Here are tips and tricks for more suppleness on the bike - and important insights into a new assembly paste for carbon parts.
Not all grease is the same: this is not a new realisation, but one that racing cyclists tend to ignore. They use one and the same lubricant when working on the bike, regardless of whether they are greasing a screw or lubricating a bearing. This requires very different skills. Although the different colours of the greases indicate their differences, they do not reveal what they are suitable for. In the so-called roller bearings (headset, pedals, bottom bracket, hubs, freewheel), balls or needles roll and generate very high punctual or linear loads on the raceways. The lubricant must be able to withstand this high pressure and at the same time adhere to the rolling element so that it is permanently lubricated; this is the domain of special bearing greases.bolted connections, but also clamp fits such as in the seat post, require a lubricant that separates sliding surfaces from each other and prevents them from being attacked. The worst case scenario is so-called galling: This is when the surfaces are so damaged that they bond together - cold welding, as the experts call it. Aluminium components in particular, which are softer than their steel counterparts, and titanium, which has a high level of friction, must be treated with special assembly paste or special grease.
What both types of lubricant have in common is that they have no place on carbon parts. Even some manufacturers do not realise what can cause difficulties when fitting carbon seat posts or handlebars. The incorrectly greased parts hardly find a hold in a clamp, screws are tightened so much that the carbon fibres can be crushed and damaged. This can lead to breakage later on.
However, not greasing carbon at all is not the ideal solution. A new assembly paste for carbon and aluminium from the Dynamic brand should now provide a remedy. The manufacturer adds small plastic solids to a relatively low-viscosity carrier component. These penetrate slightly into the surface of the carbon and are intended to increase the friction in the fit so that the screw forces can remain low. High pressure and the shear forces of a screw connection, on the other hand, wear away the granules.
The TOUR test on a carbon seatpost showed that the tightening torque of the bolt could be almost halved when using the Dynamic paste compared to dry assembly. With normal grease or a standard assembly paste, the bolt has to be tightened more than twice as much to clamp the post securely. The same tendency was confirmed with an aluminium support. With Dynamic paste half the screw torque, with standard grease one and a half times the dry assembly torque. There is inevitably no long-term experience with the lubricant yet, but it seems unlikely that the plastic particles will break down and the effect will diminish. Dynamic paste is therefore recommended for mounting carbon handlebars and seat posts or stems on carbon fork steerer tubes; for all other greases and lubricants, however, the following still applies: unsuitable for carbon!
Degree of difficulty: for everyone
You will need:
- Tool: Brush, grease gun, tool kit
- Material: Bearing grease, assembly paste, cleaning petrol, spirit or acetone, cloth
TIP 1: With assembly paste, it is not the quantity but the even distribution on the contact surfaces that leads to success.
TIP 2: Apply a thin layer of grease to both parts and wipe off any excess grease immediately after installation to prevent it from attracting dirt.
TIP 3:
Bearings should be filled as full as possible. Unnecessary grease presses outwards and forms a sealing grease collar.
