Most of the time the front and right sides of the rim contain small round holes, it is usually common with the new tires when you buy from the company and it is a fault in the manufacturing, they will drill small spoke-sized holes on the sides of the rims and they forgot to fill them, it is usually a common issue with all universal rims, you can replacer the same tire if it’s in warranty, these are tiny sized holes and these are recovered by wrapping the rim tape with thick lube or grease so that the hole should completely be filled.
When rims are built then the whole wheel needs spoke re-dishing and spoke nipples re-dishing, during this period the tires are also installed and the manufacturers use gas or other materials within the rim, so they will drill small tiny holes on the sidewalls of the rim, the size of these holes is even small than that of spoke nipple holes, just a single hole is drilled for leaking gas and for other purposes on any side of the rim.
Almost every rim has these small holes including road bikes, mountain bikes, and gravel bikes. even the rim of racer bikes also have these small holes, it is not a big problem, the factory causes these holes, its the part of the manufacturing of new wheels and rim for every brand.
When rims are wrapped with the rim tape, if your rim contains such types of tiny holes then you have to wrap large width rim tape which should reach on the sides of the rims to cover these holes, sometimes these holes require double wrapping of tape and it is usual even you can wrap three layers of tape if the air is still leaking from these holes.
These small rim holes are usually present on the sides of the rim where the rim brakes have direct contact with the wheel, it is common on road bikes with rim brakes mostly on aluminum wheels. each and every bike rim contains two rim holes one on the left side of the rim and the other on the right side of the rim, both are parallel to each other.
How rim holes are helpful for a biker?
These holes do not have any disadvantage for the rim, because rims have weight and when the wheel rotates the air particles would penetrate into the rim deeply which usually makes the rim heavier on the trails and does not help the wheel to rotate more rapidly for gaining speed, it is the reason these holes have been made on the rim sides to remove all the air and gas out of the rim to increase the bike speed.
The atmosphere contains moisture, especially on the rough terrains across the country, which continuously penetrates on a high level within the rim, the amount of moisture increases when you go regularly on the trails, also the weather condition plays a major role in the level of moisture, the inner side of the rim starts taking rust rapidly and if these holes would never be made, the expire date of wheels starts decreasing and the rim will not be able to perform after a few months and the poison air which is present within the rim cause damage to the internal surface of the rim and the material of the rim.
These tiny holes are also present within the frames of bikes, almost every frame contains such type of tiny holes, when rims are manufactured newly in the factory these are adjusted and fixed on every point from tube to tube by welding machines and other methods. the main purpose of frame holes and rim holes is that when water enters the rim this water would easily evaporate into the atmosphere and does not sustain within the rim.
These small holes on side of the rim are actually a sign and it indicates the condition of the rim, when the rim becomes old and used for a long period of rides by surviving many thousand mileages then after that, these tiny holes will become invisible from the rim, it works as an indicator that your wheel needs to be replaced and it is expired. because by continuous rubbing of the rim brakes on the sides of the rim, the material of the rim becomes thin and finally the tiny holes become invisible.
If these holes were never made then the air remains within the rim and start creating higher pressure which is always risky and there are chances of rim explosion on the trails, to prevent these kinds of issues these small tiny holes were made.
How And Which Air Causes Leaking Through Rim Holes?
When your rim tape is loose at some point within the rim, it causes air leakage all of this leaks air is firstly stored in small storage space within the rim and does not leak out immediately, and after that, it starts leaking continuously through the rim hole. That’s the reason when the rim tape is not wrapped correctly, it causes air leakage through these rim holes. a single hole is common on the side of the rim, if there is more than a single hole then it is another issue you should change the tire.
Sometimes it happens mostly people drill a large hole within the rim tape where it is going to wrap around the stem, valve place internally, which causes air leakage, so all the sides of the stem, valve air causes leakage and of this air goes outward in the environment through the rim holes.
Change the rim taper with a better reachable width till the sides of the rim to cover the holes thoroughly and prevent the leakage of air, all the issues are of rim tape, rim tapes are specific for specific brands of the rim which would not work on the other brands.
these holes would also depend on the internal air pressure of the tire and these are made for specific tire pressures, if you increase the internal pressure then it starts leaking air through these holes slowly.
The sidewalls of the rim and tire contain the recommended air pressure for the given tire and rim.
Do Rim Holes Affect The Durability Of Rim?
Small tiny rim holes do not affect the durability of the rim, moreover, it helps in judging and measuring the lifespan of the rim.
How do Rim Holes help in Escaping dry Sealant?
When the sealant is inserted into the tire, then after 2 to 3 months small particles start evaporating within the tire, and the tire is closed all around even the spokes holes are tight, so these small holes help to escape the sealant from the tire which helps in minimizing the internal residue of the rim.
If these small holes were not made on side of the rim then the internal sealant and gas air would surely destroy the internal surface of the rim by causing moisture and corrosion within the rim.