Topic: Installing tapered steering bearings

[scottly]

I whipped up a simple tool to install bearing races with stuff I had laying around today. For the bottom race, I used a slightly smaller stock upper race on the tool. I used a stock lower race to install the slightly larger Seeley upper race. The races should still be tapped firmly into place to seat them, and if the nut turns easier, it means the bearing has indeed moved. This procedure will not cause any damage to the rolling elements, such as can happen when over-tightening the stem nut to draw the races into their seats with the rolling elements installed.

[scottly]

Once the proper spacer is selected, the lower bearing can be installed on the stem with a punch. The punch should be tapped lightly, and moved around on the inner race until the bearing is firmly and evenly seated.

[scottly]

Once the stem is installed, the adjustment nut can be tightened up to insure the races are seated, 15ft/lbs should be adequate, and the triple turned back and forth. Re-tighten to 15 ft/lbs; if the nut moves, the bearings have shifted, so turn the triple back and forth again. If it doesn't move with the same torque, the bearings are seated, and you can move on to setting the pre-load. Loosen the nut, then tighten it up to .7-1.4 ft/lbs. You can get all scientific with a spring scale, but this is less than the torque to open a pickle jar; just snug it up by hand.
When the pre-load is correct, it should take only a slight pressure to move the triple, like with a pinky finger. Note: this assumes that the adjustment is made without the front wheel and forks installed. 

[NobleHops]

Great thread for reference Scott, A+

[scottly]

Thanks, and thanks to brewsky for posting the all balls instructions. To save everyone from the trouble of trying to put loose balls between the races and measuring the height of the stock bearing, it's .693". The tapered bearing is .563" tall so a difference of .130" There is a .025" washer under the bearing to support the stock bottom seal, so the total is .718 for the stock bearing + shim washer. With a .563" tapered bearing, there needs to be .155" of spacer under the bearing, including the thickness of the shim part of the All Balls lower seal.
Edit due to more accurate measurements

[NobleHops]

That there is some CONTENT^^^^

[Jerry Rxman Griffin aka MuthaF'er]

Did you put your bearings in the freezer first?

[flatlander]

great description, thanks scottly!

[vfourfreak]

Is that a Seeley frame there

Kev

[Gene]

bookmarking.

[scottly]

Jerry, no, I didn't freeze the races. The main thing when installing any bearing is to make sure it is square in the bore, or on the shaft. If the bearing becomes cocked, which can easily happen at the start, it can get wedged into place. If this happens with the races in the steering head, use a punch from the other side to tap the race back into alignment.
Kev, yes, #21

Do not use the upper seal and washer from the All Balls kit. 

[Johnny340]

Excellent write up! I did freeze my bearings which makes a noticeable difference in ‘force’ required to install them.

Btw this is the best mod for improving handling imo! My CB650 used to shimmy bad with the bars wanting to do a tank slap on each side and now it stays solidly in line and stable!!


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[Stev-o]

Good info Scott.   I linked this thread in the "official" Tapered Bearings thread....


http://forums.sohc4.net/index.php/topic,1516.575.html