Neville Jones
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| posted on 12/4/05 at 06:15 PM |
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I would have a good look at the bearings on the output shaft of the bike box before going further. They would be designed to take torque, but not the
thrust that a chain will put on them.
I only say this because we have a drier barrel similar to a concrete mixer truck running with a truck box with a chain on the output, and eats
bearings regularly. The salt does not help though.
The recent fix was to mount the sprocket with bearings both ends on a cradle, with a flexible joint between the gbox and sprocket shaft. This means
the gearbox now only provides torque as designed and no chain thrust on the output bearing.
So far, no new bearing trouble.
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sgraber
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| posted on 12/4/05 at 06:26 PM |
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quote:
Originally posted by Neville Jones
I would have a good look at the bearings on the output shaft of the bike box before going further. They would be designed to take torque, but not the
thrust that a chain will put on them.
I only say this because we have a drier barrel similar to a concrete mixer truck running with a truck box with a chain on the output, and eats
bearings regularly. The salt does not help though.
The recent fix was to mount the sprocket with bearings both ends on a cradle, with a flexible joint between the gbox and sprocket shaft. This means
the gearbox now only provides torque as designed and no chain thrust on the output bearing.
So far, no new bearing trouble.
Interesting point you make. Would you be able to make an educated guess (SWAG) by the photo below?
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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Aloupol
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| posted on 12/4/05 at 08:13 PM |
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Placing the sprocket between two bearings, and a CV joint to dissociate is the beter but increases the off-axis of the sprocket, maybe too much?
There's a mounting point on the block near this area, maybe possible to add a bearing after the sprocket, keeping this one at the same place?
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Rorty
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| posted on 13/4/05 at 01:52 AM |
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Steve, that's the basic layout of 95% of rear ends I've seen/done myself, albeit the engine's orientation is different. Should work
perfectly well.
I would look closely at the pinion shaft bearing cover in the photo above with a view to re-machining it or making a new one to take a more
substantial bearing.
If money wasn't an object, I would machine a billet sump for it to position a new output bearing and extension for the output shaft, thus
bypassing the whole bevel gear set-up. You could dry sump it while you were at it.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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sgraber
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| posted on 13/4/05 at 02:34 AM |
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quote:
Originally posted by Rorty
Steve, that's the basic layout of 95% of rear ends I've seen/done myself, albeit the engine's orientation is different. Should work
perfectly well.
I would look closely at the pinion shaft bearing cover in the photo above with a view to re-machining it or making a new one to take a more
substantial bearing.
If money wasn't an object, I would machine a billet sump for it to position a new output bearing and extension for the output shaft, thus
bypassing the whole bevel gear set-up. You could dry sump it while you were at it.
If money were no object I would have started out with a Hayabusa or a ZX12!   Certainly removing the bevel gear is the more efficient way to get
more power to the wheels. I wonder how much the machine shop bill would be for that conversion...
My last question on the subject of diffs. (for now...)
For cost savings - If I were to retain the bevel gear, and attach a sprocket onto the splined shaft (where the u-joint currently attaches in the photo
above), should I definitely support the outer portion of that shaft with an additional bearing? What would Jesus do?
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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Rorty
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| posted on 13/4/05 at 04:29 AM |
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quote:
Originally posted by sgraber
For cost savings - If I were to retain the bevel gear, and attach a sprocket onto the splined shaft (where the u-joint currently attaches in the photo
above), should I definitely support the outer portion of that shaft with an additional bearing? What would Jesus do?
Leave Jesus out of it; he'd probably make it all out of wood. 
The cost of a billet sump may not be as expensive as you think. If you know of somewhere you can stick the current sump in a CMM to establish the
geometry, then reverse engineering a CAD model would be dead simple with your friends on this forum. After that, it's just down to the cost of a
suitable billet and some machine time.
It may not be more costly than gerry-rigging a satelite bearing and associated parts.
If you were combining the change to a billet sump with a dry sump modification, then obviously there'd be considerable cost in the pump and pipe
fittings etc.
Probably the second biggest benefit of a billet sump would be the reduced overall height of the unit, allowing it to sit lower in the car.
I would still look at the existing bearing/cover as a first option. You may find with a little machine work, you could fit a more substantial bearing
in there.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Aloupol
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| posted on 13/4/05 at 09:16 AM |
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In your place I would let it like this, simply mount the sprocket in place of the CV joint. If the bearing lasts more than 10 000 km then it's
good, it's just a service part. If not it's still time to consider an expensive option.
If you are too affraid of possible dammages to other parts than the bearing you can build a short axle with the splines and the sprocket in one end
and a secondary bearing in the other, which sits on the engine mounts.
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