T47 is examined in engineering detail. Some of the quirks associated with the standard, the weights and the frame geometry limitations are discussed. Trek, Felt and Factor variations of T47 dimensional standars are covered.
This article will cover the technical and engineering aspects of SRAM GXP. Sram GXP is a very popular crankset standard used by SRAM. It offers an industrial based bearing arrangement and was touted as having the lowest weight and rolling resistance of any crankset bottom bracket standard. The engineering will be analysed in detail. Currently […]
This Scott Foil had it’s aerodynamic credentials severely burned on the Hambini barbecue. Staggeringly, the frame was the user’s second. The first was found to be out of specification. This frame was also found to be out of specification.
A Hambini bottom bracket user from Canada sent this link to their mechanic installing a Hambini BB into a Cervelo bike frame. The music and install are quite therapeutic!
A Hambini BB user sent in this video of his Specialized Tarmac SL6 with a Hambini BB30 to Shimano Bottom Bracket installed. As always, an unloaded spin test is not a good indicator of loaded performance!
If you are about to buy a Cervelo bike, watch this video. It shows the appalling tolerances the bike frames are made to. The bottom bracket pressfit specification is so bad, neither NTN or SKF will warranty their bearings in it. This particular frame had misalignment between the two halves of the frame body.
There are various camps out there on the internet that swear by threaded bottom brackets as a means to avoid creaking. This video below shows the pro’s and con’s of both.
Introduction I have had a number of cyclists contact me with issues around NTN and SKF bearings being fitted at bike shops and failing within a fairly short period of time. A number of these cyclists have sent me the bearings back to look at and I have found a large number of bearings to […]
Introduction A question that crops up frequently is with regards to Specialized’s OSBB bottom bracket and what size it is exactly. The short answer is OSBB comes in 3 variants which are all called OSBB. 46×61, 42×68 and 46×73. A summary table is below, with the detailed drawings below that. Variant (Diameter x Width) (mm) […]
If you are reading this you will have probably already come across the numerous posts by various individuals in Internet forums across the web. The issue of creaking bottom brackets has been blamed on the introduction of pressfit and directfit bottom bracket standards, where bearings either push directly into the bike frame or push into […]