You might recall that I have a tire to change. Tire changing is something that can be done at home if you have the right tools. You can buy really expensive tire changers, or fairly cheap ones (wheel scratchers), but I elected to make my own out of (mostly) scrap steel.
Tire changing can be broken down into three steps: dismounting the old tire, mounting the new tire, and balancing the assembly. Today we cover dismounting and introduce some of the homemade tools.
The first thing we need to do is remove the valve core from the valve stem. There is a special tool to do this, but it’s ridiculously cheap:
Out comes the valve core by using the tool to unscrew it. If you’re not holding on to the core it may just decide to fly off across the room like a miniature rocket, propelled by the deflating tire. Here’s what the core looks like once it is removed (two styles):
Then it’s on to the tire mounting stand. I finished welding this a few weeks ago, but I haven’t yet put a coat of paint on it:
This is basically a reverse-engineered version of a Tire Stripper, a product once made by a company which seems to have gone out of business.
The base serves three purposes: it firmly secures the wheel at a working height without scratching it, adjusts to accommodate different wheel sizes (and different brake disc sizes for motorcycle wheels), and it provides a leverage point for working on the tire/wheel.
Starting from the top, the stand is made from a ¾" threaded rod which serves to provide the leverage point and roughly centres the wheel. I have a random chunk of rubber hose on the rod to protect wheels when they are on the stand.
Below the rod are the three arms of the working surface. These are adjustable for width and are covered in 1/8" soft plastic to prevent scratches to the wheel.
Continuing down to the bottom, everything is screwed into the end of an old cable reel which has been sitting in my basement for a while. The usual method is to bolt the stand to a concrete floor, but this way I can move it around if needed.
The wheel is put on the stand:
…and secured down with the white strap you can barely see through the lug holes. I added the strap to the Tire Stripper design, which used a more complicated system of threaded clamps. These spokeless steel wheels aren’t ideal for my strap however, as it was designed to run through the spokes of a wheel rather than the lug holes. The strap is held on one side by a hook bolted to the cable reel, and by a cambuckle on the other side:
Once the strap is tightened down, the wheel is rotated around to tighten the strap like a tourniquet, holding everything securely in place.
The first thing to do is to break the bead of the tire. This involves pushing the tire down off the edges of the wheel into the narrow part of the wheel. Skipping ahead a little so you can see what we’re working with, here is what the wheel looks like without the tire:
When we break the bead, we push the edge of the tire over the little hump and into the narrow “valley” of the wheel.
The tool for this job is the bead breaker. It is a long, adjustable lever that forces down the edge of the tire:
The tool is placed onto the threaded rod on the stand, and clipped into place with a quick-release pin. The bar can then be swiveled around the base 360 degrees. The levered force acts through the wedge-shaped part in the middle of the picture. It is adjustable to account for different sized tires.
With the bead breaker in place, I start levering on the edge of the tire. Though it can help to move the breaker around the tire to a few different locations, it is most effective to focus on one quadrant of the tire until the distinctive “pop” tells you the tire is debeaded:
Sometimes, depending on the wheel and/or tire, a lot of force is needed to break a bead. My original design of the bead breaker was just a little bit weak:
Note in this picture the wooden wedges that can help hold parts of a stubborn tire down off the rim while levering on other sections. The bent lever was straightened, lengthened, and reinforced!
Once one side of the tire is debeaded it needs to be flipped over so the other side can be done. Pop!
Then comes the tire removal. The tool for the job is the mount/demount bar, again copied from the Strippers of Tires at the Tire Stripper Co. The demount side is made of a reinforced, slightly curved piece of plate with a special wedge/hook on the end, and covered in the same soft plastic as the stand:
This gets shoved in between the wheel and tire, and the hook on the end holds on to the inner tire edge:
Also note the soapy water sprayed onto everything to help the tire slide off.
Remember that picture I showed you of the profile of the wheel? That narrow part of the wheel is very important when it comes to mounting and demounting tires. Though made of rubber, tires aren’t very stretchy. To get one lip of a tire off the wheel, the other lip must be in that narrow depression, otherwise it won’t happen. With most wheels (unlike these narrow donut wheels) that depression will be on one side of the wheel or the other (not in the centre). The tire needs to come off from the side closest to the depression (ie. the tire comes UP off the stand, so the depressed side of the wheel needs to be mounted UP when removing the tire).
I push the side of the tire opposite the demount bar down into the valley, and the bar is levered around onto the centre rod of the stand:
Then it’s just a matter of spinning the demount bar around until the tire pops off the wheel:
(yes, I know my pictures suck. It’s hard to be a cellphonecameraman and a mechanic at the same time)
At this point, cooperative tires can be pulled off the wheel with minimal drama. Uncooperative wheels require the demount bar to be again inserted between the wheel and tire and spun around again, to stretch the other lip of the tire up and over the wheel.
Tada! The wheel and tire combo is now just a wheel and a tire, completely separate entities. What was once one thing is now two things.
Here are some good reference videos of tire dismounting and mounting on a different machine, but the same process applies:
No-Mar Tire Changer: car tire
No-Mar Tire Changer: racing tire
Part 1: Dismounting
Part 2: Mounting
Part 3: Balancing
Tire changing can be broken down into three steps: dismounting the old tire, mounting the new tire, and balancing the assembly. Today we cover dismounting and introduce some of the homemade tools.
The first thing we need to do is remove the valve core from the valve stem. There is a special tool to do this, but it’s ridiculously cheap:
Out comes the valve core by using the tool to unscrew it. If you’re not holding on to the core it may just decide to fly off across the room like a miniature rocket, propelled by the deflating tire. Here’s what the core looks like once it is removed (two styles):
Then it’s on to the tire mounting stand. I finished welding this a few weeks ago, but I haven’t yet put a coat of paint on it:
This is basically a reverse-engineered version of a Tire Stripper, a product once made by a company which seems to have gone out of business.
The base serves three purposes: it firmly secures the wheel at a working height without scratching it, adjusts to accommodate different wheel sizes (and different brake disc sizes for motorcycle wheels), and it provides a leverage point for working on the tire/wheel.
Starting from the top, the stand is made from a ¾" threaded rod which serves to provide the leverage point and roughly centres the wheel. I have a random chunk of rubber hose on the rod to protect wheels when they are on the stand.
Below the rod are the three arms of the working surface. These are adjustable for width and are covered in 1/8" soft plastic to prevent scratches to the wheel.
Continuing down to the bottom, everything is screwed into the end of an old cable reel which has been sitting in my basement for a while. The usual method is to bolt the stand to a concrete floor, but this way I can move it around if needed.
The wheel is put on the stand:
…and secured down with the white strap you can barely see through the lug holes. I added the strap to the Tire Stripper design, which used a more complicated system of threaded clamps. These spokeless steel wheels aren’t ideal for my strap however, as it was designed to run through the spokes of a wheel rather than the lug holes. The strap is held on one side by a hook bolted to the cable reel, and by a cambuckle on the other side:
Once the strap is tightened down, the wheel is rotated around to tighten the strap like a tourniquet, holding everything securely in place.
The first thing to do is to break the bead of the tire. This involves pushing the tire down off the edges of the wheel into the narrow part of the wheel. Skipping ahead a little so you can see what we’re working with, here is what the wheel looks like without the tire:
When we break the bead, we push the edge of the tire over the little hump and into the narrow “valley” of the wheel.
The tool for this job is the bead breaker. It is a long, adjustable lever that forces down the edge of the tire:
The tool is placed onto the threaded rod on the stand, and clipped into place with a quick-release pin. The bar can then be swiveled around the base 360 degrees. The levered force acts through the wedge-shaped part in the middle of the picture. It is adjustable to account for different sized tires.
With the bead breaker in place, I start levering on the edge of the tire. Though it can help to move the breaker around the tire to a few different locations, it is most effective to focus on one quadrant of the tire until the distinctive “pop” tells you the tire is debeaded:
Sometimes, depending on the wheel and/or tire, a lot of force is needed to break a bead. My original design of the bead breaker was just a little bit weak:
Note in this picture the wooden wedges that can help hold parts of a stubborn tire down off the rim while levering on other sections. The bent lever was straightened, lengthened, and reinforced!
Once one side of the tire is debeaded it needs to be flipped over so the other side can be done. Pop!
Then comes the tire removal. The tool for the job is the mount/demount bar, again copied from the Strippers of Tires at the Tire Stripper Co. The demount side is made of a reinforced, slightly curved piece of plate with a special wedge/hook on the end, and covered in the same soft plastic as the stand:
This gets shoved in between the wheel and tire, and the hook on the end holds on to the inner tire edge:
Also note the soapy water sprayed onto everything to help the tire slide off.
Remember that picture I showed you of the profile of the wheel? That narrow part of the wheel is very important when it comes to mounting and demounting tires. Though made of rubber, tires aren’t very stretchy. To get one lip of a tire off the wheel, the other lip must be in that narrow depression, otherwise it won’t happen. With most wheels (unlike these narrow donut wheels) that depression will be on one side of the wheel or the other (not in the centre). The tire needs to come off from the side closest to the depression (ie. the tire comes UP off the stand, so the depressed side of the wheel needs to be mounted UP when removing the tire).
I push the side of the tire opposite the demount bar down into the valley, and the bar is levered around onto the centre rod of the stand:
Then it’s just a matter of spinning the demount bar around until the tire pops off the wheel:
(yes, I know my pictures suck. It’s hard to be a cellphonecameraman and a mechanic at the same time)
At this point, cooperative tires can be pulled off the wheel with minimal drama. Uncooperative wheels require the demount bar to be again inserted between the wheel and tire and spun around again, to stretch the other lip of the tire up and over the wheel.
Tada! The wheel and tire combo is now just a wheel and a tire, completely separate entities. What was once one thing is now two things.
Here are some good reference videos of tire dismounting and mounting on a different machine, but the same process applies:
No-Mar Tire Changer: car tire
No-Mar Tire Changer: racing tire
Part 1: Dismounting
Part 2: Mounting
Part 3: Balancing
Please share more on construction of the tire changing equipment such as measurements. Thanks!
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