I’m after building a short-travel trail hardtail for those occasions when 140mm of F & R is overkill. I’ve had steel and aluminium HTs in the past and much prefer steel. So I’ve been looking around at Curtis, Cotic, Pipedream, Merlin (Rock Lobster), On-One etc and discovered that Curtis is pretty much the only one who builds a full 853 frame, the others sticking to the main triangle with proprietry own blend chromoly for the rear end…

So my question is – why? Is it down to the cost? The Curtis frame is £850 – dangerously close to budget Ti, or is there some aspect of 853 that doesn’t lend itself to building rear triangles?

FWIW it’s likely to end up being the Curtis but with an outside chance of a Rock Lobster Ti build.

It’s a good question. I thought that Reynolds only made 853 main tubes and not rear triangle tubes, which would explain why most manufacturers still use only 853 main tubes. That has either changed recently, or it was never the case, as Curtis do indeed build a full 853 frame.

If it was the case, it might be to do with practicality of 853 rear tubes. To get steel to weigh as little as possible you need to make the tubes incredibly thin. The main tubes take a lot of stress so standard tubes are already thick enough to be thinned out if you can find a way to improve the tensile strength of the material. It might be that rear triangle tubes are already as strong and thin as they can be without crumpling or denting so easily. If that were the case, then even if you increased the materials tensile strength, you wouldn’t be able to achieve any weight saving, making the process more or less redundant.

I am just guessing though.

Some friends of mine just bought two Curtis Racelite 26 frames (one each – they are a husband and wife team so bike buying is doubly expensive!) They are just lovely, but they are sooooo expensive. These are made from T45 rather than 853; I’ve no idea what the difference is, weight most likely as these things aren’t exactly light. Nice as they are, I think the price is justified by the desire to own one, rather than their performance. Having ridden them back to back with a Cotic, I couldn’t really feel the difference in material quality; if anything the Cotic was a little more ‘zingy’. The ability to get a frame entirely cutomised to your spec though is a significant factor in justifying the cost (although strangely my friends bought purely stock frames).

If it were my money, I know where I would rather spend it – for the same price Charge Blender Ti or On One Ti.

Despite the ‘magical’ ride of steel, 🙄 , I suspect that the difference between an 853 rear end and a bog standard one will not be something that matters over much…

853 rear is too stiff – something like 631 will give a better compliant ride

Don’t fret it too much it’s the way it’s put together which is more important

“Despite the ‘magical’ ride of steel, , I suspect that the difference between an 853 rear end and a bog standard one will not be something that matters over much… “

Weight… The choice of steel isn’t usually about the ride, it’s about making a lighter frame with the same strength (or a same weight frame with more strength)

Cotic say this:

“Reynolds are only offering their 853 stays in the same profiles and wall thickness as our cromoly stays so they wouldn’t any lighter, just an awful lot stronger (when our cromoly rear end is perfectly strong enough) and an awful lot more expensive. For the moment, we’ll stick with what we’ve got.”

Cotic are spot on with that quote – I was about to write the same.

As to “too stiff” – all steels have the same Youngs Modulus, so unless the 853 tubes were thicker than 631, they wouldn’t give a harsher ride.

Other problem is that Reynolds have to do the bending (before heat treating), not your frame builder which adds potential for comedy errors.

I’ll third what Cy@Cotic has said on his site. fwiw we’ll be working mainly in 853/631 for front ends, chromoloy for the rear- for tube manipulation reasons in addition to the overkill/expensive facts.

Ahhhh, so, although steel is ‘magic’, there are varying degrees of magic depending on what type of steel your rear triangle is made of?

It’s a bicycle, for riding…. 🙄

I’m glad some one got in with the Young’s modulus thing. Its not a phrase I was confident to bandy about. All steel has the same stiffness. So all steel frames made of the same tube diameters and thickness have the same stiffness. Use 853 to save weight you get thinner tubes and less stiffness

No surprise Reynolds don’t do thinner stays in 853. I’m not sure I’d want a thin chain stay

I had also heard that lots of builders rely on cold bending to align the rear triangle, not possible with 853

If you can find the geomtrey you want off the peg, go for it it will be alot cheaper

EDIT I@M REALLY WORRIED THE NEXT BIT IS RUBBISH. IS IT TRUE?

T45 is chromo that is slightly stronger than 4130. I can’t remember the units but I think its 45 verses 41.3. In the same units 853 is 85.3? alot stronger

the last bit isn’t quite right I think, but you’re close.

http://en.wikipedia.org/wiki/Chromoly

Hmmm, cheers for the replies – it’s good to get some authoritative info!

So it seems I can either get the curtis which is expensive but uber strong and can be customized for me. (longer top tube and more standover)

Or get the cotic which is strong enough, should fit ok and save £400.

Or go ti!

Don’t really know how well the 456 would work with rebas or similar fitted – seems a bit too much frame? Looked at the charge and it seems ok. Also looked at the rock lobster ti frame – bargain price for db tubing and is designed as a xc type frame so exactly what I’m after. Only thing is I’ve seen no reviews of this new incarnation…

Ivan I have a full 853 SS Curtis, there is truly no comparison. The best £900 I have ever spent, I can ride 5-6 hours( longest I’ve done so far on Mendip) because it’s custom and all sizing is as I needed I have no discomfort whatsoever. As comfy as my Flux but only the one gear…..remember if you buy it, it will be forever.

Tried a mates 456 and totally unresponsive in comparison (sorry Brant & Colin). If your local drop me an e-mail

Amazing…. Steel, truly magical, and custom steel even more magical….

853 front triange with 725 rear! That’s what I have….

So Crikey, I take it you don’t believe that steel frames give a different feel to aluminium then? Or that a frame made of scaffolding tubes won’t feel different to one made of higher grade butted tubing? Or that having a bike which fits perfectly has no benefits over a bike that fits ok? Fair enough, each to their own…

No, I don’t.

The material a frame is made of, within limits, has very little effect on how it rides, compared to the wheels, the fork, the bars, the stem, the seatpost, the saddle, the gloves, the shorts, the tyre pressures, the geometry etc…

And the custom thing? unless you are physically very odd, your position can be duplicated in an off the peg frame quite easily; most custom frames are vanity projects.

I’ve had 531, 531c, 531 custom, 753, 853, Alu of various numbers, and carbon, and the frame material is not that important, nor is the custom aspect.

You may believe differently, but I’m not buying it.

Fair enough, so are you on a highly specced apollo now?! My last ht was bought as a frame only and all the components swapped over – the ride couldn’t have been more different. Looks like we’ll have to agree to disagree.

The custom bit is for reach/standover – I’m quite tall but its all in my body not legs. A bike which is good for reach offers no standover height – some might say you don’t need it but I want it so…

The 2 things I don’t agree with, (although I’ll support to the death your right to say them 😉 ) are the idea that steel gives a better/different/magical/flexible yet stiff/lively yet powerful ride, when in my opinion, it’s not true, and the idea that a custom frame offers advantages for the physically normal.

I’ve no problem with people having steel and even custom steel, but I can’t agree that it’s betterer in some way.

Ok, I’ll jeff off and agree to disagree! 🙂

Interesting reading…thread sounds just like many a Mendip ride I’ve been sinced some friends of mine went on the Dave Yates frame building course! Incidently one of them rides a Curtis 853 also , seems very heavy to me, but a fine looking frame all the same.

I realise this is straying from the subject a little…but does anyone know anything more about Reynolds 953?…

Question to Candodavid: is your Curtis singlepseed EBB / disc only?

Well since we’re talking about specifics of rear stays and effect on ride, my uni project including cad modelling and stress analysis suggested that you’re barking up the wrong tree. The top tube is likely to have much more influence than heavily triangulated structures at the rear – splay of the frame and fork actually provides most of the “give” people talk about. Have a look at carbon road frames designed to filter out road buzz (eg specialized roubaix) and you’ll see that the top tube is very narrow vertically (particularly at the back) for just this reason.

And as to steel giving a magic carpet ride as a generalisation, well that,s just rubbish. Some steel frames do but that’s down to the design eg geometry, tube diameters, wall thicknesses, etc. Bearing in mind that lots of the long travel hardtails have beefed up top and down tubes and it’s no surprise that many ride more like stereotypical aluminium.

Crikey I expect that some of those were road frames? In any case there’s not that much difference between all the tubing you refer to, whereas the difference between say an Inbred and a frame 0.5lb lighter is significant and easy to notice.

I don’t know if I’m convinced that custom frames are worth it (I’ve never had any problem riding 6 hours or more on any frame) particularly when each frame builder will have their own “perfect” frame for a given body.

Tangent, is that Andy Chamberlains Curtis? If so it’s T45. Horizontal stainless dropouts disc only, none of that ebb for me

No offence taken DAviide. It just a collection of metal tubes after all!

FWIW, I’m Candodavids ride buddy with the 456 inbred and it does indeed feel ‘dead’ compared to his full 853 Curtis, which, by the way, is a lovely bike.

This may well be due to the curtis having a thinner down tube and top tube and the resulting splay as Clubber describes.

My uni project was on heavy metal uptake by semi aquatic and emergent plants which clearly doesn’t qualify me in any way to comment, but basically I think the same as clubber. 8)

You could get a steel bike and an aluminium bike to feel identical to ride, and if you built them light to achieve the fabled ‘steel zip’ you could perhaps argue that over the long term, the alu bike might be more subject to fatigue failure if ridden by the same rider, in the same manner, on the same trails, but there are so many variables.

The first aluminium frames were known for being flexible and quick to break due to fatigue, basically because they were built like steel frames. Eg skinny tubes…

Clubber your uni work would be if interest. Is it online any where?

I find the whole frame comfort thing really interesting. Agreed its hard to imagine a triangulated rear triangle flexing.

My theory was always that lot of early alloy bikes used fatter seat post, which do seem to flex alot less. I think its well established now?

I realise this is straying from the subject a little…but does anyone know anything more about Reynolds 953?…

I think Independent Fabrication made a road bike frame from one but it is incredibly difficult to work with. Not sure if a MTB frame has been made yet using 953

Don’t know why eveyone obsesses over 853 – there are other and IMHO better steel tubesets out there, Columbus Spirit for example

norton – hehe. define “better”

I think Independent Fabrication made a road bike frame from one but it is incredibly difficult to work with. Not sure if a MTB frame has been made yet using 953

Genesis are experimenting with a 953 MTB frame

Not sure it’s an obsession (yet!) but when most frame builders are saying “we use 853 for the main tubes cos it’s ace” you’ve got to wonder why it isn’t used elsewhere on the bike… And now we know! If you know of any frame builders using “better” tubing feel free to name them.

From what I’ve heard 953 seems to be as expensive and as much of a pain in the tits to work with as ti, has a price to match and offers similar strength/weight ratios?

Anyway the current list has narrowed down to…

Cotic Soul for the steel build it up myself option
Genesis Altitude 30 for the steel off the shelf option
Charge Duster Ti (but with a budget build – the mrs is getting a new ht at the same time.)
Rock Lobster Tig Team Ti with stock build
Whyte 905 (I know it’s aluminium!)

Cotic had a prototype in 953. ISTR it broke. 😕

My uni work was over 10 years ago, back in the days where you did your work on a pc then printed it off to submit it so I don’t have a copy though the uni may have it on file. Either way, I now work at an aerospace company so might be able to redo it since the programs are much easier to use now rather than having to key in lots of numbers… I.ll report back if I do.

Fwiw, it’s actually pretty easy to work out how the tubes deform (just think lots of s shapes) but obviously the magnitudes are the complex bit.

Well subjective I know but I’ve owned 2 853 MTBs (Rock Lobster and Blizzard), an 853 ‘cross bike and an audax bike that was 853 main tubes and stays and 1 Scapin MTB built from Columbus Spirit and the latter just feels a much livelier ride than any of the other 4 which all feel too much like an alloy frame to me – and yes there is a big difference in ride feel between alloy and steel in my experience

Candodavid, it is AndyCs Curtis, maybe thats why its so heavy…prehaps the “T” stands for tons! So sliding dropouts are a more reliable solution then.

Am riding a DeKerf (R725) here, with all sorts of magical craftwork / metalwork going on. Certainly very comfortable.

Interesting to here some more on 953…

Thinking some more, its noticable that Indy Fab dont really emphasise which tubsets they use by (admitidly it is usually a mix of 853 & True Temper) but I have the impression they prefer to concentrate on other aspects of the design

Tangent, had a 725 SS Dekerf myself, I can confirm a vastly improved ride on the Curtis, it just seems to have a more lively uptake, in comparison the 725 felt slow and lethargic

Have a 10yr old Chas Roberts Genesis custom its not long been back for a respray, disk mounts and hydro guides and is lovely. Its full 853 and cost a fapping fortune at the time its still my prefered bike despite having a full suss to ride.

Candodavid, coincidence!…this rider often feels slow & lethargic not so sure about the frame!?–springy and very light–i do have some concern if it can really take the riding it see’s these days. Curtis singlespeed could be an option — like the localness too!

Tangent Andy C has my number and where I work, contact through him if you want to see, or Swan at Rowberrow on a thursday @ 7pm

I’m pretty sure tyre pressures and seat rails have more to do with the compliance (felt by the rider) than the metal of the frame.

Having said that, I’m an unobtanium tart 🙂