Berk PROTO-TYPE Composites

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NWSAlpine
Posts: 296
Joined: Fri May 18, 2012 7:11 pm
Location: FL

by NWSAlpine

I know it's a long shot but do you have access to the NeilPryde Alize seatposts to do molds? I believe it would also work on their Bayamo TT bike. If not could to make a mold from a small part of the seatpost that was cut?

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

by Berk

Hard to say - do you have any photos of the seatpost profile? It could be done, but the moulds are quite expensive. if I would make metal moulds (that are of course very precise). I could only copy the moulds from the original seatpost if it's long enough, but it isn't that precise, although it may be ok for a few products

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NWSAlpine
Posts: 296
Joined: Fri May 18, 2012 7:11 pm
Location: FL

by NWSAlpine

Here you can kind of see the profile. It's almost Cervelo S5 style.
Image

The cost would most likely be crazy as it's a non standard job for you.

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

by Berk

Yes, unfortunately the moulds are expensive, and I don't have a CNC machine in my workshop..so it costs +400eur for a mould with a round profile (for a standard seatpost), and it would be something like this also for a new mould with an aero shape. I would love to have all those moulds, but unfortunately I can't afford to make them, and it's too expensive for only one project.

Any idea if it's the same profile as the one from Cervelo?

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

by Fuchspk

nice bar-stem combo :thumbup:
i´m just in to do this with my bar+stem on my bike as well. it looks so nice without any screws

but i hope to see something like this but with an own stem build by you :)

dereksmalls
Posts: 2305
Joined: Tue Aug 02, 2011 9:20 pm
Location: New Zealand

by dereksmalls

Very valid points in your response. This is a good exercise though.

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

by Berk

@Fuchspk
Thanks! I'll try to make it if I get an used carbon bar that fits me, or just any carbon bar from Ritchey, 3T, etc.,..it can be also damaged on the clamping area, so if anybody has anything please let me know :thumbup:

Otherwise I already have some resoults. If I would reinforce only the joint, without the beauty look also on the stem, it would add only around 17g. But in this case (the combo that is in process) it will be abit more because I covered also the complete stem and also the part between the joint and the bar tape. But just to let you know how much adds that reinforcements. You can just weigh the stem faceplate and the bolts and you can already calculate if it would save any weight. In most cases I guess it would.

I'll keep you updated about the progress. This combo will weight a bit more, but I'll do my best to make it with a nice 3K plain finish.

szaffiri
Posts: 14
Joined: Wed Dec 08, 2010 4:27 pm

by szaffiri

When you made the bar/stem combo did you use milled fibers or some kind of filler to smooth the joint between the bar and sides of the stem so to reduce the stress concentrations or did you just lay up right on the bar and stem?

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

by Berk

Berk wrote: If I would reinforce only the joint, without the beauty look also on the stem, it would add only around 17g.


I just realized that the weight is witout the bolt on the steerer clamp, so the bolt is there 4g, and then it's cca. 17g + 4g, that's more what I thought. I made a mistake in my previous measurments because I didn't put the bolt in the stem, my bad!

@szaffiri
Yes I made a radious (cca. r=8mm), but as a part of the carbon layup. So it's laminated together with the reinforcements. I rather avoid any fillers if it's possible.

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

by Fuchspk

yeah keep us updated :) it is intressting!

in my case it is more like just taking the front away (screws and inserts), than glueing the bar in place and close the gap in the front with a bit of overlay. should be come out ± in the weight i guess. But will look a lot nicer :)

PK__3499.JPG

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

by Berk

That's a quite narrow stem! Maybe you would save a few grams here, but probably more important is the look, and probably also the stiffness would be abit improved (at least you couldn't flip the stem if you hit a hole :mrgreen:).

Otherwise just another idea - maybe it will sound stupid, but it would be possible to make a stem without any faceplate, just a round hole where you would put the bar, and glue it together with the stem :mrgreen:. The stem could be very light, and also the look would be quite clean. It could be glued with an epoxy kit, something like you get with the 3T forks (an epoxy kit and a bit of sand paper), so you could just sand the area where the bar would be glued and put it in the stem, and glue it together... :noidea:

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

by Fuchspk

Then it would be better to build a Stem from the begining and directly build it to the Stem (like some friends to me do it)

In my case i´ve got not to many choises as i build my brakelevers direcly to the bar and can not take off - because of this i can not take off my stem any longer without cutting it off :D

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

by Berk

...so it would make sense to laminate also the stem, if you can't change it :thumbup:.

You could first just unscrew the bolts and move the bar to one side, add some glue and then fix it again in the stem. Once it's dry you could cut off the area where the two bolts are and add some carbon reinforcements..

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

by Fuchspk

yes i´m planing something in that way.

how is yours working out? any pictures on this one yet?

by Weenie


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

by Berk

I'll send some photos when it will be prepared for the clearcoat. Maybe I manage to send some photos in a day or two, I'll let you know! Also a combo is in process, so I'll have some new photos in a few days.

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