The gripster UP prevents punctures, or more specifically the tearing of the inner tube valve, which happens when your tyre rotates on the rim.

The wheel turns:

If you've ever seen a tyre rotating on its rim, you know the damage it can cause to the inner tube valve:
it gets cut and you end up with a flat.
To avoid this phenomenon, you can install a gripster UP in your rim,
which will hold your inner tube against the tyre preventing the rim from turning without the tyre.

What size for my motorbike?

There are 3 sizes of gripster to suit both front and rear wheels, covering all engine capacities.

1.60’ For front wheels of any engine capacity, and rear wheels for 65cc motorbikes
1.85’ For rear wheels of 125 2T/4T and 250cc 4T
2.15’ For rear wheels of 250 2T and over 250cc

If you have an 85cc, you will need to choose between the 1.60’ and the 1.85’ depending on the size of your wheels.