SHIMANO Bottom Bracket BBR60-68mm English Thread.

Product Information

The picture shows a bbr60 without its dust cover/sleeve. That's one very slim bearing. Who makes them? What are the dimensions? Do they have a short lifespan? Curious... There are a few standard shell diameters (34.798–36mm[1.3700–1.4173in]) with associated thread pitches (24–28TPI). Scott US marketing and PR director Adrian Montgomery touts similar reasons for his company choosing BB86/92 over other standards: Put another way, you’re sitting on a lemon – and in this case, no amount of sugar is going to make it taste good. When it is all set up correctly, differences between different BBs (e.g. stifness) are never perceivable when riding the bike – basically they are unimportant. So there is really no need to buy a frame with a certain BB standard because it is marketed as stiffer, better. Just see what kind of frame you like, or what components you already have, and go for the simplest, easiest, cheapest solution to make it all work.

If everything is manufactured as intended, we shouldn’t be dealing with creaking as much as we are currently SRAM claims that the focus on optimising the bearings resulted in a spindle diameter of 28.99mm. This places is right between SRAM’s old 24mm GXP cranks and 30mm spindles of modern cranks. More recently, bearings have shown up that allow a 30mm spindle to be used. The dimensional restriction mean the bearings are generally quite small, as the system was designed around 24mm spindles. This can lead to reduced bearing lifetimes. The International Spline Interface Standard" (PDF). ISIS Drive. March 23, 2001. Archived from the original (PDF) on August 20, 2019 . Retrieved February 13, 2019. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sourcesin this section. Unsourced material may be challenged and removed. ( October 2014) ( Learn how and when to remove this template message)Cons: Heavier than press-fit systems; frame design limited by relatively small-diameter and narrow shell Other notes Matches the wide bearing spacing of a BSA external BB with a large 30mm spindle BB392EVO

More recently, Cannondale announced a variant of BB30 called BB30A. This uses a shell that’s 5mm wider than the original but it’s an asymmetrical layout that only adds those extra millimetres on the non-driveside. According to Cannondale, this allows for wider bearing spacing and better spindle support (which should improve bearing longevity). Other notes Aims to solve creaking issues of press fit systems. Essentially an oversized BSA external BB Thread Fit 82.5 Trek’s BB90 system uses the same bearings and bearing locations as a conventional threaded system, but eliminates the cups entirely. Bearings are pressed directly into precision-molded carbon seats Immediate Media

PF30 and OSBB bottom brackets

Campagnolo Ultra-Torque Crankset". 2006. Archived from the original on 2007-01-04 . Retrieved 2006-12-14. With our manufacturing methods, we also have no issues holding tolerances. [BB386 EVO] wasn’t designed as a cost reduction, but not having to post bond an aluminium shell into the frame and make sure the facing and threads are correct is slightly less expensive and much more reliable.”

Cons: Shell still just 68mm wide; metal-on-metal interfaces can be prone to creaking; requires a separate bearing puller and press for service; requires high manufacturing tolerances; bearing seats can’t easily be faced post-manufacturing BB30 and PF30 cranksets won’t fit frames with different BB shell standard, because their spindle will be too short. However Shimano advertise that SM-BBR60 & BB-R9100 use 'small ball bearings'. This is not necessarily a good thing, in that smaller bearings are weaker. However there are more of them. Still it would be reasonable to assume that the RS500 will be DIFFERENT in durability from the other two, but not necessarily worse.Other notes OSBB for mountain bikes appears to be PF30 (post 2010). An older 84.5x46mm BB appears to be obsolete. PF30A and PF30-83 Ai

Unfortunately, it’s difficult to know upfront which length will be the optimal choice. For all I could try, it still boils down to trial and error. I make sure to always have the entire range of lengths in the shop and am happy to do test-mounting to confirm, starting with the length I expect to be the optimal choice first. Pros: Lighter weight; more resistant to axle twist; more heel clearance; larger-diameter shell and spindle; potential for narrower pedal stance width The Threadfit T47 standard (no relation to Colnago’s ThreadFit system) was originally developed for Argonaut Cycles by Chris King. It uses an oversize, threaded alloy sleeve to house the bearings. Among its advantages touted by Argonaut are a reliable threaded interface and compatibility with all known crank standards. Specialized uses PF30 for its high-end mountain bike, confusingly also calling it OSBB though it is a different standard to the OSBB standard found on its road bike. Compatibility Originally designed for BB86 cranksets and bearings. New integrated CeramicSpeed BB fits 30mm spindle cranksBB30’s larger 30mm-diameter spindle, compared to the standard 24mm size, allows the use of lighter alloy Immediate Media How companies decide to go about that — and precisely what design features they want — is the real issue, because everyone seems to have their own ideas on how to achieve the same goals (less weight, more stiffness, and lower manufacturing costs). Very closely related to Trek’s BB90/BB95 system is the BB86/BB92 standard used by Scott, Giant, Pivot, and many others. Crank designs that will fit: Standard 24mm external-type only. A GXP conversion kit is also available I'm actually wondering about the Tiagra bb RS500, which seems massive, compared to BBR60 and DuraAce bb. Anyone taken one of those apart? Are the bearings bigger or just the shells?