I appear to have run over some glass on the weekend and it has cut the tread of my tubeless tyre. The tyre isn’t loosing any pressure. Just wondering if it needs to be replaced or will be fine to keep riding on? The cut tread lifts back.
If you can lift a flap of the tread back, it probably should be replaced. It appears that the flap will excessively flex/squirm when the tire is loaded, especially when cornering, exposing the tire cords to further damage and running the risk of a tire failure and potential crash.
The decision to replace a damaged tubeless tire is a semi-subjective matter, with fair range of grey-area where the decision can vary by individual.
Things to take into account when making that decision are:
- Front or rear tire. A front tire is more critical in that a rapid depressurization is more likely to cause a crash if the front tire goes down.
- Age/wear on the tire. If the tire is old or towards the end of its useful life, it may be prudent to just replace it. If it is still very fresh, and the damage is not too severe or a safety issue, it may be decided to repair it and roll on.
- The actual damage incurred. This is pretty obvious and probably the biggest driver in your decision. In your case, a flap of tread that will flex/squirm while cornering, exposing the tire cords to damage is a deal breaker. That said, it is amazing what a little superglue can do, but it really depends on the tear. Every cut/tear is unique, so it really depends. If it looks possible, it is a pretty inexpensive and quick to try, but be very discerning as to the limits of trying this repair.
- Consider what your near-term needs are. If you are just doing a little local riding, maybe a short commute, maybe a not too damaged tire can suffice. However, if you are planning on and investing time to a serious ride, race, tour, etc., it is not worth risking all the training, preparation, finances, and time invested to risk a failure that could have been prevented.
Regardless, your safety is key in your decision. Getting injured trying to save some money is just not smart.
A decision-making example that I had to make a couple of weeks ago: I had failures in both my tires on the same ride. On the front I had some blisters forming due to a bad batch of tires. Being on the front and with 2k miles already on the tire, I chose to replace it. On the rear, I had a rare double puncture. Both required a small plug to seal the leaks quickly. Being a rear tire, and only 500 miles on the tire, I have chosen to leave the tire plugged and have since ridden an additional 200 miles on it without any issues at all (I have had previous experience with this approach which is a great help knowing what to expect).