Actually thinking of switching CDI with Xtreme's CDI. WIll there be any change?
I feel that hunks top end is restricted with existing CDI. you see stock hunk achieves only 11kmph within 8-9k rpm, 10kmph only with 15t sprocket within 8-9k rpm.

My review on 15T sprocket on Hero Hunk 2014:
Bike loses initial torque, feels like riding an Unicorn below 6k RPM. But engine feels very relaxed and less stressed.
Mileage increases by 2-3kmpl.
The biggest improvement is the speed per rpm:
4k rpm: mod: 51kmph stock: 49kmph
5k rpm: mod: 65kmph stock: 60kmph
6k rpm: mod: 78kmph stock: 74kmph
7k rpm: mod: 93kmph stock: 85kmph
8k rpm: mod: 106kmph stock: 100kmph
9k rpm: mod: 116kmph stock: 111kmph
Anyway my stock hunk revs till 9400rpm but with 15t sprocket it revs till 9K rpm.

So 15T sprocket is great for touring.

Best thing: Acceleration after 6k rpm is ballistic and easily out accelerates CBZ xtreme 2009 version. I tested it several times with my friend in empty highway with a 25000kms running CBZ Xtreme (analogue meter). Cbz xtreme is ahead uptill 80kmph but after that hunk accelerates till 114kmph very very fast and overtakes cbzX very easily. That cbzX was at around 9k rpm speedo showing 122kmph (speedo error ofcourse). But i must say the acceleration with 15t sprocket after 6k rpm is lot better (even with pillion) compared to stock hunk.
From me strongly recommended for Hunk users.

Actually thinking of switching CDI with Xtreme's CDI. WIll there be any change?
I feel that hunks top end is restricted with existing CDI. you see stock hunk achieves only 11kmph within 8-9k rpm, 10kmph only with 15t sprocket within 8-9k rpm.

My review on 15T sprocket on Hero Hunk 2014:
Bike loses initial torque, feels like riding an Unicorn below 6k RPM. But engine feels very relaxed and less stressed.
Mileage increases by 2-3kmpl.
The biggest improvement is the speed per rpm:
3k rpm :
4k rpm: mod: 51kmph stock: 49kmph
5k rpm: mod: 65kmph stock: 60kmph
6k rpm: mod: 78kmph stock: 74kmph
7k rpm: mod: 93kmph stock: 85kmph
8k rpm: mod: 106kmph stock: 100kmph
9k rpm: mod: 116kmph stock: 111kmph
Anyway my stock hunk revs till 9400rpm but with 15t sprocket it revs till 9K rpm.


So 15T sprocket is great for touring.

Best thing: Acceleration after 6k rpm is ballistic and easily out accelerates CBZ xtreme 2009 version. I tested it several times with my friend in empty highway with a 25000kms running CBZ Xtreme (analogue meter). Cbz xtreme is ahead uptill 80kmph but after that hunk accelerates till 114kmph very very fast and overtakes cbzX very easily. That cbzX was at around 9k rpm speedo showing 122kmph (speedo error ofcourse). But i must say the acceleration with 15t sprocket after 6k rpm is lot better (even with pillion) compared to stock hunk.
From me strongly recommended for Hunk users.

Any clue guys?

i have been using 15T for a year and completely satisfied with it. like u said once the rpm builds up the acceleration is very fast. only thing is at low revs sometime we may have to shift down the gear. its ironic that in my office parking lot when i used to climb up the circular ramp in 2nd gear with 14t it used to strggle a little bit but with 15t it used to climb easily. so unless we drive at low revs for a particular gear, 15t will have a better acceleration.

i used to have mileage boost of 3kmpl in city traffic and around 5-6kmpl in highways. if i maintain 50kmph in free road then it will give as high as 66kmpl.

Can you please state the speed within 8-9k rpm?
I get 106kmph @8k rpm but only 116kmph@9k rpm. It is supposed to be more than 120+. either the cdi or the 5th gear ratio is too small i think.

Till 8k what your are getting is correct, but at 9k rpm you should get atleast 118kmph.
you can check gearing commander website for accurate values. i have cross verified and my values are exactly matching with the gearing commander.
but xtreme can go beyond 120kimph due to its longer gearing, though i think with 15t it may struggle to reach the red line.

According to gearing commander it is supposed to do 120kmph but i am getting 116kmph only. Thats why trying to find out the reason.

top speed can be affect by following reasons:
1. Tyre pressue
2. worn out clutch plate
3. wind resistance hence you need to crouch.
4. flat road not inclined ones.

Theses are the things which i could think of.

The riding posture of Xtreme is different from that of D125. You may need to get used to the rear-set foot pegs and overall riding position, I believe.
Also, check if the handle position is changed from the stock position. Compare with another XTreme on this.
If shock-absorbers are weak, get them replaced. I think your bike has covered 50k kms; it is good time to replace the shocks.
Also, it is better if you can have the front fork oil changed, if it is not done in the past, say 20k kms.

Thanks for the reply. I have got the fork oil changed and also got the bike rear frame bushes fixed with new ones. Also got the handle and everything else checked but still experiencing the severe upper back pain. I think I will have to get the shocks changed - asked a hero retailer outside - he's quoting 2800/- for a pair much less than 4000/- quoted by showroom guys.

Thanks for the reply. I have got the fork oil changed and also got the bike rear frame bushes fixed with new ones. Also got the handle and everything else checked but still experiencing the severe upper back pain. I think I will have to get the shocks changed - asked a hero retailer outside - he's quoting 2800/- for a pair much less than 4000/- quoted by showroom guys.

Checked with Authorized Hero spares dealer (main dealer in Chennai) .

Bro can you please provide me the address.?

It is Southern motors, in GP road.
Near to Express Avenue Mall.
If you ask someone in GP road, they will guide you. It is in a small side road connecting GP road and Anna Salai.
It is a small shop too. There is a small board telling shop name and Hero logo.