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jpw
03-29-2013, 05:55 AM
Following on from this earlier thread (now CLOSED);

http://forums.thepaceline.net/showthread.php?t=125904

I see this photo from Serotta's FB feed, which appears to show a hole in a ti down tube for internal cable routing;

https://www.facebook.com/photo.php?fbid=10151319327511493&set=o.119812894701501&type=1&theater

The original thread concluded that holes in ti down tubes were not advisable for Di2/ EPS applications due to concerns about the long term structural integrity of a down tube with routing holes for wires. I'm a bit confused by this cable routing photo.
buddybikes
03-29-2013, 05:59 AM
Jamie at Firefly did it to his personal bike...

http://fireflybicycles.com/2395
Nooch
03-29-2013, 06:08 AM
Ben had mentioned in the other thread that they had legend frames that suffered failure -- this frame, however, certainly appears to not be a legend.

I don't know anything about that frame and won't pretend to, but perhaps the aero tubes on this build met the stress requirements.

is it possible that these tubes are hydroformed aluminum or aero steel? while they sure look like ti, i didn't know ti could shape like that..
jpw
03-29-2013, 06:13 AM
Jamie at Firefly did it to his personal bike...

http://fireflybicycles.com/2395

the photos suggest that the dt holes have been strengthened with the addition of welded 'rings'. That would suggest that they are drilled in areas subject to more stress. I wonder if he's done stress testing?
jpw
03-29-2013, 06:19 AM
Ben had mentioned in the other thread that they had legend frames that suffered failure -- this frame, however, certainly appears to not be a legend.

I don't know anything about that frame and won't pretend to, but perhaps the aero tubes on this build met the stress requirements.

is it possible that these tubes are hydroformed aluminum or aero steel? while they sure look like ti, i didn't know ti could shape like that..

perhaps the bike never leaves the trainer:)

It does look like titanium, but the dt seems more substantial than the dt on a typical Legend.

Anomalies interest me. This is one of them.
Nooch
03-29-2013, 06:34 AM
perhaps the bike never leaves the trainer:)

It does look like titanium, but the dt seems more substantial than the dt on a typical Legend.

Anomalies interest me. This is one of them.

definitely an aero frame, just look at the seat tube..
jpw
03-29-2013, 06:38 AM
definitely an aero frame, just look at the seat tube..

there's no doubt about that. it's aero.
Nooch
03-29-2013, 06:48 AM
doing some e-stalking and 'research' it appears the bike wasn't originally built for electric -- earlier pictures show standard sram s900 bar ends..
jpw
03-29-2013, 07:03 AM
doing some e-stalking and 'research' it appears the bike wasn't originally built for electric -- earlier pictures show standard sram s900 bar ends..

the frame doesn't look like new production. the dt holes are for cables and not wires. it's an anomaly :)
cfox
03-29-2013, 07:07 AM
the Serotta tri-bike has a cable actuated front derailleur, it's not an e-shift bike. My only guess as to what that cable is doing in the downtube is it's a wire for a wired power tap.
oldpotatoe
03-29-2013, 07:10 AM
the Serotta tri-bike has a cable actuated front derailleur, it's not an e-shift bike. My only guess as to what that cable is doing in the downtube is it's a wire for a wired power tap.

I think it's for the RH sifter cable and housing. It's a TT bike. I 'think' the point, with references in the first post, to the closed thread about drilling holes in serotta down tubes, is that here is a serotta with holes in the downtube, for whatever reason.
cfox
03-29-2013, 07:12 AM
the photos suggest that the dt holes have been strengthened with the addition of welded 'rings'. That would suggest that they are drilled in areas subject to more stress. I wonder if he's done stress testing?

Some builders, like Baum and Indy Fab, won't weld reinforcement rings on their ti bikes. They feel the stress from another super-hot tig weld is worse than any stress the hole will create on its own. They just make sure to use thick enough tubing in that area. They do, however, braze rings on their stainless bikes. The ring can be brazed at much, much lower temps and stainless tubes are much thinner that ti tubes.
soulspinner
03-29-2013, 11:38 AM
Some builders, like Baum and Indy Fab, won't weld reinforcement rings on their ti bikes. They feel the stress from another super-hot tig weld is worse than any stress the hole will create on its own. They just make sure to use thick enough tubing in that area. They do, however, braze rings on their stainless bikes. The ring can be brazed at much, much lower temps and stainless tubes are much thinner that ti tubes.

cool. It appears I learned something today.........