mx_599

i am buying a few different Soma frames (juice, groove, smoothie). Soma is in the process of switching to Tange prestige for their main tubes. they previously used Reynolds 631 for their main tubes. i think they use chromo 4130 ?? on the rear triangle for both the older Reynolds and the newer Tange frames.

two of the frames are mtb and one is a road.

would you even care which frameset you received?

i think the Tange is not quite available as widespread yet and the Reynolds is cheaper because they want to clear stock and stuff. as far as i know, the geometries are all still the same.

i do want these frames to last a long time and i plan on taking care of them and not abusing their intended use (XC only on the mtb, no jumping, dropping, dh'ing, etc...)

i weigh around 135lbs.

another question, i already have the 631 juice frame. i was being all anal and inspecting the frame and stuff. i was trying evaluate the welds, but i don't know what i am looking for. anyhow, i was looking into the head tube and i could notice just a slight dimpling (kind of like bleed through of the weld) where the top tube joined. it was just in a small area, not fully around the whole top tube junction.

is that a sign of a poor quality weld or a sign of good quality...like almost full penetrance of the weld or something. i don't know what i am talking about, but i think you know what i mean. as far as i know, the frames are made over seas.

if you don't have time to answer all my questions, i understand. maybe you know of other thread links or websites you could point me to.

summary:
1) would you care which main tubes you received? Tange prestige vs Reynolds 631, is the tange even considered an upgrade?

2) is weld "bleed through" on the inside of Head Tube a good sign or bad sign? or am i inspecting my frame way too close???

thanks!!

Thylacine

Unless you're a professional welding inspector and cut the frames open and put them under an electron microscope, you're not in a position to evaluate the welds. I know this because I once said some years ago to one of my welders "nice welds" and he said "How do you know?". Thankfully, I wasn't stupid enough to reply "Because they look pretty!"

From a practical perspective, honestly, (I'm assuming you own a shop or something - can't think of any other reason why you'd want three Somas) what you're really interested in is "Which is more sellable", right? Whoever it is that makes Somas from where I'm sitting would only make the switch if a) There was some supply or price or manufacturability issues or b) The use of Prestige would carry more credibility/saleablity in the eyes of the consumer.

However, I'm guessing that telling a customer "Well, it was cheaper and easier to weld than 631, and everyone seems to think it's retro cool, so what the heck" probably won't work.

mx_599

thanks for taking the time to read my post. i want to be a weld inspector you know what i meant. the "pretty" aspect. so what do you think about my original head tube analysis? insignificant? stop being anal??


no i don't own a bike shop!!! what is wrong with 3 soma's? hahahahah

now i need to explain. okay, i love their Juice 29er. i wanted to get into road biking....hence the Smoothie. followed by quite a few extra parts at home so i thought i would get the Groove too.

so...now, it has nothing to do with saleability. could you clarify your answer with that in mind? you confused me.

this is their reason for switching:
Tangoing with Tange Prestige:
For 2006, we will begin switching to Tange Prestige CrMo. Tange Prestige does not have the thermophilic properties of Reynolds 631, but overall its tubes are stronger – thanks to Tange's heat-treatment process. Old farts need no explaination of how nice Tange Prestige is; for the youngins' let say it is in the same league as Reynolds 725. In all respects, this is an upgrade, but we will be keeping the price almost the same as 2004 and 2005, because we all know how you feel about a good deal. Pronounced "taang-gay". It's Japanese.

should i not worry at all about the Reynolds 631? is it basically just as good? better? will it have just as much life?

thanks again, i really appreciate it!

Thylacine

I think it's all academic, but I believe that air hardening tubes are stronger in the HAZ, so although Prestige in it's raw state might be stronger than 631, when welded into a frame, the 631 would be stronger in the weld zone making it a better material.

That's my take on it anyway. They're both have 0.9/0.6/0.9 butting profiles anyway (I'm assuming), so your chances of doing anything silly to a tube that thick are pretty marginal. A bike from either would be pretty tough and heavy as a brick, so I wouldn't worry about it.

NoReg

Maybe they are changing for business reasons. I have no idea what those would be, but the price of steel is so volatile right now that there are big numbers tied up in it that would really make one's life miserable if one was in a steel related business. I buy a fair amount of metal and it is driving people nuts what the stuff costs. And the fluctuations.

"2) is weld "bleed through" on the inside of Head Tube a good sign or bad sign? or am i inspecting my frame way too close???"

It really isn't one or the other. The bad part is that there is an inconsistancy. Something went wrong in the sense that the welder either dwelled there a little long, or the tube fit was poor, etc... One comon inconsistancy is burning through tack welds. You could look on the outside and see whether it looks like a place where they would have double welded the tube and therefore there is probably a tack or a start end point that needs to be well knitted together.

The good news is that there isn't any reason to worry about the impact on the the weld's strength. Maybe you can't say "nice weld", but you can't really say "bad weld" either on the basis of what you have to look at.

So far I'm not buying the air hardening propaganda. I keep asking the question on this forum and others of how we know the hardness after welding is optimal? How do we know it's optimal where it got anealed right next to hardened zone, and how do we know it's optimal where the anealed and unaffected zones are. Hardening is not the same as the right hardness. Normally a metal needs both hardening and tempering to hit the correct hardness range for a particular use. Presumably they have the right composition in the metal to ensure it doesn't just get brittle hard, as most metals do that go through trans temp and are hardened, but so far nobody is answering whether that is the case or not (it's not a conspiracy just an information vaccum). It would be interesting to know what the hardness change is.

One of the questions that is worth asking is why are people worried about air hardening or not? The answer is because the purveyors of other systems have pushed the idea that there is something wrong with a TIG joint in Chromo, which is prepostrous. So now we have a new pardigm, the air hardening TIG joint. It may well be superior, I'm sure if someone wanted to devise something that welded better than standard chromo it could be done, but so far the explanations are a little thin on detail.

Cactus

Either tube set will build a nice frame. I have a nice 15 year-old tigged Prestige MTB frame - its a charmer. I'll be building up a 631 (silver brazed) two frames ahead in my building schedule.

bbattle

There's a study done comparing the ride properties of several types of tubing; I believe in the end the writer preferred Columbus Aelle as much as anything else. He was also surprised how difficult it was to tell the difference between one bike and the next.(several identical frames built with different tubing)

zonatandem

Designed a tandem with Tange Prestige tubing. Put 57,000 miles on it before we sold it. Have also owned 2 Reynolds 531 framed tandems, one we rode 64,000 miles (frame broke at 50,000 and 56,000 miles) and the other one we rode for 56,000 miles, no failures.

fbagatelleblack

The strength of the Prestige frame is going to depend somewhat on what they do after the welding. If they just leave the frame as is, the heat-effected zones around the weld will not be as strong as the rest of the tubing. If they do a proper post-process heat-treat, they can get the heat-effected zones back up to pre-weld strength.

Many, many framebuilders don't bother to do a post-process heat-treat, and frame failures in the heat-effected zones around the weld are not common. The areas around the welds are not the most highly stressed parts of the frame, so it generally doesn't matter so much if you lose a bit of strength there.

The 631, on the other hand, does not need to be heat treated after welding, which helps to ensure a nice, strong weld zone.

Both tubing types are very, very nice. I have a soft spot in my heart for Prestige, but you would not go wrong with the 631 either.

Nessism

I have a Tange tubing catalogue and inside they detailing joining instructions. No mention of post joining heat treatment process other than a suggested method in the event the tubing is overheated. Based on this I don't think Prestigue is supposed to be heat treated after joining under normal conditions.

fbagatelleblack

Prestige is heat-treated 4130. 4130 will always lose its temper in the heat-effected zone. The only way to re-establish the temper is by post-process heat treating.

It is entirely possible that Tange does not suggest/encourage/require heat treatment of Prestige tubing after welding, but if that is the case then they are simply accepting the fact that the tubing will be weaker in these areas. Since the welds are not generally in the most highly stressed parts of the frame, weaker tubing could be acceptable in these spots.

Yours,

FBB

bellweatherman

Tange tubes have always been in spec way more than Columbus, and especially Reynolds. Reynolds has really been inconsistent with their butts. The old 631 stuff is actually very good tubing though.

ChiapasFixed

do you mean the old 531 stuff?
it was my impression that 631 is a much newer line of air hardening steel designed to replace 531...

Nessism

The tubing is more than strong enough even after some heat related losses. No heat treatment necessary.

Torchy McFlux

I used to love opening a fresh box of Tange Prestige tubes. Thick cardboard, nicely folded plastic liner, and clean shiny tubes with the little "Tange Prestige" logo lasered into every one. The smell of that light oil they coat them in before shipping is probably going to stick with me forever.
Wasn't so crazy about opening a box of Reynolds seatstays though. The tubes were black and rough, coated in thick stinky oil, and wrapped in paperboard.
On that basis alone, I'd prefer the Prestige.

johnxyz

Hi fbagatelleblack,

In (layman's terms) can you explain what should be done to Tange tubes post-welding to return the strength? A couple of framebuilders or companies that actually take this extra step(s).

Love the detailed, factual background here by you and others on framebuilding. Looking for a steel tig-welded custom myself now. So not an issue , right? Only with fillet and lug brazing?

What tubesets do you like for tig-welded steel - Colombus, Dedacai (sp?) Reynolds or Tange? Which models/lines?

Thanks

ydrive

Love this kind of discussion!

bikemig 

Zombie threads, ?

Agreed, though, it's an oldie but goodie.

shelbyfv

Is it still a discussion if it's been silent for 6 years?

Road Fan

It looks like it never was finished well. Johnxyz asked fbagatelleblack (whom I haven't seen here or on my other lists for a while!) some questions and FBB did not get back to him, apparently.

But yes, a great discussion!

unterhausen

nobody does post-weld heat treating on steel frames, and I bet it would be a disaster because of distortion

fietsbob

OP was buying Maxway TW Made frames Batch Ordered for Importation By Merry Sales Imports ..SOMA is one of the brand names ..

Post heating Steels , in heat treatment is the Quenching while hot .. and that rate can be controlled..

part of the function of double butting is by having it thicker

where the Welding/ Brazing takes place , its still adequately strong without more than a controlled cool down rate ..





There were Pre heating strips along the seams to be welded in putting a Submarine together, in the Shipyard.
but this was Way thicker steel of Much Higher strength alloys .

xmessenger

I am reading comments regarding Prestige being inferior at the weld which is a bit misleading imo.
Yes, 631 is supposed to air harden at the weld but no one is acknowledging the fact that these are butted tubes for a couple reasons. One being that they know welding weakens the tubing and therefore they make this area much thicker.
Prestige and Reynolds 720 are heat treated tubes. I would imagine doing a post weld heat treat would also affect the rest of the tube making this redundant unless you can localize it.
These heat treated tube sets are stronger through the entire tube and allow for thinner tubing with the same strength. Air harden tubes increase strength at the weld which should allow for thinner butt profiles but they dont seem to bother, keeping the butted sections the same .9mm thickness. Afaik.
I guess what I am saying is I question the real advantages of air hardening only tubing because a frame with .9mm butts make for very robust welds regardless due to its girth. Even if they trimmed the butting to save weight while maintaining similar strength I feel thicker butts make for better connections beyond the material strength such as ease of weld and resisting haz effects.
Imo the benefits do not outweigh those of heat treated tube sets.

trailangel

So after 10 years, what's the best tubeset..631 or Prestige?

unterhausen

Both budget tube sets, or they wouldn't make it into a Soma. You probably couldn't tell the difference from a higher-end tube set without the weight difference.