The TVS Star city is a commuter level bike sold in INDIA. It has a very basic suspension set-up.
You can adjust the pre-load using a wrench-
- There will be a small lever on top of the suspension which is noticeable if you have the older version. However if you have the newer version, like shown in the above picture, then you need to open the rear cowl
That said on finding the lever using the wrench twist it to the right which will soften the suspension and improve the ride.
If its already all the way to the right, then take it to the service station, they should remove the outer coil and replace it with a new one.
Improving the ride quality:
You can improve the ride quality of the bike by upgrading to a better suspension, though you will have a hard time finding out which suspension suits you the most.
There are three options I know you could go for. The main issue being that these might increase or decrese the ride height. I am listing out the closest available suspension options -
Go with the Bajaj SNS suspension, widely available, the one with an
orange spring inside the main coil (for secondary damping) commonly
used in the discover range.
Go with the Baja pulsar 135 LS suspension which is gas charged and
will provide higher deal of comfort.
A much better option and cheap on your purse/wallet would be to increase
the padding of the seat. This will make the ride a bit unstable at like
100kmph but I don't think you will ride anywhere near that
speed(considering the bike has around 9hp power). Your back will
thank you! We did the exact same thing on a Yamaha Libero and it
worked perfectly.
Note: Please do not compare the Honda Dio suspension with the star city suspension. The Honda (mostly every scooter) has a tiny mono shock which is far softer and feels comfortable than the ones found in the bikes but it cannot handle heavy weights.