Steering knock blocks

Hattori-Hanzo

Active member
Apr 10, 2023
270
278
UK
Had a slight off during the week and managed to twist the handlebars off centre.
I loosened the stem bolts and put the bars back straight but when turning the knock blocks are off centre restricting turning in one direction.

I want to drop the forks out and correct this, has any one done this before as I'm not sure how they work?
is it possible to remove them entirely or is it best to keep them in and just centre them.

Any help on the process is greatly appreciated (y)
 

Overkillit

Member
Aug 23, 2022
39
21
Downingtown
I don't have an answer but I had a similar experience with a Trek. After a minor wreck, I found that the knock-block had been forced just past the stopping point, and even though I had the shop "fix" this, it lost that solid stopping point. From that point on it had a softer stopping point that never felt right - like as if the nub had been slightly sheered but I couldn't find that and neither could the shop. I found a video on how to remove this on a Trek but I don't know if it applies to your bike.
 

RipGroove

Active member
Jun 3, 2022
375
185
Glos/UK
I may be wrong but I believe the cubes steering lock is built into the headset a bit like the image below, so if thats the case whats possibly happened is your headset cup gas slipped round in the frame a bit.

Not an actual Cube headset, but I believe the Cube has something similar
IMG_0010_2.jpg
 

RipGroove

Active member
Jun 3, 2022
375
185
Glos/UK
Some of the Cubes use an ACROS AZF-1035 headset that has the built in 120° lock, so maybe worth trying to find some images of that to give you an idea of what might have happened.
 

Hattori-Hanzo

Active member
Apr 10, 2023
270
278
UK
Thanks for the info RipGroove.
Just had a look at the specs for my bike and it has the ACROS AZF-1035.

Looks like I'll need to remove the cup and re centre it :(
 

RipGroove

Active member
Jun 3, 2022
375
185
Glos/UK
Thanks for the info RipGroove.
Just had a look at the specs for my bike and it has the ACROS AZF-1035.

Looks like I'll need to remove the cup and re centre it :(
No worries, I was just about to post the link where you could find the exact spec of your bike, here it is for anyone searching for it in the future:


I'd be interested in seeing some photos if you take it apart because mine is listed as this and I want to know what it looks like inside and also the possibility of being able to replace it with something better. .

ACROS AZF-1035, ICR (Integrated Cable Routing), BlockLock 120°, Top Zero-Stack 1 1/2" (ZS 56mm), Bottom Zero-Stack 1 1/2" (ZS 56mm)

Unfortunately on the size Medium Stereo 160 ('22 & '23) you have to have a steering lock of some sort because the top of the forks will hit the downtube so changing the headset for a different brand could be tricky or even impossible
 
Last edited:

steve_sordy

Wedding Crasher
Nov 5, 2018
8,472
8,732
Lincolnshire, UK
@Hattori-Hanzo Before you start dismantling anything....

I too have a stop block and I noticed after an off that the bars were not even when it came to turning the wheel left or right. I didn't think much about it, I just did this:
I trapped the wheel between my legs, held the bars at the grips, and turned the bars steadily and with increasing force until the lock block restraint was where I wanted it; ie even on both sides.

I have had zero problems since.

PS: I have a Merida eOne-Sixty. It has a Merida Expert eTRII stem and a MERIDA-8152 headset.
 

Hattori-Hanzo

Active member
Apr 10, 2023
270
278
UK
Had a quick look at this today, took the bars and stem off the steerer tube but it looks like it's going to be a total pain in the arse to get to the bearings and knock block.
With all the cables and wires running through the head set, it's likely I'll have to strip the whole front end down to gain access.

With the head set loose I did manage to even the stop blocks out by applying pressure in the opposite direction to the off set side.
I'm not 100% sure but I think this has rotated the cups in the frame back to centre. Not ideal for this to keep happening with a carbon frame, I'm wondering if it does need stripping down and the cups removed then reinserted with a carbon grip paste, like you'd use on the bars and stem?

For now the stop blocks are back to where they should be.......until I crash again 😩
 

RipGroove

Active member
Jun 3, 2022
375
185
Glos/UK
Had a quick look at this today, took the bars and stem off the steerer tube but it looks like it's going to be a total pain in the arse to get to the bearings and knock block.
With all the cables and wires running through the head set, it's likely I'll have to strip the whole front end down to gain access.

With the head set loose I did manage to even the stop blocks out by applying pressure in the opposite direction to the off set side.
I'm not 100% sure but I think this has rotated the cups in the frame back to centre. Not ideal for this to keep happening with a carbon frame, I'm wondering if it does need stripping down and the cups removed then reinserted with a carbon grip paste, like you'd use on the bars and stem?

For now the stop blocks are back to where they should be.......until I crash again 😩
Yeah I figured that's what would have happened, not technically concerning as at the end of the day headset cups are just pressed into the frame without anything holding them rotationally so of course they will rotate if forced. Gripper paste may help to a degree but the cups will still move given enough force. Poor design choice for a steering lock IMO, what concerns me is that on some bike models and frame size variants the forks will hit the frame if the headset cup rotates during a crash. Would Cube warranty a carbon frame that's had a fork crown smashed into it because their steering lock of choice failed during a crash? Probably not.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,179
4,699
Weymouth
I have yet to see a knock block design that would prevent the forks hitting the frame in a decent crash...sometimes not even that! It is a stupid idea. The best solution is to research ways to lower the fork crown such that is does not hit the frame and I believe there are some on this forum that have done that..........maybe do a search?
 

RipGroove

Active member
Jun 3, 2022
375
185
Glos/UK
I have yet to see a knock block design that would prevent the forks hitting the frame in a decent crash...sometimes not even that! It is a stupid idea. The best solution is to research ways to lower the fork crown such that is does not hit the frame and I believe there are some on this forum that have done that..........maybe do a search?
I was thinking of machining a spacer to go under the bottom of the headtube somewhere but you have to wonder why they've designed it like that in the first place, a different fork crown shape would solve it too. Obviously the geo would be affected if you dropped the forks by 15 or 20mm or whatever it needs to be and obviously you'd also void your warranty. Just seems like an odd design choice to me because it's a potential point of failure, the knock stop slips round and the forks hit the carbon frame. People crash MTBs all the time so it's not out of the realms of possibility at all.
 

cube160

New Member
Mar 1, 2024
2
0
Kent
Hi everyone, I'm new too this.
I have the same problem.
I'm wondering if the stop block can be removed, is it conected to the bearing at all, eg is this a special bearing with a stop block added on? has any one given this a go? I'm thinking this as when I turn the bars, they miss the frame, so I see no need for it.
Also does anyone know how to remove the stop block bit that on the fork? Is this just pressed onto the fork?
 

cube160

New Member
Mar 1, 2024
2
0
Kent
Hi everyone, I'm new too this.
I have the same problem.
I'm wondering if the stop block can be removed, is it conected to the bearing at all, eg is this a special bearing with a stop block added on? has any one given this a go? I'm thinking this as when I turn the bars, they miss the frame, so I see no need for it.
Also does anyone know how to remove the stop block bit that on the fork? Is this just pressed onto
I've just looked again, the handle bars won't hit the top tube, top. But the top Fork will hit the battery cover
 

AndyS2

New Member
Jul 31, 2023
7
5
sheffield
I had the same problem the other day after a minor off, its easy to fix. Mine looked like the picture in post #5, so take the pinch bolt out of the stem, remove the handlebars and let the forks drop down to expose the bottom of the stem, the lock stop ring is just pressed onto the stem, so I just used a small pin punch to tap it back round until it was central.
 

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