Hammering the bearings

[sillyme]

I have two Rohloff hubs, never needed any service besides the regular oil changes so i never bothered to read about them... I am not mechanically inclined so i did not develop  a passion for the complicated internals, mostly i was sold on the covenience and lack of maintenance. But recently one of the hubs started skipping so, while researching, i stumbled upon this board.

So, here's my problem:

Gears 1-5 work fine but 6 and some others above produce a loud ping and a momentary skip.

From a post on mtbr.com i proceded to go down a short checklist of possible causes:

First I found the QR skewer to be quite firmly tightened, which i did not know was verboten. But when loosening it, the skipping did not go away, in fact it seemed louder, though that might be because of the echo in the garage.

Then i removed the wheel and checked for sprocket tightness and indeed it felt really tight. I wasn't sure so i compared it with the other hub that is working ok, and that one seemed tight too, though somewhat looser. Now that i think of it, on this looser hub there's some drag on the pedals while freewheeling. It is mounted on a Cannondale Bad Boy with an EBB. The tighter hub may have the same symptom, but it is mounted on a full suspension bike with a chain tensioner that is pretty tight, the pressure from the chain tensioner may prevent the force from transmitting onto the pedals. I'm not sure how to check this or if it is important, as the hubs can't be switched into each other's frame, they have different axle plates.

I suspect i have to take a rubber mallet to both axles, but i have found some conflicting information: mtbr posters say 2x plate side then 1x cog side, but the latest version on the rohloff website says 1x cog side, then 1x axle plate side.

So which is it? Does the order really matter? Can i ruin the bearings or other parts they touch (axle, housing) by doing this? I have a lot invested in these hubs and i wouldn't want to rush into hammering and break stuff with my lack of mechanical skills.

I hope you guys can sort this out. Thanks for reading so far, and i apologize for such a long message.

Regards,
Alex

[sillyme]

I noticed this comment here:

How much slippage is occurring, is the hub engaging after 1/4 of a crank or not at all?  Also is it only happing once after a gear change some time after a gear change or many times while in the same gear?  

I have the same problem, but i think my hub is only skipping once after a gear change into 6th and a few other higher gears. The amount of skip also seems to be dependent on the gear, the higher the gear the less skip. Does that give me hope of it being a quick fix?

[geocycle]

Sorry to hear about the problems.  I'd not go about hammering anything!  I would suggest an extended flush of cleaner and then change the oil.  If problem still persists then call rohloff fpr advice.

[expr]

It is ok to use a rubber shot mallet on the non drive side, but this will only help to alleviate any internal stress through misalignment of the bearings, symptoms being crank trying to spin while pushing the bike etc...

the problem you have needs to go back to rohloff to be re shimmed!

[onmybike]

I solved a similar problem on tour by removing the wheel, then removing a rubber soled shoe... and simply whacking the ends of the axle with said shoe's heel. Low tech I know, but give it a go before you get too worried about this. The problem hasn't recurred.

[stutho]

+1 to try a mallet! It may or may not work but this is the prescribed procedure by Rohloff.  I would also try running for with the flush oil for a good 100 miles. 

However I think that you may end up sending the hub to Rohloff for re-shimming