Non-ICR headset, internal frame cable guide conversion for the SZZS-specific CEF50

TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
Acros now has the ZS66/40 lower bearing set in stock (they were out for a while) and ready for order so I was going to order that from Germany for the CEF50 but now they also have the non-IRC headset also available (ZS56/28.6) but has two options in a drop-down box when ordering (OD 63mm or OD 62mm). No other upper headset has this option that I have seen.

Which of the two would be correct the CEF 50 the 63 or 62mm OD? I was planning on getting the Hope for the upper but just ordering the one lower bearing from Acros the shipping cost is a lot but the same to get the upper a long with it. I acknowledge the Hope has greater bling factor but Acros is German. Plus it just feels better to get both from the same manufacturer for some reason and be done with it.

Thoughts?
Yeah, I've never seen the 63/62 mm option. And since my top cup is installed I can't easily measure headtube OD.

4 possibilities.
1. Ask SZZS the headtub ODs. (Might take a while).
2. Buy both 63 and 62 mm (more costly for return shipping so probably eat the cost or eBay it.)
3. Order the Hope in black to match.
4. Or maybe go to Hope Tech website and download the headset specs to compare OD fitment. Whatever Hope specs are they'll tell you if 63 or 62 fits.
 

ficorama

Active member
Oct 9, 2021
375
302
Croatia
Acros now has the ZS66/40 lower bearing set in stock (they were out for a while) and ready for order so I was going to order that from Germany for the CEF50 but now they also have the non-IRC headset also available (ZS56/28.6) but has two options in a drop-down box when ordering (OD 63mm or OD 62mm). No other upper headset has this option that I have seen.

Which of the two would be correct the CEF 50 the 63 or 62mm OD? I was planning on getting the Hope for the upper but just ordering the one lower bearing from Acros the shipping cost is a lot but the same to get the upper a long with it. I acknowledge the Hope has greater bling factor but Acros is German. Plus it just feels better to get both from the same manufacturer for some reason and be done with it.

Thoughts?
and what's wrong with the original headset?
 

PaulH

New Member
Apr 23, 2024
29
22
Dallas, Texas USA
and what's wrong with the original headset?
I await my bike so do not have any personal experience but these CEF50 forums describe a variety of issues with creaking and excessive cable/hose/wire wear being the most common and slop and grinding being second. That's my general understanding from reading here. I assume though there are an untold number of owners with no issues I just want to be prepared for when it arrives to minimize possible downtime.
 

TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
I await my bike so do not have any personal experience but these CEF50 forums describe a variety of issues with creaking and excessive cable/hose/wire wear being the most common and slop and grinding being second. That's my general understanding from reading here. I assume though there are an untold number of owners with no issues I just want to be prepared for when it arrives to minimize possible downtime.
I think you're going the right route. Most of the OEM hardware from these direct factory purchases are inferior, often out of spec or just have low spec bearings. I had to gamble with the top ICR headset going with SZZS. And got burned twice.

But the issue for traditional frame cable routing was that on the frames this year, there were many issues of headset slop, so they started gluing in the top bearing cup only. A few were able to remove easily with a headset press/remover. One guy just requested a no-glued top/bottom cup frame successfully before they shipped.

One guy used their headset non-ICR successfully with a few shims, but still he changed out bearing with high-end Enduro brand (Hope uses them too for crappy UK mud and rain). And it sounds like one other now.👍

Overall, going aftermarket for the headset insures durability and precision across the board. It's a simple, cheap upgrade on a critical area.👊
 
Last edited:

PaulH

New Member
Apr 23, 2024
29
22
Dallas, Texas USA
Yeah, I've never seen the 63/62 mm option. And since my top cup is installed I can't easily measure headtube OD.

4 possibilities.
1. Ask SZZS the headtub ODs. (Might take a while).
2. Buy both 63 and 62 mm (more costly for return shipping so probably eat the cost or eBay it.)
3. Order the Hope in black to match.
4. Or maybe go to Hope Tech website and download the headset specs to compare OD fitment. Whatever Hope specs are they'll tell you if 63 or 62 fit

Yeah, I've never seen the 63/62 mm option. And since my top cup is installed I can't easily measure headtube OD.

4 possibilities.
1. Ask SZZS the headtub ODs. (Might take a while).
2. Buy both 63 and 62 mm (more costly for return shipping so probably eat the cost or eBay it.)
3. Order the Hope in black to match.
4. Or maybe go to Hope Tech website and download the headset specs to compare OD fitment. Whatever Hope specs are they'll tell you if 63 or 62 fits.
Great tips! And just as a follow-up the CEF50 head tube upper OD is 62mm. The option from Acros for 63mm apparently is to account for wear in some frames.

My CEF50 is mid-Pacific and making good time at 20 knots!! Can't wait to start putting this all together.
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
@TCFlowClyde when you did conversion to non-ICR headset, did you keep your cable housings used with ICR headset? I have the same layout as you (shifter/brake on the left, dropper on the right) and I'm wondering if their length will suffice. I'd rather avoid replacing the housings as routing the shifter and brake housings through rear triangle with foam damping was extreme pain. I think I've left some slack in the housings in case I need to make cuts.
 

TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
@TCFlowClyde when you did conversion to non-ICR headset, did you keep your cable housings used with ICR headset? I have the same layout as you (shifter/brake on the left, dropper on the right) and I'm wondering if their length will suffice. I'd rather avoid replacing the housings as routing the shifter and brake housings through rear triangle with foam damping was extreme pain. I think I've left some slack in the housings in case I need to make cuts.
I kept the brake line and luckily fit. But I switched out dropper due to abrasion from friction movement. I have wireless shifting.
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
I'm planning to perform non-ICR conversion this weekend. My biggest worry is that the bearing cups of my new headset (upper nukeproof, lower acros) will come loose just like the current SZZT's cups which were factory glued in. Did you encounter this problem, should I be prepared to glue them with Loctite 603 just like SZZT did?
 

TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
I'm planning to perform non-ICR conversion this weekend. My biggest worry is that the bearing cups of my new headset (upper nukeproof, lower acros) will come loose just like the current SZZT's cups which were factory glued in. Did you encounter this problem, should I be prepared to glue them with Loctite 603 just like SZZT did?
I didn't encounter any issues...the upper cup bearing assembly was a snug fit for my Hope ZS56 bearing/cup assembly. I tapped it with a 2x4 pine wood block. My frame should be from the same mould but never was headset pre-glued as an early first batch customer. So, hoping specs will be equivalent for subsequent batches.🤞

Worst case...glue it if you have to and then request a warranty replacement frame that is not pre-glued? It still should be under the SZZS one year warranty. 💸
 
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voigtkampff

Member
Oct 18, 2023
97
97
Poland
the good
  • carving holes in the frame went without issues
  • existing cable housings are long enough so that I don't have to replace them
  • so far no creaking or knocking on impact, even though I replaced only the upper headset assembly with Nukeproof
the bad
  • my worries about loose cups were valid, I can easily press and remove the new cups with my bare hands - I've ordered Loctite 603 to glue them in, also I'm thinking about some other ways to ensure tight fit - a piece of foil wrapped around the cup?
the ugly
  • I could not press the Acros crown race onto the steering tube, this definitely requires special tool like a piece of pipe; so far I've left the lower ZSST headset in place. I will install Acros later. Anyway, lower part of ZSST headset wasn't problematic, I just don't have much trust in its quality.

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TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
the good
  • carving holes in the frame went without issues
  • existing cable housings are long enough so that I don't have to replace them
  • so far no creaking or knocking on impact, even though I replaced only the upper headset assembly with Nukeproof
the bad
  • my worries about loose cups were valid, I can easily press and remove the new cups with my bare hands - I've ordered Loctite 603 to glue them in, also I'm thinking about some other ways to ensure tight fit - a piece of foil wrapped around the cup?
the ugly
  • I could not press the Acros crown race onto the steering tube, this definitely requires special tool like a piece of pipe; so far I've left the lower ZSST headset in place. I will install Acros later. Anyway, lower part of ZSST headset wasn't problematic, I just don't have much trust in its quality.

View attachment 142974
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View attachment 142982
Looks great!👑
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
I have this idea regarding loose bearing cups: I could take strips of carbon fiber cloth (or even CF prepeg) and glue it inside the headtube openings with resin or structural adhesive like 3M DP190, maybe even using a latex baloon to ensure proper pressure for bonding to the frame. This will obviously create uneven and too thick a layer, so as a next step I'd take it to a specialized bike shop to use headset facing machine to grind it to a proper thickness.

The problems I see:
- I've never worked with CF before (I did some glass fiber work, I guess it won't be much different)
- I'm not sure I'll be able to impregnate CF with resin properly or buy prepegs anywhere around
- I'm not sure I'll be able to find a workshop with headset facing machine anywhere around and even then they might not have heads for this wide and rarely used cup diameter, is there any DIY method to do this?
- I'm not sure I'll be able to do this with good enough precision to maintain tolerances needed in this area, given this would be my first CF work

What do you think about this, any ideas?
 

TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
I have this idea regarding loose bearing cups: I could take strips of carbon fiber cloth (or even CF prepeg) and glue it inside the headtube openings with resin or structural adhesive like 3M DP190, maybe even using a latex baloon to ensure proper pressure for bonding to the frame. This will obviously create uneven and too thick a layer, so as a next step I'd take it to a specialized bike shop to use headset facing machine to grind it to a proper thickness.

The problems I see:
- I've never worked with CF before (I did some glass fiber work, I guess it won't be much different)
- I'm not sure I'll be able to impregnate CF with resin properly or buy prepegs anywhere around
- I'm not sur,,,e I'll be able to find a workshop with headset facing machine anywhere around and even then they might not have heads for this wide and rarely used cup diameter, is there any DIY method to do this?
- I'm not sure I'll be able to do this with good enough precision to maintain tolerances needed in this area, given this would be my first CF work

What do you think about this, any ideas?
So your using the ZS 56/66 aftermarket cups correctly, that is Nukproof up top and the Acros below?

You removed the previously glued-in SZZS factory cups successfully.

Now there is play with new ones,?

Or you insert them by hand with some resistance like light tapping? I also greased mine with waterproof type grease.

As long as there is no movement with the new aftermarket cups you should be fine. The key would be that they don't simply fall out when inverted.

On my first frame, it was factory matte black, super thin paint. The cups went in with slightly less resistance then on my second (warranty frame) DIY painted frame (3 spray color coats + 2 clear coats).

I didn't face them and had to only lightly tap in with a flat 2x4 lumber block and mallet/hammer. I used water proof grease on the headtube and wiped off excess when snuggly seated.

I think you should be alright re-gluing them in since that seems to work direct from the factory.

Me personally, I would just use primer grey paint and spray a few coats in order to build up the layer thickness s little. I just never heard of cups that can be glued into the frame, so that is an unknown variable.

Just for reference. I've had a total of 5 Chinese direct factory carbon frames. 4 were ZS cups. All were slightly variances, all were DIY painted unfaced. All snugged in using my method describes above, that is light tapping with wood block/hammer, no formal headset press. No problems years later.💪

Again bottom-line. Unless the cups move after greasing them in, that should solve it! 🤞
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
So your using the ZS 56/66 aftermarket cups correctly, that is Nukproof up top and the Acros below?
correct

You removed the previously glued-in SZZS factory cups successfully.

yup, without any effort, the glue wasn't strong

Now there is play with new ones,?

there is no noticeable play on the handlebar while riding nor in the bearings. the only real problem is that the bowls can be removed with ease without any tools.

Or you insert them by hand with some resistance like light tapping? I also greased mine with waterproof type grease.

no resistance at all, the lower bowl falls out on its own, see New video by Kocelot Gepardieu

As long as there is no movement with the new aftermarket cups you should be fine. The key would be that they don't simply fall out when inverted.

there is no noticable movement but they do fall out, esp. the new Acros lower cup

On my first frame, it was factory matte black, super thin paint. The cups went in with slightly less resistance then on my second (warranty frame) DIY painted frame (3 spray color coats + 2 clear coats).

I didn't face them and had to only lightly tap in with a flat 2x4 lumber block and mallet/hammer. I used water proof grease on the headtube and wiped off excess when snuggly seated.

I think you should be alright re-gluing them in since that seems to work direct from the factory.

Me personally, I would just use primer grey paint and spray a few coats in order to build up the layer thickness s little. I just never heard of cups that can be glued into the frame, so that is an unknown variable.

Just for reference. I've had a total of 5 Chinese direct factory carbon frames. 4 were ZS cups. All were slightly variances, all were DIY painted unfaced. All snugged in using my method describes above, that is light tapping with wood block/hammer, no formal headset press. No problems years later.💪

Again bottom-line. Unless the cups move after greasing them in, that should solve it! 🤞

after a day of jumps they hold nicely, but I fear ultimately the repeated hits on slightly loose fit will lead to growing play and destruction of the headtube
 

voigtkampff

Member
Oct 18, 2023
97
97
Poland
tip: I was able to squeeze the display cable through the cable guide hole without cutting guide side after grinding the hole a bit wider with 6mm burr. this way the guide cover will not flex under dropper cable pressure when turning handlebar to the right

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TCFlowClyde

Active member
Feb 26, 2022
1,343
867
Mesa, AZ
correct



yup, without any effort, the glue wasn't strong



there is no noticeable play on the handlebar while riding nor in the bearings. the only real problem is that the bowls can be removed with ease without any tools.



no resistance at all, the lower bowl falls out on its own, see New video by Kocelot Gepardieu



there is no noticable movement but they do fall out, esp. the new Acros lower cup



after a day of jumps they hold nicely, but I fear ultimately the repeated hits on slightly loose fit will lead to growing play and destruction of the headtube
Hopefully, it won't be a problem for you..👊

Post-thought: if they do slacken, measure the diameters with a digital caliper take a few pictures and request a warranty replacement ASAP.

I'd agree that somehow your frame is out of spec. tolerances. I can't imagine how if it's from the same mould.

My is first batch and can not run a coil....so maybe that requires a second mould, but Calintys has 4 frames with all coil fitments.👇
Screenshot_20240627-125135.png

Ultimately, I suspect if you are a regular jumper or drop huck-to-flat you'd know sooner rather than later.

Red flag: But if your Across 66 just fell out due to gravity alone, I might be strongly thinking how soon to show pics of the headtube measurements and request a warranty replacement. That way, you can still ride and watch your current frame setup closely while the warranty frame is being prepped. Plus, you could request measurements after they paint it and you get the frame routing too!

My warranty replacement frame took 6 weeks (unpainted). The good thing, my damage wasn't structural, so I could ride relatively free of anxiety.

Keep us apprised! 🍻
 
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voigtkampff

Member
Oct 18, 2023
97
97
Poland
So eventually I finished my conversion by gluing both top and bottom assemblies into the headtube with Loctite 638. I couldn't find lots of resources covering use of cyanoacrylates with carbon fiber, except for one article by one Hambini, where he claims that glueing the bearing cups is now widely practiced in the bike industry as it allows for lower manufacturing tolerances and increase servicability (Engineering Analysis: Grease or Retaining Compound - Hambini Engineering). I'm not entirely convinced in the guy's expertise but at least he's giving some clues that this idea isn't entirely flawed.

So far, after 3 days of curing of glue it seems this worked well. I don't have to preload the ahead screw a lot, it's enough to stop at first resistance like with ordinary quality headset. Obviously, bottom Acros headset assembly no longer falls out, they just feel like they were properly pressed in.

The bike handling feels good, there is no vibration transferred from the ground on the bar, all moves quietly, smoothly and without much resistance. Finally, this is the feeling I would expect to have from day 0. Hopefully it will last...
 

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