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Discussion Starter · #1 ·
I have been building a bike from scratch since November. I was finally able to assemble it last night. It was a lot of fun and an awesome learning experience for me. The bike: I decided to go with a full rigid 29er. Tubeset is a DEDACCIAI .8/.5/.8 from nova. The only 'trick' thing I did with the frame is internal cables. I used car brake lines to snake through the tubing, so only a few inches of cable show on either end of the bike.
I obviously built a jig in order to build the bike (no pics) Surprisingly the frame came out pretty straight (for my first frame build) My local bike shop mechanic just made a few adjustments on the dropouts. The whole bike is tig welded 4130 Chromo And I did some brazing as 'body filler' I turned the headtube on the lathe, and made reinforcement rings on the lathe also.
I sprayed the bike with HOK Hot rod flatz daytona blue metallic. Exactly the color I was looking for.

Its really rewarding being able to ride something that no one else put any work into, except for chasing the threads on the bottom bracket. I also laced the wheels myself (a few times.. don't ask).

Here is some pics:











 

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Gabe.....
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The DT design is interesting..........more details please. That particular spot on a frame is very important in the structure department and it would make a good subject for discussion.
 

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Wow.

Constructive criticism:

-Spend more time practicing your welding, especially if you want to use heat-treated 8/5/8 tubing. I am guessing that this bike will not last long (just a guess, though). Get a bucket of scraps and lay beads until you can get shiny, even welds - not overcooked, blobby grey messes (my first frame was at least as bad, but it was made from .049" 4130 pipes)

-If that is a butt joint on the DT stuck together with brass, throw the frame away and don't even try to ride it. You've put a very weak joint at a very highly stressed spot. If you've done something clever there and it's not what it appears to be, please tell us about it.

-The internal routing is *probably* going to make all kinds of horrible noises rubbing against itself and the tube walls. It's tough, but better to try to make them not touch each other. Could be fine, too, though.

My feeling is that you should put this one on the wall and start again. No offense intended - I just feel that the combination of nasty porous welds, weird DT butt joint, and super-thin (8/5/8 is thin for PROS building 29ers in most cases) tubing is asking for trouble.

Everyone has to start somewhere. Learn from it and try again!

-Walt
 

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I have to say that I have built some equally ugly frames and rode them for a time with no failure.

However, I didn't waste the effort of painting them and they definately didn't have ridgid forks.

On a serious note I would not normaly rain on your parade, but be cautious with a ridgid fork on a frame of that build quality. I would say 99% of front triangle failures I have seen had ridgid forks on the front, from Jamis to Ti IF's.
 

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Discussion Starter · #6 ·
The DT design is interesting..........more details please. That particular spot on a frame is very important in the structure department and it would make a good subject for discussion.
See below :thumbsup:

Walt said:
Constructive criticism:

-Spend more time practicing your welding, especially if you want to use heat-treated 8/5/8 tubing. I am guessing that this bike will not last long (just a guess, though). Get a bucket of scraps and lay beads until you can get shiny, even welds - not overcooked, blobby grey messes (my first frame was at least as bad, but it was made from .049" 4130 pipes)

-If that is a butt joint on the DT stuck together with brass, throw the frame away and don't even try to ride it. You've put a very weak joint at a very highly stressed spot. If you've done something clever there and it's not what it appears to be, please tell us about it.

-The internal routing is *probably* going to make all kinds of horrible noises rubbing against itself and the tube walls. It's tough, but better to try to make them not touch each other. Could be fine, too, though.

My feeling is that you should put this one on the wall and start again. No offense intended - I just feel that the combination of nasty porous welds, weird DT butt joint, and super-thin (8/5/8 is thin for PROS building 29ers in most cases) tubing is asking for trouble.

Everyone has to start somewhere. Learn from it and try again!

-Walt
Yes I need more practice on the thin wall tubing. I can weld 1/16"+ no problem. The welds were shiny before oxidation set in.

The DT is NOT a butt joint, rather I guess you could say it is sleaved. The larger diameter is covering the main DT by anywhere from 1/2" to 3/4" Spacers made to take up space and weld them together.

Internal tubing has o-rings at various points to reduce noise. So far the bike is silent.

I know that the bike should be hung up, but I just cant help riding it. It really is the nicest riding, and fitting bike i own.
 

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Discussion Starter · #7 · (Edited)
TortugaTonta said:
I have to say that I have built some equally ugly frames and rode them for a time with no failure.

However, I didn't waste the effort of painting them and they definately didn't have ridgid forks.

On a serious note I would not normaly rain on your parade, but be cautious with a ridgid fork on a frame of that build quality. I would say 99% of front triangle failures I have seen had ridgid forks on the front, from Jamis to Ti IF's.
I may switch to a sus. fork if I plan on really riding it. And I had the paint laying around.
 

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TK -

Yeah, riding your handbuilt bike for the first time is AWESOME. I went on what was, in hindsight, a really boring ride on my first frame the first time, and I still have fond memories of it - it was just so cool to be rolling on something I built myself.

On the welding front, practice on thinner stuff. 1/16" is twice as thick as what you're going to want to be welding for a bike frame. And the welds should stay shiny even quite a while after you'd done them - you've overheated everything and the metal has indeed oxidized - but it's oxidized deep into the weld, not just on the surface. Hence the grey/ashy/pockmarked appearance.

Practice makes perfect. Be careful out there.

-Walt

Timekiller said:
See below :thumbsup:

Yes I need more practice on the thin wall tubing. I can weld 1/16"+ no problem. The welds were shiny before oxidation set in.

The DT is NOT a butt joint, rather I guess you could say it is sleaved. The larger diameter is covering the main DT by anywhere from 1/2" to 3/4" Spacers made to take up space and weld them together.

Internal tubing has o-rings at various points to reduce noise. So far the bike is silent.

I know that the bike should be hung up, but I just cant help riding it. It really is the nicest riding, and fitting bike i own.
 

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Discussion Starter · #9 · (Edited)
Could I ask... what tubing is not considered thin?

Here is my specs:

EDIT: Now that I think about it, The above is incorrect.. my tubeset is:

DIA(MM) WALL(MM) LENGTH(MM)
DT 31.7 0.9/0.6/0.9 650
TT 28.6 0.9/0.6/0.9 650
ST 28.6 1.2/0.6/0.8 630
CS 22.2 0.8 425
SS 16 0.7 560
HT 31.8 or 36** 1.1 200
 

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Discussion Starter · #10 ·
Walt said:
...On the welding front, practice on thinner stuff. 1/16" is twice as thick as what you're going to want to be welding for a bike frame. And the welds should stay shiny even quite a while after you'd done them - you've overheated everything and the metal has indeed oxidized - but it's oxidized deep into the weld, not just on the surface. Hence the grey/ashy/pockmarked appearance...
Ok I see what you mean, Thanks! Well I have a bunch of short pieces I can now practice on. The thin stuff is all new to me, haha.
 

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Discussion Starter · #13 ·
Update on the bike..

I have logged probably close to 30 off-road miles on the bike the past 4 days. Everything is still in one piece. The bike tracks perfect, and is surprisingly light (in corners/jumps) You can really throw the bike around. I'm surprised with the larger wheels that it acts like this. And WOW the brooks saddle is amazing. No pain what so ever, I used to be sore after 5-10 miles. I was just barely getting sore after day 4 on the bike, but that was after a 4 hour ride with a 40 minute break. Trust me I have beat this bike the past few days. Rocky downhills, log hops, jumps (small doubles), rooty fast singletrack, and even a stream crossing up to my knees.

Had to ride through a bit of mud yesterday:

 
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