Steering Head Bearing Kit

[breahn riley]

Has anyone purchased these kits from Mikes or 650central? I like the idea of replacing the loose ball bearings. What do you guys think?

 

[xjwmx]

I'm getting ready to rebuild my steering head, but I'm going to use ball bearings like was originally there. I might get the grease seal for it from Mike's if he has it. I think there's a grease seal. I've heard more than one story of tank slappers coming on with perfectly good, new, roller bearings. They do move the resonances around, one would presume. The ball bearings are 1/4", and $.24 ea at Do It Best hardware. I hope the races are ok.

 

[breahn riley]

what do you mean by tank slappers?

 

[xjwmx]

Search it on Youtube

 

[yamaman]

Yeah, the balls suck, ditch em! There's a top pictorial how to on Gorans blog
HERE

 

[breahn riley]

what causes tank slapping? the sealed bearing collapsing and causeing speed wobbles?

 

[xjwmx]

Good motorcycle designers know what causes them, not me. But it doesn't require that the steering bearing fail, although worn bearings seem to be one thing that can induce them, from what I've read. My impression is sections of bikes have resonant peaks and if the peak is large and it's strongly excited, then watch out.

 

[malloym]

been running the tapered roller bearings from mikes for 2 yrs... works great.... tapered roller bearings are the way to go. more surface area, and smoother steering. with the OEM style the races get pitted and the steering becomes notchy... (yikes)

 

[72XS2]

Does someone knows the part numbers for these cup/cone bearings ? I would like to search around here if I can find them.

 

[inxs]

- your dealer should be able to work backwards from the bearing size
...25-48-15.2
...30-48-15.0

 

[xjwmx]

Does anybody know the size of the original stock races? There are four. Yamaha dealers want around $25 for each.

 

[jay760]

Aren't ball bearings for push bikes, I can't think of a single reason anybody would choose ballrace over taper roller bearings.

 

[xjwmx]

Call me old fashioned.

So, does anybody here know the size of the original stock races?

 

[72XS2]

- your dealer should be able to work backwards from the bearing size
...25-49-15.2
...30-48-15.0

Thanks inxs ! I called at a shop who sells bearing, seals and all stuff and they said me that can't do nothing with these numbers.

 

[inxs]

- your dealer should be able to work backwards from the bearing size
...25-49-15.2
...30-48-15.0

Thanks inxs ! I called at a shop who sells bearing, seals and all stuff and they said me that can't do nothing with these numbers.

- you must have struck one of the minimum wagers
- one of the sizes was wrong anyway-have changed it to

...ID-OD-total thickness in mm​

...25-48-15.2​

...30-48-15.0​

- KML: # 30Y/48KS and # 25Y/48YS

 

[72XS2]

I call back the two bearings suppliers that we have here and they don't have these sizes in their catalogs. I even talk back to this "minimum wager" and he understand the numbers ! I will order them on the internet.

Thanks again for your help !

 

[Viper]

I just received my head bearings from mikes.

They sell "Parts Plus" SSY500. If you do a quick search you'll find a huge variety of places which sell them.

They're also used in
Yamaha
TX500 1973-75
XS500 1976-78
XZ550 1982-83
FZ600 1986-88
SRX600 1986
TX650 1970-76
XJ650 1980-83
XS650 1977-83
TX750 1973-74
XJ750 1981-83
XV750 1981-83
XV920 1981-83

 

[72XS2]

Thanks Viper, I'll take good notes of that.

 

[gggGary]

I'm getting ready to rebuild my steering head, but I'm going to use ball bearings like was originally there. I might get the grease seal for it from Mike's if he has it. I think there's a grease seal. I've heard more than one story of tank slappers coming on with perfectly good, new, roller bearings. They do move the resonances around, one would presume. The ball bearings are 1/4", and $.24 ea at Do It Best hardware. I hope the races are ok.

The races are NEVER OK they have dents in them from where the balls sit and pound into the race bump after bump after......... Some early XS650 are notorious tank slapper bikes just the way Mamaha made them. Been there slapped that. Survived only because I figured out just in time that PUSHING on both handle bars will damp out the oscillation. Pulling on them makes it worse. The 71 was slapping so bad the front wheel was bouncing up OFF the road and landing alternately about 3" to one side then the other at about 75 on a freeway in Missouri. I was 19 at the time and had only about 6 lives left. At 55 I am not sure there are any spares left now. It's tapered rollers for me.

 

[Viper]

I'm reassembling my frame after my tear down, and I'm looking at putting the new tapered bearings in. To my understanding 30Y/48KS is the bottom, and 25Y/48YS is the top and the cup gets inserted into the frame.

How does everyone install theirs? Just Freeze the cup, and it drops in apparently?

Does it have to be fully seated before bolting it together? or does bolting it down pull everything together.

Thanks.