Originally Posted by
bulgie
Yeah not sure if I got to see the post-mortem on that hub back at the shop, but I did see the aftermath with my own eyes from a couple feet away there at the scene, same as many other spectators. The wheel definitely collapsed when the spokes all got loose from the flange moving inward, while 3 strong dudes were still sprinting. My assumption was the threads stripped, probably the threads in the aluminum not the steel. I agree the flange can't thread further on without rotating, which the spokes absolutely prevent.
This was almost 50 years ago, so my memory may be off on details, but it was a very memorable event!
I didn't think Santana had anything to be embarrassed about, but it was a very public failure, with probably a couple hundred people watching. So they didn't stick around, they whisked the crippled bike away ASAP. Even Phil shouldn't be too embarrassed IMHO, given the insane amount of force that was going through that hub when it failed. Jim asked if any hub would have held up to that load, and it's a good question, I'd expect that Phil to be one of the strongest hubs ever made, and I can't think of any other I'd call stronger.
Nice hub refurbishing!
This discussion is right up my alley. Given the situation, I'm surprised the freewheel didn't fail on that triplet climbing a 33% hill. Hub or axle failure comes as no surprise.
But stronger hubs? Yes, they're out there and Chris King, DT/Swiss (previously Hügi), Rohloff and Onyx would qualify as "stronger." I took possession of my Cannondale mountain tandem in late '96 or early '97 right after DT/Swiss redesigned the rear hub's star ratchets. They made the star ratchet ramps shallower than originally designed by Willi Hügi, the Swiss engineer and namesake of the hubs. Customer complaints about the hubs being too loud prompted the redesign. Well, multiple star ratchet failures ensued. My first failure was on Slickrock Trail. I spoke to Willi at Interbike and he was NOT happy about them redesigning his hub. (My road tandem Hügis from 1993 have never been overhauled or even serviced and have never skipped.) They have subsequently addressed the issue and I haven't heard anything about widespread high torque failures since. (Yes, I've seen he Cal Poly engineering paper investigating surface hardness QA/QC issues on the star ratchets.)
Chris King WAS going to be my replacement hub after two DT/Swiss failures (before they rectified the situation). But back then, King was still using aluminum Ring Drives and I just couldn't put my faith in them surviving mountain tandem torque, despite Chris assuring me at Interbike that they would survive.
So I went with Phil Wood's Field Serviceable Cassette tandem hub.
It lasted about a mile into Slickrock Trail:
The drive or engagement ring in the hub shell broke free of its retaining compound and screwed into the hub shell so far, it split the shell in two. PW was great about it and replaced the hub under warranty. Subsequent to this, I have not returned to Slickrock for the "full test," so I cannot attest to its ability to survive. However, my stoker and I have gone on to mangle another two freehub body internals & pawl sets, which Phil has remedied over the years for a very fair price. Still love the PW tandem hub though. A thing of beauty for sure.
Subsequent to my choice of PW on the tandem, Chris King switched to stainless steel Ring Drives. Had they done that earlier, CK would have been my choice.
Funny aside... I ordered a used CK hub service tool on Ebay about 10 years ago. The seller contacted me and asked, "I have a bunch of spare King bearings & parts. Want me to send them too?" I eagerly replied, "Yes, please!" Well, lo and behold, what appears in the box with the coveted King hub service tool and misc. bearings? A pair of old and obsolete aluminum Ring Drives, COMPLETELY worn down from years of use! Ha, ha! That seller totally made my day. And that I happened to buy a tool from a guy with worn Al Ring Drives after discussing the very issue with CK is awesome coincidence. I love the King rear hub and to have a legacy Al Ring Drive is totally cool!
Also, only DECADES later and after the fact did I learn that one of my father's late physician partners was Phil Wood's primary care doctor! I was just about five years too young to have come to appreciate this amazing coincidence. Oh how close I was to meeting the legend in person!
PS Anyone catch Berm Peak's recent video where Seth and friend try to tow thousands of pounds on a tandem?
ULTRA low gearing via a 74T rear cog led to what I expected: freehub failure!