All broken.

Sounds perfik for the average STW nichemonger……

🙂

Cy from Cotic addresses this in that IMechE lecture on YouTube – the gist of it is that it’s so strong you can make a frame extremely light – but also very flexy. Add material to make it stiff enough and it ends up about as heavy as 853, is way stronger than it needs to be and costs a bomb.

Yeah, but it’s shiny! And pretty:

Doesn’t need painting, so would be lighter than an 853 frame by a little bit. As for ‘flexy’; I had a go on a Cotic once (Soul), found it too stiff. So, 953 would probbly be fine for me. And in fairness, Cotic is an importer, whereas the likes of Rourke and Anderson are actually frame builders, and their stuff is much, much nicer imo.

I’m with Elfin, very aesthetically pleasing.

Seen too many Ti frames crack.

Keep it real (if you’re a lottery winner) 😉

Indeed he does!

I really like the idea of getting a handmade British frame – however the engineer in me says that you’re not going to get as good performance as from a frame that’s been thoroughly designed using techniques like FEA for optimisation.

This is very interesting: Reynolds alloy characteristics

Note that stiffness to weight is almost constant for all these alloys, whether they’re aluminium, steel, magnesium or titanium based.

Yes, you can have thinner walled tubes than 853 for the same strength, but by doing so you will lose stiffness.

You can of course increase tube diameter to increase stiffness to counter this, but as the tubes would have a larger diameter there would be more metal… so increasing the weight.

So, it’d be whether the decrease in weight by thinning the ways offsets the increase in weight by increasing tube diameter…

Ooh….

Gallery cos pics ain’t working.

Oh sod it bloody stupid thing.

You can keep yer FEA optimised bike. I’ll have one of these instead, and I’ll be happier and sexier. 🙂

Ta Geetee!

but if you can have the same or larger diameter tubes (plus thinner walls and dent resistance) you can still have the stiffness.
i have a steel road bike with oversize tubes (38mm d/t) with .5-.38 butting. would definitely go stainless if i was looking to save a bit more weight and gain corrosion resistance.

A frame builder has told me it’s diameter that affects stiffness rather than wall thickness.

Just did some quick maths on this, comparing the second moment of area vs mass for two tubes. If you double the diameter whilst halving the wall thickness the second moment of area quadruples (i.e. resistance to bending) whilst the mass stays the same.

However, that’s in a perfect world! In the real world, the thinner the tube walls, then more likely they are to buckle due to being imperfect shapes. There’s also the issue of crash damage causing dents which make this even worse, hence very thin walled tubes being a bad idea for MTBs.

So although 953 could be used to make a lighter and equally stiff frame by using larger tube profiles to make up for the reduction in stiffness allowed by the thinner walls, going to those large diameters tubes means the walls have to go thinner still to keep the weight down. Viable on-road, not so wise on anything that’s going to be crashed in the name of fun.

Cy had a 953 Cotic once, it was custom made for him by Reynolds to show what they could do with the tubing. It was a phenomenal bike, Cy very kindly let me ride it on a Peaks day out once and it was SO much fun. Really stiff front end with the Magura forks but the back end was light and skippy. Great bike.

Cy broke it a few months later. 953 just isn’t strong enough for MTBs yet. Mind you it wasn’t that long ago that they said the same about 853 – you could get 853 road bikes way before you they’d worked out how to make strong, light MTBs out of it.

What I like about Ti and 953 isn’t their superiority as a material, although that’s a plus, but the lack of a need for a painted finish which inevitably gets scratched or faded.

The main problem I found with 953 is that for MTB’s it’s not possible to get thick enough tubing (almost regardless of diameter) to take the loads a compact frame and 400mm seatpost + offroad riding put on a frame. The seat tube is where mine went, and I didn’t do another one because Reynolds can’t get material any thicker I was used on that frame. The head tube also suffers from this problem. All the other tubes were much lighter than their 853 counterparts on the Soul, and the whole frame weighed in at 3.7lbs for the large. Not quite Soda weight, but giggly light nonetheless. And it looked GORGEOUS. I’m not normally one for this kind of outpouring, but it is a lovely thing. It’s hanging up on the wall at the workshop in fact. The main drawback at the time was a lack of a cromo equivalent tubing in thicker walls to get around these problems. It was either crazy strong/thin/expensive 953, or 304 grade which is basically chemical pipe and is really weak. Shame though. I’d love to do something more with it. I should give Reynolds a call and find out where they are with it.

You’ll see road frames out there because it allows trad steel builders to build nearly ti weight frames without having to learn too much in the way of different manufacturing techniques. It works for those frames because the seat tube and head tube loads are that much lower that you can build lovely long lasting frames.

.65

953 corrodes…..well stains….it needs the same carefully purging as ti to weld….tube sizes and wall thickness at Reynolds current list is mainly for road

Isn’t it an American produced tubing anyway?

had a 953 Genesis MTB made a couple of years ago, rode nicer than anything else i’d ridden inc a ti version with same angles, passed CEN but broke in further testing ( it was of the earlier-produced 953 tubesets so may well have broken on the trail.

Some improvements in production method and metallurgy mean it’s far less crack-prone now though.

KVA do heavier guage than reynolds as well as plain guage tubes. At NHBS this year there were a few KVA MTBs.

The difficulty in bending to shape is a valid point and it will be interesting to see what happens with further tube shapes and profiles.

does this apply to brazing of 953?