Berk PROTO-TYPE Composites

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danny
Posts: 239
Joined: Fri Jan 28, 2005 11:51 am
Location: arezzo (italy)
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by danny

Berk wrote:
Image



which material is for the rods can I see on right table?

by Weenie


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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

Most of them are wooden, some metal etc.,...it's just to make the prototype out of wood/metal, to have a model to make sure how it should turn out...for example, even Parlee makes first some wooden models:

Image



jgrano wrote:Did you use any kind of special epoxy while working with the brake surface on that rim? It looks super smooth.


Yes you are right, I use a different resin that can hold higher temperatures. Here just another photo from a different angle, it was photographed so that you can see the reflection of the repaired part:

Image

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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

And a new prototype product: spring for AX Lightness brake

Image

This one on the photo is too stiff and still some more material that can be removed...but anyway, the weight is only 1.5g

As soon as this one is tested I'll see how to continue...my aim is to make it <1g, and I think that it should be possible.

For example, one spring weights as much as one piece of these:
Image
So a pair of springs would weight the same :mrgreen:

donald
Posts: 294
Joined: Sun Sep 11, 2005 11:32 pm
Location: san francisco ca. usa

by donald

Berk, I really like all the things you are doing. You are very talented and dedicated. I hope you make those ax springs available, I am interested, and close to one gram each is fantastic.

HillRPete
Posts: 2284
Joined: Tue Apr 12, 2011 8:08 am
Location: Pedal Square

by HillRPete

Jure, did you cure the repaired wheel? Last time I looked into doing brake track repair, I was given the rule of thumb that for resins usually curing temperature is the same as max allowed operation temperature.

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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

@donald
Thanks for the compliments! I'll keep you updated here how it turns out. But I think that most probably it will be possible to make it even lighter, just want to make sure how this will turn out.

@wassertreter
It's not always like that - already some "basic" epoxy resins that can cure at room temperature can hold up to 80°C, depends of course from the resin.
I did cured it, but not on +200°C because I would damage the wheel...as you mentioned the biggest problem is the temperature that you can reach while braking (up to 300°C on the brake track). For the repair I actually don't really use an epoxy that is used for laminating some parts, but I could almost say it's a special glue, that can hold higher temperatures. So that's the "tricky part" of it. And I'll just stick with that method because it turned out very well.

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

Berk,
what do you think about making a carbon spring that doubles as an aero cover for some EEbrakes?

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Fuchspk
Posts: 416
Joined: Tue Apr 10, 2007 7:38 pm
Location: Sweden

by Fuchspk

Berk wrote:This one on the photo is too stiff and still some more material that can be removed...but anyway, the weight is only 1.5g


the spring looks kinda thick, i´d suggest to made it thinner but even wider in the "bowpart" (from the front to the back - if you know what i´m talking about)
with this you can get them softer but without breaking right away

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Berk
Carbon Cowboy
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Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

thisisatest wrote:Berk,
what do you think about making a carbon spring that doubles as an aero cover for some EEbrakes?


Most probably it would be possible, but I didn't yet had those brakes in my hands. If I could get some then I could probably find a way how to make an aero cover for them. But unfortunately I don't know anybody in Slovenia who would have these brakes.


@Fuchspk
Yes I made it too thick, and that's why I made the springs then so thin (they were wider). I know what you mean and it's for sure the right way. I'll see how this will turn out (regarding the stiffness) and will then make some new prototypes.

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Fuchspk
Posts: 416
Joined: Tue Apr 10, 2007 7:38 pm
Location: Sweden

by Fuchspk

Berk wrote:@Fuchspk
Yes I made it too thick, and that's why I made the springs then so thin (they were wider). I know what you mean and it's for sure the right way. I'll see how this will turn out (regarding the stiffness) and will then make some new prototypes.



yes there is always a lot of testing for the right way of lightweight springs :)
I would take almost just UD on the bow and something like 1x100g 90/90matt on the top of it as there is no torsion on the spring.
and have the part to the screw just in 90/90 2or 3times 100g matt with 1going over the bow and one even going under the bow a bit.
and look that on the tipps of the bow really are some 90degrees UD of the 100g matt (otherwise have some extra there)

But this is a lot of work for almost nothing. You can come down to maybe 1,2g i guess. Some other People have gone to glasfibersprings as Glasfiber seems to be a bit better for a Spring. but then it become heavy again and there is almost no point for making this kind of work instead of just taking an titanium spring instead.

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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

I'll see what I can make with it and will keep you updated.
Otherwise almost all the structure is UD, only the "beauty layer" is plain. The "neck" of the spring is a bit more reinforced because I already saw quite a lot of these springs that broke on that part. Anyway, I'm interested how this will turn out. Unfortunately I can't test them by myself because I don't have these brakes, but we'll see in a few weeks how it will perform.

BmanX
Posts: 3841
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

Most probably it would be possible, but I didn't yet had those brakes in my hands. If I could get some then I could probably find a way how to make an aero cover for them. But unfortunately I don't know anybody in Slovenia who would have these brakes.


Well I am not close but I would be more than willing to send you a pair of EE brakes so that you can try a spring for them in carbon and of course aero covers. Let me know if you would like them sent and I can do that. I am a huge supporter of your work as you know so I have no issues taking them off my build for a while so that you can do your magic.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT for 2 decades

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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

Thanks for the help BmanX, really appreciate that :beerchug:
I'll first see if I can get them in my hands within EU, unfortunately our customs tax even gifts outside EU..well in most cases they don't care at all if it's a gift, and when you get a real gift you even have to pay for it in most cases ...anyway, I'll see if I'll be able to get them in my hands and if it would be possible. My first idea was to laminate some neodim magnets in the aero cover, and then just put it on the brake...probably that would be the most simple way and even very lightweight..just an idea :mrgreen:

danoontje
Posts: 55
Joined: Thu Jan 15, 2009 7:57 pm
Location: Helmond, Netherlands

by danoontje

Berk wrote:Thanks for the compliments @Bianchi10!

@Dimitri
I finally made some progress on the saddle rails and hopefully I'll be able to make them in February, I'll for sure let you know


Otherwise here just one quick photo of my bike, 6.16kg as it is:

Image

Could change the ALU bar and stem to save some more weight, also the bottle cages and tires,..but at this moment it is like I want! Ready for 2013 :thumbup:


What handlebars are these? And what size?

Thanks!

by Weenie


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Berk
Carbon Cowboy
Posts: 1100
Joined: Sat Sep 04, 2010 7:20 pm
Location: Slovenia

by Berk

Ritchey WCS Logic II, matte black aluminium, 42cm (c-c).

It may look a bit strange because the angle of that photo, but they are my favourite bars. I already had the SuperLogic (190g), but still prefer ALU (242g). If possible I'll try some day the Ritchey Curve bend...I already tried the classic bend but don't like it. By the way, the stem is Ritchey ALU C260 in 130mm.

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