# A carbon / Kevlar DJ/Street/trial frame



## Mr.Magura (Aug 11, 2010)

The latest project taking shape.


Magura


----------



## Drew Diller (Jan 4, 2010)

Subbed.


----------



## Mr.Magura (Aug 11, 2010)

Drew Diller said:


> Subbed.


I hate to disappoint you, but this will be just another day at the office to you 

The only difference is the frame design, and the Kevlar armed tubes.

Kevlar armed tubes might be something you'd gain something from looking into though.

Magura


----------



## Mr.Magura (Aug 11, 2010)

I just came to think of, that I have something as unusual (for me), as a drawing to show 

It at least gives an idea about what I am on about.

Add to this a removable seat tower, like the old Intense DH bikes had it.

Magura


----------



## dead10 (Jul 27, 2008)

Sub'd 

Did you fab your own drop out or cut them from a pre fab'd sheet of carbon?

-aron


----------



## Mr.Magura (Aug 11, 2010)

Made of a sheet that I made a while ago.

More to come the following days, as I am at a mates place working on it.


Magura


----------



## Fix the Spade (Aug 4, 2008)

What happened to the DH bike Mr Magura. I want to see the DH bike!


----------



## Mr.Magura (Aug 11, 2010)

Fix the Spade said:


> What happened to the DH bike Mr Magura. I want to see the DH bike!


To be honest, I lost interest in it, so I gave it away to a friend of mine. 
The bike it was supposed to replace, has not moved an inch since last summer, so it seems a bit pointless to make another bike to collect dust.
Last summer I built up a cheap and simple single speed DJ 24" bike, and since that bike saw the light of day, all the other bikes have seen little to no use. 
Hence this change of direction.

The DH bike still needs a rear end, but the main triangle is done. I guess the guy I gave it to, will finish it during the winter.

Magura


----------



## Mr.Magura (Aug 11, 2010)

Here you got a pic of the current state of the project.

Next step is prepping for stratification, and gluing in the last bits and pieces.


Magura


----------



## Mr.Magura (Aug 11, 2010)

Maybe it's time to tell about the aim and specs.

I want to make this bike as versatile for my specific needs as possible.
So, to be able to use it for street trial, the seat tower has to be removable, and the head tube angle must be like 70 degrees.
For DJ there has to be a seat, so the tower goes on, but in the lowest position.
For AM the head tube angle must be 66 degrees, and the seat can be moved up like an adjustable seat post, but the entire seat tower will be a parallelogram, with hydraulic height adjustment, and the seat angle will rise by itself, as the seat is lowered.
The head tube angle will be possible to change within a few seconds.

The specs: 

160mm rear
370mm chain stays (I like that for some reason)
BB 15mm above wheel center
24" wheels
Fork: RockShox Revelation dual air, lowered to 110mm.

Aim to get the frame including hydraulic adjustable seat height, and saddle, down around 2700g. 
So far that seems within reach.

Magura


----------



## mimi1885 (Aug 12, 2006)

Nice!! Keep it coming Magura.


----------



## Mr.Magura (Aug 11, 2010)

This project is btw. also the first I will be able to get scanned for voids.
A friend of mine has promised to do x-rays and a CT scan of the finished frame.
Now that will at least make for some nice wall art for the workshop 


Magura


----------



## Mr.Magura (Aug 11, 2010)

Ok, time for an update:

The frame is pretty much finished by now, but I'm still lacking a bunch of the metal parts.
Work seems to have gotten much in the way lately. Now I'm just dreaming of the days (like half a year ago), where I worked like 8 hours a week.

Anyhow, I just got around to doing the mould for the seat tower, and will get the layup done tomorrow. 
It took a bit more calculations than expected, to get the seat height adjustment right, while maintaining a reasonable degree of suspension of the seat tower boom. 
I got myself a RS Monarch for that job, which now just need a few modifications, in order to work as height adjustment/suspension.

A mould for a carbon/Kevlar saddle is also in the cards tomorrow, if things works out as planned.

I'll try to get some pics of things tomorrow, before I put it all back on the shelf for the next couple of weeks.


Magura


----------



## Guest (Nov 25, 2012)

hmmmmm:thumbsup:


----------



## wmac (Sep 29, 2010)

Subscribed


----------



## mikkosan (Jun 26, 2009)

Subscribed! Would love to see this one finished.


----------



## Mr.Magura (Aug 11, 2010)

Ok, no update anyway, as yesterday turned into the biggest fail day.

I experimented with a new type of breather, which I considered marginally different from the one I usually use.
Well, not so. It compressed completely, and didn't let the vacuum through. 
The result was like 40% fiber content 
In other words, the result of this, was something for the bin. 

Back to square one, and no more experiments for now. This bike simply has to run before Christmas.


Magura


----------



## Drew Diller (Jan 4, 2010)

Aww man. That's an f7u12 moment. I'm sorry to hear that.


----------



## Mr.Magura (Aug 11, 2010)

Drew Diller said:


> Aww man. That's an f7u12 moment. I'm sorry to hear that.


Yeah, real stupid to make tests now.

The good news is that it was after all just the seat tower boom.

So like 100g of UD, 20g of braided sleeve, and like 200g of the most expensive epoxy I have.

:madman:

Note to self: make experiments on little pieces destined for testing, not stuff you plan on using.

Magura


----------



## shibiwan (Sep 2, 2012)

subbed. 


The way the seat-tube is diagonally cut looks like it could hurt in a bad crash. Mebbe should have laid the TT over it .....

Just random thoughts - don't like my musings get to you.

-S


----------



## Mr.Magura (Aug 11, 2010)

shibiwan said:


> subbed.
> 
> The way the seat-tube is diagonally cut looks like it could hurt in a bad crash. Mebbe should have laid the TT over it .....
> 
> ...


I did give that some thought, when I did the drawings (quite a bit actually).

.....till I came to think of, that it's all hidden by the seat stays, and under the seat tower.
All that would be a lot clearer to you, if it wasn't because I was too lazy to draw the seat tower 

Thanks for the heads up though, much appreciated.

Magura


----------



## PMK (Oct 12, 2004)

Bummer on the Breather not bleeding off excess resin. 40:60 resin content is a bit rich, pretty much like a chopper gun built boat, not good.

I'm guessing the breather was a prepreg spec breather.

OK, so now the big question, the Kevlar is obviously hybrid into the lay? Assuming you used 49 based Kevlar and not 29, plus hopefully it was not dyed unless an exterior decorative ply.

You build some cool stuff.

PK


----------



## Mr.Magura (Aug 11, 2010)

PMK said:


> Bummer on the Breather not bleeding off excess resin. 40:60 resin content is a bit rich, pretty much like a chopper gun built boat, not good.
> 
> I'm guessing the breather was a prepreg spec breather.
> 
> ...


Yes 40:60 is a far cry from the approx. 70:30 we usually get.

Back to pressure and heat. To be honest I don't know why I all of a sudden found it smart to vacuum bag this, when the rest is made with pressure bladders.

The breather was sold as wet layup type, but it looks different from the usual type, so it may be intended for prepreg. I didn't know there is a difference between the two. 
Fact is though, that roll of breather is no longer to be used for its intended purpose.

Yes it's a K49. I have tried playing around with K29, but never managed to make it work with carbon. It seems to be too soft, and I either had to use a very flexible epoxy, ot the epoxy would crack if you looked at it wrong.

By hybrid, do you mean weaved into the other layers, or just made in the same layup?

Magura


----------



## PMK (Oct 12, 2004)

Mr.Magura said:


> Yes 40:60 is a far cry from the approx. 70:30 we usually get.
> 
> Back to pressure and heat. To be honest I don't know why I all of a sudden found it smart to vacuum bag this, when the rest is made with pressure bladders.
> 
> ...


Technically there is not really a prepreg vs wet layup specific breather. It comes down to the prepreg starting life around a 55:50 resin content so much less is bled off and therefore the breather is not choked. They do offer some breathers that won't "crush" flat to low flow under the higher pressures attained in claves or non vacuum bag setups.

As for hybrid, I was asking in regards to two materials in one ply. Hybrids can also be two materials in the same layup.

As for your previous choice of K29, I can imagine it was not optimum in a structural type application. K49 is a structural type aramid and will layup easily. Why are you using the K49, protection or flexibility of the component?

Send me a PM about what specific brand and weight plus other details about the breather. Maybe I have some laying around and can offer more experience details on using it.

PK


----------



## Mr.Magura (Aug 11, 2010)

PMK said:


> Technically there is not really a prepreg vs wet layup specific breather. It comes down to the prepreg starting life around a 55:50 resin content so much less is bled off and therefore the breather is not choked. They do offer some breathers that won't "crush" flat to low flow under the higher pressures attained in claves or non vacuum bag setups.
> 
> As for hybrid, I was asking in regards to two materials in one ply. Hybrids can also be two materials in the same layup.
> 
> ...


So it's a hybrid  but it is a layer of K49 on top of the carbon. 
It is part of something I did some testing on a while back. 
With K49 in the layup as the outer layer, and 0.3mm titanium sandwiched on with a 1mm neoprene layer afterwards, it seems to be virtually unbreakable. 
I did the tests on a square edge, which is my concern for the downtube in that place.

I have not made any experiments with a 50-50 carbon/K49 layer. Would I get a better result with that for this application?

I tried to find out what type the breather that failed is, but the company I bought it from claims it is the same as I usually get, which it obviously isn't. 
Sound like a good time to change supplier.

You are most likely right, that the breather that failed, crushed under the pressure.
I compared it to the breather I usually use. It can carry much more load, and seems to have a more open structure as well.
Thanks for the offer to help though, much appreciated. You obviously have a load of experience in this field.

The good news of today, is that I finally managed to make the titanium rear axle inserts.
If there ever was a nasty piece of work, this would be it. 
It took like 3 hours to make them, as I lack power for machining that big diameter titanium. I only had 50mm diameter laying around that was big enough. It ended up with two inserts of 13g each, and a whole lot of Ti chips.

Magura


----------



## Mr.Magura (Aug 11, 2010)

So here they are.

Magura


----------



## shibiwan (Sep 2, 2012)

Mr.Magura said:


> So here they are.
> 
> Magura


Nice... if only I had some titanium lying around like you do.... 

I hate machining titanium... almost as much as inconel.

-S


----------



## Mr.Magura (Aug 11, 2010)

shibiwan said:


> Nice... if only I had some titanium lying around like you do....


I have a "market mirror stock". 

All the stuff that is easy to get, I have none of in stock.

All the hard to come by materials, you name it, I got them all.

Magura


----------



## Mr.Magura (Aug 11, 2010)

Hey, it seems I broke the cycle of bad karma.

The inserts for the head tube, were hidden inside a piece of aluminum I had laying around 

This officially makes this project ahead of schedule, as I have made the bearing mounts for the seat tower and the shock as well.

Magura 

EDIT: that pic needed something for scale. They are for a 2" head tube.


----------



## Guest (Dec 5, 2012)

nicely done carry on!!


----------



## Mr.Magura (Aug 11, 2010)

I just machined the biggest rear through axle I have ever seen.
14mm diameter, 185mm long!

I still lack the fittings for it, so no pic yet. 


Magura


----------



## Mr.Magura (Aug 11, 2010)

Here is the finished 14 x 180mm through axle.
I made the titanium hex insert today, and glued it in.

For scale is the 160mm Hadley hub it's made for.


Magura


----------



## TrailMaker (Sep 16, 2007)

Sweet Stuff;

I'd like to be able to do that, but I don't have the knowledge, I know, nor a capable machine, I don't think. Between me and Old Floppy, we make some pretty grody looking stuff.

I noted when I blew it apart to polish that my new Salsa by Formula front hub had the adapter bushes on the ends to make it a 9mm QR, but had a pretty large bore on the actual axle. Makes me think about machining projects.

Please continue for the vicarious machinists among us.


----------



## Drew Diller (Jan 4, 2010)

TrailMaker said:


> Old Floppy


Please name it something else


----------



## wyatt79m (Mar 3, 2007)

Another awesome thread...Its nice to see stuff like this.


----------



## TrailMaker (Sep 16, 2007)

Drew Diller said:


> Please name it something else


Hmmm...

A lathe by any other name, is yet still a tool, after all. It's really a question of end play.


----------



## Mr.Magura (Aug 11, 2010)

The finished rear axle assembly.


Magura


----------



## Guest (Dec 15, 2012)

thats some purdy stuff i rekon so.


----------



## shibiwan (Sep 2, 2012)

Mr.Magura said:


> The finished rear axle assembly.
> 
> Magura


Darn it, Magura. Now you have me wanting to put discs and a rear derailleur on the kids' BMX. LOL.

-S


----------



## Mr.Magura (Aug 11, 2010)

shibiwan said:


> Darn it, Magura. Now you have me wanting to put discs and a rear derailleur on the kids' BMX. LOL.
> 
> -S


With the skills you hold, and the toys you have, that ought to be a nice project, no?

Care for a 40 hole blank?

Magura


----------



## Clockwork Bikes (Jun 17, 2006)

Mr.Magura said:


> Here is the finished 14 x 180mm through axle.
> I made the titanium hex insert today, and glued it in.
> 
> For scale is the 160mm Hadley hub it's made for.
> ...


I was just thinking about how to make a 20mm through axle and thought I couldn't without broaching an allen hole. Can you explain how you glued the insert in?

Thanks, Joel


----------



## Mr.Magura (Aug 11, 2010)

Clockwork Bikes said:


> I was just thinking about how to make a 20mm through axle and thought I couldn't without broaching an allen hole. Can you explain how you glued the insert in?
> 
> Thanks, Joel


It's threaded and glued in, using Hysol 9466.

Magura 

EDIT: After thinking it over, I don't think you can use this method for a through axle for the front, as you need considerable torque. In my application, it's just for a limited amount of counter torque.
Broaching a hex in aluminum, is fairly easy to do. If you machine a hex and harden it, you can just press it through the aluminum. I do that a lot, though I usually grind a hardened rod to hex shape, but the principle is the same.


----------



## stinkyWinky (Dec 19, 2012)

post 6 for photo. fun fun fun


----------



## shibiwan (Sep 2, 2012)

Mr.Magura said:


> Here you got a pic of the current state of the project.
> 
> Next step is prepping for stratification, and gluing in the last bits and pieces.
> 
> Magura


Hey, is that an RC control propping up that frame? ....next to that battery pack?

Didn't know you were into R/C.

-S


----------



## Mr.Magura (Aug 11, 2010)

shibiwan said:


> Hey, is that an RC control propping up that frame? ....next to that battery pack?
> 
> Didn't know you were into R/C.
> 
> -S


That pic is not from y place, so not my plane (plane peeking through the door), but besides that, you're right.
I like RC Marblehead yachts though, and build such myself. 
Think composites 

Magura


----------



## sasquatch rides a SS (Dec 27, 2010)

This is going to be awesome


----------



## Mr.Magura (Aug 11, 2010)

sasquatch rides a SS said:


> This is going to be awesome


I bloody well hope so 

This project is on the wrong side of 200 hrs. by now, and still in need of another 100 hrs. I guesstimate.

Magura


----------



## mimi1885 (Aug 12, 2006)

Mr.Magura said:


> I bloody well hope so
> 
> This project is on the wrong side of 200 hrs. by now, and still in need of another 100 hrs. I guesstimate.
> 
> Magura


Wish I can trade my cooking skills for your skills, I'd be hungry but happy

Good job Magura:thumbsup:


----------



## shibiwan (Sep 2, 2012)

Mr.Magura said:


> I bloody well hope so
> 
> This project is on the wrong side of 200 hrs. by now, and still in need of another 100 hrs. I guesstimate.
> 
> Magura


It's a hobby. A couple hundred or thousand hours doesn't matter.

-S


----------



## Mr.Magura (Aug 11, 2010)

shibiwan said:


> It's a hobby. A couple hundred or thousand hours doesn't matter.
> 
> -S


Well, you know, I have other hobbies to tend to 

I did the math btw. for your suggestion to use PTFE for a plain bearing headset.
I had actually guesstimated it to be far off, but it turns out that it's within the surface load limit. 
Thanks for the heads up. That's sure the next project to fit in this frame.

Magura


----------



## Mr.Magura (Aug 11, 2010)

mimi1885 said:


> Wish I can trade my cooking skills for your skills, I'd be hungry but happy
> 
> Good job Magura:thumbsup:


One does not exclude the other 
You might wanna give it a shot?

Magura


----------



## grundy (Jan 12, 2004)

Mr. Magura,

Your fan club is waiting for an update


----------



## Drew Diller (Jan 4, 2010)

grundy, Magura doesn't post here anymore.

Info can be found though. Google!


----------

