Gears skipping in lower ratios

[E-wan]

Hi

I'm heading out on a tour for a few days tomorrow and have taken my Mk 2 nomad (it's around 12 years old) for a test ride fully laden this morning.

I've noticed that the gears seem to be skipping in some of the lower ratios, particularly gears three and five.

I've always serviced the hub regularly and double flushed it with cleaning oil each time.

Any suggestions on what might be causing this what I might be able to do to remedy it or work around it before I leave tomorrow.

Thanks

Ewan

[in4]

Slipping gears in a Rohloff Speedhub can be caused by several factors:

   1.   Incorrect Cable Tension: If the gear cables are not properly tensioned, it can lead to improper gear shifting and slippage. Make sure the cables are adjusted according to the manufacturer’s specifications.
   2.   Worn or Dirty Gear Cables: Cables that are worn, frayed, or dirty can cause poor gear engagement. Regular maintenance and replacement of cables can prevent this issue.
   3.   Improper Gearbox Maintenance: The internal mechanism of the Rohloff hub needs regular maintenance, including oil changes. Neglecting this can lead to wear and slippage.
   4.   Internal Wear and Tear: Over time, internal components of the hub may wear out, which can cause gears to slip. This typically requires professional inspection and potentially replacing worn parts.
   5.   Incorrect Shifter Position: If the shifter is not properly aligned or has moved out of position, it can result in incomplete gear engagement and slippage.
   6.   Contamination Inside the Hub: Water or dirt ingress into the hub can affect its performance, leading to slipping gears. Ensuring proper seals and regular maintenance can help prevent this.

Addressing these issues typically involves checking and adjusting the cable tension, inspecting and possibly replacing cables, ensuring regular maintenance of the hub, and making sure the shifter is properly aligned. If these steps don’t resolve the problem, it might be necessary to consult a professional bike mechanic or the manufacturer for further diagnosis and repair.

From ChatGPT

[E-wan]

Any good videos on adjusting and checking cable tension?

[mickeg]

Any good videos on adjusting and checking cable tension?

You do not need a video.  Just make sure that they are loose enough.  For example, if I am in gear 10, my shifter knob will easily turn from about 9.5 to 10.5 from the slack in the cables.

Adjusters are where the cables go into the EX box in back near the hub.

But if your slipping problem is specific to a few gears, this is unlikely to be the problem.

Not from any form of AI.

[martinf]

Link to the appropriate Rohloff FAQ page:

https://www.rohloff-au.com/faq-gear-loss-slipping

They don't mention cable issues. Not so long ago I accidently bent one of the aluminium gear cable adjusters. Until I replaced this adjuster, shifting was stiff due to excessive friction in the cable at the bend, which is how I noticed the bent adjuster. But I experienced no slipping in the gears. If the shifter turns easily and the cables both move, slipping is IMO very unlikely to be due to a cable issue. 

Maybe number 6 in the FAQ page - a very worn sprocket or chain, or perhaps a new chain on a worn sprocket or vice-versa ? Never had this on a large-wheel bike with hub gears, but I have had what I call chain "skipping" with small sprockets on derailleur gears and with hub geared Bromptons that use 13T sprockets as standard.

If it's not that, I'd try number 1 in the FAQ page - a double rinse and oil change, this might flush out any metal particles blocking pawl operation.

Numbers 2 and 7 are probably not relevant, number 5 unlikely unless you have recently adjusted the axle plate.

Number 4 is easy to check visually, number 3 is also easy to check if you have a suitable torque wrench. 

If it's none of these, you will probably need to take or send the hub to a good Rohloff dealer, for example SJS, especially if you got the hub from them.

[PH]

If the slippage is predictable, but it into one of those gears, disconnect the cable and see if it still does it.  You'll them know if the issue is the cable or hub.

[mickeg]

When I first built up my Rohloff bike, I did not know anyone that had a Rohloff and no local dealers sold Rohloff bikes.  Thus I was on my own for learning this stuff.

Initially I had my cables too tight, I was used to derailleur gearing where they are supposed to be tight.  Sometimes when I shifted, the indexing did not reliably put me into a specific gear, but instead some place in between gears.  I think that is where the comment on slipping comes from if the cables are not adjusted right.

I eventually got used to needing my cables to have a lot of slack for proper shifting to occur.

This is another thread on slipping gears, in this case the owner got lucky and Rohloff covered cost for new internals.
https://thorncyclesforum.co.uk/index.php?topic=14848.0