Ya. its zapper Y. Sorry it was mistake. if you fit wont performance get affected ?

even im looking to change only rear but some saying its always good to have same pattern tires at both wheels.

Also i heard sirac is heavy. Can someone enlighten this ?

I will try and answer your query.

Your bike's rear OE tyre size is 100/90 18.

In Michelin, you have the following options. You can fit 4.00 18 M45 which is nearly the same size as 100/90 18. You can also upgrade to a wider tyre like 120/80 18 Sirac, which would be wider and taller than your existing tyre.

When you upgrade to a tyre which is larger, it means that the diameter of the bigger tyre is also going to be more than the original tyre diameter. The speedometer of the bike is caliberated with the original tyre such that in 1 revolution of the tyre, the bike will travel "X" distance. The larger diameter tyre will travel more than "X" distance in one revolution since its diameter is more. This inturn will increase your top end speed marginally and would reduce the pickup slightly. This is because the larger diameter tyre takes longer to rotate as compared to original tyre.

The other factor is the weight of the rear tyre. If the tyre is designed for higher CC bikes, then it has stronger casing and would be slighly heavier than normal tyres. This also reduces the acceleration / pickup very marginally.

The positive tradeoff is the immense grip that you get when you upsize as a result of more contact patch of the tyre with the road. This will enhance many factors such as Riding Comfort, Dry Grip, Wet Grip and Cornering amongst others.

Hope this explains what you are looking for.

sirac 120/80 18
m45- 4.00/18

Thanks. Im afraid of any alterations so will go for M45. AS i asked previously.. changing rear alone will do good ? or i have to change both ?

Whatever upsides and downsides suggested are very marginal. I have described in detail just for your understanding.

Rear tyre itself can be changed. Not necessary to also change the front tyre along with it.

Tyre Prices are ok. Prices should be inclusive of taxes but tube cost is additional. $.00 18 should have costed you more arond 1860, but you won't mind a good price I guess ; )

hi gaurav, I have a question for you. My stock settings are 100/90 18. As mentioned above I can go 4 a sirac. However, you mentioned that the new tyre will be wider and taller. I understand that the section width will increase to 120 from 100. However, the section height will decrease from 90 to 80. Correct me if i am wrong. I dont want height of the bike increased as it is already very high. Also, somewhere in the internet i find people using michelin tyres as tubeless although they are tube type. What is your take on this? Finally other than sirac is there any other dual purpose tyre from michelin in india? Raj

Guys,

Im getting confused here. i inquired in store in chennai. He suggested to go for sirac and said its 2500 and need one hour to fix in my bike.

So sirac is not tubeless ? he mentioned it as tubeless. So what else is tubeless then ?

sirac is NOT tubeless. Some dealers do tend to sell them as tubeless. I have also heard users using it as tubeless without any issue. However this is not recommended by the company. Gaurav will be able to explain better. I have been quoted price of rs 2700 for 120/80. I guess the price is good keeping in mind that its a michelin. I was also told that an indian version of sirac will be launched in april and will priced aggressively. Raj.

Oh... Even he said apart from sirac no much tubeless options. So no tubeless tires (100%) for my(our) bike ?

well I am not sure if tubeless is not an option for gs. As I was not looking for tubeless I never enquired about it. However, I am sure other members of the forum will be able to comment on this. Raj.

I recently changed my apache 180's tires to MRF Zapper FS and S for the front and rear. Now the problem i am facing is that my bike has lost quite a lot of straight line stability which is easily understandable while riding at low speeds in narrow lanes. I know that is because i have downshifted from 110/80 stock tyre to 100/80 Zapper S. Although the grip of this tyre is awesome, im feeling really uncomfortable at the loss of the stability and hence would like to change back to the stock size.
Now the question is that i dont really have many options if i want to stick to 110. I could only find IRC here in my city at one shop and the shopkeeper is asking 2800 for that. Thats way to costly for me especially considering the fact that i recently spent money on new tyres. The other option i have is to change back to the stock TVS tyre but i will have to buy a new one again coz i sold off the old one . And the main problem with TVS tyres are their horrible grip on wet.
The other option i have is to change to 120/80. I have a few options like Zapper C, Dunlop Magic, Ceat. But im skeptical again at the idea of not sticking to the stock size because the chassis is not built for this size.

So what would you guys suggest me other than sticking to the Zapper S? What will be the pros and cons of putting a 120 section and if it is advisable then which one to go for?

Thanks for the information. I will contact Rajesh.

I had a vist to a tire shop. He quoted following rates for M45 series.

M45 2.75 18" Rs 1400/-
M45 3.00 18" Rs 1600/-
M45 3.25 18" Rs 1800/-
M45 4.00 18" Rs 2000/-

And Sirac 18" as Rs 2400/-

Anna, pirces seem to be high. Which shop did you visit? Tadbund Showroom prices are lesser.

I got my 17" 120/90 Sirac for 2550 from tadbund dealer.. The MRP is around 2700 now..