rogun

Hi guys,

My first post here and I'm new to servicing bicycles; just so you have a little background on me. This seems like a great site and I've already learned a lot from just reading, but I do have a couple of, hopefully, simple questions that I couldn't find an answer to.

I was given a 1987 Schwinn World Sport that works, but it's been sitting in a garage for awhile and probably needs a lot of servicing. I hope to use this bike for commuting around town, as well as to learn how to work on bikes, since I'm not too worried about messing anything up here. Right now I'm trying to service the front wheel -- the front hub in particular -- by rebuilding the hub. The thing is, I don't what size bearings I'm supposed to use to replace the ones currently inside the hub? Sheldon Brown's old article on overhauling hubs says that "Most front hubs take 10 three-sixteenth- inch balls per side. Almost all rear hubs take nine 1/4 inch balls per side." Is this most likely the size I should use? The hub shell has Joytech G87 written on it, if that helps any.

San Rensho 

Take on old bearing to the lbs and buy a bunch. They are cheap and you will use them in the future. while you're at it, buy bearings for the bb, headset and rear hub.

ridelugs

yeah, shops have a bearing sizing gauge built into thier spoke measuring ruler. so thats the best way to fly, unless you have good calipers.

rogun

Sorry for the slow response, but thanks to both of you for the help!

moxfyre

Here's the poor-man's way to measure the bearing size: fold a piece of paper in half sharply and put 8 bearings in the crease, right up against one another. Then take an ordinary ruler and measure the length of the row of bearings: if they're 3/16" it'll be 1.5 inches long, while if they're 5/32" it'll be 1.25 inches long.

But I'd bet 100 to 1 that yours are 3/16" ... I've never seen Asian made front hubs that use anything else. (Joytech is Taiwanese I believe.)

rogun

That makes perfect sense and is so simple that I'm mad at myself now for not figuring it out on my own...

Thanks!

update: I should have added that you were right; they are 3/16" bearings and that matches what they gave me at my lbs also.

becnal

You need this thing to tell you what size you need:

https://www.parktool.com/products/det...=17&item=SBC-1