[Kyser]

So after browsing around the forum as a complete and utter Noob. I was wondering what is the maxium tire size that we can put on the stock wheels of the Z125? I already know some people have put bigger tires on their z125 and was wondering aout the limits since tires are the first upgrade I will be doing to my z125. So if anyone has the info it be appreciated. Right now I'm looking at the Michelin City grips front: 120/70-12 and Rear: 130/70-12.

 

[James Carballo]

So after browsing around the forum as a complete and utter Noob. I was wondering what is the maxium tire size that we can put on the stock wheels of the Z125? I already know some people have put bigger tires on their z125 and was wondering aout the limits since tires are the first upgrade I will be doing to my z125. So if anyone has the info it be appreciated. Right now I'm looking at the Michelin City grips front: 120/70-12 and Rear: 130/70-12.

I have the 140 in the rear on my Z

 

[Leandro Paparelli]

I decided to move towards the lightest set I could find. Unfortunately most of vendors out there don't mentions the tires weight; I found a website from the UK that was an exception, and I confirmed my guess that Pirelli were the lightest ones.

I bought a Pirelli Evo 21 110/70 to the front, I know it is smaller than OEM 100/90, but it is amazingly light, just 5.8 lbs. For the rear, I got the Pirelli Evo 22 120/70, same size as OEM but quite lighter as well.

These weight reductions will contribute a lot with the pair of BST carbon fiber wheels that I bought for her.

Cheers!
LP

 

[Motorazr]

I bought a Pirelli Evo 21 110/70 to the front, I know it is smaller than OEM 100/90, but it is amazingly light, just 5.8 lbs. For the rear, I got the Pirelli Evo 22 120/70, same size as OEM but quite lighter as well. These weight reductions will contribute a lot with the pair of BST carbon fiber wheels that I bought for her.

Those weight reductions will "contribute a lot" towards what - increased twitchiness at higher speeds? The 12-inch wheels/tires on the Grom and Z125 aren't exactly paragons of high-speed stability as it is. Just because you can make something lighter doesn't mean that you should. Will you be adding a steering damper too? Because, well, ****. I've ridden with a steering damper on my TL1000S and hated the sluggish way it felt at lower speeds. To me, some high-speed twitchiness and headshake was preferable to suffering heavy steering. Light, stiff wheels on a pedal bike are awesome and I'm all about it - I have seriously expensive Easton Haven tubeless wheelsets on both of my 29er mountain bikes (a hardtail and a full-suspension). From my own experience though, I have zero desire to lighten my Z125's front-end any more than it is already.

As for carbon-fiber anything - it doesn't bend when you hit something hard. It cracks. And the damage to the carbon weave is neither easy nor inexpensive to diagnose and repair. Again, just because you can make something from a lighter material doesn't mean that you should (although it may impress people who don't understand it's implications). You can ding an aluminum rim or have to throw away a cracked carbon one. I don't mean to be a hater, just advising caution and thoughtful consideration of the engineering involved. What the **** do I know though.

 

[Zaph]

Those weight reductions will "contribute a lot" towards what - increased twitchiness at higher speeds?

Better traction. Less unsprung weight is one of the biggest improvements anyone can make to a bike. Better performance at higher lean angles is a good reason. Don't underestimate it.

 

[Lobot]

To continue with the lightweight theme, one man's "increased twitchiness" is another man's improved responsiveness. Personally, i think this bike is very stable when stock and it could stand to be lightened up a bit(it's around 225 lbs!). On the tight go kart tracks we ride it can't turn too quickly, just yet. And the fast Groms we are chasing already have BST carbon fiber wheels and none of them have a steering damper or any signs of headshake. So it's really a matter of bike setup and personal preference. But to each his own...wasn't this thread about tires??