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If i cut and reweld my trek 820 frame how much weeker will it be?

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If i cut and reweld my trek 820 frame how much weeker will it be?
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Posted: Jul 31, 2008 at 19:26 Quote
DO IT DO IT DO IT DO IT DO IT!

Posted: Jul 31, 2008 at 19:31 Quote
mooseman180 wrote:
nwd26 wrote:
mooseman180 wrote:
thats all i want to now. i just want to shorten it up a bit by moving the rear end bars and then a part of the middle pole that the seat post goes it. how much will this afect the overall frame?

dude.

are you doing this yourself? maybe not the best idea. it will weaken it a ton i'd imagine. gusset the hell out of it, or just buy a new frame.

well my brother would be doing the welding. i see how it might weeken the frame. do you think the frame could take some dirt jumps just normal. cuz if so i wouldnt mess with it. but i dont know it was just a hand me down from a close friend and now i got a new bike but i need somthing to jump..

The 820 is a steel frame, it could take a couple good hits. But I wouldn't cut it.

Posted: Aug 1, 2008 at 5:45 Quote
If its steel than you can absolutely cut and weld it. Just because they heat treat a frame doesnt mean you cant do it again you know. Its just an extra step that is hard to complete without the right connections. With steel however you dont need to heat treat it. I dont heat treat my steel or 4130 frames and they are plenty strong to take 20 foot drops and the like because I have done them.

I cant believe all you nay sayers out there who are telling this guy not to take a risk and make his bike his own. Just because you dont have the knowhow or the sack to try anything that you didnt buy from a store doesnt mean this guy doesnt. And if you are that queer than why wouldnt you want him to do it and fail at least.

Posted: Aug 1, 2008 at 12:54 Quote
I wouldn't do it, it will ruin the geometry and your bike won't be as strong because as far as I know bikes are specially designed to make the geometry help with the strength. So if you change this by shortening bits, different parts of the bike will be under more strain then they should be and will snap/bend/crack quicker and more easily.

O+ FL
Posted: Aug 1, 2008 at 14:01 Quote
sirknumskullgt wrote:
I cant believe all you nay sayers out there who are telling this guy not to take a risk and make his bike his own. Just because you dont have the knowhow or the sack to try anything that you didnt buy from a store doesnt mean this guy doesnt. And if you are that queer than why wouldnt you want him to do it and fail at least.

What you have to realize is those tube weren't just arbitrarily welded to different spots on the main triangle. The were welded in such places to give the right handling, to work with the correct fork, to turn more easily, or make the the bike more stable! changing anything on the frame would wreck this all.

By the way use the word queer again like that and you can say bye to PB for a while.

Posted: Aug 1, 2008 at 14:27 Quote
Exactly as Carnell said. Even if you use a fork too long for your bike it reduces it's strength drematically. This to me means that cutting down anything to do with the frame will make it a lot weaker.

Posted: Aug 4, 2008 at 5:00 Quote
Unless Im mistaken neither of you guys have any experience cutting and welding bike frames, or engineering. So Im telling you in my professional opinion that it could work. If he keeps the geometry he wants for different sized fork then it would be fine. Hes already going to be removing the head tube so this can be done. It doesnt make a bike weaker by putting a bigger fork on. It just slackens the head angle more than designed and if there isnt proper gusseting to accomodate for the extra stresses then it may crack easier. And your idle threats mean nothing to me. Fanny bandit

O+ FL
Posted: Aug 4, 2008 at 10:16 Quote
I do have expierance cutting and welding (although not bike frames), and as a bike mechanic in my oppinion it is a bad idea for some one with no expierance to do.

Posted: Aug 4, 2008 at 10:31 Quote
Bad plan. Unless you have an aluminum welding torch and know what your doing.

Posted: Aug 4, 2008 at 11:19 Quote
are you kidding? has anyone ever seen a trek 820? that frame is NOT made for jumping anything. go buy a frame made to do what you want to do with it, don't mod-job some crummy old cross frame which will probably only ride worse after you hack it up (unless it falls apart first)

Posted: Aug 5, 2008 at 12:51 Quote
how badly do you really want it shortened seems a bit excesive and there are a load of things that can go wrong,

wouldnt risk it myself

Posted: Aug 5, 2008 at 13:42 Quote
sirknumskullgt wrote:
Fanny bandit


hadn't heard this one before...made me laugh.

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