Titanium is a nobile metal that requires a demanding
manufacture. We have suceeded in manipulating this material with great
effectiveness. For example the oblique tube has an oval section and also
coned, while the tubes of the triangle are slightly “S” shaped. Both
are forms decisively difficult to realise.
‘ NEVI ‘buys the tubes from U.S.A. ( company
name is Ancotech ), which are then worked completely at home by Nevi.
The weldering of the tubes is done using
the Tig method, therefore in an atmosphere of inert gas. All weldering
materials used are always titanium. All points of weldering are left exactly
as when they leave the welder’s hands.
Now lets take a closer look at how the tubes
compose the frame structure, all titanium. The chemical formula is titanium
3AL-2,5V, classified also as grade 9. The scope of this alloy is to render
titanium a little more malleable but at the same time harder, without damaging
its mecanical characteristics.
The vertical tube has a diameter of 31.7mm.,
the horizontal tube 28.8mm, they have a thickness of 0.8mm.
The handlebar support tube has a diameter
of 33mm, and has a thickness that varies from 0.7mm to 1.4mm.
The oblique tube must be noted; while all
the other tubes of the frame are round and without weldering, the oblique
tube is made modelling a titanium sheet and then welded . this sheet is
also used to build military machinery and it’s for this reason that to
put in difficulty this type of metal it would need 105Kg. Weight focalised
all on one square millimeter of this titanium. It is classified as Grade
5, which comports a difference in percentage of alluminium and vanadium
from Grade 9. The chemical formula is “Titanium 6AL-4V “.
The oblique section is oval and is characterised
by gradual folds used to harden the tubing in a longtitude direction. Furthermore
the tubing is all coned in height and width. That signifies that at the
handlebar support tube the measurements are 53mm in height and 34mm in
width, while at the central movement box it registers 59mm height and 32
mm width. It must be said that as the oblique tube is very high at the
extreme point, it is weldered at the bottom bracket box, it is then cut
in a way to unite perfectly to the vertical tube, so strengthening that
whole part of the frame.
In various road tests the frame hasn’t demonstrated
in any way signs of flexing. It has however a solidness that doesn’t drive
the level of rigidness to exasperation.
The frame remains sensitive and is able
to assume an important role when asked to work and must assorb the shocks
coming from the surfaces on which it transits.
Passing to the triangle tube it is characterised
by sloping tubes, perfectly cylindered from a diameter of 15mm. The lengths
are limited because they begin straight under the seat support block and
finish at the fork, these lasts are drawn from a worked titanium sheet.
The characteristic of the sloping triangle
tube is that the tubes are not straight but must have a slight ‘ S ‘ shape.
At their ends ( triangle tube ) then begins
the back horizontal fork with a continual coned form that becomes oval
in the section that unites at the central movement box.
Also the headset stem in titanium Grade
5 and mtb handlebars in titanium Grade 9 is made by Nevi.