DIY Bung for Carbon Steerer (Instead of Star Nut)



So when I received a shipment with carbon fork for my bike from China, I realized that I will not be able to install the star nut, such as on forks with steel or aluminum steering tube.
I looked on the internet what is used in this case and I found this thing with a funny name – bung. In view of this, it does not look like an engineering challenging thing I decided to do it myself.
I dig the drawers and found the following:
M10 screw with allen head
aluminum nut for which I’m not entirely sure about the origin,
the plastic washer,
a small end of the rubber tube,
rubber seals and
some garden hose.
I put M10 bolt in a vice and through the hex head bore a hole with diameter 5,2 mm and about an inch deep.
Then I was carved M6 thread in that hole in which will later be screwed top cap bolt.
in the aluminum nut I carved M10 thread Instead of aluminum nut and the end of a rubber tube it could simple be used M10 nut and a washer. In this case, the garden hose must be slightly longer.
Then I assembled the parts and measure the distance between the plastic washer and aluminum nut, this is the length of garden hose that I cut.
All the elements must fit tightly in to the steering tube, as well as they must fit nice with one another. I assembled all together and tested in the cut-off of the steering tube, which was too long. I gently tighten bong with an allen key that the seal is compressed, but not too much.
Bung really works, as I expected, and it can be used on a bike.

The bung I made weights 36 grams without the M6 bolt and a top cap

Torej, ko sem prejel pošiljko s karbonskimi vilicami za moje kolo s kitajske , sem spoznal da jih ne bom mogel namestiti z zvezdno matico, kot na vilicah z jeklenim ali aluminijastim steererjem. pogledal sem na internet kaj se uporabi v tem primeru. Našel sem to zadevo s smešnim imenom – bung. Glede na to, da ne izgleda kot neka inženirsko zahtevna stvar, sem se odločil, da jo naredim sam. Pobrskal sem po predalih in našel naslednje: vijak M10 z imbus glavo, aluminijasto matico za kateri nisem povsem prepričan o izvoru, Plastično podložko, majhen konec gumijaste cevi, nekaj gumijastih tesnil in vrtno cev.
M10 vijak sem vstavil v primež in skozi imbus glavo zvrtal luknjo premera 5,2mm. Nato sem v to luknjo vrezal M6 navoj v katerega se bo kasneje privil top cap bolt. V aluminijasto matico sem vrezal navoj M10. Nato sem dele sestavil in izmeril razdaljo med plastično podložko in aluminijasto matico, to je dolžina vrtne cevi, ki sem jo odrezal. Vsi elementi morajo dimenzijsko ustrezati tako dimenziji krmilne cevi , kot tudi ena z drugo. Namesto aluminijaste matice in konca gumijsate cevi bi lahko uporabil tudi navadno matico in podložko. V tem primeru bi bil konec vrtne cevi malce daljši in potreboval bi več tesnil.
Vse skupaj sem sestavil in najprej preizkusil v koncu odrezane krmilne cevi, ki je bila predolga. Bung res deluje, kot sem predvideval in lahko ga uporabim na kolesu.

bung tehta 36 gramov


Post time: Jun-12-2017