Kenda Moped tyres on Cannondale Hybrids?

[UpWrong]

I recently bought a Cannondale Adventure hybrid bike. Came with 27.5" wheels and Kenda tyres which are marked as MOPED tube type tyres 60/100x23. I think the rims are 23mm internal width and the tyres are a nominal 60mm width. I've no idea what the 100 means. I'm unable to remove the tyres. I can't unseat the bead at any point in order to get a lever underneath. With the tyre deflated and using both thumbs I can't get any movement of the bead whatsoever. I'm thinking of taking a Stanley knife to the tyres. Any advice?

[Airsporter1st]

It sounds like they have used some kind of bead/rim lube for fitting, which has dried like glue.

I would definitely try pouring very hot water in the area where you are trying to insert the lever. Once you break the bead in one place, it should be possible to work the levers all round.

[UpWrong]

It sounds like they have used some kind of bead/rim lube for fitting, which has dried like glue.

I would definitely try pouring very hot water in the area where you are trying to insert the lever. Once you break the bead in one place, it should be possible to work the levers all round.

That make sense. Will give it a go. Thanks.

[UpWrong]

No joy so far. They are Kenda Kwick Seven-5 tyres. I tried a whole kettle of boiling water. I just can't squeeze the wire beads into the central rim section. I'll try using mole grips to squeeze the tyre and then pull it to one size. That might unseat a bead.

[UpWrong]

Found this video about breaking the bead, but I don't have a bench vise

[Jdsk]

...
I'll try using mole grips to squeeze the tyre and then pull it to one size. That might unseat a bead.

Found this video about breaking the bead, but I don't have a bench vise

You can mimic a vice by using two G clamps and two long pieces of wood. Then stand on the protruding ends of the wood pieces and the diameter of the wheel gives the lever distance as in the video.

Jonathan

PS: I wouldn't use "brake cleaner" as the releasing agent as it's often based on acetone and there's a risk of damaging polymers and surface finishes. Isopropyl alcohol, as in the video, sounds appropriate. WD-40 should be OK. And clean it off the tyre asap.

[UpWrong]

...
I'll try using mole grips to squeeze the tyre and then pull it to one size. That might unseat a bead.

Found this video about breaking the bead, but I don't have a bench vise

You can mimic a vice by using two G clamps and two long pieces of wood. Then stand on the protruding ends of the wood pieces and the diameter of the wheel gives the lever distance as in the video.

Jonathan

PS: I wouldn't use "brake cleaner" as the releasing agent as it's often based on acetone and there's a risk of damaging polymers and surface finishes. Isopropyl alcohol, as in the video, sounds appropriate. WD-40 should be OK. And clean it off the tyre asap.

Two G-clamps did the trick. With two clamps gripping the tyre above the rim, I could lever the tyre sufficiently to break the bead. Just had to be careful of scratching the rim which is why in the video he used some cloth in the bench vise.

[Jdsk]

Well done.

Was that with your hands on the clamps, and without additional leverage?

Jonathan

[UpWrong]

Well done.

Was that with your hands on the clamps, and without additional leverage?

Jonathan

Yes, with my hands on the clamps and the bottom of the wheel braced against my knees whilst kneeling down.

[Jdsk]

Thanks

Jonathan

[tim-b]

I've no idea what the 100 means

For a car tyre it's the aspect ratio, i.e. 100% or 60mm wide and 60mm high

Car tyres without a marked aspect ratio are around 80%, everything else is marked, e.g. 200/50 would be 200mm wide and 100mm high

[Brucey]

cars and motorcycles (amongst other things) commonly measure tyre widths, aspect ratios etc. in mm, but rim diameters in inches. Some tyre makers eg. michelin have tried making tyres in full metric sizes, so for example a bmw I used to own was originally fitted with michelin TRX tyres fitted onto 390mm rims. The metric rim sizes didn't really catch on, so you had a choice of just one tyre, very expensive, assuming you could actually get it. To this day you can still buy a set of wheels and tyres in inch sizes for about the same money as a set of metric tyres.