good day,
I have a 06 street bob with 2 in 1 rinehearts, I'm getting a lot of backfireing when I ride, I was curious as to what could cause the backfireing.
thanks

 

If you mean decel pop and not backfiring, that is normal. You just can't hear it with the stock pipes. A good tuner can eliminate a lot of that.
Do you have a tuner or high flow intake?
Check for exhaust and intake leaks.