fulcrum rims. Out of the box, I just didn't have enough hand strength to do it, but after a week of being inflated on another rim, they were doable with hands only.

Are you using an appropriate tubeless rim tape? Thick traditional cotton rim tapes are a poor fit for tubeless rims.

The thread linked in post #9 is good, though as warned, contains tips on technique. Maybe ask for opinions as to trimming the bead of the tire?:foo:

how about specifics on the tire+rim combo --perhaps someone else has had experience with it.

and NO. that's just a dumb idea.

dumb question: are they 27.5 (650b) tires on a 700c rim? So tight that they're breaking tire levers indicates something else is going on. need more details---

Swap your rim tape for two wraps of 1 mil Kapton tape (5/8" or 16mm for traditional rims, 3/4" or 19mm wide), totaling just 0.005" thick versus .020" for Velox and .010" "thin" rim strips/two wraps of stans/two wraps of packing tape/etc.

Finish your installation at the valve stem, pulling the bead towards the center, keeping tension on it, and milking the slack around until you can flip the tire over with your thumbs.

Those two things make the difference between cussing at tools and comfortably hand mounting tires.

i got some panaracer gravelking sk's 700x35mm. brand new, i could hardly imagine getting them on any of my several sets of wheels save one set araya single wall rims. tubeless ready, btw. they're meant to be tighter, but this was ridiculous. i had to stretch them before i could get them on the intended wheelset. i couldn't even get a lever in there to set the bead

The rim's outer most diameter is important for tire retention (as well as a few other design factors). I would not sand it down. Now the rim's well, the lowest diameter between the bead seat beds, is very important to tire mounting ease.

To answer the simple question. Yes, we see rims that have been ridden with no tire, on paved surfaces, resulting in the same effect of sanding every so often. (Keep working in the LBS field for years and you'' see a lot of...) Now the "sandpaper" is rather coarse and the rim's side walls tend to also have some pressure "molding" (to put in mildly). Please believe me when I, and others have said, suggest you don't do this even with hardware store bought sand paper. Andy

So far I have zero helpful responses. And zero point five tip or tricks I didn't already know decades ago. I asked a simple question: Has anybody actually tried milling the rim a little, and people say things like "oh you must be an idiot" (which maybe I am) or "just use a little soapy water, works great for me!". Like I didn't know your favorite tip or trick already in the 1970's. But OK, nobody so far has tried this idea, with good *or* bad results. I'm kind of surprised, you'd think people would have a little more imagination than fixating on the tire as the source of the problem. But maybe I'm the idiot and am about to ruin a perfectly good set of wheels. I think I should probably roll out the new wheels and a few of my old ones to see if there's an actual difference in circumference at the bead. If not I better think twice before modifying anything.

Anybody want to make a prediction?

A helpful response would be "I know a guy who tried it, got his tires on just fine using his pinkies, but had a blowout and died on a descent". Or "I saw that some cheap rims just have very rough grooves along the braking surface and those might be what's making it so hard to work the tire on. Maybe you just need to knock those down a little bit on the side".

To be fair I should have mentioned: these are 700cx25mm *used* road tires going onto brand new Chinese rims.

Cheers,

Jon.

Since you don't like what many years of people's experience have suggested I think you should sand away. Report back after you have findings. OH, do it to your rear rim first so you can report back. Andy

Knows already everything - except how to mount a tire.

Just grind it off and glue tubular tires on.

Since you are going to do this anyway, you need to take accurate measurements before and after. If I were going to do this, as a DIY without a machine shop, I would mount the bike on a trainer with the tire removed and have someone pedal the cranks smoothly at a sufficient speed to simulate a lathe.

The tricky part is having an extremely close tolerance radial runout on the rim and a method to remove a consistent amount around the circumference. Just sitting down and trying to do this by hand with the rim in your lap will be a certain disaster. There is a good chance it won’t work, and you may incur serious njury if the rim fails. But at least “you” will be the one to say I know someone who did this.

If it works, you will need to lace the second rim to the rear hub and repeat exactly the same way. You have professed great knowledge and skill.

Good luck

John

Edit Added: I am not an engineer and if you proceed with any of my suggestions you are following the advice of a complete moron and therefore you assume all liability.

One last thing. If you do pull this off, you can never sell or give away those wheels to anyone. When you are done with them the rims get destroyed. If someone else uses a different tire and it comes off at high speed, or the rim fails from removal of material, you will be responsible since you altered the rim. It will take the OEM 2 seconds to discover that.

John

You got the most helpful response in the very first reply, by cxwrench. He said, "No."

You said you already know all the tricks. Why would someone try to give you advice? You don't need it, and yet, you cannot get the tire mounted.

You now consider a helpful response to be one validating your idea to sand down, or mill the rims. In that case, I cannot give you a helpful response, but it you bring the rims over, I'll mount the tires for you.

try some different wheels. i mentioned it in a post above with tires i had that especially difficult to mount. and, what you're dealing with quite common when mating different tires and different rims as tolerances will vary with either. it drives the tubeless crowd to madness ;)
thing is, tires do stretch. it would be better to wait for them to do that than ruining your rims....because you will. that edge is just as strong as it needs to be and will still fold under a rock and low enough tire pressure. it only gets more prone by taking off more metal. furthermore, as someone mentioned, you stand the chance a tire popping out of the bead in the future.