# of loose ball bearing in a Dura Ace Hub??
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# of loose ball bearing in a Dura Ace Hub??
I took my 7800 Dura Ace rear hub apart yesterday to add in a bit of grease, and I think I may accidentally dropped a couple ball bearings.
I ended up with 14 on each side, and they seem kind tight, but I'm not really sure. Does anyone know how many ball bearings are supposed to go in each side? What are the risks if I had one less than it is supposed to?
Also, I think I may tightened the freewheel a bit too much. It is somewhat difficult to spin the freewheel, and when it is on the bike, the pedals move forward by themselves when freewheeling. When is the freewheel adjusted properly?
Thanks,
Ming
I ended up with 14 on each side, and they seem kind tight, but I'm not really sure. Does anyone know how many ball bearings are supposed to go in each side? What are the risks if I had one less than it is supposed to?
Also, I think I may tightened the freewheel a bit too much. It is somewhat difficult to spin the freewheel, and when it is on the bike, the pedals move forward by themselves when freewheeling. When is the freewheel adjusted properly?
Thanks,
Ming
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If you can fit another one in, you've lost one.
I read somewhere there's around a 1/2 a BB's width left when they're all seated.
Tighten until there's no play when you move the wheel side to side with it locked to the frame.
It should spin fairly freely, don't ride it if it doesn't, or if it has even a little play. When you tighten the quick release it will actually put more force on the hub, so you may need a very small amount of play before it's mounted to the wheel, but it should be gone completely when the wheel is re-attached to the frame.
Gah Tugger's link covers all that mess.
I read somewhere there's around a 1/2 a BB's width left when they're all seated.
Tighten until there's no play when you move the wheel side to side with it locked to the frame.
It should spin fairly freely, don't ride it if it doesn't, or if it has even a little play. When you tighten the quick release it will actually put more force on the hub, so you may need a very small amount of play before it's mounted to the wheel, but it should be gone completely when the wheel is re-attached to the frame.
Gah Tugger's link covers all that mess.
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I didn't know 7800 hubs had freewheels...
Could you be a little more specific about what you "adjusted"?
Exploded diagram is here. The internet is good.
BTW - assembly diagram calls for 28 balls total - 14 each side.
If it's your 3 pawl mechanism that is binding then make sure the pawls are in correctly and seated, make sure the retaining ring/spring is on correctly. Make sure the pawls are free to collapse and expand without binding. Place against hub and use a small screwdriver to depress pawls and replace...I didn't check it out, but I am sure BT's link to Park says the same thing.
Could you be a little more specific about what you "adjusted"?
Exploded diagram is here. The internet is good.
BTW - assembly diagram calls for 28 balls total - 14 each side.
If it's your 3 pawl mechanism that is binding then make sure the pawls are in correctly and seated, make sure the retaining ring/spring is on correctly. Make sure the pawls are free to collapse and expand without binding. Place against hub and use a small screwdriver to depress pawls and replace...I didn't check it out, but I am sure BT's link to Park says the same thing.
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Thanks for all the diagram guys I counted 28 ball bearings before I put the hub back together so I guess I was lucky.
The pawl was sitting properly. I didn't realize you could tighten the hub with two allen keys. I was just adjusting everything hand tight, and I tightened the cassette side too much, so the hub wasn't freewheeling too smoothly. I just had to back off the tension a bit, and all is well.
With some grease inside, the hub is almost silent like my DT Swiss 240 hubs and I'm very impressed with the inside of the Dura Ace hub. The engagement is at least as good as the 240s.
Thanks!
Ming
The pawl was sitting properly. I didn't realize you could tighten the hub with two allen keys. I was just adjusting everything hand tight, and I tightened the cassette side too much, so the hub wasn't freewheeling too smoothly. I just had to back off the tension a bit, and all is well.
With some grease inside, the hub is almost silent like my DT Swiss 240 hubs and I'm very impressed with the inside of the Dura Ace hub. The engagement is at least as good as the 240s.
Thanks!
Ming