Hi everyone!
From time to time I see posts about chain case bearings going bad and that people try different solutions to cure the problem. This is my solution and I will try to describe it below with some pic´s.
Normally, as far as I know Yamaha uses 6205 C3 type bearings for the chain case, on some models the bearings are equipped with a seal on one side and pre lubricated with grease, and other models came with non sealed units like mine, an SX 700. The C3 states that the bearing has a larger internal play than normal and this is used to allow the bearing to take up movements caused by flex in the chassis.
Never the less, these bearings take a lot of punishment and will go bad even if the oil is changed frequently.
The solution to the problem is to use Ceramic Hybrid Bearings. This type of bearing consists of a standard steel outer and inner ball ring with ceramic silicon nitride balls instead of steel balls.
The performance from this type of bearing can be expected to be much higher than from a standard steel ball bearing, with a lifetime up to 10 times longer! This type of ball bearing can also run without oil for very long periods and are not sensitive to oil contamination. If a damage would occur in the ball race the ceramic balls will in fact heal the damage to a certain degree.
This sounds almost too good to be true, right? No, it is in fact true but there is a catch, the cost for the ceramic bearing which can be more than 10 times higher compared to a standard steel ball bearing.
Anyway, I work with testing and design of products which are equipped with this type of bearing and I thought it could be fun to build my own hybrid ceramic bearings for my machine.
For this I used a standard 6205 C3 bearing from SKF, and the ceramic balls from left over bearings that were supposed to be scrapped.
I do not know if the pictures are presented in the same order as I uploaded them but if they are not, I suppose you can find which picture that goes to the correct text below.
Picture no. 1, this is before disassembly of the bearing
Picture no. 2 shows the disassembled bearing with the outer and inner ring, the old steel balls and the two ball cage halves. The halves are removed by carefully grinding down the rivets and gently punching the rivets out.
Picture no. 3 shows the ceramic silicon nitride balls. The diameter of the balls is 7.930 mm which is exactly the same diameter as the steel balls. This is very important since this diameter will determine the internal play of the bearing
In no. 4 the assembled balls are seen at the lower half of the bearing. The balls are assembled by pushing the inner ring towards the outer and then carefully inserting the ceramic balls in the gap that is formed at the bottom of the bearing. The inner ring is then gently pushed downwards until it pops into position.
No. 5 shows the balls evenly distributed in the bearing rings.
Next picture shows the ball cage with new rivets. The cage is riveted back together by hand, sonstantly checking for correct play of the cage to avoid internal friction of the bearing
And the last picture shows the finished ball bearing (and my dirty fingers).
Why have I done this? Because it is possible and because I think it could be kind of cool to do it myself for a fraction of the cost it would take to by this type of bearing from a bearing manufacturer.
Hope you guys enjoyed the world of home built hybrid bearings !
/ Daniel
From time to time I see posts about chain case bearings going bad and that people try different solutions to cure the problem. This is my solution and I will try to describe it below with some pic´s.
Normally, as far as I know Yamaha uses 6205 C3 type bearings for the chain case, on some models the bearings are equipped with a seal on one side and pre lubricated with grease, and other models came with non sealed units like mine, an SX 700. The C3 states that the bearing has a larger internal play than normal and this is used to allow the bearing to take up movements caused by flex in the chassis.
Never the less, these bearings take a lot of punishment and will go bad even if the oil is changed frequently.
The solution to the problem is to use Ceramic Hybrid Bearings. This type of bearing consists of a standard steel outer and inner ball ring with ceramic silicon nitride balls instead of steel balls.
The performance from this type of bearing can be expected to be much higher than from a standard steel ball bearing, with a lifetime up to 10 times longer! This type of ball bearing can also run without oil for very long periods and are not sensitive to oil contamination. If a damage would occur in the ball race the ceramic balls will in fact heal the damage to a certain degree.
This sounds almost too good to be true, right? No, it is in fact true but there is a catch, the cost for the ceramic bearing which can be more than 10 times higher compared to a standard steel ball bearing.
Anyway, I work with testing and design of products which are equipped with this type of bearing and I thought it could be fun to build my own hybrid ceramic bearings for my machine.
For this I used a standard 6205 C3 bearing from SKF, and the ceramic balls from left over bearings that were supposed to be scrapped.
I do not know if the pictures are presented in the same order as I uploaded them but if they are not, I suppose you can find which picture that goes to the correct text below.
Picture no. 1, this is before disassembly of the bearing
Picture no. 2 shows the disassembled bearing with the outer and inner ring, the old steel balls and the two ball cage halves. The halves are removed by carefully grinding down the rivets and gently punching the rivets out.
Picture no. 3 shows the ceramic silicon nitride balls. The diameter of the balls is 7.930 mm which is exactly the same diameter as the steel balls. This is very important since this diameter will determine the internal play of the bearing
In no. 4 the assembled balls are seen at the lower half of the bearing. The balls are assembled by pushing the inner ring towards the outer and then carefully inserting the ceramic balls in the gap that is formed at the bottom of the bearing. The inner ring is then gently pushed downwards until it pops into position.
No. 5 shows the balls evenly distributed in the bearing rings.
Next picture shows the ball cage with new rivets. The cage is riveted back together by hand, sonstantly checking for correct play of the cage to avoid internal friction of the bearing
And the last picture shows the finished ball bearing (and my dirty fingers).
Why have I done this? Because it is possible and because I think it could be kind of cool to do it myself for a fraction of the cost it would take to by this type of bearing from a bearing manufacturer.
Hope you guys enjoyed the world of home built hybrid bearings !
/ Daniel
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ModMMax
New member
Well done daniel. I just love this kind of info.
PZ 1
Member
- Joined
- Mar 12, 2005
- Messages
- 987
Make some for me !!
I am wondering about using the bearings in idler wheels. Do the ceramic bearings work okay when packed with grease? Are they made that way in a size that fits the wheels?
I am wondering about using the bearings in idler wheels. Do the ceramic bearings work okay when packed with grease? Are they made that way in a size that fits the wheels?
The bearings works just fine when packed with grease and they come in all sizes. However, the cost to buy this kind of bearings from a manufacturer would be astronomical and not worth it. The only way is to build them yourself and that is not easy if you do not have acess to the silicon nitride balls. The cost for a ball of this size is about 3-5$ and they are pretty difficult to buy.
The bearing manufacturers knows that this type of bearing is kind of secret to the public and therefore they can price them so high. But as you can see, there are no speciall secrets regarding this type of bearing.
I have seen that the prices are dropping since the Chinese suppliers are pressing the prices down and threating the US and European manufacturers.
I have been thinking of modifying the speedo side bearing as well but the seal is a bit difficult to remove without damage so I will have to consider it for a while.
/Daniel
The bearing manufacturers knows that this type of bearing is kind of secret to the public and therefore they can price them so high. But as you can see, there are no speciall secrets regarding this type of bearing.
I have seen that the prices are dropping since the Chinese suppliers are pressing the prices down and threating the US and European manufacturers.
I have been thinking of modifying the speedo side bearing as well but the seal is a bit difficult to remove without damage so I will have to consider it for a while.
/Daniel
toydoc
Member
Very good info Daniel! Nice work with step by step pics.
I found silicon balls at:
http://www.bocabearings.com/
I bought all my silicon bearings from Dave at world wide bearings.
They are around $70 each, sealed both sides.
http://www.worldwidebearings.com/
I found silicon balls at:
http://www.bocabearings.com/
I bought all my silicon bearings from Dave at world wide bearings.
They are around $70 each, sealed both sides.
http://www.worldwidebearings.com/
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