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Chinese Carbon Road Bikes => Road Bike Frames, Wheels & Components => Topic started by: Majoeric on July 06, 2026, 12:44:42 PM

Title: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on July 06, 2026, 12:44:42 PM
Greetings,

I was hoping someone can give ideas on which frames have the smallest stand over, stack, and reach.

Ideally I’m looking for sub 700mm stand over with the shortest stack and reach possible.

Thanks :)
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: gbrnole on July 06, 2026, 05:12:17 PM
i think the Big Rock Sohtea might be as close as you get from China direct manufacturers. Their XXS is a 45cm but the seat tube is only 40cm - it has a pretty aggressive slope on the top tube. it has a standard 27.2mm seat post so that would be flexible for fit. that bike could be built up very light.
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on July 06, 2026, 06:38:57 PM
Excellent, I will check these out! We currently use a HUP 37cm CX bike but was hoping for something lighter and maybe more aerodynamic for the next build!

Thanks :)
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Lotnik on July 07, 2026, 12:10:54 AM
BXT comes even in XXXS frame size:
https://bxtbikes.com/products/bxt-155-evo-new-carbon-disc-road-bike-frame-1050g-super-light-road-bicycle-carbon-frame-fully-hidden-%E5%89%AF%E6%9C%AC
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: c4s4la on July 07, 2026, 01:53:32 AM
I was on the same point a few weeks ago.

I wanted to build a bike for my 8 year old son. The Bigrock Sothea is pretty much the smallest frame you can get, but I didn´t want to spend that much money.
Therefore I ended up with a R088 in size 44.
Stem 35mm  ;D
140mm crank
The saddle height in the picture is not final. I had to cut the seatpost and slide it in as far as possible.

Since he´s racing, the gears are limited and I went for a 1x11 Shimano 105.

Final weight including everything is 6,8kg
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Lotnik on July 07, 2026, 02:33:17 AM
How tall is your son at 8yo?
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: c4s4la on July 07, 2026, 02:41:50 AM
He´s 1,32m
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Garreth on July 07, 2026, 02:50:17 AM
I was on the same point a few weeks ago.

I wanted to build a bike for my 8 year old son. The Bigrock Sothea is pretty much the smallest frame you can get, but I didn´t want to spend that much money.
Therefore I ended up with a R088 in size 44.
Stem 35mm  ;D
140mm crank
The saddle height in the picture is not final. I had to cut the seatpost and slide it in as far as possible.

Since he´s racing, the gears are limited and I went for a 1x11 Shimano 105.

Final weight including everything is 6,8kg

Nice build.
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Lotnik on July 07, 2026, 03:46:59 AM
He´s 1,32m
I'm thinking about this frame in size 44 for mine too for the next season. He's now 1,41 m and will grow till next year.
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on July 07, 2026, 03:07:06 PM
I was on the same point a few weeks ago.

I wanted to build a bike for my 8 year old son. The Bigrock Sothea is pretty much the smallest frame you can get, but I didn´t want to spend that much money.
Therefore I ended up with a R088 in size 44.
Stem 35mm  ;D
140mm crank
The saddle height in the picture is not final. I had to cut the seatpost and slide it in as far as possible.

Since he´s racing, the gears are limited and I went for a 1x11 Shimano 105.

Final weight including everything is 6,8kg

Awesome setup and i’m sure little man is flying on that!

:)
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Kar25 on July 08, 2026, 04:43:51 AM
This is an x68 in size 44... she was nearly 140 cm tall when she started riding and training on it... I think that’s the minimum height for this frame size... She loves it 😉
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on July 29, 2026, 09:56:08 AM
To circle back on this post, I went ahead and gambled on the Microck aka Bigrock Aethos Clone in a size XXS 45. The seat tube is listed at 400mm although it appears I could maybe take upwards of another CM or two to get it even lower. It’s also listed at 580g which I find hard to believe. I will be sure to follow up once it’s received.

:)
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Takiyaki on July 29, 2026, 01:53:50 PM
Would it make sense to get some 650b wheels to drop the height and gearing? This is all very cool stuff
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: gbrnole on July 29, 2026, 03:39:01 PM
To circle back on this post, I went ahead and gambled on the Microck aka Bigrock Aethos Clone in a size XXS 45. The seat tube is listed at 400mm although it appears I could maybe take upwards of another CM or two to get it even lower. It’s also listed at 580g which I find hard to believe. I will be sure to follow up once it’s received.

:)

the weight is unpainted with all the attachments removed but those frames are shockingly light, the fork is a featherweight too. I pondered grabbing one before i got the SL8. if, or more appropriately when, your kid drops me on this new rig, i'm gonna be hella embarrassed and have to get an unrestricted e-bike!
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: jhearrtot on July 29, 2026, 03:39:10 PM
This is an x68 in size 44... she was nearly 140 cm tall when she started riding and training on it... I think that’s the minimum height for this frame size... She loves it 😉

hello, could you please confirm what frame brand is this and a link to it if possible?

I am 157cm and currently riding a CAAD10 in size 44 and this frame looks similar in size and geo.

thank you!
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: gbrnole on July 29, 2026, 03:42:40 PM
hello, could you please confirm what frame brand is this and a link to it if possible?

I am 157cm and currently riding a CAAD10 in size 44 and this frame looks similar in size and geo.

thank you!

that's a TanTan X68 - basically a Tarmac SL8 clone. seraphbikes dot com.
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: jhearrtot on July 29, 2026, 03:46:15 PM
that's a TanTan X68 - basically a Tarmac SL8 clone. seraphbikes dot com.

Thanks! Saw the original thread. My eyes are prolly tired i read it x86 instead and that threw me off  ;D
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Kar25 on July 30, 2026, 04:43:52 AM
hello, could you please confirm what frame brand is this and a link to it if possible?

I am 157cm and currently riding a CAAD10 in size 44 and this frame looks similar in size and geo.

thank you!

This is a Tantan x68. If you're interested in this frame, be quick to buy it, because it looks like there isn't much stock left.

https://tantanbikes.com/Superlight-Disc-Road-Bike-Frame-TT-X68-BSA-Bottom-Bracket-Max-Tire-70032C-With-Integrated-Handlebar-p7094176.html
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: 2wheeledbarbie on July 30, 2026, 06:30:03 AM
Excellent, I will check these out! We currently use a HUP 37cm CX bike but was hoping for something lighter and maybe more aerodynamic for the next build!

Thanks :)

Daughter has a HUP straatrace and I looked at bigger bikes as she is 150cm tall.  She still fits the HUP and going up to a 44 isn't really worth it at the moment. 
second pic is older with shorter cranks and a lower saddle.
Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on July 30, 2026, 09:33:48 AM
the weight is unpainted with all the attachments removed but those frames are shockingly light, the fork is a featherweight too. I pondered grabbing one before i got the SL8. if, or more appropriately when, your kid drops me on this new rig, i'm gonna be hella embarrassed and have to get an unrestricted e-bike!


Haha.. and yeah even if it’s 650g with paint, that will still shave 600+ grams from his current frame. I will go all in and see how close to 5kg I can get.

His current setup is around 6.8kg

:)



Title: Re: Current State of XXS and XS frames - Junior Sized
Post by: Majoeric on August 28, 2026, 08:06:50 PM
Got the frame in and overall I’m very impressed. Quality looks great and weight was right at 650 for the frame with dropout and fork was 310 uncut.

I’m doing the maths and even with some heavier wheels, I will be close to sub 5kg. The picture is with a cut fork, headset, spacers, stem, and handlebar at 1220g.

:)