I recently snapped the top off of one of my Presta valves, and saw it as an opportunity to learn how to change an inner tube, which I have never done before. I watched YouTube videos on it (I particularly liked the video from Trek) and felt fairly well-prepared. I bought some new tubes, some plastic tire levers, and off I went.

The Trek video shows how to do it with taking the tire only halfway off of the rim, but I followed a guide that suggested taking the entire tire off. I inflated and then deflated the inner tube, and loosely lined it around the rim (which most guides don't suggest...). I then stuffed the tube into the tire as I worked my way around, getting the tire beads back into the rim. As suggested in the Trek video, the final segment was difficult and required the most force, but I did it. I inflated the tire, and everything looked pretty good, except... there was one area where the tire didn't seem to be as tucked in to the rim as the rest. I prodded at it, deflated the tube and prodded some more, but I couldn't get it to look like everything else. I couldn't see any traces of the inner tube, though, and figured that the true test would be with a ride.

Everything was fine, initially. I was watching the tire carefully and paying close attention to the ride, and everything seemed to be as usual. But then it seemed like there was some asymmetry - hard to tell, though, since I had gone through a damp patch and only part of the tire was wet. Quality of the ride was unchanged. I kept going for a while farther, hit a few bumps, and just when I was thinking that I'd better dismount to really make sure that there was no asymmetry... *POP*

Trying to keep a good attitude, I figure that this is a chance for me to learn from my mistake and simultaneously practice patching an inner tube, which I have also never done before. The hole was easily found, right near the stem, where the tire had appeared suspicious to me. I patch the tube but am not totally confident in it, so I get out a fresh tube and go through the process again. This time I try it with the tire only halfway off of the rim, as they did it in the Trek video. Same issue, though - I just can't get the part of the tire near the stem to look like the rest of the wheel. I pushed and pulled at the valve, but on one side of the tire some of the inner tube remained, blocking it from going down as far as the rest. Worse yet, I discover that the tiny pump I had with me is broken, so I can't even inflate it. I wasn't too far from home, so I walked it back with the flat front tire.

Back at home, I take off the entire tire, line it with the inner tube, ever so slightly inflate the inner tube (as suggested in a wikihow guide), and then go through the process of putting it back on the rim, starting with inserting the stem first. It was even worse then, though, as the tire seemed to want to stay on the outside of the rims, and wouldn't go back inside. I deflated the inner tube and had the same problem.

It was then that I noticed a small tear in the tire - nothing that went all the way through, but a bit of the outside was revealing the material underneath. It was at that point that I figured I'd best stop mucking around, as I wasn't sure if the tear had always been there or if it was my doing. I had been intending to take my bike in for a tune-up, anyway; the wheel issue could be added to it. Feeling dejected and pathetic, I dropped my bike off and was told that there's a turn-around time of two weeks.

It's clear what happened the first time around: part of the inner tube got pinched by the tire, leading to the blow-out. Why was it so difficult to get the tire on properly near the stem, though? For reference, my wheels are 700x32, the tire is Nashbar Gridlock, rims are Alex R500, and the inner tubes are meant to fit tires 700x28-32 in size. It looks pretty easy in the YouTube videos, so why was I struggling?

Advice and kind words appreciated. I thought that this was supposed to be one of the most basic skills that cyclists should know; I'm not feeling too great about having to ultimately defer to a shop to handle it.

1. You may not have pinched the tube. If the tire's bead is not seated properly in the rim, it will eventually do what yours did.
2. When seating the tire near the valve, push the valve up into the tire and seat the bead, then pull down on the valve. Also, pinch the tire opposite the valve while you are doing this so it goes down into the depression in the middle of the rim and gives you as much slack as possible to seat the tire.
3. Sometimes you get a tire with a defective bead that just will not seat. Since your tire had already been used, I doubt this is your problem.
4. 700x32 tires tend to be thicker and stiffer than 23 or 25 tires, so may be more difficult to wrestle over the rim for the last few cm. Try to resist the temptation to use levers for this, as it is very easy to put a hole in the tube doing this.
5. Keep at it, and you will eventually get it. Perhaps the next time you have to go to the shop, you could ask them to let you do it and coach you, but pay the usual price (or ask a more experienced friend).

Good luck.

OK the most serious error was to not seat he tire evenly before inflating. After mounting a tire, inflate enough to fill the tire out and give it shape. Then spin the wheel slowly and look at the molded reference line just above the rim's edge. It's there as a guide "reference" to let you know if the tire is seated evenly. Unevenly seated tires blow off, so this is a critical step.

Now to make it easier, inflate the tube with 3psi or so so it fills out but doesn't stretch, then stuff it into the tire. Opinions vary, and either is right, so you can do this before mounting the tire at all, or after mounting the first side of the tire. (I do it before mounting).

Skipping to the end, mount the second side of the tire starting opposite the valve, and working in both directions working to the valve. Be sure to push the tire to the middle of the rim where it's deepest, and push the slack ahead of you as you go. (this often calls for letting air back out of then tube, so it's limp). Finish mounting at the valve, being careful not to pinch the tube, then push the valve deep into the tire to pull he tube out from under the tie's bead where it might be trapped. Pull the valve back down, inflate to 10psi, and check/fix the seating. Then inflate to 25psi, and check again (just in case) before topping to full pressure.



check all the way aro

Hmmm, you used parts of two different techniques and added your own variation instead of following a simple standard procedure. Does not sound like a formula for success.

Think a minute before you try again. Many millions -- probably billions -- of bike tires have been mounted correctly and functioned well for countless miles. Does that give you a clue how to proceed?

+1

I'm one who believes that there's more than one way to skin a cat, so let this slide,

But to the OP, if you don't know how to do something to the extent that you're seeking tutorials, don't you think that you might be ill equipped to improvise? First learn and sticks to the basics, then when you understand those, feel free to improvise or adapt at will

Exactly. Look at any or all of the tutorials, then pick one and follow it. Simple, no?

I recalled reading your second point (made by someone else) on these forums before, and attempted it the second time around. I just couldn't manipulate the inner tube far enough to get the tire in. I appreciate your fourth point - the tutorials all seem to use very thin road tires, which could explain why it seemed a bit more difficult than what the presenters did. Your fifth point is a good one, I'll see if the shop is willing.

I neglected to mention it, but I did spin the tire and inspect it for asymmetry before fully mounting it and riding on it. The issue is that there were no obvious signs of asymmetry while spinning, the bead at that one small part just looked slightly off compared to the rest of the tire. I'm guessing it was the issue, but at the time I couldn't remember if that's what it had always looked like.

I'll keep the rest of your advice in mind for next time.

I take it you're referring to my first effort, to which I can only say that you're probably right. I couldn't recall exactly how that part was done in the tutorials and figured that it didn't matter too much so long as the tube was nicely covered by the tire, and the tire was mounted properly into the rims. That part seemingly wasn't the problem, though. My main reason for posting here was because even when I followed the guides exactly, I was unable to manipulate the inner tube and/or the tire properly. Millions or billions of tires have been successfully changed, but I'm not trying to say that there's some flaw in their design. I just figure that I'm not the first to have had this issue, and wouldn't mind hearing how to overcome it from those who have either experienced or observed it, themselves

I don't know if this was mentioned, but once you do get the tire mounted but before adding any air or going around the wheel checking for tire position you may want to check all around between the tire and rim (by pinching the tire's sides to peek into the rim) to make sure the tube isn't stuck anywhere. Keeping a little air in the tube (as much as you can manage and still fit the second side of the tire, really) helps to avoid pinching the tube between the bead and the rim. But a quick check all around on both sides is good for making sure.

I usually perform this check at the same time as I'm running a little soapy water on the bead and on the rim's hook, which then helps me when seating the bead evenly.

If you use halfway decent practice when mounting, the only place you might trap the tube is when you finish, which is another reason for finishing at the valve. Trapping the tube under the bead anywhere else is a royal PIA because there's no easy way to free it.

Sometimes the inner tube wants to lay out very flat and bridge the lips of the rim, making it hard to impossible for the tire's beads to set properly on either side of the valve. You won't really see or feel the tube because it's on the lower hump area of the rim's shoulders. If your tire is ever sticking up slightly or bulging around this area, then deflate the tube all the way and gently work the tube up inside of the tire with something blunt like your tire levers. It's nothing you did wrong or incorrectly, it just happens sometimes.

This is the best tire mounting video IMO, How to fit a Marathon Plus Tyre.mp4 - YouTube
It's mounting a marathon plus tire which is usually considered one of the more difficult to mount, but it applies to all other tires it seems to me. So it should be of use to you . Good luck.

[MENTION=54127]Northwestrider[/MENTION] Thanks for posting that video.

I struggled for years whenever I had a flat, now no tools are needed, not even the straps mentioned in the video when mounting a marathon or any other tire I've come across . I'm glad you like his video, it sure helped me.

I have repaired and replaced a fair number of tubes over the years for myself and others, but I've never pulled the tire completely off of the wheel to remove or insert the tube. Is there a reason for doing so that I'm not aware of? Is it to enable complete inspection of the tire before putting a tube back in? [/QUOTE]

There's more than one way to do this job, and whatever works well for you is the right way.

I generally pull the tire, because over the years I find it's faster to stuff the tube first, then mount the tire. It also has the small advantage of not having to work the valve past the tire, but that's not a big deal either way.

I also remove the tire because I like to inspect the tire thoroughly and again, it's easier off the wheel.

But, I also do the complete opposite sometimes if pressed for time (trying to catch a train), and the cause is obvious (piece of glass plainly visible). Then, I'll remove only a foot or so or tire from the rim, pull down and patch the tube (glueless is good for this, but have used bandaids, and once a piece of gum), put it together, pump and run.

BTW- in mass production, bicycle companies have tires shipped with the tube already stuffed in, and mount the way I do.

There's a couple of things I always do when remounting a tube/tire. After inflating the tube before insertion inside the half mounted tire, I always take some talcum powder and put some in my hand and run the tube through it a couple of times to coat in with the powder. It makes the tube a bit slippery when inside the tire and easier to get the valve stem lined up with the rim hole. If you want, you can even get some powder inside the tire. It won't hurt a thing. Then as you work the second half of the tire over the rim, you must keep the tire centered and force it down as deep as possible into the rim. This gives you just enough more tire to leverage over the rim as you work it around the wheel. Always remember to give your rim strips a going over before remounting a tire to make sure the spokes are covered.