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///////////////////////////////////////////////////////// made in Germany ///////////////////////////////////// 2008
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  Welding desk
The fabrication
 
Intro
We do mechanical engineering. Mechanical engineering is a classic engineering science and is no longer limited to the construction of engines, motors or gears etc. Mechanical engineering is a combination of basic research and design. It concerns itself with the targets and the methods an engineer must follow during the construction process. Meanwhile components, assemblies or systems are created with computers by means of CAD-programs. This CAD-data is then subject to a simulation (finite elements analysis) and afterwards it can be manufactured on a CNC-machine. All this happens before the first metal shavings touch the factory floor, and the engines we manufacture are called mountain-bikes.
 
 
"das medium ist Aluminium"
The basic raw material from which our frames are built is aluminium, delivered to us as blocks and tubes. We use several butted tubesets from the brand EASTON® as well as aircraft grade 7020 and 7005 aluminium tubing. Milled parts which are not welded are made out of Al Cu Mg 1 aluminium. We also now produce additional frame components out of Magnesium and Titanium. From these raw materials to a NICOLAI frame is a long way. In order for you to have a better understanding of our products in this area, there follows below a description of the whole process.

The first step is the precise cutting of the tubes. In order to reduce further welding distortions as much as possible, the tubes must be exactly cut at the mitre joint. A single tube can have up to four mitre cuts. Because of the variety of the different tubesets and thus the different clamps they require, this work can turn out to be quite complex and expensive. This is why we have built a new machine specifically for this task.
 
 
CNC work stations
All milled parts are made in-house from raw aluminium or from semi-finished extruded aluminium profiles manufactured specifically for us. Here too, precision has to be coupled with a high production rate. To accomplish this we now have three CNC work stations in use. These include two of the most modern CNC tapping centres: A BROTHER® TC-32-A, is capable of milling most of our 220 or so different milled parts. For the serial production of all the G-Boxx parts, we are using a brand new Haas VF2 Superspeed.

A Weiler CNC turning lathe with powered tools enables us to produce very technical and intricate turned parts; for example, the separable COR rear hub of the Nucleon TFR and TST models. It allows us also to quickly and precisely manufacture parts that are required in large numbers, for example bearing axles or bottom bracket housings. A lot of parts though are still made on a regular turning lathe: principally small production parts like tailored bolts, special spacers, head tube with a modified length and turned parts for prototypes and fixtures.
 
 
Welding
For each model and for each size we have a specific welding jig. On this jig, the tubeset with the milled parts are fitted together. Afterwards, our welders tack weld this assembly in precisely defined points in an exact sequence. Then, in order to minimise distortion and warping, the tubes are TIG (tungsten inert gas) welded together in multiple passes. Our smooth and evenly scaled welding seams are obtained through a very slow welding speed that enables a deeper penetration of the material than a spread seam. The wide and flat form of the seam provide for an optimal force distribution at the welded joint. People often ask: Were these seams welded by a robot? To that we must answer no and point out that all our frames are welded by hand by our experienced welders. A Nicolai frame can always be identified by its welding seams.

Right after the welding process the frame is trued (straightened). The welding process changes the microstructure of the aluminium and makes it softer; it is thus easier to true the frame at this moment. Aligning the frame two or three days after it has been welded would require a much greater effort. Finally the frame is put into a special oven to be hardened by heat over 14 hours. In the oven, the microstructure of the aluminium is renewed and the material gets back most of its original stiffness.
 
 
Before and after coating
The next step is the reaming of the seat tube at its upper end, and the drilling of the axle bores. The frame is then ready for final finish. Frames undergoing a powder coating are cleaned and degreased. Any ridges or scratches are ground. Frames undergoing the anodizing process are bead blasted. Thanks to our powder coating facility we can deliver almost any of your colour or design fantasies. This powder coating process is detailed later on in this document.

After the coating process, all bearing and axle seats are reamed on a special turning lathe. The inner surface of the head tube and the bottom bracket housing are reamed parallel. The bottom bracket housing is brought to standard dimensions and the threads are tapped.
 
 
Powder-coating or anodising

Powder-coating is a dry paint process where a coloured powder is applied to a frame by an electro-static charge and then melted by heating the frame in an oven. Normally two layers are applied, a coloured layer and then a transparent layer that can either be glossy or matt in appearance. Due to the thickness of this finish, powder-coating provides good protection from impacts, for example from rocks. On the other hand, the layer thickness gives some additional weight, about 200 to 300 g depending on the frame model. Another disadvantage is the risk of cosmetic damage to the coating in areas of high mechanical load like the drop outs. We provide a large choice of colour options. For the complete range check this page.

Anodising is an electrochemical process that coats the frame with a dyed oxide layer. The advantages of this are a hard and scratch-resistant surface with low weight. Unfortunately some disadvantages have to be accepted as well. The anodised surface is hard and resistant against abrasion, but there is little protection from impacts – for example stones and rocks kicked up into the down tube. In addition the colour is affected by the different alloys used and also influenced by different heat zones of the frame material from the welding process. This can lead to slight differences in the finish between different frame parts. Compared to the large choice of powder coat colours, the anodised colours we supply are limited to black, silver and bronze.
 
 
Final assembly

The last step of fabrication is the final assembly. Here, all the individual parts are examined once more, any remaining ridges are removed, bearings and axles are pressed and assemblies are mounted on the frame. In order to ensure your NICOLAI rides perfectly in a straight line, the frame is measured and precisely aligned once more. The camber and toe-in of the rear dropouts are adjusted. The disc brake mounts are also milled parallel for a hassle free mounting of the disc brake calliper. The replaceable derailleur hanger is pinned, the shock is fitted according to the rider’s weight and the stickers are affixed on the frame. After a final check and a thorough cleaning the frame moves to the shipping department where it will be assigned its final destination.
 
 
 
 
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