Deutsche Tech Projekt: 3.8kg Tokyo banger

Who are you (no off-topic talk please)

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by Osoi3900

Greetings all,
My name is Zane.
I would like to share my bike project with you.
The aim is to build a usable daily rider with a sub 4kg weight.
This project has been several years in the making, many hours of research, $ spent and hours of work have been applied.
Please join me for the ride.

Let's start this with the frame and fork. The frame is a swift sculp 54cm. The frame is a re-branded ax-lightness vial. This is a rare frame, I'm unsure if swift ever actually sold these to the public, this one is number 12.
The fork is a thm scapula CT.
Current actual weights are as follows
Frame: 735g (including bb bearings approx 43g, I'm not removing them now, but my ceramic speed ones weigh 42.8g and these are regular steel) frame clear coat has been lightly wet sanded with 2k grit to take it to a matte finish, decals will be redone in matte black.
Fork weight: 263.5g including plug and alumi crown race.
A buffing disc was used with a proxxon (japanese version of dremel) to remove all logos from the fork, then clear coat lightly wet sanded with 2k. Clear coat on both the frame and fork has not been removed, just carefully dulled to a matte finish.
Please enjoy the pictures, much more to come!

Last edited by Osoi3900 on Wed Jul 08, 2020 7:57 am, edited 4 times in total.
Deutsche Tech Projekt: 3.8kg Tokyo banger

by Weenie

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by Osoi3900

I'm about to go for a ride, but first here is another piece,
This project will utilise carbon downtube shifter(s) so the brake levers will be a standalone affair.
These started life as 11 speed super record levers, internals were gutted and carefully machined by hand to a bare hood and lever arrangement. These will be held in place by schmolke carbon clamps, the original alumi pin will be replaced by a carbon rod (most likely of the inanimate variety)
Current weight is down from 77.1g to 50.2 per assembly.
Please enjoy the pictures.

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by beanbiken

Should be good, hope you achieve your target weight, will be watching this thread :thumbup:
Last edited by beanbiken on Tue Jun 09, 2020 11:00 am, edited 1 time in total.

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by kgt


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by Yoln

Looks like a pretty nice start of a thread, will definitely be watching it!
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by mike

you've got real dremeling skills!!!! very nice weight

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by BmanX

AERO & LIGHT is RIGHT for 2 decades

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by Osoi3900

Hi all, thanks for your supportive comments.
I hope you enjoy this build.

First a word about working on carbon. I've done some reading on the dangers of carbon dust, or rather the dust of resins. I believe the dust to be quite dangerous, therefor I take the following precautions when doing anything with carbon fibre.
If I am drilling or cutting carbon parts, I do it completely submerged under water, if I am using a dremel or sanding carbon I do it under flowing water (I made a flow tank using a storage box and a fish tank water filter, which produces a constant stream of water over whatever part I am working on)
I would never recommend dry sanding carbon, always use water to avoid airborne dust. On top of that I always work outside with plenty of fresh air and always use a very good quality face mask with filters rated to deal with asbestos particles.
I'm not sure what precautions you guys are taking when you work on carbon, but I'm not taking any chances.

Ok now that we've got that out of the way, let's check out the wheels that will be going on this build.
I will be using a set of tune skyline tubulars, running on tufo elite jets (at least for the time being) when they blow up I have some others to try out, but this initial build will use jets.
Weights as follows
Tyres: 305g for the pair
Front wheel: 370g
Rear : 505g
Wheels/tyres/glue/100psi air : 1195g

I am very happy with the final weight of this wheelset and can't wait to ride on them.
Deutsche Tech Projekt: 3.8kg Tokyo banger

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by Osoi3900

Hey ladies and gents,
I have a little bit of an update for you.
This bike will utilise carbon downtube shifter(s) sometimes in 1x configuration and sometimes in 2x (for purity reasons only)
I like downtube shifters and they are also a very light solution.
A hollow carbon rod will hold the shift levers, this will be bonded both inside and outside the frame with carbon lugs. Brass threads have been resized to fit in the ends of the tube and will be bonded in place. A carbon end washer will hold the shift levers in place with a schmolke carbon bolt (this may be replaced by an alumi bolt if I need more tension to hold everything.
The shift levers themselves are retro items, nos modolo from the early 90s. I would love some btp ones if anyone knows of any (and the btp rear mech while were on about btp)
the washers and lugs were fashioned from a solid carbon cylindrical rod, I cracked a few of them while drilling but eventually worked out a technique and produced some usable examples.
Weights are not final yet, but you can get some idea from the pics below.

I am a big fan of Gunter Mais rig from many years ago, that's when I first thought of using downtube shifters, another advantage of downtubes is that there is no need to run cable housing which will save some grams.
Deutsche Tech Projekt: 3.8kg Tokyo banger

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by tonchy

Very very interesting!
Looking forward for updates and to see a complete bike. :)
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by Osoi3900

ome rodriguez wrote:
Thu Jun 11, 2020 11:28 am
But you drilled the downtube?

We have similar frame.

Hi Rodriguez!
2 holes were made, I used a proxxon , not drill and finished with hand sanding, so as not to crack or chip the carbon.
The whole area will be reinforced from inside and outside on both sides.
Your bike is sick! I love it, very nice build, you should ride it every day.
I am wondering about the weight of your wheelset. What is the complete weight of the wheels/tyres/glue/air/skewers?
Thank you and great to meet a fellow ax owner!
Deutsche Tech Projekt: 3.8kg Tokyo banger

ome rodriguez
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by ome rodriguez

Thanks also.
I do have their individual weights, hope this helps.
Btw, i only used tubtape from uk.

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by Osoi3900

ome rodriguez wrote:
Thu Jun 11, 2020 1:35 pm
Thanks also.
I do have their individual weights, hope this helps.
Btw, i only used tubtape from uk.
Thanks Rodriguez!
Wow your bare wheelset is almost 100g lighter than mine. Actually I was wanting those, but got a very good deal on the tunes.
Also I think your wheelset has a 100kg rating where as mine is only 90kg, amazing stuff.
Ill be sure to stop by your page and say hi.
Deutsche Tech Projekt: 3.8kg Tokyo banger

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by Osoi3900

Greetings All!
Just a small update for now,
I would like to share some parts with you.
The bar and stem combo, cables and cassette.

The bars are schmolke TLO in a 420mm. I chose these because I got a good deal on them, but secondly I also like the name. But seriously this bloke did his university thesis on carbon handlebars before they were a thing! Darimo would be a bit lighter, but possibly flexier and besides when I bought these bars darimo weren't even making handlebars.
At 144g I'm happy with the weight.
By the way, anyone know what is the absolute lightest bartape available?
The stem is by extralite, 100mm 6 degree. At 77g it's not the lightest, but it should be very strong.
The cassette arrived recently, by Seqlite. Stumbled upon this by accident and at 105g for a 12-25 thought it was worth a go. Alumi body with Titanium cogs. Also pictured is my kcnc 12-25, similar (by noticeable more solid) construction but coming in much heavier. Kcnc comes with a 2g lighter lock nut, so yep I will be using that one.
Gear cables will be powercordz (are these guys out of business??) and brake cables will be Kcnc tiwer titanium with aican bungarus link. Powercordz would have been lighter but not quite as user friendly with my planned brake set up.
Final weights will be posted when everything is cut to size.
Deutsche Tech Projekt: 3.8kg Tokyo banger

by Weenie

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