rubber bit for D ring bitted horse

Question
sorry Lyn. a small mistake in the previous question. its rubber bit guards not rubber bit. let me repeat the question with correct wording.

my friend bought a 6 year old dark bay gelding from our local racetrack and kept in his farm. i want to buy a new bit for the horse. since it had a stainless steel D ring bit during his racing career, even i want to use that product along with rubber bit guards even though it doesn't has any cut injuries on its lip corners. may i know your opinion? shall i use rubber bit guards for D ring bit horse?

Answer
Rohit,

I don't know why you want to add something that the horse hasn't needed in the past and shows no signs of rubbing on the corners of his mouth.  Stick with what he's used to and comfortable in.  If you do insist on using rubber guards then remember they decrease the width of the bit by about 1.5 cm due to their thickness so the bit needs to be wider than has been used in the past.  Personally I would stick with what the horse is used to.