Is there a current equivalent of the OnOne 456 Carbon?

I guess it depends on what you class as "trail" these days, but the Yeti ARC and previous generation Santa Cruz Chameleon carbon are probably among the closest (although not in price bracket!).

The same thought pops into my head once a year or so.

In terms of affordable bikes/frames, there's not a lot I can think of. Halfords do a carbon Bizango but the build kit is a bit crap IIRC.

But there were a few trail carbon hardtails a few years ago - SC Chameleon, Saracen did a carbon Mantra, Transition had one.

I reckon Vitus could have made a really good one at a decent price, but they're in trouble ATM obvs.

Bizango carbon is a good shout, and probably closest to the original brief. They're a bit portly though (as were the C456 if memory serves) which begs the question if they are worth it over a decent alloy frame at a similar price point.

Is it a case that the carbonz is not actually the best material anymore? It is environmentally crap compared to steel or aluminium which can be recycled. Alu frames are within a hairs breadth of carbon, as long as it is not a 'one season' XC ultralight thing.

Sonder used to do a carbon Transmitter.

God I hope not. That thing was the stiffest, ugliest and most uncomfortable bike I've ever owned.

Went uphill well though.

as long as it is not a ‘one season’ XC ultralight thing.

What are you on about man, a one season XC thing?  People just don't throw them away after a few months you know.

As for a replacement 456C, can't you just have  a look on Chinertown, pick a suitable open mould frame and replicate what the On-One essentially was?

Tideace FM-M068 is 27.5, 67 degree head angle, boost axle spacing, plenty of room (up to 3" tyre claimed) and weight suggests pretty sturdy. 530mm a-c so OK for a 140mm fork?

What are you on about man, a one season XC thing? People just don’t throw them away after a few months you know.

Agreed. But then the 850g Scott is just not as durable as the 456 and ilk were. The 456 was quite beefy - fit for a lot of hard use. So many carbon frames are about the lightness, not durability...

As for a replacement 456C, can’t you just have a look on Chinertown, pick a suitable open mould frame and replicate what the On-One essentially was?

Well Chinertown isn't super-well known, I only found out about it last year - and I thought I was a bike geek.

Do you know of a trail 29er frame that would fit OP's bill?

It'd have to be 29 in my mind, as the c456 was a bike that you could XC race if you wanted, but was more for zipping about in the woods.

67 degree head angle

...which is a bit steep these days for a HA, most 'trail' bikes are 65. And 67 is the slackest I've seen.

Was the 456c actually light, or just lighter than the steel 456? My steel 456 weighs heaps more than my aluminium Ragley.

It was pretty light, yeah.

I think they were functional rather than ugly, here's mine 12 years ago:

I've still got one and twas my regular ride until I inherited an ebike recently. I've looked to replace it in the past and as above only found the sonder transmitter carbon that was anything like it, altho must admit I didn't try very hard.

Was the 456c actually light, or just lighter than the steel 456? My steel 456 weighs heaps more than my aluminium Ragley.

My friend converted his small carbon 456 into a rigid gravel bike for bikepacking. 650b in a 29er carbon fork and 26er on the rear. Works pretty well for something he already had. Very light too but it is small with small wheels and tyres compared to my XL 29er with 2.6 tyres.
However, it's as stiff as a very stiff thing from stiffsville and he gets battered on the downhills.
His is a later model as he snapped his original one so they weren't completely bullet proof.

I'd echo matts points. Does it have to be carbon? Plenty of great metal 29er hardtails around for really good prices. The money you save on not going carbon could pay for carbon wheels and better drive train and be around the same weight.

I like carbon frames a lot, and I like them a lot more than steel or Al , and I'm very sure that Scott will outlast a light Al frame.

Who has ever actually recycled a frame? Really?

Pivot Les?  But I don't like mine as much as my previous Scale (stolen not broken)

I hated my C456, it was light, comfortable, but completely void of any feel. It just felt dead. Replaced it with a Soul, which was much nicer. Currently on a Signal ti.

Transition had the Throttle, they no longer make a carbon hardtail, just a steel one

Here's my Throttle

https://flic.kr/p/2oHDhuD

Who has ever actually recycled a frame? Really?

Eh? Surely most people do if the frame is metal. Its really easy. There always a few in the metal bin at the dump. Or leave it in the street and someone will scoop it up. The aluminium recycling rate is around 75%

However, it’s as stiff as a very stiff thing from stiffsville and he gets battered on the downhills.

I read this a lot and think back to first riding mine and how I kept stopping convinced that the rear tyre was losing pressure because it felt so comfortable. Also the small frame so I would guess the stiffest.

Who has ever actually recycled a frame? Really?

I've put three steel frames directly in the metal recycling skip.

I can echo the comments about the 456 being the stiffest, deadest feeling thing I have ever ridden. Built one as a winter hardtail and was disappointed within ten minutes of the first ride. Flogged the hateful thing.

At the start of 2023 I bought a new Scott Scale - the RC model HMF frameset so 100g heavier than the version linked above by @matt_outandabout - my version: https://www.scott-sports.com/gb/en/product/scott-scale-rc-team-bike?article=290166 (frame only, but the geo chart and spec on the frameset web page is all incorrect)

This frame was right up my street as finally it had 'trail ready' (not extreme, but not old-skool XC) geo mixed with XC weight - and looks. It sits at 67.3 degrees HA as I have it configured, a reasonable reach and ST length. I absolutely LOVE it - and use it exactly as you describe, a 'trail' hardtail.

I have no zero qualms with ride quality or potential strength issues - It feels great, I've done some long rides on it, raced XC on it, some pretty tech singletrack stuff when my FS 'trail bike' is out of action, it fits 2.4 tyres, 180mm rotor, a decent length dropper...

I've had loads of the fabled steel trail hardtails - Cotic soul, Bfe, Dialled, Genesis etc. now they have finally updated the Geo, this Scott is better in every way, I am afraid to say. Ride quality, comfort, silence, weight...

In fact I've been so impressed with it I've since bought another bike from the Scott family with more of the same tech.

ETA - the equivalent recent Cannondale is also really simliar too, and the other one I fancied.