Quite busy these days and the progress is quite slow, but here some new photos.

A few days ago I managed to glue all the tubes together, and before I glued also the seatstays I couldn't resist to just build it quickly to see if everything is like I want:





And some larger photos:


First I'll use a 3T Dorico Team seatpost (that I repainted) to make sure about my position and then I'll make also a combo for myself. Also for a combo it's quite a lot of work and before I'll manage to make it I'll use a SLR saddle that I already posted (the one that I covered with a new white leather), because I still prefer to ride my bike and will work with carbon when I'll have some free time

Anyway, after I glued all the tubes together the frame was prepared for the carbon reinforcements on the joints:



And also the rest of the work was already made during a night , when I worked also on some custom projects..

Here is the frame, completely rough and still in process...I still have to laminate the upper headset groove, the brake bridge etc.,..




At this moment it's 886g and at the end it should have a bit more than 900g. But it's really stiff, you can already feel when you press the dropouts together that it's a bit stiffer (altough without the brake bridge) than PT3 and it's also a bit more reinforced,..it should be a really stiff frame, but still quite lightweight, like I want to have it! Can't wait to build this bike!!

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites
http://www.berk-composites.com
info(a)berk-composites.com

This is a great build and every build just gets that much better. Amazing work. I would love to see what you could really do if you went as light as possible with as many tricks to keep the weight down.

I am going to put this out there right now that I believe you are the next generation of Rue, Crumpton, Calfee and I think your attention to detail is amazing.

Rob English = Steel
Jure Berk = Carbon

AMAZING AMAZING WORK

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs

@BmanX

Thanks for the compliments!

I'll for sure work on it, and as soon as I'll manage to get all the metal moulds I'll try to build something crazy light! Will see, maybe I'll start with a new project soon after this one. This frame is for the whole season, probably for around 15 000km, and I want to have a really stiff and reliable frame. I could still save quite a lot of weight, but "there is no magic", it wouldn't be that stiff then.
I'm really happy with the design of this frame and would most probably keep it like that.
I could make it with internal routing, but as long as it's a proto-type frame I'll go for some standard cable routing and will see if there is anything more to improve as soon as I'll have a few thousand km . I already know that internal routing is no problem for me, but it adds weight.

Here just one more photo that I forgot to post:



Still quite a lot of work to do on the surface, but regarding the tube-to-tube procedure you can already see that it's quite clean looking. Still have to shape it a bit around the dropout area etc., but I'm really happy with the resoults at this stage

_________________
Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites
http://www.berk-composites.com
info(a)berk-composites.com

Everytime I get a mail that this thread is updated I get excited to see your progress!

Looks very good (as always)!

//Ulf L.

I love the look of the frames where top and down tube get bigger at the head tube!

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TREK Madone 5.9 SL #7
ex COLNAGO C50

Jure,what's the weight of this 95% of frame?? I like nopainted color of carbon:)

Berk

Nice work with the frame. It's really starting to come together nicely now!

In the above photos of the finished frame, have you just cleaned up around the bonded joints or have you already wrapped them in carbon as well? I can't tell from the pics

B

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a riddle wrapped in an enigma wrapped in lycra

Life is like riding a bicycle - in order to keep your balance, you must keep moving.
Albert Einstein

THANKS TO ALL!!

@bikemaniack
The frame at this moment has 886g, but I still have to do some more work (brake bridge, cut the bottom bracket tube, add cable stops etc.,..). At the end it will be probably a bit more than 900g.

@bJay
If you can't tell from the pics then that's a good sign for me , the carbon reinforcements are already done I just have to make some more work on the surface, at this moment it's still completely rough

_________________
Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites
http://www.berk-composites.com
info(a)berk-composites.com

900g is still pretty damn good; especially if it is as stiff as you say!
I hope that you do set up your own company I would love to own one of your bikes!

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650b Ritchey
Colnago Mapei
S-Works Tarmac

Thanks, I'm really glad that you like it

If I'm honest I tought that it will weight even a bit more, because this time I really want to make it solid. First I made the chainstays like a one piece, and already here there is a quite big improvement, compared to the previous 3 frames, where I made the chainstays with two separated tubes.
Here are already around 20g of weight savings with a lot better resoults. Then here are also the new materials that I use, of course much more expensive, but as I calculated there are around 6-7% of weight savings compared to the "standard" materials (!).
It may not seem a lot, but for a 1000g frame it's 60-70g. Then I didn't made it with internal routing, around 30g less in that case. In the end there are around 110-120g weight savings, compared to my PT3 frame.
The PT3 was 1013g with the integrated saddle, so without the integrated saddle/seatpost it would weight around 900g. And here you can see that it weights almost the same, but you have to take into account the weight differences (it would weight 110-120g less with the same layup/design). That means that this frame (PT4) is much more reinforced - 110-120g more reinforcements (!!) and that's quite a lot in this case, and also the reason why I think that it will be a really stiff frame. I compared the PT3 frame last year to my team bike, and it wasn't that stiff, but quite close to it. Then of course I reinforced /changed the layup on the areas where it should be stiffer..So I really can't wait to build this bike!

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites
http://www.berk-composites.com
info(a)berk-composites.com

Jure,

Do you think with your current build process you could do a frame with ISP and saddle for around or under 900g?

I would love to have a frame with external cable routing, ISP, saddle, BB30 bb and your new head set set up that would be around 900g and I would buy one in a second. I think that would be amazing. I know what my BB to top of saddle measurement is so it would be just TT distance, HT length and stem length.

When you are ready with your molds and want to take orders, please let me know and I will be one of the first to order.

JURE BERK ... CARBON MASTER!

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BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5890g/12.98 lbs

Fantatsic,beliisimo, great looking frame Jure

Looks/sounds awesome. Great progress!

@BmanX
If I would make it similar like the PT3 and with external routing, then it would have even a bit less than 900g . But before I'll make any frame for someone else I would firt test it in a lab, to be 100% sure about the product. If I'll start with a small company then I would sure start with frames, already slowly working on it...anyway, regarding the question about the weight, it would be possibel and thanks once again for the compliments!!


@billspreston & artray
Thanks!


I would love to finish my frame, but I'm really very very busy these days, and I'm really sorry that it takes soo long, also for some custom combos that I'm working on. Sometimes it can take a bit longer to make them, and I'm really sorry for that, but I'm glad that people understand how it is to be a student and that I sometimes really don't have enough time, and for a work like that you can't rush, if you know what I mean. I'll give my best and continue working on it will keep you updated as soon as I'll have some news

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Berk PROTO-TYPE Composites - Handmade In Slovenia
Berk Composites
http://www.berk-composites.com
info(a)berk-composites.com

Berk: Can't wait to see your work

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My 7.3kg/6.4 kg 29'er project buildthread!
My Bianchi Oltre XR