I Cut my Soma frame in two today -- updated with pics
 

**4 April updated with pictures below**

Seriously! I took the sawzall to it, hacked right through the seat tube and the down tube. I must say I enjoyed it.




...I am starting on my project to make a "Ritchey Breakaway" style travel frame. Thanks to 23skidoo from this forum who donated the Soma frame. I'm using a Ritchey style double seatpost clamp that will hold the two halves of the seat tube together, and a sleeve with two pinch bolts that will hold the down tube together.

Nova had all of the small parts to make this easier; I bought a seat clamp lug, several cast steel pinch bolt assemblies, a stainless steel piece of tubing for the down tube sleeve, STI cable adjuster stops, water bottle braze-ons, etc.

Today I cut the seat stays loose from the top lug, for later reattachment to the second (lower) lug. I used a 3" piece of stainless tubing sized to slip fit over the down tube, brazed pinch bolts to it, slit it -- voila, down tube clamp.

Next I have to braze the second seat lug, along with modern style cable and STI stops. Then I'll shorten and reattach the seat stays. I'll post pics in a day or two; wish me luck!

...pictures?

Why wouldn't you use S&S couplers?
http://www.sandsmachine.com/

S&S requires you to have insurance that names them in the policy. That's $1800 up front for a project like this.

please explain this.

I think it means that S&S requires people to know what they are doing before they will sell their product to them.

Typically it's about $300-$500 to have a frame properly retrofit.

Sorry friends, I'm lost here. Too many acronyms and insider terminology for me.

have a look at sandsmachine.com/ to see

S&S will only sell their couplings to framebuilders that have an insurance policy where S&S is specifically certified to be covered for any claims arising from your use of the couplings. There is one insurance company that is used by framebuilders, and a policy costs a minimum of $1800 a year. It has nothing to do with knowing what you are doing.

unterhausen nailed it; S&S won't sell to non-insured framebuilders, even for personal use. Really though, I don't feel any compelling need to use them. I'll have about $50 in my frame when I'm done, and I believe it'll be more than adequately strong.

I think the seatpost double clamp solution is simpler and more elegant than the S&S coupler. I never liked the look of Ritchey's little v-band clamp on the downtube, and thought that a sliding clamp sleeve would be stronger and more maintenance friendly. The tube cut is angled and I'll cap the ends of the tube, giving it some more resistance to torsion.

I can't take credit for that idea either though; someone on the framebuilder's list sent me to pictures of Rene Herse's frames using the sliding sleeve for a coupling.

My builds can fall apart for far less money, but I'd love to see the folder.

I'm curious how the system you're using compares to S&S couplers. S&S couplers seem so...elegant.

I don't really understand how this system works, do you have a link? Is it just the pictures at Bicycle Quarterly?

Robbietunes, I LOL'ed. :p

Here's the link someone sent me:

http://www.43bikes.com/herse-demountable.html

Herse actually used quick release levers so that the bike could be quickly taken apart with no tools. I'm not doing that because I don't want the levers in the way, extra weight, etc. but it was a pretty cool execution.

that's pretty nice, but the shift levers under the saddle looks like a really bad idea. The modern method of breaking the cables is far superior. I'm a little disappointed that nobody bothered to take a picture with the bike disassembled.

I done a similar thing
 

I made my bike into a folder and took it on an 800km tour with no ill effects.
A few details can be found at http://www.crazyguyonabike.com/doc/p..._id=80414&v=8G. This is my third bike with the same frame joining method. Got the ideas from http://www.sonic.net/~maryking/index.html who builds take apart bikes. Cheaper the S&S and very adaptable to the DIYer.

Mike

I'd love to see pictures from your conversion. I was working on something similar a while back, but using a cut down headset to join the frame. I had a length of wood inside to give rigidity to the join. It did work alright, though the headset joint worried me as it was maybe only 3 inches in leghth, and I wasn;t convinced.
Unfortunatley, I can braze, but haven;t really got the skill to make something from scratch, so have to rely on something ready made to do the job.

I worked on the thing a bit more last night; couldn't find the camera so still no pictures.

The original lug work was pretty rough, and taking the seat stays off of the seat lug didn't improve it. Oh well, this is about function, not beauty. :D ..not to mention, I'm pretty much a hack in the brazing/framework business anyway.

I cleaned up the seat lug, shortened and re-cut the seat stays for their new attachment point, and verified that a long reach brake will still work in the back with the moved stays (barely).

I need to braze the lower seat tube lug, re-attach the seat stays, and make new caps for them. The last few things will be brazing STI stops and new cable stops for the rear brake and derailleur cables.

Maybe I'll get some more brazing done on it and take some pictures tomorrow night. Tonight, I will ride my plastic wonderbike...

Looking forward to seeing it.

OK, here are a few pictures of the frame, ugly charred paint and all. :) After I took these pictures I sprayed some grey primer on it to keep it from rusting and built it up. I'm going to ride it for a week or two and make sure everything's OK before powdercoating it, probably bright red. It's so ugly I may have to take it on the Tuesday night World Championships ride. :D

http://www.secondhandsix.com/temp/bi..._frame_001.jpg

http://www.secondhandsix.com/temp/bi..._frame_002.jpg

http://www.secondhandsix.com/temp/bi..._frame_003.jpg

http://www.secondhandsix.com/temp/bi..._frame_004.jpg

http://www.secondhandsix.com/temp/bi..._frame_005.jpg

Interesting, looking forward to hearing more.

Thats an ingenious design. I was thinking it was going to be very dangerous to ride a home made cut and shut but I like the way its been done.

Ritchey BreakAway homebuilt
 

Hey- seeing as your post is almost 4 years old now, and I just stumbled onto it, I'curious how your bike has held up? I'm in the process of trying to build a Ritchey Breakaway like frame, without the funky downtube clamp. I'm planning to use a downtube joint more like the one on the Rene Herse you linked to, only using two binder-bolt braze-ons with a length of 26.2mm aluminum seat post tubing for an internal sleeve instead of your external SS sleeve. My brazing is not great either, but I'm learning :)
Thanks for any insights-
Scott

Its pretty easy to make a folder out of old steel bicycles. If you take some old mtb bikes, and cut in front of the seat post on one bike, and behind the seat post on another bike, then weld on some plate steel so you have a good mounting surface.

Another idea of mine was using a full suspension bicycle, and just easily unbolt the pivots - Be good for occasional folding use, like for me when my bike breaks down and I need to bus it to the train.

Please note that you are replying to a thread started in 2009 and last touched (before you) in 2012.