Head tube issue on Delite GX Rohloff HS.

[pedelecsva]

Hi.

I have a 1,5 month old Delite GX Rohloff HS, and I've been experiencing "shimmy" or "wobble" if taking my hands of the handle bars.

Video of the shimmy -

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I decided to take the Head tube apart to see for myself what was going on. I was a little surprised to see that the two bearings had little to no grease, and that both were starting to deteriorate on a $9000 bike...
Another thing that made me wonder, was the way it was assembled. There was no head tube adjustment bolt, but there is no top cap either, so maybe this is why. I've never really had to take a top tube apart before, so can anyone tell me if this is perfectly normal?

Pictures of the dissembled head tube -

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Thanks.

 

[VarioHSDelite]

wow that video was terrible (called that a death wobble on fords.) I don't know what i'm looking at either on that stem and all that, so hopefully someone can chime in with more knowledge


Where'd you buy that in Va? Charlie?

 

[batmick1]

Those are cartridge bearings. The grease and actual moving parts are under those blue rings (do not lift those out). The rust you see likely ran down the tube from higher up when it was raining and is likely not from the actual bearings but from the clamp bolts or something like that. You cannot adjust cartridge bearings like you could the conventional type. They are held in place by the frame and fork hardware.
That shimmy in the video reminds me more of something from a loose wheel bearing but I will not begin to remote diagnose. Take it to your dealer and have them figure it out.

 

[smorgasbord]

That sure looks like a loose headset. Does your Delite have the Acros Block Lock headset? If so, it doesn't use the central bolt into a star nut to adjust. Instead it has a lock ring that you twist to adjust the bearing preload. This enables them to have that stem with the built-in display and even cable management. See this video:

You don't want to tighten headset bearings too much. Just snug enough to not wobble.

There are apparently a few different versions of this headset around. If you don't have that set screw adjustment, you should check this thread out: https://electricbikereview.com/forums/threads/stem-headset-adjustment-on-a-delite.28445/

If so, post #7 seems to have the right answer.

 

[pedelecsva]

That sure looks like a loose headset. Does your Delite have the Acros Block Lock headset? If so, it doesn't use the central bolt into a star nut to adjust. Instead it has a lock ring that you twist to adjust the bearing preload. This enables them to have that stem with the built-in display and even cable management. See this video:

You don't want to tighten headset bearings too much. Just snug enough to not wobble.

There are apparently a few different versions of this headset around. If you don't have that set screw adjustment, you should check this thread out: https://electricbikereview.com/forums/threads/stem-headset-adjustment-on-a-delite.28445/

If so, post #7 seems to have the right answer.

Thank you. That was most helpful. As I disassembled the bike, I got the understanding that this was how it worked. The spacer was completely loose, but it has not helped a whole lot after I’ve given it a thorough checkup. I’ve done another check today, so I will see how it turns out tomorrow when I go to work.

 

[pedelecsva]

It did help a lot. On my ride to work the shimmy was gone... but on my way home, it came back. So i've tried to adjust the two spacers again, and hopefully this will do the trick.

My Bike dealer suggested that I'd increase the pressure in forks and wheels, but this didn't help. My experience from motorcycles tells me the problem is the headtube... Like it is suggested here. My Bike store has sent the video to R&M to see what they have to say.

 

[Chris Nolte]

If your headset was previously loose and ridden that way for some time it’s possible that the headset bearing became compressed and needs to be replaced.

Have you used the 33mm (I think that’s the size) wrenches to tighten the compression underneath the stem? You’ll also need to tighten the set screw which is a 2 or 2.5mm (going from memory at the moment).

It’s also important to tighten the stem bolts to the appropriate torque rating as there is no top cap so that friction is what holds the compression. If they aren’t tight enough it’s possible for the stem to loosen up.

 

[pedelecsva]

Thanks Chris.

I did ride 900 km before I became aware of the wobble. I don’t know if it has evolved during these 900km, or if it was there from the start. I don’t ride that much with no hands

The compression rings and the set screw was completely loose when i began to inspect the head tube after experiencing the wobble the first time.

Everything is nice and tight right now, (not over tightened). But especially the stem bolts as I don’t want to drive around with a loose handle bar all of a sudden.

Hopefully no damage has been made to the bearings.