Stiffness in New Bearings

[Lewis Moon]

I replaced the bearings in my DT 240 rear hub and the new bearings seem unusually stiff. No roughness, just drag. This is also a problem on a set of Chorus cranks I got a while back. I figured they would "break in" but... It's been a while and they still drag. Is something wrong or should I just wait?

[CiclistiCliff]

Remove the seals, they’ll spin faster for your next Gran Fondo

[FlashUNC]

Campy stuff doesn't drag outta the box. Something's wrong.

[lhuerta]

...what tool are u using to install the bearing cartridges, both on hubs and cranks? Tool should press both the inner and outer diameter race evenly throughout the pressing process...when pressure on cartridge is uneven the cartridge can deform and yield uneven races, which may result in the roughness u r reporting.

[Lewis Moon]

...what tool are u using to install the bearing cartridges, both on hubs and cranks? Tool should press both the inner and outer diameter race evenly throughout the pressing process...when pressure on cartridge is uneven the cartridge can deform and yield uneven races, which may result in the roughness u r reporting.

For the DT hubs I'm using Wheels MFG tool. Everything is stock...could there be a slight diff in the width of the axle and the hubshell causing drag?

I don't know what is happening with the cranks. There is no side load when it's installed.

[Dave]

The tool to press bearings onto a shaft should only contact the inner race.

[Buzz Killington]

Some bearings come with contact seals that take some time to “free” up. Some come with non-contact seals that will have much less initial friction. Make sure the bearings were installed correctly.

[Mikej]

Give it some time, the grease will break down and the seals will soak up some of that lube and they’ll spin fine.

[BdaGhisallo]

The tool to press bearings onto a shaft should only contact the inner race.

Wouldn't that seriously boost the chances of mis-aligning the bearing races and damage it from not putting even pressure on the bearing?

[oldpotatoe]

I replaced the bearings in my DT 240 rear hub and the new bearings seem unusually stiff. No roughness, just drag. This is also a problem on a set of Chorus cranks I got a while back. I figured they would "break in" but... It's been a while and they still drag. Is something wrong or should I just wait?

2 things come to mind..making sure they were the [proper size(unlikely it's this) and the bearings aren't seated completely..Did you use a proper bearing press?
Chorus crank...making sure they are seated all the way, seals not buggered up, they are indeed 6mm width, not 7(saw that once)...

[Gummee]

The tool to press bearings onto a shaft should only contact the inner race.

You sure you don't mean the outer race?

M

[bigbill]

Campy stuff doesn't drag outta the box. Something's wrong.

Yup, when I got my Chorus group about two years ago the crankset would only spin less than one turn when pushed. I thought it was the seals and it would get better but nope. I ended up replacing the bearings about a month in. It wasn't a big deal to do, I keep a set along with the Park tools in my box, but didn't expect it from a new crankset.

[Rusty Luggs]

You sure you don't mean the outer race?

M

You press on the race that has the interference fit so that force is not transmitted through the balls/rollers. If you apply force such that it passes through the rolling elements of a bearing, you will damage the bearing races.

if the press fit is between a shaft and the inner race of the bearing, you press on the bearing through the inner race, if the press fit is between the outer race and a housing, you press the bearing through the outer race.

[FriarQuade]

OE bearings or aftermarket?

The press fit situation in a bicycle hub is very dynamic and while bearing manufactures typically hold pretty tight tolerances it only takes a few thousandths of a milimetter to go from TT star to pack fodder.

[ultraman6970]

Lewis, publications and web sites from bike manufacturers say that stiffer is better... so there you have it... stiff wheel bearings.. so you might be compliant :D

[Mikej]

You press on the race that has the interference fit so that force is not transmitted through the balls/rollers. If you apply force such that it passes through the rolling elements of a bearing, you will damage the bearing races.

if the press fit is between a shaft and the inner race of the bearing, you press on the bearing through the inner race, if the press fit is between the outer race and a housing, you press the bearing through the outer race.

Right, but cartridge bearings in bicycle hubs are pretty much always secured by the outside race and hub shell, so when you remove the axle it’s either threaded cones for loose balls or the axle slides out. So, outer race to install.