Tis the Season, for wildfires.
Summer is the season for wild lands fires.
If you are riding on Forest Service, BLM or State managed lands you are required to have an approved spark arrestor on your bike, if riding on private land, that has the potential to burn a spark arrester is also good safety addition to your bike.
This year, in the West, we had a very wet spring and the grass and other vegetation is tall and becoming very dry, if you are going on a trail ride or to a competition anywhere a fire could start a spark arrester should be on your bike. One small spark in a dry field of grass could start a major fire that you don't want to be responsible for.
There are several new styles of arrestors available that have a larger screen area to better allow your bikes' exhaust to past through. Some of the older style arrestors had a small screen diameter, they may fit and look nice on your bike, but they can really restrict the flow of exhaust, especially as they become more restricted with oil residue on the screen from the exhaust.
I have ridden with riders that have melted the small spark arrestor on the exhaust tip on long uphill trails. I have also ridden with and serviced Trials bikes that have had spark arrestors that were so plugged up you could not see light from a flashlight looking through the screen of the arrester or the rider thought he needed a top end due to lack of power when all that was needed was to remove and/or clean the attached spark arrestor.
Be fire safe and use a spark arrestor when the chance of fire is high.
Remove and clean your spark arrestor after each days ride.
Contact Thumbs Up Trials with any questions you have concerning spark arrestors and/or if you would like to purchase a spark arrestor for your Trials machine.