Bicycle Mechanics - rear hub identification (bearings)

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wocketpatch
01-27-09, 04:33 PM
Hello,

I'm looking to replace the bearings on a friend's bike. I've never done it before but of course that's why I volunteered to do it. I've read online in several places that "most" rear hubs have 9 1/4" bearings on each side so I was just about to order some 1/4" bearings when I thought "maybe I should have a look." Well, inside I found only 7 bearings on both sides which makes me wonder if they might also be a different size.

The only identifying mark I can find on the hub says:

K T
ROCTAIWAN

It's from a 70's World Traveler (schwinn import) and I don't know if the wheels are original but they are straight and look pretty nice on the bike so I feel like it's worthwhile.

Thanks!


Panthers007
01-27-09, 04:38 PM
Most likely it was short by a few. This happens. Some manufacturers/stores are cheap. You need as many 1/4" BB's as will fit on each side into the races. Put in some grease, place the BB's in, add more grease - and begin adjusting.

frankenmike
01-27-09, 07:03 PM
The shipping on the bearings probably costs more than the product. Bring the bearings with you to your lbs and you'll be guaranteed to get the right size, for cheaper than ordering online.


DOS
01-27-09, 07:41 PM
Get one of these a measure the bearings but probably they are 1/4".
http://www.coloradocyclist.com/product/item/PARSSSBC1

Panthers007
01-27-09, 08:43 PM
With the shipping on the Park Tool ruler, or whatever, you could buy a digital caliper, batteries included. Costs about $15.00.

For instance:

Amazon.com: Stainless Steel 6" Digital Caliper with Extra-Large LCD Screen - Instant SAE-Metric Conversion: Home Improvement

You can find them cheaper, too. Just hunt on Amazon. Same one - re-branded - that Park Tool sells for about $40.

Here it is for $14.94 including the shipping:

Amazon.com: 6 Inch Large Display Digital Caliper With Data Interface and Molded Case: Home Improvement

DOS
01-27-09, 08:51 PM
[QUOTE=Panthers007;8260088]With the shipping on the Park Tool ruler, or whatever, you could buy a digital caliper, batteries included. Costs about $15.00.

Yeah, but can it measure a spoke?

Seriously, my tool box does not have digital caliper, and I didn't know they were so cheap. Thanks for the tip.

Panthers007
01-27-09, 08:59 PM
I checked the one I got for $14.94. Same outfit as the ad. Arrived real fast - sometimes a bad sign. So I checked with my $$$ dial-caliper for accuracy. It was spot-on. Park wants $50. I found Park for as low as $40. Which way ya gonna go, cowboy?:lol:

jccaclimber
01-28-09, 05:41 AM
Harbor Freight also has cheap calipers which I have been pleased with. They generally agree with the $$$ calipers I have compared them to. Note the generally, they do have a posted accuracy and while they are usually better than that should probably not be trusted to say, 0.001" at 6 inches out. I do not know what the posted accuracy is on the nicer machine shop ones I have used is.

Panthers007
01-28-09, 11:50 AM
The accuracy for these DC's are stated as .02mm, readable to .01mm. Comes in a plastic, cut-out foam case with an extra battery (2 batteries are enclosed).