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The hub has just been serviced at a bike shop. With the bike on a work-stand, the rear wheel rotates when I turn the pedals backwards. There is a lot of resistance if I hold the wheel and turn the pedals backwards. If I turn the pedals forwards and stop suddenly, the wheel will stop turning within 3 - 4 rotations instead of free-wheeling for 30 seconds or so. With the chain removed, the wheel rotates completely freely. I had earlier complained to the shop about loose wheel bearings after the service and they 'fixed' this problem. It was then I discovered the stiff rotational resistance on the sprocket. Regards.

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  • 4
    Take it back to the shop and complain. They messed up!
    – Carel
    Jun 24 '16 at 11:02
  • 5
    No respectable shop should have returned a bike in this condition. Jun 24 '16 at 11:58
  • But one thing to check: Examine the wheel closely, while it's off the bike, and make sure nothing (eg, a piece of string or a fragment of twig) has gotten wedged between the sprocket cluster and the hub. Jun 24 '16 at 20:50
  • There's a problem with the lubricant in the hub which isn't letting the internal gears rotate freely. Or when they 'serviced' it they over tightened something they weren't supposed to
    – c10yas
    Jun 25 '16 at 3:45
  • Thanks for advice. The last one is the most likely. The wheel has been to the shop 3 times. Will try and disassemble the hub myself without disturbing the actual gear mechanism.
    – Rollercone
    Jun 25 '16 at 11:50
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OK. I love the nexus series. They are great pieces of kit with a lot of utility in crappy environments. Low maintenance, ease of use and nearly bullet proof.

Except when it comes to water. Your model uses grease to lubricate the internals, not oil. Water intrusion, even in small amounts, will cause the symptoms you describe. The hub most likely needs to be taken apart, cleaned and repacked with the super special shimano grease (I wouldn't play with that one here as the wrong grease might cause damage.) It's pretty straightforward if you take your time. For more information, including diagrams, instructions and shimano factory manuals go to Sheldon Brown's (RIP) at Nexus Internal Gear

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  • The hub had just been taken apart and repacked with Shimano's recommended grease, according to the bike shop. The gears work very well; it's just the free-wheeling resistance I don't like. May just have to live with it.
    – Rollercone
    Jul 8 '16 at 14:41
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    NO, you shouldn't have to live with it. So you are saying that when you turn the cog it doesn't rotate backwards as easily. Suspend the bike (or turn it upside down) and spin the wheel whilst in 1st gear. Give it a good turn and standardize this for the rest of the gears. Does the wheel turn the same amount of time (in seconds) in each gear?
    – user26705
    Jul 8 '16 at 15:46
  • Hello B Team. Applying the same pedal force each time, the rear wheel spun for 3 secs in 1st gear, increasing to 4 secs in 7th gear. The difference is basically negligible. Each time I spun the crank, I stopped it after 1 revolution. Maybe I should rotate the crank and let the wheel's momentum spin the pedals until stop. Could give a different result and help identify the friction area.
    – Rollercone
    Jul 12 '16 at 6:52
  • Take wheel off of bike and place an axle in each hand. Spin the wheel and see how long it goes for. Also, what type of brakes are you using on your bike? Rim, roller brakes , discs?
    – user26705
    Jul 12 '16 at 14:31
  • Removed the wheel and got max 7 secs spinning on the axle. Bike has "V" brakes.
    – Rollercone
    Jul 14 '16 at 6:26

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