Author Topic: oil puddle during sprocket change  (Read 213 times)

E-wan

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oil puddle during sprocket change
« on: May 14, 2024, 03:15:15 pm »
I just did an oil change on my hub and then a couple of days later (after only riding less than 10 miles in between) changed the screw-on sprocket.

A lot of oil came out when I unscrewed the sprocket.

Is this to be expected or might something be amiss with the hub?

If normal should I now perform another oil change to replace the lost oil?
Thanks

Ewan

UKTony

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Re: oil puddle during sprocket change
« Reply #1 on: May 14, 2024, 07:21:33 pm »
According to Rohloff this is normal if the wheel is laid flat with drive side facing down and sprocket removed. See last bullet  point in the General Intro here,

https://www.rohloff.de/en/service/handbook/speedhub/workshop/splined-carrier-lockring-conversion

If you’re concerned about the amount of oil spilt then I suggest you do another oil change after  the sprocket is replaced and see how things go from there.
Hope that helps.
Tony

JohnR

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Re: oil puddle during sprocket change
« Reply #2 on: May 14, 2024, 08:40:07 pm »
How much new oil did you put in the hub? Rohloff recently reduced the recommended amount of new oil from 25ml to 12.5ml https://www.rohloff.de/en/service/handbook/speedhub/workshop/oil-change.

E-wan

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Re: oil puddle during sprocket change
« Reply #3 on: May 15, 2024, 08:10:34 am »

I used 13 mL of oil during the change 12.5 is hard to measure

Don't quite see how they expect you to be able to change the sprocket without it facing downwards given that the easiest way to do so is by holding the wheel stationary in a vice rather than with a spanner.

I suppose I could mount a vice to the ceiling, but then it wouldn't be very useful for much else.

JohnR

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Re: oil puddle during sprocket change
« Reply #4 on: May 15, 2024, 08:43:05 am »
Thanks for the clarification - I wondered if you had added 25ml (or thereabouts - I agree that 12.5ml is somewhat precise). One approach to deciding if you need to add more oil to compensate for that which escaped is to drain the oil in the hub and see how much is there (then put the oil back in the hub). If less than 12.5ml then add some more.

mickeg

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Re: oil puddle during sprocket change
« Reply #5 on: May 15, 2024, 01:36:21 pm »
If you did not ride it at all after the sprocket removal, if it was me I would be tempted to add a few ml of oil.  But if you rode it a short distance so that the fresh oil could coat all the internal parts, then I would not worry about the oil loss.

I use big wrenches, not a vice, but if I lacked such wrenches, I would be inclined to use a vice like you did.  (See photo.)

In the future, once you get it loosened to the point that a smaller wrench will work, that might be a good time to change the orientation of the hub so minimal oil is lost.

RonS

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Re: oil puddle during sprocket change
« Reply #6 on: May 17, 2024, 12:00:45 am »
I use an" impact wrench" style method for removing the sprocket. That is, once the chain whip and wrench are set up opposite to each other I lift the wheel about 6 inches off the ground and drop it and push down on the wrenches at the same time.  This usually gives enough shock load that it really doesn't take much effort to break the sprocket free. It can pretty much be removed by hand after that, so, like mickeg, I just lay the wheel flat on the ground, sprocket up. That way there is almost no oil loss.

PH

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Re: oil puddle during sprocket change
« Reply #7 on: Today at 12:01:29 pm »
Just an idea, rather than a theory - Maybe the oil that was behind the sprocket was already there? maybe it wasn't the fresh oil you'd just added.
E-wan may never need to unscrew the carrier again, so advice on doing so may be redundant.  Though just for interest, I use the squeeze method for breaking the bond, wheel on lap, chainwhip and spanner close together and squeeze with both hands.
Quote
If normal should I now perform another oil change to replace the lost oil?
If you've bought bulk oil and want the reassurance, it'd do no harm and isn't a huge expense.  I don't think it necessary, Rohloff say that even if you lost all the oil there would be enough coating the parts to last till your next scheduled oil change. The oil change method I use, similar to that recommended by Andy Blance, only leaves 7ml of lose oil in the hub, I'm pretty sure that's all disappeared before it's due for a change.