fit and geometry v. tubes

[Needs Help]

Would I be able to tell the difference between a Concours with double butted tubes and Legend with triple butted tubes assuming they both had the same geometry? Could anyone?

It seems to me the Seven Axiom should be compared to the Concours based on the double butted tubing and price. The Legend has different tubes--they're triple butted--and therefore it's more expensive.

Thanks.

[JohnS]

butting doesn't affect ride quality. It only lightens the sections of the tubes that don't have any stress on them. The Legend costs more because there are more tubes available in each size.

[Richard]

Jeez, I can sense the ride difference when bikes are painted with different colors of paint. If a two color bike carries the dark color above the center of mass, it handles like a pig. Always put the light color on top and the strongest color on the seat/chainstay triangle as this improves acceleration. I also noticed that sloppy welds reduce my aero advantage in time trials and cost me about a nanosecond per 10K.

[dirtdigger88]

As it was explained to me when I began looking at Serottas, no you most likely would not. The triple butting helps reduce weight, especially on bigger bike where the thinner section of tube is longer. The Concours has an up charge for polished tubes where the Legend does not. I was asking the same questions, but when it came down to it, by time I paid the extra $$ for a polished Consours, I was with in a couple hundred bucks of a Legend. Guess what one I got :bike:

[jpw]

Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeee!

Now i think i just learned something of real interest from this forum.

The Legend is more expensive than the Concours because there are more tubes sizes to choose from for a Legend than for a Concours. So the price is a reflection of the range of tubing available for each frame. Is that right?

[dirtdigger88]

As I understood it, and remember this is only how I understood it. The Legend has triple butted tubes for the top and down tube where the Concours has double butted tubes. The Legends tubes reach their thinnest in the middle. Depending on how long the tube is, the length of the thinnest section increases or decreases. The tubes have to be so think at the welds. Like I said before, the polish is also a N/C option on the Legend, I think it was several hundred dollars on the Concours. You also have many more N/C paint options on the Legend. I think you could build your Concours to be 99% if a Legend, but it would probably cost you more than a Legend, or darn close. Again, remember I am not expert, I am only letting you know how my decision was made to buy a Legend vs a Concours

Jason

[Smiley]

Its the Top Tube unless things have changed from the old days, the TT is triple butted and really you'll never tell the difference unless you get into the large frame sizes and then the TT in combo with rider weight would affect the ride as this TT is Now oversized and would make a difference. Yes add to this you have many more STOCK or standard options for a Legend that if you dress up a Concours with too many finish options you'll be close to the Legend price. It used to be that you could not buy a Concours in a full polish version as an example and now if you got the $ you can. Take the ST stay as an option only available with the Legend and lets not forget you get the attractive Head Badge with a Legend and not the Concours and that may have put me over the edge with making my choice.

[jpw]

So, riding with my eyes shut i wouldn't really be able to say which frame i was on?

[BigMac]

NH:
Most of what previous posters have said is absolutely true, particularly when comparing your "average" 56-58cm frame. The frame mass difference is so nominal to be indistinguishable. Triple butting, double butting, straight guage...yada, yada...it may help tune ride incrimentally but mostly its sales jargon to separate you from your $$. Butting ti tubing is expensive. Swaging or tapering the tubes ala "Colorado Concept is even more difficult and expensive, considerably more difficult than steel for reaosns only a materials engineer or possibly a physicist could explain.

What really distinguishes a Serotta Ti frame is those CC tubes. If one were to maintain same OD of a given tube but only change butting and/or wall thickness, you really gain very little in increased load capacity and nothing in torsional stiffness. If however we increase tubing diameter you acheive large gains in torsional stiffness. Serotta's CC tubes capitalize on this by acheiving large diameter cross-sections in high load areas such as BB while decreasing diameter in lower load areas to maintain compliance and resiliency. So what distinguishes the Concours from Legend? Tube selection is certainly an issue; there are apparently a much smaller selection of DT's, and TT's for designing a Concours than a Legend. The most important item however is the CC TT on the Legend while the Concours employs a non-tapered (swaged) TT. The large OD section of a Legend TT is at HT end. Where this is most important is in large frames. Remember, a longer tube flexes more than a short tube. Large frames are more prone to front-end shimmy and stability problems. Shimmy or no, there is nothing worse than descending at speed on a frame with front-end torsional flex. :crap:

I won't bother with comparisons on Concours v Axiom, I think the engineering differences are substantially obvious. I have never ridden a Concours, Serotta could not build me one in my size. You really need to get a proper fit, have it sent to Kelly for his review and then call him to discuss your exact needs. He knows better than anyone what Serotta can and cannot do with the Concours tubes. FWIW: Kelly himself is a big guy, he speaks from experience concerning the foibles of large frames, particularly those of ti variety. If in fact a Concours can be built to your needs, sure I'd say buy it, the $$ saved is considerable in my book. For my size, riding style and needs, Kelly was very honest and forthright in stating it could not be accomplished with Concours tubes in 2000, whether the Concours tubesets have sufficiently changed or your needs are sufficiently different can only be answered by Kelly.

I have spent extensive time on a custom Axiom, approx 1200 miles in total. The bike was built for a friend, one who is considerably larger and heavier than I (6'5", 265lbs) using what Seven claims was their most stout tubes -- at least circa '99. That frame was among the scariest descenders I've ever ridden, I could never get it over 50 mph and even 40 was 'adventuresome'. I could also get the rd to upshift under heavy pedalling load. Axiom's certainly have a fanbase but I'm betting none of them are riding frames larger than 60cm and certainly none over 200lbs. I have personally descended at 60mph on my Legend according to Ergobrain computer and have descended hands free at 50mph to lean back and stretch a bit, never concerned with any instability or shimmy problems. FWIW: My friend bought a custom Legend within 6 months of me getting mine. He took one ride and was amazed how much more responsive and stable my Legend performed.

Spring has sprung, you need a frame. Get properly fitted, have Kelly review your worksheet, give him a call, order your bike, then get out and ride.

Ride on! :bike:

[Johny]

Bravo BigMac! I am a small guy but can understand what you're talking about...

:bike:

[Climb01742]

based on the legends that i test rode over the years, i always thought they were big boy bikes, way too overbuilt for wusses like me. based on what bigmac says, i can now see why. but based on riding my hors, i'm beginning to believe that kelly can build a legend that anyone, any rider, of any size, would love. having the additional tubing choices the legend offers will help make sure you get the ride you're looking for, i think. call me a new convert to legend worship.

[Needs Help]

Thanks for all the responses. I learned a lot.

[gt6267a]

bigmac -- so, for a smaller size. for example, my frame is a 53 x 53.5 is there any benefit to getting a legend over a concours? is seems, as you describe it, the TT would not be long enough to get much benefit if any?

thanks,
k

[BigMac]

GT:
In my opinion, save the money and get the Concours. Being however that this is in fact Serotta's playground, I would suggest you call Kelly directly and discuss this matter with the master builder.

Ride on!

[DWF]

butting doesn't affect ride quality. It only lightens the sections of the tubes that don't have any stress on them.
Technically, that's not true. If the tube OD remains constant and ID is increased, the the tube becomes more and more flexible. This can affect ride quality. The idea behind butting is to increase wall thickness at joints where the tubes are more highly stressed and, depending on the joining method, to counter the loss of mechanical properties in the heat affected zone (HAZ) and to decrease mass where it is not.

Simply put, a straight gauge tube will always be stiffer than a butted tube of the same OD and whose thick sections are the same wall thickness as the straight gauge...a .7mm wall straight gauge is stiffer, both in bending moment and in torsion, than a .7/.4/.7 butted tube.

[jpw]

Well, it's good to get the experiences of a rider who has already been there done that when it comes to choosing between the Concours and the Legend. So, for a smaller or average size rider a Concours would seem to hold up well against the Legend. The only other area of debate in choosing would seem to be the extra cost options for th eConcours which are standard for the Legend- paint, polish et.c. A matte finished Concours with no frills looks like a good deal set against the Legend. However, the Legend has it all. It's a classic dilemma. What fun.

[Climb01742]

hey, bigmac, it sounds like we now might have two resident technical whizkids on the phorum: you and DWF. its cool to hear you guys put facts on the backbones of all of our half-baked theories. thank you both for sharing your know-how and please, please continue. speaking for myself, ignorance isn't bliss. :crap:

[Kevin]

I'm with you Climb, I don't understand half of what BigMac and DWF are discussing, but I am learning a great deal. Thanks guys.

Kevin

[Too Tall]

Reflecting BMacs comments...that's EXACTLY why I went with the Ti Legend. A 64X64 Ti frame that rides like a good steel bike. Yep, same here pal...hands come off the bars with confidence at speed. Amazing bike.

And it's not just me. Two nights ago I re-cabled a 99' Ti Legend for a guy. While he was watching he said "you know, this really is an amazing bike...I get on it sometimes and can't hardly believe how well it rides".

'Course the other player in the big Ti frame dept. has to be Tom Kellog RIGHT?

[jpw]

Based on what has previously been said, am i right to hold the view that the Legend really comes into it's own when the rider is big, and that for the 'less big' rider the difference between the Concours and the Legend is minimal?