Thursday, May 28, 2020

Retrogrouch Tool Time: Tire Jacks

Ever had that moment when putting a new tire onto a rim, and after you work the tire onto the rim all the way round, you get to the last couple inches, and no matter how hard you try, you can't get those last couple of inches of tire bead over the lip of the rim?

When that happens you want a tool known as a "Tire Jack."

Chances are, most cyclists have encountered a difficult-to-mount tire at some point or other. It's hard to pinpoint exactly why it happens. Sometimes it's the tire, sometimes it's the rim, and sometimes it's just the wrong combination of tire AND rim. Some brands or models of tires just seem to fit extra tight no matter what rims they're tried on. And one occasionally finds rims that, for whatever reason, will present a problem with any tire (a little larger in diameter than spec?). In any case, a tire jack is the tool that will safely coax those last inches of tire bead over the rim.

I've seen a couple different brands/models of tire jacks out there, but the most common one is sold by Kool-Stop, like this one here:

Interesting thing - the Kool-Stop name appears nowhere on the tool - but the name "Simson" is molded into the handle. I can only assume that is who actually manufactures the tool for Kool-Stop.

It's a simple tool that lets you apply a good deal of leverage. There is a stationary arm that ends in a "Y" shape, and a hinged arm with a hook at the end. The "Y" part braces against the rim on one side of the tire, while the "hook" part is placed under the bead on the other side, then you use the leverage of the long handle to pry the bead over the lip of the rim.
Like this:

And this:

I've had some frighteningly tight tire/rim combinations, but I've never had a tire that was so tight that I couldn't coax it onto the rim with this tool.

The Kool-Stop is a good tool to keep in the toolbox or workshop. But if you're out on the road and need to change a tire (and you know from experience it's going to be a challenge to mount), then there is a great "mini" version made by VAR that fits in the palm of your hand and can be packed easily in a saddlebag.

The VAR tire tool is pretty brilliant - consisting of a pair of tire levers for removing a tire, and a mini-version of a tire jack for getting it back on. The levers are maybe a bit too flexible to be ideal for removing a really stubborn tire, which I find to be true of most plastic levers. But the jack can be helpful in saving your thumbs when re-mounting the tire out on the road. As good as the full-size jack? Well, no -- it's only a fraction of the size, and a lot less leverage -- but it does make a difference. I have a couple of them stashed in saddlebags on different bikes.
One of the tire levers is stored in the center of the tool. As far as I know, VAR still makes these, but if you find them for sale today, expect the current production ones to be blue, not gray.
Both tools are pretty reasonably priced. The full-sized Kool-Stop tool sells for somewhere in the neighborhood of $15, and the travel-size VAR tool sells for anywhere from $10 - $20 depending on the seller, and where they're located - but it's probably the least expensive tool you'll ever get from VAR. Considering that many bike-specific tools can be awfully "spendy," these ones are a good addition to the tool collection, even if you're on a budget.


  1. I use the non-bristle end of a plastic toothbrush handle to "coax" a wire-bead tire onto or off-of a rim. TBH, I long-ago switched to folding-bead tires.

  2. The one and only tire that needed help with installation was a solid-foam tire that I used 15 years ago. Big mistake using foam tires, but I was much younger back then and very new to riding a bike. I haven't used them again for 14 years. It was so tight that I used a couple of clamps from my workshop to install it.

    I've since switched to pneumatic clinchers, foldable and non-foldable, and I haven't had any issues with installing it on the rim.

  3. The Kool Stop tyre jack is a great help! i ride Panaracer folding Paselas & fight with them on the initial installation but later find that the casings have relaxed somewhat when it comes time to do a roadside change.

  4. It wasn't a certain tire & rim combination that gave me problems; the very same tire and rim would sometimes be easy to mount and sometimes nearly impossible. Most of the tips online involve using soapy water, multiple tire levers, zip ties, etc and I wondered what I was gonna do if I couldn't get the tire back on during a ride.

    Then one tip I found mentioned moving the tire bead to the center of the rim. When there's few inches of bead left that won't go in, go to the opposite side, push the bead to the center (the lowest point if you were to look at a cross-section of the rim), do this to the rest of the bead until you reach the part that's still out. It will go in easily without tire levers.

    I learned this about 4 years ago and have never needed tire levers to get a tire back on. It's a bit harder but you can also use this method to get the tire off the rim without using levers.

  5. I have a different problem with 'open tubular' Challenge tyres. They are very flat and pliable and the first mounting is, well, challenging. I have resorted to tying down the length of tyre already inserted into the rim with pedal straps to keep it from popping out again before I have the chance to finish popping the bead in. It is not a matter of the tyre being too tight but of wanting to go back to flat, although a tight rim makes it extra frustrating. I wonder if there is a proper tool for this?

    Second time around the tyres are no problem to mount as they seem to settle into shape after being pumped up.

  6. My replacement tire bead jack (gave the last one to a friend) arrived today and is now marked "Kool Stop". The Simson marking is gone, though it is still made in the USA. The tool does need a hole in the handle to hang on peg board. Aside from that minor quibble, it's perfect!

  7. As Morlamweb says foam is hell, never, NEVER, offer to fit foam tyres to a friend's wheelchair, it could drive you demented and then you still have the other one to do tomorrow!

    I have been using Kieth s's bead deep in rim for over half a century but still some are too darn tight. From that last sentence you can deduce that I no longer have the strength to wrestle with a tight tyre which is factored in when choosing which bike I ride for a chosen distance.

  8. Oh jesus christ, I have tubeless rim that will put horrible time and hurts your finger as much as you could imagine.

    Ultimately to the point that I must cutting it off the rim just to dismount it. No, I am serious, I don't care if that's stupid, I can't literally squeeze the tires bead to pull off...

    I want this, really. I try big wrench and dent the rim (I know, its fucked up) but fortunately, rim still functionally.