Dia Compe Headset woes

[RobMC]

Ive stripped my recently purchased 95 Stumpjumper down to give it a good clean and regrease. I stripped the Dia Compe Aheadset and cleaned all the components, binning the existing bearing races (first mistake :roll: )

Ive now put it all back together and it sounds terrible, almost as if the bearings are lightly 'grinding' whenever I turn the fork! The bearings Ive used are 5/32 which I believe are the right size and Ive tried loose bearings and in cages. Ive tried the bearing cage both ways up but this doesnt seem to make much difference although does feel better than with the loose bearings. Sequence followed -

Grease fork crown race
Grease lower cup
Fit small plastic crown race seal
Fit bearing (open side towards the floor/cone shape of crown race as per Park Tool guide?)
Turn over and grease upper cup
Fit bearing (open side up?)
Fit Dia Compe Aheadset cover (upper race)
Fit centering cone in to race
Fit cable hanger
Fit spacer
Fit stem
Fit and nip up top cap
Tighten stem and cable hanger

Can anyone shed any light on what might be wrong? When I fitted the loose bearings I removed 2 to allow a bit of space but this sounded worse than with the bearings with the cage. I dont remember it feeling/ sounding like this before I stripped it!

Picture post stripdown. Thanks in advance...

 

[TheAntsPants]

Bearings come in different grades (out of roundness). It's unlikely to cause "grinding", but could you have bought very low grade bearings or low grade race? The cheaper they are, the harder it is to tension it to prevent grinding. Also, I assume you haven't over tightened the top cap?

 

[RobMC]

Bearings come in different grades (out of roundness). It's unlikely to cause "grinding", but could you have bought very low grade bearings or low grade race? The cheaper they are, the harder it is to tension it to prevent grinding. Also, I assume you haven't over tightened the top cap?

I havent over tightened it, thats the first thing I checked, however you might be right about the bearings. I just bought the cheapest packs from SJS so there is every chance they arent of the highest quality. Or the headset is worn out, of course.

 

[mdvineng]

Have you kept using the old balls? You can keep the old cage and pop out the old balls, then fit grade 10 balls.

 

[RobMC]

Have you kept using the old balls? You can keep the old cage and pop out the old balls, then fit grade 10 balls.

No, binned the old bearings and cages and have replaced with new bearings without cages. Have added the 2 additional bearings I removed to fill the cup and it has improved so suspect worn headset is probably part of it.

 

[mdvineng]

More likely low grade balls. The ones sold in bike shops etc are 1000<2000, grade 10 is what you need, same for axles etc. Check the spec for bearing grades online https://bike.bikegremlin.com/2255/stand ... all-sizes/

 

[RobMC]

Re:

Thanks - will take a look!

 

[legrandefromage]

Have you put the races in correctly? some headsets run two different types and it is easy to muddle them up when putting back together.

To get it right, put the top bearing in first and just run the top part of the headset as if you had some forks in, if it turns smoothly you have the right bearing race and bearings and its the right way up.

Same with the forks, just offer up the fork with your chosen bearing , dont attach the top half and see if it turns smoothly

Then put it all together, touque it up and see what happens

 

[dyna-ti]

99% of ball bearings a cyclist is likely to buy are accurately ground. I dont believe for a second its that precise.

 

[mk one]

I always coat the bearing races in grease too, rolling the bearing around so they are completely covered.