cbr125 forum

A common complaint by folks who try their hand at installing their own tires is just how hard it is to do it. It's not taking the wheels off the bike that's rough, it's installing the new tires onto the rims...

I've been running Metzeler Interac M5's for some time now, enough to have installed 6 of them (or so) over the last year. They are a 110/70/17 tire which means they are actually wider then the stock tires. This alone makes them tough to install but, in the specific case of the Metzeler's, they are a mordern high-performance tire designed for high-horsepower litre bikes. This means, among other things, that they are Z-rated which means they are really, really stiff. I just about broke my wrist installing them once and the other day I had to get rid of some worn tires and my father was doing his annual brush burning so...I hucked a few on the pile

Here's what I found out later though. One, that fire ran for 12 hours and it was really, really hot. I mean, stand next to it and you'll start to burn. Red hot coals, bonfire size. In short, with temperatures that high there should be nothing, and I mean nothing, left of those old Mezeler's.

Instead, after everything was said and done, I got to see first-hand why those tires are as still as they are, and, just a little of the German 'over engineering' that makes these puppies grab so well...and..also why they nearly break my wrist every time I install them....

Here's a shot of a new install on the rear of a Metzeler Interac M5 taken when I was loading it up DynaBeads last year...

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Best & Thanks!
Marvin Miller
cbr125world Store

...because every day is MotoGP day when you own a CBR 125r...

Literally, no less then 32 (!!) steel belts surrounding those M5's. Now I know where a lot of that incredible handling comes from. Between that and the rubber compound it's no wonder they work so well

_________________
Best & Thanks!
Marvin Miller
cbr125world Store

...because every day is MotoGP day when you own a CBR 125r...

Keep in mind too that several of those steel wires will have come from the Bead too...

But in any case, that is a BOAT load of wires!!

I too replaced the stock tires (they had less the 4,500Kms on them, but I wanted wider tires) with Pirelli M75 110/80 and 90/80.

I did the front tire first. I've done tires on my bikes before and never had an issue with breaking the bead and R&Ring them.

On another Forum, one of the guys built a weird contraption to break the beads (like a jack and 2X4 up against a ceiling beam). All I have ever had to do was use a tire iron (the same one used to remove the tire with) and press down on the inner bead and pop!

The front tire went that easy, the rear tire I used a pair of Pistol Grip Clamps to break the bead. After that, removing and installing the tire was a bit different for each tire. The front the tire came off VERY easy and the new one was a beep to install.

Now the rear was different. It came off a bit harder , but the new one went on VERY easy.

As for popping the bead back on, well, that was a bit different. The front tire had once side pop back on with no problem, but the other side took me several attempts over several days before she finally popped on.

The rear wouldn't pop for love or money. Mind you all I have to work with is a 100PSI - 3 gallon compressor. Not enough pressure and/or volume to get it done, so I had a shop that I know do it for me.

In both cases I used some lubrication. The front I used dish soap and the rear I used Bead Butter (VERY good stuff!!). Both tires now also have T6 CNC Aluminum Valve Stems and Balancing Beads (1 oz per tire).

Can't wait to see how they perform!

Yeah, they can be a bitch to do. I use a C-Clamp to squeeze them together in an effort to get them to pop off the bead. Nothing else will really do it - they're just too damn stiff. I think I mentioned before that it's normal for me to have to pump them up to 110 PSI to seat them wacko.gif

For me, they're a double-edged sword. I hate changing them but on the other hand, new tires are such a treat that I know when I'm done it's going to be unreal all over again. The important thing for me is safety. That's what put me onto these tires in the first place. When I was coming back from my skills test a while back it was raining and it was the first real rain of the summer. The roads were unbelievable. I blew through an intersection because I could not stop and also went pretty close to sideways crossing over a railway track at 80K. It really shocked me.

Up until that point I had been under the impression that if I got killed on the bike it would be by something I did. It really had not occurred to me that cheap tires could kill me. Once I got home I sat down and researched tires with a big emphasis on we weather performance. That's how I found the Metzeler's. They were the top rated wet performance tire around with several people blasting through corners in rainstorms on a serious lean at high speeds.

I was really surprised how they changed the bike. It has made it much more dull as the safety has improved to a point where it's basically idiot-proof. That takes a lot of the risk out of riding and, consequently, some of the excitement.

Simply put, the performance of these tires is way, way beyond what our bikes can inflict on them. I do pretty well on mileage too though. They seem to wear less rapidly the closer you get to the wear bars. Certainly a fall can do 7,500 on them if he wants to.

But the stock tires - those things can easily kill you in the rain.

_________________
Best & Thanks!
Marvin Miller
cbr125world Store

...because every day is MotoGP day when you own a CBR 125r...