A Little Sturmey Archer Debate on a Wednesday Evening...

 

 Certain bike-related sources take on the feel of "gospel" in the vintage bike community, the more they are used. I think Jobst Brandt and Sheldon Brown have both reached that status. People often cite Brandt on the subject of wheel building (he was certainly an expert) and Brown for all-around vintage bike information (particularly British 3 speeds and French road bikes). I will admit to learning a great deal from Sheldon's website and from correspondences with him (which I now see as all-too-short; his presence in the hobby is missed today).

 I was recently thinking about a debate between Sheldon and Jobst over Sturmey Archer AW hubs. 

 HERE

Brandt's position is that the AW suffers a more or less fatal flaw in the design of its clutch engagement: that under heavy load in high gear, the hub can suddenly slip out of gear, freewheel forward, and hence send the rider over the bars. The problem he cites is the slight play and straight profile of the planet gear pinion pins. (This is NOT the more common issue of a badly adjusted shifter cable allowing the clutch to slip out of gear - Jobst is claiming an inherent flaw regardless of shifter chain adjustment).

Sheldon's response was that while this was theoretically true, and it may even have happened in certain extreme cases where the rider was very strong and in top gear for extended periods, that the vast majority of riders on these hubs don't have the clutch engagement problem. 

John Allen adds to the debate that the bigger problem with old AW hubs is that the shifter connection can unscrew unnoticed by the rider, allowing a hub running in normal (2nd) gear to slip into neutral. 

I am firmly in Sheldon's camp on this topic. Although the old AW's clutch mechanism is by no means perfect, the problem Jobst describes is a far, far outlier. 

First, Sheldon's reason regarding the AW attracting more casual riders is correct as a general thing. 

Second, when riding an AW in top gear, most riders (even the sportier ones) tend to "spin" rather than thrash the hub. The reason for this is that most climbing, especially hard climbing, is done in low gear rather than high gear. High gear generally is used for flat or dropping terrain, where the rider will rather quickly get into a spinning mode. Even sportier riders aren't thrashing away on high gear for extended periods at full strength. This almost seems to me to be a form of abuse of the hub, given the amount of force exerted on the hub.

Third, Jobst's use of the Sturmey SW hub as an example of Sturmey Archer is unpersuasive in undermining the manufacturer. The SW hub was a totally different design with far, far more engagement problems than the AW ever had. It's not a fair comparison.

 Fourth, history doesn't seem to bear out Jobst's claim. Millions of these hubs were made, and they were heavily used in difficult conditions all over the world. I have yet to see proof that a substantial number of people using these hubs had the problem Jobst describes. This includes many athletic club type riders who used AW hubs reliably on a regular basis. In short, I don't think history backs any claim that this high gear pinion problem was a serious and recurring thing..

Ultimately, I tend to agree with Sheldon and with John Allen on this subject. It's not that Jobst's proposed flaw is totally false (perhaps if we dug, we could find a case of it happening), but that it's a far outlier that comes nowhere close to warranting writing off the AW. The bigger problem is when the shifter cable is not properly adjusted, which allows the clutch to slip into neutral on the old AW. With proper care and adjustment, the old AW is a reliable hub. 

This all reminds me of an old discussion Jobst had with a man who was rebuilding a 1960s era Schwinn Racer. (see HERE) I think perhaps Jobst was a little too dismissive of the man's questions. The Racer, Sturmey AW, kickstand, and all, is a very practical bike, if a bit heavy. They make good commuters and utility bikes.

The lesson here is that we have our "go-to" experts whose advice has become a form of "gospel" for vintage bike enthusiasts, but sometimes it's perfectly OK to disagree.