K2 / Proflex Riders Group
General => Tech Forum => Topic started by: Proflexman on August 19, 2003, 06:51:03 am
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Hello all.
I have a problem in that i found a large long crack in my frame just above the swinging arm.
It starts just above a cable guide on the right side going up above the swinwing arm mount for maybe 80 mm long begining to end.
I was thinking of splitting the frame and repairing the damaged half with Diagonap Tri-axle or quadri-axial woven roven matt which is stronger than the carbon used to make this frame and useing West system epoxy.
Or maybe useing a lighter carbon on the outside or both.
Has anyone else suffered a crack to the frame and would splitting the frame work.
Any ideas on this or any help would be great as i am stuck.
The underside of the frame has started to open so maybe i could continue the split and open the frame.
:-[
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Their was a similar case of a broken frame just about a week ago. I remember replying to it. I wasn t real serious when I told him the very thing that you had in mind. That is to brake the frame in two. Maybe you could check out that post. The comon consencus on that page is that cracks in carbon frames are inviting catastrophe. Don't listen to them. Try it. You will probably be the first one on the forum to brake a frame in two. Once you do so You will be able to make it as strong as you want. I doubt You will be able to pull it abart with your bare hands. try using a High RPM cuting tool with a diamond wheel.
http://http://idriders.com/cgi-bin/YaBB_K2/YaBB.pl?board=news;action=display;num=1060370870
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Wow ! this I never heard of happening before.
Got any pix?
In a perfect world you could take the frame to a machine shop, have them mount and indicate it flat ( on the seam ), on a mill bed ( manual or CNC ) and they could walk a horizontal cutting wheel around the perimeter. This would keep the cut even all the way around. That is of course if money is no object, as a shop rate starts at 65.00 an hour. Ouch !
Just a thought for splitting the frame.
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[smiley=worry.gif] Right today i open the frame, i Have removed the swinging arm but need to remove the screwed collor for the swinger this passes through the frame and will stop you opening it.
It has a two pin connection for a special tool, this i dont have so will have to fabricate a tool.
I work in the Marine trade working with differant compersites so the repair will be no problem and as i said above useing a tri axle matt in Aerospace quality is perfect it will be much lighter and stronger.
I did think about covering the frame both halves in a thinner carbon matt say .6 but i will have to take advice on this from the guys at F1.
I will make a new collor and nut that i have to remove from the frame in Ti as it will be lighter and stronger.
I think the tubes like the seat tube and steerer tube are epoxied in so there may be a problem removing them.
I am surprised that they used such a coarse quality matt in the construction as normally this is only used between finer matts to build up thickness and a finer quality matt would look better to the public.
In a strange way i like the coarse matt it gives it a coarse edge.
I have a special tool to split the frame.
In my opinion the frame is not worth repairing and i will take photos of it as i go so you guys can see the problems i encounter but i do like this bike and because of that i will continue the repair. [smiley=blankstare.gif]
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I think you are a brave man!
Jeroen.
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pictures dominic -
if you could, borrow a digital cam and squeeze off a few from start to finish
OP
(and if thru it all you end up with just a swingarm that's functional - i'd be willing to buy it from you but it would have to be fairly cheap - )
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This is an example of why I'm going to stick with my Evo frame. A while back I had several opportunites to purchase 5500 frames for small $'s. I took the late IFO's advice to leave 'em alone because they have no functional benifit other than saving a 1/2 lb.
The good news for you Dominic, is that if the repair doesn't work you can throw that frame in the trash and mount all of your components on a $150 aluminum EVO frame that will last a lifetime.
Good luck with your repair job.
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[smiley=beer.gif]In need of one of these.
Well today i took some digi photos of the cracked frame and set about removing the collors then un-screwing the nuts either side, this done, next step was to seperate the frame.
This is where it gets interesting as the frame seems to be glued together and not very well and the two halves have a complete inner peice between them which i assume to be some kind of brace member.
I was right about the tubes in that they are glued in position and i will leave the old glue in place and just add some more epoxy and a two pack filler called Pro filler i use this on yachts with Osmosis once the blisters have been removed.
Tomorrow i intend to take some more photos and clean up the sections.
My other problem and one you could help with is i imported the photos into an album in i-photo on the mac but when i wanted to up load them to the site it wont show the album only other albums so i moved the album to the top of the list and still it does not show...?.
As i am in the UK and i guess most of you guys are in the USA does anyone know did K2 have the frames built for them by another firm as is done by most companies.
Is it possible to buy the seperate halves of the frame...?
I removed all my bike kit and built it onto my other frame a Merlin Echo, a nice bike but i am still not sure about the back end.
Theres a big market in the UK for K2 and we still dont have a supplier over here.
My local lbs used the be an agent for K2 and still stocks most of their spares.
Later guys its nearly bed time for me.
[smiley=blankstare.gif]
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Just a quick hello and to let you know the photos to date are on the site one is not so clear but the is perfect and a picture of what she once was.
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Clear your cache in Safari and it will show the new album in the order you want it to be in.
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all frames were built by an outside company-
OMNIUM CYCLE WORKS - couldn't find a web page for them but i did come across this
http://interbiketradeshow.com/01_2001/2001_06/2001_06_15_6975.htm
the frames were made in two runs, one in 97 and one in 98. i recall were in california somewhere
OP
you got a small crack forming behind the swingarm mount as well? from the pic - that appears so - i wouldn't risk my life on a bike with that kind of potential 'issues'
the carbon frames are inherently strong but all things suffer from fatigue - even and especially the afore mentioned aluminum evo frames. i've seen pics and had first hand witnessed experiences of their failures - big time.
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Omnium Cycle Works
3070 Skyway Drive, Bldg 400
Santa Maria, CA 93455
805-928-7089 - phone
805-928-7529 - fax
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Hello one and all.
Thanks everyone for your help much appriciated.
As i said the two halves had a middle section which was glued to both outer shells.
I had to destroy the middle section in order to clean up.
However i am not worried as i will make a new one by laying up a new middle peice on a sheet of formica which has slip wax applied to it to enable me to release it when it has dried, the middle will be re glued in place then glue the outers on and re-rivet the frame.
When i looked inside the frame the two outer shells showed practically no damage.
However i will apply a carbon tape to the inside and make a baffle out of small sections of carbon and epoxy in place then pump in two pack high density foam filler into the sections on both halves and clean up then join both togteher and once done the frame should be stronger than before.
I have decided to test out the frame by doing harder things with it and should it stand up to it then i will completely re build and use as i used to.
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Dominic, you are the man when it comes to carbon repair! When all these carbon riders start crack'in their frames, you might consider starting an OZ repair business (note to OZ lovers, I'm kidding). ;D I'm curious how you cracked that frame though. Were you doing big hits?
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[smiley=laughing.gif] Big hits not a chance not me no sir.
No i was riding a race course called the Newnham 90 with some friends whilst out training and as we are riding this course on the 14 Sept we also practice on it.
There is a couple of places if your going fast enough on the Blue bell run you can grab some air and i did, that's when i heard a crack.
We are doing a small training ride this Sunday if anyone fancies comming its the short course of 50 miles only thing is i am in the UK...!!.
Once i repair this frame and it looks good and nothing happens to it because i will give it some abuse then i will be happy to help others out with their frames if i can.
You supply the money for materials and i will repair them at no cost because i enjoy it.
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Op, were those EVO frames that are "especially" prone to failure you refer to possibly used for any freeride activity? If so, I've also witnessed "big time" failure. :o
Dominic, that is really nice to offer your help. [smiley=beer.gif]
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i believe i ment 'especially the frames' being aluminum suffer from metal fatigue not that the frames made of aluminum were 'especially prone' -
OP - sorry for the miscommunication
and well, yes they did seem to see a bit more adventure than the average xc bike.
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:) Hello all on this lovely Sunday evening.
Well i spoke to a fellow composite repairer and retailer who said that the use of Carbon tape was not needed on the inside if the frame as the epoxy would be good enough but that a woven roven matt would be strong enough.
So the right side has been repaired and i am finishing cleaning up the left side ready for applying the west system epoxy and glass fibre tape.
I will post a photo of the repaired side and the side ready for repair for you to look at.
The middle section will of course be carbon sheet.
Whilst i was at it i epoxied in place the BB houseing and the swinging arm tunnel.
When i am finished i intend to coat the frame in a satin semi gloss two pack lacquer.
I rode this Merlin echo today and have been reminded why i ride a full susser as i am back on the pain killers for my spine again.
The Merlin is a good bike but like one of you said to me i will go to my grave with my K2.
I will keep you posted as things go and should you need any help please feel free to ask and i will try and help. [smiley=nod.gif]
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Dominic,
Are you vacume bagging the repairs or just laying it up?
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nm
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:) Its a lovely sunny bank holiday today.
Right i am not vacum bagging the laying up process as it does not need it on the inside of the frame.
But if i was going to lay a finer weave over the outside then yes i would vacum bag as that would suck the resin through the matt and then i could flat back and polish up without the need to lacuer.
Though West sysem is not impervious the ultra violet sunlight so in a hot sunny country a lacquer would be required.
I am interested to know how much i could pick up another ozx carbon frame for from the States.
I will load the pics today.
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Would vacume bagging make a stronger repair by pulling the resin deep into the matt? I've never worked with vacume bagging, but is the idea to eliminate all trapped air in the layup and basically just suck it all together?
It should be possible to buy an OZ frame for around $300, but you may have to watch for a while to find one. I haven't seen any for sale recently.
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still wait'n for the pics here - and check your gallery every day
when you get a chance
OP
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:( Do you ever get one of those days where things seem to gang up on you.
I put the digi cam down and moved the two halves of the frame to get a good picture and i just felt something go clunk and quick as a flash i knew i had touched the camera and even then knew it was too late to do anything except wait for it to hit the concrete and it did
It never ceases to amase me how many pecies something will disintergate into given half a chance [smiley=disbelief.gif]
So now i get the chance to buy myself another camera, spend more money :'(
That will teach me never to under estimate chance and what it will do.
Sorry guys but your going to have to wait a little longer.
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post some pictures of the broken cam too!
jeroen.
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[smiley=laughing.gif] Jeroen thanks for that i think i will.
Well to update everyone.
I have repaired the inside of the frame with carbon as the standard woven roven is a tad too heavy and not quite as strong.
The inner baffle with seating lips i have removed completely and just have the orginial faces.
I then rubbed down the frame with a coarse sand paper to form a key and covered each half with a finer weave of carbon.
I then cleaned up the edges and joined both halves together.
Then i used a small grinder and a file to make sure the joined faces had no high spots and i removed the lip that runs around the outside of the frame except at the seat post and at the tube for the fork tube these i felt had to be as strong as possible.
I was unable to buy a finer weave of carbon tape to match the weave that covered the frame and a coarser weave would not be flexible enough to wrap along the seam edge so i carefully cut the required strips of carbon out of the finer weave i had and applied the epoxy to the frame around the seam edge then applied the tape to it then applied more epoxy until the mat was well soaked in resin, this i had to do in stages as i needed to keep turning the frame which was clamped and bolted where the rivets normaly go.
Before i joined the two halves together i applied epoxy to the fork tube housing and seat tube housing hence they were clamped and bolted together.
All seams are now dry and today i intend to sand down the frame untill it is smooth, along all seams carefull not to go through the epoxy otherwise the mat will be damaged, then i will apply another coat of epoxy and wet and dry that down clean up and de grease apply the decals and apply a two pack satin lacquer.
To those interested when i had cleaned both halves of the frame i should of applied a lacquer then wet and dried them and applied a wax release agent to each frame then covered each half in four layers of 450 gsm matt to make a mould that way i could always make myself more frames as and when i required them.
My only problem with that is what would K2 of said when they had found out.
Should i get hold of another large ozx/m frame i will make some moulds.
;D
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You know my views on this Dominic from our conversation the other day, please try and make a mould I'm sure every one will agree, can't see anyone telling K2 ? they don't make it anymore, and I'm sure theres a lot out there who would like to get there hands on an Oz or even if you just had a mould for anyone unfortunate enough to of broken there beloved Oz.Simon [smiley=nod.gif]
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You are badass Dominic, sounds like you know what you are doing. Be aware that K2 follows this forum, if that matters. Rich
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:) Good morning class shall we start.
Well it took me quite a few hours sanding down the edges and the excess epoxy yesterday.
If i had of vacum bagged the frame i would of ended up with a more uniform finish but the result was very much the same.
I sanded down with 40 gritt sandpaper, this i thought to be a little coarse but it did remove all very quickly my only fear being that it would leave marks in the frame when i re applied the epoxy.
All were unfounded as i coated one side with a finishing coat and you should see how it came out, the carbon matrix of the matt shines through with a depth of colour showing off the weave and texture.
I am pleased with the result i have got and feel confident now to repair and build more frames.
I know how you feel Simon and i will contact K2 and ask how they would feel about me useing one of their frames to run a mould from then i will build them useing the finer weave of matt as this would be as strong and more pleasing to the eye and easier to work with as the frames at the mo are pressed and i am unable to do this.
The metal work for the BB and the swinging arm housing i can get made out of Ti which again will be lighter so any frame supplied to anyone will be much lighter than K2's.
I am not sure about the swinging arm this i think i will ask Mark if he can map it and make out of Ti or maybe T6 alloy.
Maybe someone else out there has insider knowlege of how they would make them.
So guys/gals i am in the market for a large ozx carbon frame.
Anyone.
You can have the first one off the line so to speak.
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i do have a couple of 'extras' either hanging or boxed in the garage. what's your plan?
disfunctional, abused units come up on occasion for sale tho'
OP
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I'm almost starting to think that Dominic had a dream about fixing the crack in his frame. In that case I'm happy for him that his cam didn't really brake...
Jeroen.
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Dominic
I'm in the UK and have a brand new Oz-m Large frame I'm just going to start to build up into a bike.
If in making the moulds my frame could be guaranteed to be undamaged, I might think about loaning it out for your mould creation process. For which the return of my undamaged frame and one of the first batch of your new creations would be a consideration.
Would.nt it be great to export these back to those over the pond? Let's not forget we gave them the Harrier VTOL, and supersonic travel with Concorde, what did we get in return - MacDonalds! (tongue in cheek).
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[smiley=nod.gif] Hello one and all, sorry about being so tardy with this subject but i had to rebuild the bike as you will know as i had paid to do an Enduro called the Newnham 90, meant to be 60 miles more like 50 in the end but great none the less.
Well as i said i rebuilt her and showed her off to a few old K2 shops over here and they liked what they saw. You know when they test a new modal and take it out on the road it doesnt look like the finished article, like my bike, as i said it needs rubbing down and a mix of graphite powder and epoxy mixing up and applying to any holes or dips ( low spots ).
Then the decals need to be applied and a coat of lacquer applying.
Whats your choice gloss or satin or just mat.
Anyway i tried it out on a training ride and the seam at the back of the frame opened so the seat post sleeve turned, this was a weak spot as i had not covered this section in carbon fibre but when i got back i removed the sleeve and ground down the lip and applied five layers of carbon fibre and epoxy let it dry and sanded it down then applied another coat of epoxy.
I then epoxyied in the sleeve.
Then i took the bike out again on another test ride of about 24 miles and all was fine.
I rode the bike last Sunday in the event and all was fine again in fact it was brill no creaking just me groaning, I had a lot of comments from people offering me web sites showing the types of composites i use and what they get used for, how they are applied and such like.
I have been offered a few frames and there is something you the lender must understand i have been in contact with K2 and they have agreed to let me repair carbon frames and take a mould and make them though they will not look the same as a finished article but bear in mind this it will null and void your warrenty with them as they want to repair them, this is okay because if you are in the UK the turn around will be many months where as in the States its K2's home ground and the turn around is quicker.
Its your choice but me i want my bike yesterday not to have to wait.
But i would say that.
Now as to the taking of a mould from a frame i will have to remove all fittings attached to your frame these can be put back.
The frame will need to be split in half and what you have if you look on the plans to the frame is that it has an inner section which the two outer halves are glued to, this will need to be removed and wont be able to go back and the seam this will also be removed.
So when the frame is re joined together i will need to bond the two sections together with a carbon fibre tape which will not match the matrix used in making the frame but it will be stronger.
It may be better for me to buy a Medium size Oz carbon frame to build up as it wont matter what i do to it.
Most people say that for a six foot rider the Medium frame is better as it is easier to control and chuck around.
Have others found this.
A friend and myself are looking at changing the metalwork to Ti and redesigning the swinging arm to cure the tail wag this will also be made out of Ti or T6 depending upon cost.
I am actively looking for a Medium frame.
Regards Dom
[smiley=beer.gif]
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Oh before i forget i still have not bought another camera as i keep on being outbid on E bay for a Minolta 7Hi.
But i will buy one or maybe claim on my house insurance and i will take photos of my busted camera.
And when i get a frame and start to do all the work needed to make a mould and build one i will have a web site made by someone with pictures leading you through the process, and how to repair the frame yourself should you need to.
I believe nearly all of you out there a adept enough to do such a repair and i am always willing to help anyone in need.
:)
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Hi Dominic,as you know I'm 6' 1" and an currently using my medium Oz while I repair my large 4500, I'm getting on great with the medium frame but this is just a personal choice, I know the consensus is that the large frame is the preferred choice, and I also have no problem with the large frame,I think a large frame would be a more popular size to have a mould for, if you wish to try a medium frame because you think it may be more suited to you, your welcome to try mine.Simon [smiley=nod.gif]
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Evening all.
I received in the post this afternoon a carbon frame sent to me from Nigel.
It has a small crack in it most likely caused by a car hitting the swinger and it forcing on one side which caused the crack to appear.
This frame of Nigel's will be the one i use to make a mould from and once i have split it and cleanded it up and it is ready i have to make sure the surface is blemish free so the frame will have a two pack lacquar applied to it untill i get to the point i am happy with it because when taking a mould from this whatever imperfection is on the frame will be re produced onto the newly made frame and we dont want that.
I will post photo's as i go so you guys can see what is going on.
[smiley=beer.gif]
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Does anyone know what happend with this repair? Any pics?
Trevor
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That's a good question. But Unfortunately I haven't seen any posts from him lately. I was particularly invested in this forum. I have a medium 4500 that has a very small crack.
I remember telling you that ripping apart the frame would be a good idea. Although I still think it is if you want a quality repair. I am not going to do it. It sounded like it was allot of work. What I am going to do is put a coating of epoxy over the whole frame to seal the outer shell.
Could I do that by manually rolling or brushing the epoxy on or by using a vacuum bag.
Dominic if you're out there then drop a line.
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I might be able to update things a little as I've kept regular contact with Dom though we've yet to meet up,first he's received Proflex GB's old cracked 5500 frame and split that one with a view to using it to make a mould to replicate the frame in Carbon (not as a thermoplastic shell),he also got permission to do this from K2,things have not gone straight forward and I believe he is planning a complete redesign,don't mention the stolen and burnt out car along with the new digi camera that was inside though,sore point,I'll try and get him to update every one with how its progressing.Simon