Mine does the same thing and Trek has warrantied my complete headset twice and it still does the same thing. No one can figure out what is going on but it doesn't affect the steering at all and the fork doesn't come in contact with the frame.


Sent from my iPhone using Tapatalk

 

I would move the spacers out from underneath the stem to above the stem and try again. Make sure that the stem is engaging with the HS top cap with no spacers in between.

I'd venture to guess that what your seeing is due to intolerances in the spacers.


Sent from my iPhone using Tapatalk

 

Yeah. There's a small amount of rotational play between the stem, each spacer and the top cap that add to allow a bit of rotation.

 

Video with just the headset cap, still some play in it:

There is less play without the spacers, still get a lot of friction and getting the stem onto the notches of the cap is extremely tight. Seems like the tolerance between the knock block cap and steerer somehow became a bit too tight.

 

Video of the knock block hub assembly cap:

Going to try and warranty through Trek tomorrow. Doesnt seem like it should be like this.

 

By the look of that tab, that would be why it seams like a lot of friction and tight to get the notch in the stem. Looks really distorted.


Sent from my iPhone using Tapatalk

 

Hi boys.
I have your same problems whith the knock block.
Have you resolved it?

Inviato dal mio SM-G930F utilizzando Tapatalk

 

The conclusion i've come to is that the bearing cap has a small ramp. There is not really any way to fix this other than to grind the ramp down. I would suggest keeping it lubricated because if you don't, the metal will wear and make the cap/spacers difficult to remove when you need to replace/do maintenance to the headset.

All the bikes I own do this exact same thing:

2018 Slash Frameset (I ordered this as a frame and built the rest)
2017 Remedy 9.8
2017 Powerfly 8 FS

Some are slightly worse, some are better... depends on which has the most wear. Almost all the bikes I checked at the bike shop seem to do it to some degree as well. There is no solution at this time that we have gotten from Trek or anyone else. Lubricating doesn't change the amount that I can turn it or how smooth it is.

My guess is it's meant to slow the ramp to full lock. Doesn't make much sense but that's the only thing I can see. If you complain to Trek the best i've gotten is an offer of a new headset.

 

I get it. Thank you for your reply.

Inviato dal mio SM-G930F utilizzando Tapatalk

 

Mine’s the same. I thought “they’re all like that”.
Will need to keep an eye on it for sure.

 

Is this issue specific to 2017 or does the 2018 Remedy have the same issue?

 

Not an expert on this by any stretch but do you think the lock ring spacer may help this since it would only be 1 interface instead if 3? I believe it clamps on the steerer tube at the bottom of the stack and meshes with the knock block bearing cap.

 

There is a 2021 model trek slash.

I had a small accident today. and i have the same problem.I opened the pieces. but there seems to be no problem. I'll go to the bike shop tomorrow and compare

 

There is a 2021 model trek slash.

I had a small accident today. and i have the same problem.I opened the pieces. but there seems to be no problem. I'll go to the bike shop tomorrow and compare

What did the bike shop find?

 

They all do this and it seems intentionally designed

 

There is a little bit of free play between each knock block spacer ring and the next. There are 3 spacer rings on my Rail 7 so it all adds up to a noticeable movement. If you draw a chalk mark down the stack of spacers, then turn the bars from one lock to the other, you'll see the chalk marks get slightly misaligned, then realign when you return the bars to the original position.
The reason you feel a bit of resistance before hitting the limit is due to the friction between the rings. If it bothers you, try using less torque when you tighten the head stem cap.

 

Guys and Gals, let's face it. Knock Block ain't designed well.