NSR125R Bearings and such like

Chuck100 · Two Stroke Sniffer Joined: 14 Jan 2003 Karma :

Quick question for you technical gurus...

Are 'bushes' the same as 'dust covers' or 'dust guards'. The reason I ask is that a bike shop had no idea what I was talking about when I asked if they carried 'bushes' for some front wheel bearings. They did seem to think that I would need dust guards/covers though if I wanted bearings.

Also, are the bearings and bushes the same on the left and right hand side of the front wheel on an NSR125R?

Lastly, how do you remove the old bearings? I had the front wheel off a month ago and the bearings didn't seem to want to come out (although I didn't try anything too harsh, just some gently prying)?

Many thanks for your help.

Rgds,

Chuck.
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Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

There are no bushes in the front wheel assembly that you would expect to have to replace (unless you lost them).

There is a seal on the NSR, which also contains the speed drive and is very easily damaged (at which point the speedo stops working, then a few weeks later the front wheel bearings fail).

To change the bearings you need to hammer them out from the other side. Between the 2 bearings there is a steel tube which spaces the bearings out. This tube is supported at one end so at the other end it is free to move a small amount. Find the end with a bit of movement, put a punch in from the other side onto the inner edge of the bearing and tap it out (move round the area of the bearing you are tapping so that it comes out straight). Once that one is out remove the steel tube and knock the other bearing out.

When you replace them use a large socket as a drift to push the new bearing in place. Only put any force on the outside of the bearings. Make sure you do not forget to put the steel tube in place.

All the best

Keith
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Chuck100 · Two Stroke Sniffer Joined: 14 Jan 2003 Karma :

Thanks for that advice Keith, although I have to say that I do have one further query...

When I removed the front wheel from my bike, a small disc (about 4mm thick) that seemed to be made of rubber and steel was sitting over the bearings. It came out and under inspection it appeared that parts of the rubber were coming off of the disc. Underneath that, there was a very thin disc (<1mm) of metal that seemed to fit over a gap in the bearing disc. When that came out I could see the ball bearings inside the bearing ring (please accept my apologies for using the incorrect terminology).

This was all on the speedometer drive side of the wheel.

I had to hammer the thicker ring mentioned above into the side of the wheel to get it back in. It's this thicker disc that I'm interested in. I presume you're going to tell me that my bearings are knackered and that I need to replace them, which I will shortly be doing.

To better illustrate, please see the image below. I think it's part numbers 12, 13 and 14 I'm talking about, but am not fully sure.

Thanks for your help,

Chuck
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jimbo · Borekit Bruiser Joined: 23 Aug 2003 Karma :

The bits you are looking at (12 and 13) are the axle seals. These are an extra set of seals that are the first line of defence against water and crap.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Looking at the manual (although for the earlier NSR, but this bit is probably the same), on the non speedo drive there is a "dust seal" which sounds like the bit you are describing. These can generally be reused a fair few times if you are careful removing them.

On the other side there is the speedo drive gear, and also a piece of bent metal with a rubber coating with 2 pegs sticking out. This sits in the wheel with the 2 pegs driving the speedo drive gear. This is the bit that is easily damaged, normally with the 2 pegs bending back and damaging the seal on the bearing. This is probably what has happened with your front bearing, with the extra 1mm thick bit being the seal from the bearing pulled out by the speedo drive.

Bearings do not like being removed, so you need to replace them if you remove them, and generally always replace them in pairs. They will not be expensive.

The bearings you want need to have rubber seals. They will have a "2RS" in the code for them which is "2 rubber seals". You can use the "ZZ" type but they are metal seals and probably will not last as long.

I cannot remember what size bearings the NSR uses I am afraid.

All the best

Keith
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jimbo · Borekit Bruiser Joined: 23 Aug 2003 Karma :

Oops thanks keith,yes the bearings are 2RS, not ZZ.
ZZ have negligible resistance to water ingress, never use them. (Been working on electrical motors too long, ZZ is stuck in my head)

Depends where you live if you want to re-use "dust"-seals. They are pretty efficient water seals. In Ireland where it always wet it's false economy, as they'll start to let water in sooner. Water that gets in can't get out, so it sits up against the bearing and happily works its way in past the bearing seal.