Bearing balls: what is the best?

[Elev12k]

I need bearing balls for sevicing hubs, headsets, bottom brackets and so on. I need balls 1/4, 5/32 and 3/16. I still have sufficient supply 7/32 (for Nuovo Record front hub).

I think I will buy them online in UK. Ball bearing specialist in Holland have balls in mm's and the bikeshop is no longer focused on this kind of servicing. They prefer to sell new parts and bikes instead.

Online shop: http://simplybearings.co.uk/shop/index.php?cPath=23

I see 3 variations: chrome, stainless 316 and stainless 420. The site gives a brief explanation on them, but I am wondering on what is best suited for use with bicyles. Does anyone has an opinion on this?

Brief explanation by the site:

A Simple Explanation of Stainless.

Stainless steel balls will resist corrosion but are not as hard as the chrome steel balls.
316 Stainless is suitable for food and marine applications and is not magnetic (can be magnetised eventually)
420 is a cutlery grade, is harder and polishes up well, 440 is magnetic and is one of the hardest stainless grades.

 

[keithglos]

Chrome steel would be the cycle grade.

 

[Elev12k]

Hello Keithglos,

Thank you for your contibution.

I am puzzled a little: my old packagings inform me that some balls are chrome, while other are stainless (dura-ace). Not specced is what stainless variation.

I tend to the following: purchase both chrome and stainless 420. Use the former for for less expensive parts that are not serviced often and the later for valuable parts that are treated with more care. The stainless ball is softer, so the ball wears to accomodate the races and not the other way round is my reasoning. Unless people advise me another approach is more wise

All balls will be fitted loose to move freely. Fill cup, take one out. The grease I use is Motorex or Cyclon MTB. I think the former has better dynamic behavior, while the later is even harder to wash away.

 

[AR-CoolC]

I've been dealing with a chap called John HERE about some plastic bearings we need for a tool at work. He is a very knowledgable chap.

To boot they were cheaper than any other suppliers.

Bearing Warehouse Ltd
Unit 14 Hambridge Trading Estate
Willowbrook Road
Worthing
West Sussex
BN14 8NA

Tel: +44 1903 212223
Fax: +44 1903 232888
Email: [email protected]

 

[bm0p700f]

Grade 100 is surely to soft for high end hubs. Grade 25 would be better.

The lower the grade the lower the variation between balls. Grade 100 have spherity of 0.001 in, grade 25 a spherical to 0.000025 in. Not all balls are created equal! Also surface roughness of grade 100 is 5 microns but grade 25 is 25 microns.

The higher the surface roughness the higher the friction and the higher the wear rate on the balls and bearings surfaces.

Also softer "rough" balls with erode over time creating small metal fragments. Lower grade balls are harder but are only surface hardened so they should retain "elasticitity" under load so prevent damage to bearing surfaces.

In short given balls are cheap why not buy better ones. Grade 100 is standard bearings supplied by bearing shops. Phone up and you will be able to order what ever grade you choose.

However those bearings from simplybearings are better than the ungraded carded bearing from some bike shops. Those are grade 1000 argh.

 

[Elev12k]

Thank you. Interesting.

I think I once have been told that grade 25 is what Dura Ace and (top end?) Campagnolo use. You're right that I should go with that grade for the finest bits.

 

[bm0p700f]

Camp may use a higher grade than 25. They have there own bearing selection proceedure they keep secret. I would love to work for the and learn just some of there secrets.

 

[1duck]

i think its good that campagnolo have had the intelligence to hold onto their intellectual property through strict secrecy.

Much better than the other italian brands like pinarello who are now facing chinese companies knocking out fakes of their bikes and components (you see them listed on ebay as OEM at a fraction of the price even though they will have naff all to do with the oem)