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Questions and answers about sports

Why do front and rear wheel hubs have different sized ball bearings?

5 min read

Asked by: Tonya Young

Are front and rear wheel bearings different?

Conventional front wheel cup and cone bearings have 10x 3/16″ ball bearings per side, whereas the rear wheel has 9x 1/4″ ball bearings per side. Manufacturers have been on a continuous quest over time, to simplify bikes in terms of ease of assembly, and of inventory.

Are front and rear bike hubs the same?

The front hub is simply designed to enable the wheel to spin, while the rear hub is a little more complex as it also forms part of the bike’s transmission – the cassette or sprocket which drives the rear wheel is attached to the rear hub, which on most bikes also features mechanism to allow you to coast or freewheel (

Are all bike hub bearings the same size?

Bearing sizing

There are a few common sizes. Headsets and pedals tend to be 5/32”. Front hubs tend to be 3/16”. Rear hubs and bottom brackets tend to be 1/4”.

Are all car wheel hubs the same?

Therefore, in order to fit the new wheels correctly, it is important that the car’s wheel hub size perfectly matches the wheel’s centre bore. Especially in the aftermarket, however, car wheels come with different hub and wheel center bore sizes.

Can I just replace the wheel bearing and not the Hub?

Your mechanic is correct in that the only repair for the bearing is to replace the hub. It is a sealed unit and cannot be disassembled without destroying it.

Are wheel hubs universal?

Wheel hub replacement assemblies are available as a direct fit or as universal items. As the name suggests, universal wheel hubs can fit a wide range of vehicle models, while direct fits are specifically made for one vehicle.

Are all hubs the same size?

Hubs have to be matched to the front or rear of your bike; each will be a different size.

How do I know my hub size?

Hub Flange Diameter – The distance across the hub’s flange from hole to hole.

Here’s how to measure these distances:

  1. Figure out the distance between the lock nuts (where the hub sits in the dropouts) – 100 or 110 mm is typical for the front. …
  2. Take that number and divide by 2.
  3. Then measure from the flange to the lock nut.

Do better hubs make your bike faster?

Hubs that are “louder” usually have more engagement points. This means your drivetrain picks up faster, so less energy is lost. Hubs that have sealed cartridge bearings or needle bearings usually never need to be replaced, they’re far stronger and stay cleaner.

How do I know what size bearings I need for my bike?

Quote from video: So widely among the different models. But if you use your head you should be able to do a little arithmetic to figure it out for example you'll start by measuring the entire depth of the hub bore.

What size bearings are in bicycle hub?

4.762 mm (3/16″) – front wheel hubs (2 times 10 balls – i.e. 10 balls at each side most often). 6.35 mm (1/4″) – rear wheel hubs (usually 2 times 9 balls) and cup and cone bottom brackets (2 times 11). 5.556 mm (7/32″) Campagnolo Record front hubs and some exotic hubs of other manufacturers (2 times 9 balls).

What size bearings do Shimano hubs use?

Shimano’s 3/16″ steel balls are standard spare parts for the cone bearings in Shimano rear hubs, older front hubs and dynamo hubs. They are used on the right side of the rear wheel (freehub side) and on both sides of the front wheel.

What happens if you over tighten a wheel bearing?

Over-tightening can damage the lug nuts, wheels and hubs – and worse, result in a wheel-off situation.

Can you over press a wheel bearing?

Some bearings have an internal tone ring for a wheel speed sensor. Press on the outer part of the new bearing, not on the inner race as it will separate and damage. If the new wheel bearing is not being pressed in straight, do not over-press the bearing. Over-pressing will damage the new bearing.

Can you put a wheel bearing in wrong?

Q: Is it safe to drive with a bad wheel bearing? A: No. It can, in fact, be very dangerous to drive if one of your bearings is worn out, especially since it may cause the wheel to stop while driving. Additionally, a damaged wheel bearing puts a lot of stress on the hub, the CV joint, and the transmission itself.

Are all wheel bearings the same?

There are two types of bearings: hub and wheel. Both employ the same physical characteristics of a bearing in that they house bearing spheres that are lubricated for spinning to allow the wheel to rotate. A major difference between the two is how they are assembled.

Are wheel bearings interchangeable?

Front and rear wheel bearings are different for many cars, meaning that your car’s bearings aren’t interchangeable front to rear. Sealed bearings should be brought in for inspection every 30,000 miles or sooner if you hear any unusual noises.

Are left and right wheel bearings the same?

Yes they are the same part on both sides, and replaced in the exact same manner.

Do FWD cars have rear wheel bearings?

Usually, only the non-drive wheels (that is, the front wheels on rear-wheel drive vehicles and the rear wheels on front-wheel drive vehicles) have repackable wheel bearings. Vehicles with front-wheel drive have sealed front bearings, but some have packable rear ones.

What causes rear wheel bearings to go bad?

Impact damage or poor road quality – all impacts from driving through a pothole, driving over speed bumps or hitting the curbstone can damage a wheel bearing and reduce its lifespan.

How do I know if my rear wheel bearings need replacing?

The most common and most easily identifiable symptom of a bad wheel bearing is an audible one. If you notice a grinding or grating noise coming from your wheel or tire, take note that this is very likely caused by a bad wheel bearing—especially if the noise gets louder as the vehicle accelerates.