Please don't fit anything wider than the standard size, all you are doing is slowing your bike and the handling down. Furthermore, the same size between brands can vary greatly in actual physical dimensions. My advice... Fit standard size dunlop alphas... I would even consider going down to a 100 section on the front.
Purchased a set from these guys https://www.motorcycletyrewarehouse.com.au/dunlop-alpha-14-14060r18-rear
Suprisingly very good in the rain. Wouldn`t expect that from the lack of tread it has but then again it is a very soft tyre
@Linkin have you ran a wider to know? Or know others who have? I mean, they run wider tyres on other bikes - yes, variations in weight, power, rake, trail, rim width and so on changes things, but doesn't mean it won't work, and things can be changed to compensate. Changing the rear or front height could be enough. Someone said they run a 160/60-18 on the zxr250 (just clears the swingarm), though they might not be cornering like a racer, they seemed happy. Others thought the 150 wasn't good, but they might be riding differently. But the 160 does look good! It seems QLD might be behind, the Alpha 14 isn't even offered here, only the 13/Z.
They perform like it, too. Sorry, but people fitting wide tyres to small bikes not designed to run them does my noggin in Reasons to fit wide tyres to your small bike 1. Looks (That's a 180 I've got on the back of my 250 brah! It's fully sick and I can pull mad skids on it!) Reasons not to fit wide tyres to your small bike 1. Increased weight (better go on a diet to compensate) 2. Increased rolling friction (robs you of top speed and worsens fuel economy) 3. Decreased handling performance (it changes direction like a barge and increases the rider effort required) 4. Decreased tyre temperature (Big bikes have bigger rear tyres to absorb the incredible amount of heat they generate) 5. Safety issues (Chain/swingarm touching the tyre) I've had several FZR250's, one had a 110 front and 140 rear. The standard sizes were 100 and 130 respectively. I can honestly say that they handle and perform much better with the standard size tyres. Why would the ZXR, CBR or GSXR 250's be any different?
The zxr250 has 110 and 140 as standard, so surely they suit it well? I currently have a 120 on the front, though it is worn to nearly a 110, but I find it pretty good. I haven't had to push much, my rear tyre is too old for that (I've been stepping out rear a few times), so I guess I'm not in a position to compare. And my budget isn't strong enough to buy both options for testing. Not yet, at least.
You should use whatever the standard sizes are, and indeed for the ZXR it is a 110 and 140, because it was designed to use them. With my riding style, I can very easily get to the edges of the rear, but I do not push the front to the edge, because crashing hurts. Some guys use all of the front and don't use all of the rear. Different strokes. Try the standard sizes and see how they feel. Why waste money on worsening your bikes handling? There will be zero chance of safety issues with the standard sizes and you won't lose any performance from where you are now I want to emphasize again that the same sizes between brands can vary wildy in actual physical dimensions. There is also a difference between say Dunlop Alphas and Pirelli Sport Demons... the former is a sticky / race tyre that is road legal. It's quite an aggressive profile, which lends itself to agility. They are also radial. Compared to the sport demons which are bias cross-ply tyres, have a less aggressive profile to them, and are designed with commuting in mind, despite the 'sport' label The sizes, 110/70-17 and 140/60-18 are exactly the same, but the tyres are not the same. EDIT: Have a read of this link - https://www.quora.com/What-is-the-r...ng-ability-and-width-of-tyres-on-a-motorcycle and a watch of this video
looks like it . A1 judging by the box swingarm. 'ZXR250's Australia' on facebook is where that came from
