Shimano Nexus Inter8 hard to twist grip shift in higher gears

Question

After my local bike shop did a tune-up on my HaiBike Radius, it has become very hard to twist my grip shift into higher gears when I am riding. The grips shift twists easily when I shift down or when the bike is stationary. When I ride, it is so hard to twist that my wrist is sore by the time I get to work. My bike has a Shimano Nexus Inter8 SG-C6001 internally geared hub. I took it back to the bike shop but they said that this is normal because the grip shift is connected to a cable that pulls on a spring. As you shift into higher gears, the spring gets extended and it is harder to twist. I just don't think this is normal since it is noticeably different than before the tune-up. The bike shop said they replaced the gear cable from the grip shift to the hub during the tune-up. The yellow markers are aligned.

I am going to show the bike shop the response that user26705 provided Kurdunas and the response that Swifty provided Grigory Rechistov but my question is:

Is there anything else that the bike shop could try to reduce some of the force needed to shift into higher gears?

Unfortunately, I do not have the tools etc to complete my own repairs.

Thanks for the help!

Answer 1

If it wasn't like that before, but it is now following a cable change, there's not a lot that can explain that other than a problem with the setup of the new cable and/or housing. Common examples could be:

• Bad routing choices.
• Housing too long or too short.
• A kink in the cable or housing.
• Bad housing end prep.
• Liners or nosed ferrules left out that are needed to reduce friction.
• Mid-drive motor pinching down on the housing once mounting hardware is secured.