Framebuilders - Design Idea. Is it possible

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View Full Version : Design Idea. Is it possible


yellowjeep
04-13-07, 07:50 PM
I am playing with the idea of building a lugged track frame for myself. I am trying to think of some ideas that would make the bike kind of unique and I was wondering if it would be possible to do a "seat mast" like the Giant TRC Advance with a lugged frame. Something where the seat tube would go all the way though the seat lug and serve as a seat mast. I would cap it off with something like this sleeve (on the bottom right) (http://www.framebuilding.com/Lugs%203.htm), which would leave a lot of room for some creative filing. I think it would look pretty damn sweet. Can it be done? Has it been done with lugged steel?



Giant TRC for reference.

http://www.cyclingnews.com/photos/2006/tech/reviews/giant_advanced_LE/giant_tcr_advanced_le11.jpg

http://www.cyclingnews.com/photos/2006/tech/probikes/t-mobile_giant_teutenberg/ina_teutenberg_t-mobile_giant66.jpg


cs1
04-14-07, 04:27 AM
You mean having the seat tube extend beyond the actual lug? I can't see why it can't be done. I'm not too sure it would have an advantage. The only wasy too find out is to try. Good luck sounds interesting.

Tim

SamHall
04-14-07, 08:52 AM
No real performance advantage, but it sure would look different, and that's what you're after, right? The main problem I can see is making sure the ST is strong enough at the seatcluster. A regular ST would be too thin, but I guess that's a moot point as I doubt you could find a ST that long in the first place. How are you gonna attach the seat anyway?
So, you can get a straight gauge .035 tube or an .049 depending on your weight and the overall length of the tube above the seat lug. Should be plenty strong then.
Cool idea either way.


MichaelW
04-14-07, 09:28 AM
On some older, quality womens style or mixte frames, the dropped TT is brazed quite low on the ST so the metal must be thick enough for this to work. Check out some of the lugs for this style of bike.
The saddle can be held at the correct height by spacers rather than a clamp. All the clamp needs to do is prevent rotation so it can be very lightweight.

yellowjeep
04-14-07, 11:39 AM
The this is what i was thinking for finishing off the seat mast, it leaves me room to be creative.
http://img409.imageshack.us/img409/2677/009ninesilvapressedlugsbv8.gif

I would just use a regular seat post and cut it way down.

All of this is done purely for aesthetics so any performace benifit would be a bonus.

Good call on the straight gauge, i hadnt thought about that

yellowjeep
04-14-07, 01:04 PM
it shall be done.

Bruce Gordon

http://img19.imageshack.us/img19/8590/99999991ui7.jpg

http://img266.imageshack.us/img266/848/99999990qj5.jpg

dbohemian
04-14-07, 01:56 PM
Bruce Gordon Rocks! Um, that has been done a ton of times. Especially amongst of the time trial crowd of old. I hate to be dating myself.

Most of the issue was that the middle of seat tubes was typically un-butted and this would eventually lead to a failiure right above the seat lug. If you used the right tube or reinforced it enough it would be fine and I see no real issue.

Always wondered why on custom bikes, if you knew your exact seat hieght why we needed vary adjustable seat posts. Sasha White from Vanilla also had a bike like that with just a few CM of adjustability.

Dave Bohm
Bohemian Bicycles

filtersweep
04-14-07, 03:46 PM
So your heirs can sell it after you pass on.




Always wondered why on custom bikes, if you knew your exact seat hieght why we needed vary adjustable seat posts. Sasha White from Vanilla also had a bike like that with just a few CM of adjustability.

Dave Bohm
Bohemian Bicycles

yellowjeep
04-14-07, 08:45 PM
hey dave can i borrow your jig? :o

bellweatherman
04-17-07, 08:21 AM
The this is what i was thinking for finishing off the seat mast, it leaves me room to be creative.
http://img409.imageshack.us/img409/2677/009ninesilvapressedlugsbv8.gif

I would just use a regular seat post and cut it way down.

All of this is done purely for aesthetics so any performace benifit would be a bonus.

Good call on the straight gauge, i hadnt thought about that


If I am not mistaken, that part is intended to be inserted into a seat tube and brazed in place.

dbohemian
04-17-07, 06:12 PM
It goes on the outside, not the inside.

D bohm
Bohemian