Article [13] ST1300 - Maintenance - Fitting Wheel Bearings - What the manuals don't tell.

Ndfrc said:
left side

Where I wiped off the crud, semi dirty/greasy..
Click to expand...
In all of your photos of the left side there also seems to be damage to the wheel hub that houses the bearing. It was rubbing against something at some point based on the photos.

IMG_5466.jpeg

IMG_5467.jpeg
 

Attachments

  • IMG_5466.jpeg
    IMG_5466.jpeg
    302.9 KB · Views: 3
That is good progress. Seals are toast.
Bearings - at 25000, they are probably ok. One test you did not mention is how smooth they feel when you jam your finger in the hole and rotate it back and forth.
I would probably replace them - but I have the tools and some experience.

DO NOT hold the wheel one finger in each bearing and spin the wheel. It may not turn out very well ! All you are feeling for is smoothness.

The spacer between the bearings - you will be able to feel it and it ought to be jammed tight, but it may drop down slightly and scrape against the bearing as you feel how smoothly the bearing turns. Check that that spacer is there - it is a long alloy tube that is a loose fit for the axle to slide through. I think I can see the end of it on the photo of the rhs with the seal removed. Use the axle from the other side to keep the spacer in place. If it is very slack, then the bearings are not properly seated. ask about that before trying to fix it .

That scoring of the hub on the left - that is odd. The only thing that I can think of is that the left hand spacer was not fitted at some point. The wheel would slide easily on the axle and that scored hub would collide with the bottom of the inside fork leg, above the axle hole. Take a look there to see if there is any damage/score marks.
 
Both bearing surfaces are glass smooth, if thats what you mean, however they turn slow and stiff, the outer one turns more stiff, this is the one against the backwards spacer.. but they do turn.
How freely or tightly should they turn? I wish I had a new one to compare.

The spacer is there and it’s not loose at all, but I didn’t go out of my way to loosen it.

As for the hub, I find no corresponding mark on the forks. To me it looks like hub damage from mishandling the wheel, that hub edge is the highest point on that side of the wheel, one or 2 slightly high setdowns on a garage floor would easily do that, besides it should be just cosmetic.

IMG_5493.jpeg
 
It's nice when we find some "problems" go back to the most basic issues.
There's some doggone smart ST folks 'round here!
I submit that your vague handling issues at um, ... elevated speeds will be subdued with replacement bearing (as needed), and just having the front wheel mounted properly.
Mechanics may be good or not so good, but there are common ST techniques that MUST be correct.
Not all "good" mechanics know this fine example of a motorcycle, as we have seen time after time.
The front wheel axle, pinch bolts and spacers must be done right, and the same for bleeding these brakes.
Glad you're here to learn the RIGHT way.
And thanks to @jfheath and @Andrew Shadow for jumping in with the correct observations.
 
Ndfrc said:
Both bearing surfaces are glass smooth, if thats what you mean, however they turn slow and stiff, the outer one turns more stiff, this is the one against the backwards spacer.. but they do turn.
How freely or tightly should they turn? I wish I had a new one to compare.

The spacer is there and it’s not loose at all, but I didn’t go out of my way to loosen it.
Click to expand...
Spacers should be tight up against the inner face of the bearing, so that is ok

However one bearing should not be stiffer than the other - but that is difficult to tell since the spacer and both inner races will likely turn together.m

I might have a spare bearing - I'll dig it out if I can (I haven't seen it for a while) and try to give you an idea of how easily they move. They are not loose, but they should move round smoothly with gentle finger pressure.
 
Last edited:
A new bearing, right out of the box and wrapper, will feel silky smooth with some resistance from the grease. With some use, the bearing will show less resistance from the grease, but it will still feel smooth. When installed in your wheel properly, there will be some (very little) side pressure on the inner races so the tendency will be for turning one to turn the spacer and the other bearing. You are looking for that smoothness while you turn either or both bearings. An old bearing might feel smooth, but make some noise because it is dry, or it might feel notchy as the round bearings roll over worn spots on the outer (or inner) race.

This kind of thing is probably as hard to communicate via the written word as it is to describe the taste of, say, chocolate to someone who has never tasted it. It would be easier to learn if you grabbed a new bearing or two and played with it for a while.
 
Totally agree, and what you said helps.. they do roll smoothly, but I feel they should be more free.. it takes quite abit twisting with 2 fingers to get it to move and your not going to get grip to turn it a full circle.

There’s a bike shop close by, been tempted to use them for other things but ended up doing myself or changed directions, I’ll take my wheel to them in the am and they should be able to check them out in seconds right?
Next question then is seeing how I am not counting on them to install my wheel, is this bearing replacement work pretty standard stuff that a good bike shop should have no issue or does this procedure have its own secrets you have to know?
As for replacement bearings.. I assume oem? If not is there a go to?
Thanks!!
 
Last edited:
Ndfrc said:
Totally agree, and what you said helps.. they do roll smoothly, but I feel they should be more free.. it takes quite abit twisting with 2 fingers to get it to move and your not going to get grip to turn it a full circle.

There’s a bike shop close by, been tempted to use them for other things but ended up doing myself or changed directions, I’ll take my wheel to them in the am and they should be able to check them out in seconds right?
Next question then is seeing how I am not counting on them to install my wheel, is this bearing replacement work pretty standard stuff that a good bike shop should have no issue or does this procedure have its own secrets you have to know?
As for replacement bearings.. I assume oem? If not is there a go to?
Thanks!!
Click to expand...
Standard stuff is depending on how mechanically inclined you are and what tools are at your disposal. You can't judge a bearing alone by how free you think it should spin. Failed bearing can spin very freely. IMO your bearings by your description sound perfect.
 
Ndfrc said:
Totally agree, and what you said helps.. they do roll smoothly, but I feel they should be more free.. it takes quite abit twisting with 2 fingers to get it to move and your not going to get grip to turn it a full circle.

There’s a bike shop close by, been tempted to use them for other things but ended up doing myself or changed directions, I’ll take my wheel to them in the am and they should be able to check them out in seconds right?
is this bearing replacement work pretty standard stuff that a good bike shop should have no issue
Click to expand...
Yes, a good mechanic should be able to suss out the condition of the bearings in seconds. And if you are elbow to elbow w/ him while he does it, you should be able to figure out just as quickly if he knows what he is doing. Ask what he is looking for and ask him to show you - teach you.

Yes, it is pretty standard stuff that anyone can do. You can do it yourself...just go slowly, read the book and tap the second one in, feeling for the bearings just holding the spacer in place. In this case the big problem is using a mechanic who does not know the procedure (which side goes in first) or does not care.
Ndfrc said:
does this procedure have its own secrets you have to know?
As for replacement bearings.. I assume oem? If not is there a go to?
Thanks!!
Click to expand...
The secrets are going slowly and learning by doing. Yes, we all make mistakes and if you have to replace damaged parts it is part of learning. If you bang in the second bearing too tight and are side loading the inner races they might fail in a few thousand miles. Big deal, this is not an expensive or high labor job.

If you go OEM there is little to no guesswork. You can also buy bearings by number (on the side of the bearing) from many sources. Go with name brands and check prices. Here are the big guys (also called Tier 1 manufacturers) by country. The link was my source for this (no secrets). There are other brands out there, but I like the big guys. YMMV

Sweden: SKF
Germany: FAG, INA of Schaffer Group - Barden
Japan: NSK, NTN, THK, IKO, Nachi, Koyo, NMB
USA: Timken, RBC, Torrington

 
Yes, there are secrets. Well documented, but many make assumptions and just hammer them in. If you do that, you will destroy both bearings. If you don’t insert them in the correct order, then the wheel will be slightly off centre when it is fitted.

I only ever buy OEM bearings. They have the correct load rating, speed rating and amount of play. Non of this is indicated by the 6205UU code, which merely indicates the type and inside diameter and the fact that they are fitted with oil seals both sides. The more I tried to understand the coding, the more I realised that I didn't know enough about it - so I err on the 'buy OEM' side. But only becasue I have seeen the name on some of the fiches for some of the bearings.

Check the videos of me removing and inserting bearings for an ST1300 front wheel.

For the front wheel, the right hand bearing must be inserted first.
Then the spacer
then the left hand bearing driven in until the centre race meets the spacer. No further.

Also check out the comments in the thread that contains the video (link in post #1 of this thread). Scrool down to Post #19 - 24 May 2024. Some official tools and some makeshift tools created from old bearing shells and a grindstone.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom