Mercian build

fucking taxes aye?

to tell you the truth I never spent that kinda money on a bike before but as I said to the man in the shop eight hundred quid is the price of a set of new tyres for a car and I sold my car so it don't sting so bad

there a shed load of different steels aren't there only knew about a few do they just keep on coming up with slightly different alloys of steel and just naming them any idea what the reynolds number mean ? parts per different metals ?

The higher the number the purer the content - i.e. there is more of said metal that is good for making bike frames in the alloy

Dig that metalurgy!

http://www.strongframes.com/material_tech/?PHPSESSID=dfe42d97a053d8daaabde703345dfa8e

http://www.reynoldscycles.co.uk/english.html

what I want to know though is what the difference is when you RIDE the bike

Reynolds 725 was described to me as being 'lively' which I took to mean good acceleration

Build the exact same bike differing in only tubing type and see if you can tell.
I don't reckon there's much difference - but that be a guess because I've never conducted the test above.
More difference surely comes from the frame geometry, the contact points (saddle, bars, etc), tyres and tyre pressure.

i test prototype mtb's for a friends company, I rode a reynolds 520 and 853 frames back to back with identical components tyre pressures etc (i swapped every component over from one bike to the other)
the 853 was slightly whippier but the difference was subtle, i would imagine you would notice it on a road bike more. the 853 weighed half a pound less. i would imagine a lot of the difference in feel came from the change in tube sizes as the 853 tubes were slightly smaller diameter and wall thickness.

http://www.sheldonbrown.com/frame-materials.html#myths

"Carbon fiber has great potential, but contemporary carbon fiber frames have not demonstrated the level of reliability and durability that are desired for heavy-duty touring use. In particular, a weak point tends to be the areas where metal fitments, such as fork ends, bottom bracket shells, headsets, etc connect to the carbon frame. These areas can be weakened by corrosion over time, and lead to failure."

Surely that is not the case anymore - aren't all contemporary pro track and road frames carbon?

Track is a bit different to touring. The loads are all different, the riding surfaces much, much worse, equipment is bolted to the frame.
Road more similar, yes, but try getting a carbon frame repaired in India.

i got a 753r and a 531 753 flexy as....... 531 stiffer so the 753 is closer to 100% steel less impurities / alloys 531 would have more cr-mo / manganese whatever?

The higher numbers aren't "purity" values. They are some value a guy at Reynolds decided to give a tubing type.

For example, higher numbers might indicate things like butted tubing (eg. tube that's thinner in the middle, thicker at the ends) or they might indicate it's heat-treated tubing (makes the tubing stronger therefore thinner tube can be used in a frame) or air-hardened tube (again so thinner/lighter tubing can be used).

There's a lot of info on the internet about the differences between tubing, but the different Reynolds numbers do not indicate "purity". They are all steel tubing and steel is an alloy. If you make it "purer" you will get iron and there's a reason iron bikes aren't popular.

531 originally stood for the percentages of the alloying elements - something like 5% chromium, 3% molybdenum (or whatever) and 1% something else. Or maybe it's 0.5%, 0.3%, 0.1% - you get the message.

For a long time Reynolds made a variety of 531 tubesets (eg 531c, 531ST) for different applications. They varied tube sizes, butting etc. Then they came up with new alloys and made 653 and 753 which had different properties (ie stronger) once heated. These aren't around now but you can find some really nice frames made from them. My first fixed gear was a converted 653 frame - lovely bike until a cabbie rearranged its geometry for me.

Now most of their tubesets (631, 725, 853 and 953) have this "heat-hardening" stuff. The main difference as you go up the range is that the tubesets are lighter cos they can be made thinner or they are stiffer at the same weight. 953 is the newest - it's almost stainless and very light so it's pretty cool. There's a big price tag for a 953 frame though.

That's what I said :P

953 is stainless apparently and very thin which is the reason it's so hard to weld and not everyone is using it.

"Using what is at this time the strongest steel alloy Reynolds is able to make seamless butted tubes with exceptionally thin walls down to .3mm. 953 should be able to produce a sub three pound road race frame. Because it is stainless steel it is corrosion resistant and also can be polished. Appropriate for either TIG or brazed construction."

853, which is what my Jackson is made from, has the additional property of the weld points becoming harder as the welds cool in the air.

The differences between the numbered tubing isn't linear. 953 isn't necessarily better than 853 or 725. It depends on the application and desired qualities of the frame that you want to build.

It's worth noting that a lot of these tubes weren't developed with bikes in mind. They've come over from different specific applications that paid for the R&D of the tubing and happen to apply very well to bicycle frames. 853 supposedly comes from roll cages in rally cars, the need for weight and strength is obvious, and weld points were the weakest link so that's where the air hardening comes in.

There are general improvements in stepping up the numbers. 953 is lighter than 725, it's also more corrosion resistant. But 953 tubing isn't easy to work with, you generally find that forks are made with 725 tubing on a 853 or 953 bike... different tubes lend themselves better to different applications. It depends on what you want to get from the bike in terms of weight, anti-corrosion, welds/lugs, ride quality, etcetera. There is no rule that says higher numbers are better, some of the lower numbers lend themselves far better for touring bikes.

If in doubt, ask your frame builder and describe your usage.

Momentum 531 originally stood for the percentages of the alloying elements - something like 5% chromium, 3% molybdenum (or whatever) and 1% something else. Or maybe it's 0.5%, 0.3%, 0.1%

That's what I meant by the amount of which metal in alloy - I just used the word purity instead of the right word to get you all talking ;-)

Cheers.. this is much more interesting than work!

Talking of different applications for bike tubing, I think that a lot of the Cro-Mo tubes were originally developed for aeronautical use and they are still used for this. I read a thread somewhere about a guy who built a bike frame using aero Cro-Mo tubing. I seem to remember it was plain gauge but significantly cheaper than a comparable bike tube set.

I read a thread on the BF.net framebuilders section (I think) where some extremely high level materials science argument developed around the fact that 953 isn't truly stainless, although I think for all intents and purposes it is.

Momentum Talking of different applications for bike tubing, I think that a lot of the Cro-Mo tubes were originally developed for aeronautical use and they are still used for this. I read a thread somewhere about a guy who built a bike frame using aero Cro-Mo tubing. I seem to remember it was plain gauge but significantly cheaper than a comparable bike tube set.

Your correct, many BMX bikes until recently where built from plain gauge 4130 tubing, and infact it is still used on some hard hitting bikes even if it is only one or two of the tubes just to beef it out. Strong stuff.

scandium is the shizzel, the day i'have enough cash to get a proper steel frame i'll get that non corrosive reynolds tubing, made either by Pegoretti ( if i can make contact with 'em) or Roberts.

This headset is going on the bike

I am looking for a couple of headset spacers if someone knows where I might find some

MERCIAN 'Strada Speciale' built as a 1970's 'road track'
chrome track drop outs
55.5 cm Square
73° seat tube angle
74° head tube angle
close clearances front and back
French blue enamel
Royal blue - luglining, headtube banner, fork crown and seat tube bands
White gothic transfers
Fork Crown Ceeway LC19
Tubing Reynolds 725
Campagnolo Serie Sterzo Record Track Pista Headset 1x24

Campagnolo Record Hubs ready to be rebuilt

Super Champion Competition Tubular rims, I know very little about these rims other than they are narrower and more curved that Super Champion Arc-en-ciel rims. Not sure of the year but they look as if they might come from the correct period '1970's'. They have about 4 -5mm of braking surface, I am not sure how they will perform under braking but they look rigid enough. I need to polish them up but even unpolished they look really really nice. Twenty quid on ebay.

Buddha, this bike is going to be great! When I get my Mercian, we'll have a meet and compare lugs :-)