All about bicycles, electric-assisted bikes, technology and safety in the press

The most common safety risks that we come across in our daily work around bicycle safety, technology and operating instructions are also published by us in articles in the leading German special-interest magazines TOUR (Europe's road bike magazine no. 1), BIKE (Europe's mountain bike magazine no. 1), MYBIKE and EMTB in order to make this information, which is important for the industry, available to a wider public.

For many years now, the Eurobike Show Daily, trade fair magazine of the annual Eurobike Show, has also given us the opportunity to publish our view of major developments in the cycle industry in full-page articles.

We also speak regularly in independent expert presentations about all areas of bicycle technology and the bicycle market. In addition, we are quoted by further special-interest magazines of the industry and the trade as well as increasingly by radio and television in their media reports, which shows us that we are spot on with our advice. The section "News" informs you about the latest news from our specialist areas. The reports and publications of this section are listed chronologically or according to areas of interest.

TOUR 09/2017
Reading time 1:50 minutes

Press-fit bearings: a reasonable thing?

Reader’s question

While looking for a new road racer, I keep coming across press-fit bearings used on both less expensive as well as high-value carbon frames. The manufacturers save costs as they no longer have to cut threads for bearing shells. But what is actually the advantage for me as user? In addition, I came over videos during my inquiries, in which the bearing was removed by hitting it. In the case of a steel frame this is acceptable, but in the case of an aluminium or carbon frame? In the forums there were discussions about a faster wearing down, because the bearings could not be built in like threaded bearing cups. What do you think?

Reply by Dirk Zedler, TOUR technology expert and bicycle expert

It is correct that more and more press-fit bearing cups are used, as this reduces the number of work steps. In the past, when carbon frames were fitted with screwed in aluminium bottom bracket shells the cutting of threads into the bottom bracket shells had often led to damage to the carbon frame. In the long run, this was not only annoying for the manufacturers, but also for the customers. This means, press-fit bearings not only save time and money for the manufacturers during the first assembly, but are also a sound solution for the customers in the long run. To date, we have knowledge of clearly less failures with this procedure than of notched cups in the past. Nevertheless, the manufacturer must take care that the fit is round and even, thus ensuring a precise pressing in and fitting. Of course, there are differences between the manufacturers. But the bearing shells of carbon frames also wear down when mounting and dismounting the bearings quite often.
On the basis of our experiences, however, we cannot generalize broadly that the system is poor. As a matter of fact, the press-fit bearings must be hit out when they are worn down, but only in this case. If carried out appropriately, this does neither result in damage to a carbon frame, nor in damage to an aluminium frame. In this case as well the disadvantage compared to for example corroded cups in aluminium shells or to aluminium frames in the case of threaded bearings are not clearly more important. This means that if appropriately done, the press-fit bearings, regardless of diameter and type, are not a poor solution.

Go back