I posted in Mezo's build up thread
that the bearing contact area using the DR bearing races/ cups with the KTM tapered bearing is not ideal. This is what the bearing specialist said. The taper angle is different comparing the two taper bearings. It would be great to know the angular difference but cant I find it on google!
As Lukas replied, he's got more than 10,000 km on his DR/ KTM hybrid setup. I also think that there is enough play in the rollers, and that they probably don't work hard enough to be a problem.
To overcome the contact angle issue and having to have to buy two sets of expensive bearings (and the urge to get it right)... I thought I'd press and swap the DR/ KTM stems from their respective bottom brackets. The diameters are difficult to measure whilst on the bracket (with the bottom bearing siezed on), but they look roughly the same, and I was pretty certain that they could interchange - plus Torben mentioned that he did this swap (just dunno on what bike models). If you were to do this, you'd probably need a 2mm thick spacer sleeve on the DR stem so that the KTM epper triples could clamp on.
Using a 15 tonne press, the fitter could not press out the KTM headstem
. Is there a trick to it? We haven't tried cooling the alluminium.
So... I think that i'll get some SS spacer sleeves over the 29mm KTM stem to fit the 30mm ID DR taper bearings.
More on Wed hopefully...