Hey Jure, mind how you go with the carbon screw in the clamps . Sounds like another winner and I will grab a pair if they work out ok . Infact I think you will get a lot of takers .

I'm guessing these would be universal and fit all shifters if they work out, not just SRAM?

Sure, it would be possible, but the only problem is to start with it (financially...), but hopefully some day




I'll have to make them, wanted to start with it already last week, but just didn't had any time for it. But as soon as I'll manage to make the first prototype products I'll keep you updated




I'm not sure, because if I'm right different shifters use different screws/threads for those clamps?

There is already a difference between the new and old Sram Red. The old has clamps with screws, and the new with threads if you know what I mean..

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites

A small update for the PT5 frame project:

the tubes for the front triangle are already prepared for gluing. Here just one quick photo:


As you can see the headtube, bottom bracked and the ends of the tubes have a bit different look. That's because I used peel-ply, that will provide a better bonding. I just put it in the mould when I laminated those tubes . Of course the tubes are completely rough..


And here another new detail - a "shim" that will be glued in the seatpost tube, that has the exact ID for the 27.2mm seatpost. It will be glued in the tube for a perfect fit, without a chance to get any water in the frame:



So the frame will be completely "closed". It won't be possible that water would come in the frame, only for the headtube if it will go throug the headset, but other than that it won't be possible. And most probably I won't go with the internal routing.. I'll keep you updated as soon as I make some more progress, depends from my free time..


Regarding the shifter clamps - I didn't managed yet to make any work, but as soon as I'll have some resoults I'll let you know.

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites

So you can finally fill it wit helium

The birth of PROTO-TYPE 5



The chainstays and carbon dropouts are alaredy prepared, just have to make the seatstays and glue it to the front triangle.

As on photo it's only 398g!
Although the tubes have in average one layer more than PT4, it's has very similar weigh at this stage. It's because a better procedure used - even less exces resin. For example - the downtube with the same layup is almost 20g lighter compared to PT4...

Compared with PT4 this frame will be for 27.2mm seatpost instead of 31.6 (the seattube has 31.9mm OD - PT4 has 34.9mm). The Downtube is 47mm OD (PT4 48.5) and the toptube is also changed - much more "cone shapped" because the thinner seatpost tube..
The seatstays will be even thinner (P4 has 12.5mm from the profile) now it will be only 10mm (and 13mm wide, it will be oval). The chainstays will be quite similar, only with a bit more place for the tire and the wheel (in case that there would be used some wider rims..).

It will be for BB30 PF bearings...and with tapered headtube 1 1/8 - 1 1/4

The surface is of course still completely rough. The bonding area has a special surface for better bonding,... I'll keep you updated!

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites

Jure ,what weight do you think the frame will be when finished ?

It is really impressive to see how great the results of the tubes are, especially the top, down and seat tube.
I am in the midst of building my first carbon fibre frame, and I am far from acquiring such smooth finish...not to mention weights!

Really solid craftmanship, Berk

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~ Men of steel need fibre ~

Hard to say at this moment because I though it will weight more. I guess it should be very similar to PT4, although the tubes are stronger and also the reinforcements will have a few layers more. Around 950g would be great.

The chainstays weight also less than I expected, and they have even 2-3 layers (80g/m2) more...they came at 214g. The dropouts are 28g both (4.5mm thickness).

That's exactly 640 for the frame without the reinforcements and seatstays. I just laminated one seatstay today, probably it will weight around 70g for both + brake bridge.

If it will really turn out like that then I'll have cca. 720g frame without the reinforcements. And that's really light for me, because PT4 had only around 170g more after the reinforcements. Because better equipment I think that the reinforcements will weight the same although I'll add 2-3 layers more (because less exces resin compared to PT4).

So that would be a cca. 900g frame + cable stops etc.,..so 950g would be really great, and it will be stiffer than PT4. Actually I prefer to add stiffness and keep the same weight instead of loose more weight and then of course also some stiffness. After that project I'll again try to loose some weight and keep that stiffness etc.,..if you know what I mean.

PT4 rides a lot like the older models of Scott Cr1 and I would really like to add some stiffness, although it isn't bad at all. I think that I can be happy with a 950g custom tube-to-tube frame. I could also make it lighter, but of course with the sacrifice of stiffness, and I don't want that. But maybe I'll also make an "über light project" some day . I really have great fun with those projects, it's a great feeling to make a frame like you want from the raw fiber to the finished product completely by yourself (I don't buy any tube for my frame - only the cable stops and the threads for bottle cages ).




Thanks!
Nice to hear that, make sure that we'll be able to follow your progress

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites

Your work is absolutely fantastic, this thread has been a pleasure to watch!

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Exp001

Jure: You can absolutely make a lightweight frame but you have to sacrifice stiffness and internal cable routing and some other "modern" stuff like tapered headtubes and so on.

In the end, for who will you build this frame for?, for you or Weightweenies?

If I had a lot of money and time, I would do so:
1. Very light and simple looking frame , hang it on wall for Weightweenies.
2. A frame in my taste and ride quality and a bit heavier and ride it.

2 frames

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Experimental Prototype

Hi Jure, I've just read through all 60 pages in one sitting, for someone so young the knowledge, work ethic, attention to detail and skill you obviously have is exceptional

Found this thread while looking for composite companies in Slovenia as I'm interested in finding one to make me low volume (quantity 5-10) runs of various carbon fibre car parts.

My preference is to work with a small start up company as I would also like to help contribute to its growth. Not by buying into it but by using my knowledge gained from over 20yrs of being a advanced composite design engineer working on high performance cars, 17yrs of this time and still counting working in F1.

Not as exciting as bicycles I know but I thought if you had some extra work to run along side it might help subsidise your bicycle projects.

I have a house in the NW of Slovenia as my family fell in love with your country 4yrs ago and plan to enjoy it as much time there as possible so the more excuses to visit the better. I will be visiting the end of Oct. so if you are interested please let me know so we can arrange to meet up.

Stephen

Thanks, glad to hear that .

Just made the second seatstay and also the chainstays are already glued to the front triangle..will post some new photos in the next few days.



Otherwise I'm also working on a new leg splint. Already my third project to help someone who can't walk normal without any help, and I'm always glad that I can help with some of my work! Here just one photo, where you can see the exact copy of a part of his leg. It will help me to make the splint and I'll basicly use it as the mould for the carbon work..if you're interested how the final product will look like I can also post it, but it will take a bit that I'll finish it..


I was also contacted from some doctors here in Slovenia and we'll meet in the future, probably I could help even more people who would need a custom splint/prosthesis. I also get some paperst/permissions for building wheelchairs etc., so I just need to sort some more papers and maybe I'll even work on those projects, you never know what the future will bring..





+1



@Leichtbau
Nice to hear that! Thanks for those compliments, and it's for sure welcome to meet with someone like you. So if/when you'll be in Slovenia just let me know . Otherwise I'm very close to the capital city, it's almost in the centre of Slovenia, and as you know it's a very small coutry, so we shouldn't have a problem to meet..

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites

Keep up the good work, you have a lot of talent