Seraph Bikes Superlight 836g X68 - Alternative to SL8 Fakes?

[Cnasta]

buongiorno a tutti, sono nuovo in questo forum e visto che sono interessato anche io a questo telaio x68 volevo chiedere a chi ne possiede uno se lo riacquisterebbe e il se lo ritiene sicuro dopo aver letto che alcuni utenti hanno avuto problemi con reggisella, forcella e telaio. grazie a chi mi potrà consigliare.

Non parliamo Italiano qui. Per favore scrivi in Ingelese, grazi!

[Lotnik]

Short update:

TanTan is messing around since 3 weeks and did not source and ship a UD matt frame after accidently painting it.

So I'm waiting since the 5.03. so more then 9 weeks and the frames are not ready to ship!

My opinion is that they will strip the paint and paint it matt black. It will not be new frame

[Jack Russell]

good morning everyone, i'm new to this forum and since i'm also interested in this x68 frame i wanted to ask those who own one if they would buy it again and if they consider it safe after reading that some users have had problems with seat post, fork and frame. thanks to anyone who can advise me.

[Sander2177]

good morning everyone, i'm new to this forum and since i'm also interested in this x68 frame i wanted to ask those who own one if they would buy it again and if they consider it safe after reading that some users have had problems with seat post, fork and frame. thanks to anyone who can advise me.

i and welcome to the forum!

Great to see you doing your research before committing — it's smart, especially with a frame like the X68 that’s generated some debate. You mentioned concerns about safety, and I’ll try to share what I know and my own experience.

Yes, there have been a couple of reported issues — one fork failure and a minor crack in a seatpost. That said, I’ve also had failures on premium components: a €400 Gelu seatpost cracked within torque spec, and a Felt carbon frame cracked at the seatstays. These things unfortunately aren’t exclusive to lesser-known brands.

TanTan, the manufacturer, claims their products undergo ISO 4210-compliant testing (impact, fatigue, vibration), but they don’t provide detailed test results or even basic sales figures — which makes it hard to put the reported failures into perspective. I asked for sales numbers to do a rough risk estimate, but they understandably didn’t provide them. So yes, I was probably clutching at straws there.

Based on what I’ve seen and experienced, I personally still consider the frame reasonably safe — for me. But I completely accept that others may have deeper technical knowledge or different standards, and they may reasonably come to a different conclusion. Risk tolerance varies from rider to rider, and in my case, I’ve weighed the pros and cons and made a decision I’m comfortable with. Others may (and should) make their own judgment based on what level of risk they’re okay with.

Hope that gives a bit of perspective — and definitely feel free to reach out if you decide to go ahead or want

[Jack Russell]

thank you very much for your experience

[Sander2177]

thank you very much for your experience

What frames have you been looking at?  A lot of people I know  have been looking at the obvious  counterfeits with specialized branding.

[Jack Russell]

I'm sorry but unfortunately I don't know English, I use Google Translate and it doesn't help me understand your question!

[Sander2177]

I'm sorry but unfortunately I don't know English, I use Google Translate and it doesn't help me understand your question!

Che telai stai valutando? Conosco molte persone che stanno guardando ai soliti falsi con il marchio Specialized

[Jack Russell]

TT-X68 Disc Superlight Road Frame

[Sander2177]

Let’s add a bit of context to the ongoing debate around the X68 frame weights and forks. The frame and fork weights fall more in line with the Tarmac SL8 Pro frame range — with the size 56cm version claimed at 780 grams.

Looking back at the  video from Patrick on YouTube when he first received the Pro Frame, his painted 56cm frame came in at 827g, the uncut fork at 397g, and the seatpost at 169g.

I would say this Pro frame likely uses a lower proportion of T1000 carbon compared to the S-Works version. That’s probably also the case with Tan Tan X68 frames, as using less T1000 helps keep production costs down and reduces the likelihood of durability issues. T1000 is known for being more fragile, despite its higher strength-to-weight potential.

This may also explain how some of the rebranded or counterfeit frames manage to achieve their impressively low weights — possibly by using more T1000 carbon, which could compromise reliability.

This may have been discussed earlier in  the thread but what are peoples thoughts

[glepore]

Tried fitting the Darimo seatpost in the X68 frame and noticed the seat tube is just a tiny bit wider more play side to side.
 I could get the X68 post—probably an inch diameter—into the SL8 frame, but that’s it. .

The Darimo post fits the SL8 nicely and snugly. But the X68 post, if you don’t hold it tightly, will just slide right into the framem. I wouldn’t buy a genuine SL8 post because the Darimo one felt a bit loose in the X68 frame.

For the X69 seatpost hardware weight:
   •   Carbon cradle: 12g
   •   Saddle yokes/clamps x2 No: 10g
   •   Two M5 Ti bolts (30 and 35mm): approx 4g
   •   Original barrel nut: 1g
Total: 27g

So overall, the seatpost weighs about 131.9g. I’m thinking of cutting the post down to 350mm and re-drilling the Di2 battery holes as well.

One more thing—the original rear bolt is M4 size for the seatpost clamp hole at the rear but an M5 bolt will thread through the back hole in the seatpost without issue.

Excellent. Are you using m5 nut on the rear yoke or were you able to source one with threads?
J&L cradle? Mine fits "close" but not perfectly, haven't used it yet. But that's an easy 40g, and the expander another easy savings.
I think an oem specialized top cap would solve the "fits high" issue.

[glepore]

Let’s add a bit of context to the ongoing debate around the X68 frame weights and forks. The frame and fork weights fall more in line with the Tarmac SL8 Pro frame range — with the size 56cm version claimed at 780 grams.

Looking back at the  video from Patrick on YouTube when he first received the Pro Frame, his painted 56cm frame came in at 827g, the uncut fork at 397g, and the seatpost at 169g.

I would say this Pro frame likely uses a lower proportion of T1000 carbon compared to the S-Works version. That’s probably also the case with Tan Tan X68 frames, as using less T1000 helps keep production costs down and reduces the likelihood of durability issues. T1000 is known for being more fragile, despite its higher strength-to-weight potential.

This may also explain how some of the rebranded or counterfeit frames manage to achieve their impressively low weights — possibly by using more T1000 carbon, which could compromise reliability.

This may have been discussed earlier in  the thread but what are peoples thoughts

Hard to say. T1000 is enough of a cost difference to be unlikely. Guess its possible but there's no way I'd ride an unknown copy bike lighter than an sworks given that sworks frames have a reputation for being fragile enough. Could just be less filler etc in the finish, and skimping on some reinforcement here and there.

[Sander2177]

Excellent. Are you using m5 nut on the rear yoke or were you able to source one with threads?
J&L cradle? Mine fits "close" but not perfectly, haven't used it yet. But that's an easy 40g, and the expander another easy savings.
I think an oem specialized top cap would solve the "fits high" issue.

Hey Glepore,
Yes, I’ll be using an M5. I managed to thread the supplied bolt through the rear hole, but I’ll probably just file a little off both sides so I don’t have to basically force-screw it through.

I ordered an Elita One cradle (claimed 12g) for £9.69,

https://www.aliexpress.com/item/1005006666237770.html?spm=a2g0o.order_list.order_list_main.5.428118029lhl7P

Two titanium M5 bolts — one 30mm and the other 35mm — for £3.41

https://www.aliexpress.com/item/1005006118920483.html?spm=a2g0o.order_list.order_list_main.11.428118029lhl7P

And a pair of Zrace aluminium yokes (10g) for £7.83.

https://www.aliexpress.com/item/1005007653744576.html?spm=a2g0o.order_list.order_list_main.16.428118029lhl7P

I measured everything, and the cradle should fit. I’ll make sure to use anti-seize on the yokes and bolts as well.

I have the lightweight HOPP top cap — the fit looks okay. The Tan Tan top cap (as shown in the picture on the other pages) is ever so slightly larger than the OEM SL8 one. I did notice in some of the build photos from other people’s bikes that the fit wasn’t great — the top cap looked almost like an afterthought.

[Sander2177]

Hard to say. T1000 is enough of a cost difference to be unlikely. Guess its possible but there's no way I'd ride an unknown copy bike lighter than an sworks given that sworks frames have a reputation for being fragile enough. Could just be less filler etc in the finish, and skimping on some reinforcement here and there.

I would say it was done for durability myself then. The S-Works top and down tube is paper thing even when you tap them.  Seen picture online and the bikes always appears to snap in these areas in a crash which is likely for most of the superlight weight frames these day

[Bonus79]

Photos

Is the expander identical for both models (X68 and SL8)?
Thanks