Assymetric vs Symmetric Campagnolo 111mm Bottom Brackets

My old triathlon bike has a Campy Record Triple crank, which I got because I was doing the Silverman triathlon in 2006 with almost 10,000 feet of climbing on the 112 mile bike leg, and Probikekit.com had the crank on closeout because Ultra-Torque for Chorus and Record had replaced square taper bottom brackets.  I actually wanted the Chorus triple which was even cheaper because it was the same crank as Record with steel instead of alloy chainring bolts, but Chorus was out of stock when I placed the order (and back in stock a week later).  The Chorus assymetrical 111mm square taper bottom bracket only cost 19 British pounds, about $35 USD at the time.

In 2003 I put a 170mm Centaur triple crank on the wife's Bianchi Eros Donna, which had narrow 38cm bars and short 165mm cranks for petite riders, and she didn't like either.  I first added a 36x24tpi Italian threaded 111mm Campy Racing-T (AC-H equivalent) BB for $9 to an online order because I figured "Italian bike with "Made in Italy" sticker on the frame, it's gotta be Italian threaded."  Then I'm ready to install the new crank, start removing the old BB, and find out the driveside cup is reverse threaded, it's 1.37x24tpi English.  The $9 Italian BB wasn't worth returning, so I added a $19 AC-H BB to an online order from a different store.  About 2 years later Bianchi started having the same frame made in China.

This year I notice some bearing play in the AC-H on the Bianchi, and I find out I can't get cheap Campy AC-H bottom brackets for $20 anymore.  The cheapest square taper Campagnolo bottom bracket sold now is the symmetrical $50 Centaur.  I wish I could go back in time and tell myself "hey buy 2 more AC-H's now while you still can."  But I never had a cartridge BB go bad on me until this year, the first one I ever bought around 1995 still has no bearing play, a Shimano UN71.  And the asymmetrical Chorus bottom bracket, already on closeout when I bought it in 2006, now lists for stupid money on ebay, sometimes over $100 new.  With some patience I finally won a Centaur BB for $29 and a Chorus BB for $50.

Searching online, some say the symmetrical Centaur 111 will work with a Chorus/Record triple.  Now I can finally measure the difference.  I also finally got a cheap gram scale and they weigh exactly the same, 235g.  The AC-H weighs 298g.

So the asymmetry is only about a millimeter, the Chorus spindle sticks out 1mm further to the right of the frame than the Centaur's.  But the Record Triple crankarms are actually perfectly equidistant from the seat tube, it's the Centaur Triple's right crankarm that's about 2mm further from the seat tube than the left, despite the AC-H/Centaur bottom brackets having the symmetric spindle. 

The Centaur and Chorus bottom brackets both use the same size 6903RS and 6803RS bearings.  The cups can be interchanged, but that doesn't accomplish anything because the Centaur shell is 3mm longer, which makes the left cup stick out from the frame 4mm vs the Chorus cup sticking out 1mm.  This is probably to mimic the 3.5mm thick flange the AC-H cups needed for their BB tool, so that there won't be a huge gap between the left crankarm and left cup.  The Chorus/Record bottom brackets don't use the flange tool, so the cranks sit further up the spindle closer to the frame.

The left Centaur triple crankarm installed on the Centaur BB is about 6.9mm from the frame BB shell.  My left Record triple crankarm, which has never been uninstalled, is about 4.2mm away from the frame, so maybe the Centaur BB moving the spindle 1mm to the left will make it 5.2 mm away, which will give 1.2mm of clearance between the left crankarm and the Centaur left cup sticking out 4mm.  So the Centaur 111 BB will probably work fine with a Chorus/Record triple crank, the arms will just be shifted 1mm to the left.  I don't know how much closer to the frame a crankarm that's been reinstalled several times will be, from theoretically sitting further up the spindle taper.

On a forum discussion about replacing the 6903/6803 bearings, one long time mechanic in Boulder said he had a 50% success rate in removing the right retaining clip without deforming it, which causes the new bearing to bind.  I may try replacing the bearings later whenever one goes bad.

I may yet get some use out of the Italian threaded AC-H.  I don't have a hydraulic or arbor press, but I managed to get the swaged on driveside cup off of the cartridge with a 2 jaw puller and the BB shell of an Italian threaded frame I found on a curb (which had wrinkled top and down tubes at the head tube lugs from crash or roof rack into garage damage).  I managed to get the driveside cup off the worn English AC-H too, and pressed it onto the new AC-H cartridge. 

There's a lip on the inside of the AC-H driveside cup that still locks into the groove on the cartridge, but now the cup can rotate on the cartridge.  The outside of the cup looks like it gets swaged to tighten it around the cartridge, so I must of slightly stretched the lip when I pressed it off.  There's also a fraction of a millimeter of end play between the cartridge and cup, but it goes away when the driveside cup is tightened into a frame (without installing the left cup), not sure why.

The bike I saved from someone's trash last year has a Shimano LP-26 cartridge bottom bracket.  First it had one rough tight spot, later it was rough over the whole entire spindle revolution and I thought I was going to have to replace it, and then I found out it has adjustable cup/cone loose bearings!  (here and here)  It has a reverse threaded lockring and reverse-threaded cone on the left side after you pry a plastic cover off the lockring. 

So you can wear out SPD cleats

Left:  SPD cleat that came with my PD-M747 pedals I bought new in 1996, I replaced the cleats after a few years thinking they were worn and later realized maybe they're not.

Right:  SPD cleat I've been riding on for 8 years, and recently started thinking it's been too easy to accidentally unclip lately.

1997, 1992 Colorado Cyclist catalogs

I hung onto this catalog cause it seemed cool at the time.  Summer 1997, I had just finished my B.S. in General Engineering, didn't have any job lined up yet, was half living in a friend's basement 1 bed apartment who was away for the summer on an internship, he'd already leased the place in May for his upcoming year starting grad school so I didn't have to spend as much time in my own $260/mo efficiency 1 room apartment.  Big arms on the cover guy, Rockshox Judy SL, Ringle parts, 20 years later I have my own 1996 Rockshox Judy XC to play around with from a bike I rescued from the trash (turns out 1996 Judy forks actually aren't that good).
 

Back then I thought this guy's hair was cool

 

Another one I held onto because the cover seemed creative.  Summer before high school senior year.  8-speed Dura Ace/Campy Record, probably Bullseye pulleys and Phil Wood hubs on there too.

Why is the garage door chain sprocket cover on the floor?

Something's not right

I took apart the opener to see if I needed to order parts or if I could fix it with local hardware store parts, decided I needed to order parts, put it back together hoping it would still work until the parts came in, and then the sprocket sheared off completely. 

Why is the shaft so skinny by the sprocket?  Oh wait.

I didn't bother tightening the chain last year after already tightening it twice in the last 7 years.  It turns out that after the shaft wears through the bushing, the lip of the plate that holds the bushing wears through the shaft from a 1/2" diameter to almost 5/32".  A Liftmaster 41C4220A kit including the worm gear and bushings for the motor output shaft ended up being $21 on ebay.

So the steel of the plate holding the bushing is harder than the shaft steel?

1996 BB-UN51 meets 2017 BB-UN55

The bottom bracket on the 1996 Trek 970SHX finally showed some bearing play.  I decided to get a new one while I still could, none of Shimano's current MTB lineup uses square taper bottom brackets anymore, even the cheapest groups use octolink now.  As usual, manufacturing of the cheapest stuff is outsourced to outside of Japan.

1996 BB-UN51:

• made in Japan
• 30mm cartridge diameter on non-drive end
• says patent pending
• steel non-drive side threaded piece (I keep wanting to call this an "adjustable cup" because before cartridge BB's the piece would be the adjustable bearing cup for loose ball bearings, and the drive-side threaded piece would be the "fixed cup") 
• drive-side threaded piece is pressed onto BB body, in less light it's clearly a different kind of steel.  The BB body looks like it might actually be stainless.
• bearing seals say "Japan, HIC, DUA"
• the instructions that came with a UN71 I bought in the 90s listed the 50-70Nm tightening torque
• solid spindle

2017 BB-UN55:

• made in Indonesia
• 31mm cartridge diameter on non-drive end
• center of BB cartridge is machined down to save weight
• aluminum non-drive threaded piece, which now has a lip that could prevent full tightening if your frame's BB shell is a little wider than spec
• drive-side threads might be cut directly onto BB body, which does not look like stainless
• it comes with useless instructions that say have the part installed by a qualified mechanic, your pants cuff may become dirty near the chain, and refer to si.shimano.com for service instructions but all they have for the UN55 is the exploded diagram.
• a few product descriptions say the spindle's hollow but I think I remember confirming it isn't

Damn chainsuck.  True Temper OXIII triple butted steel tubing.  After 1997, asian aluminum frames got so cheap that mass produced high end steel frames disappeared.  Last of the V8 interceptors.  I suppose chainsuck is no longer a problem with the dumb new single-ring drivetrains that now need stupid huge 50 tooth rear cogs.

When I rescued the 1997 GT and 1999 Diamondback from someone's trash last year, one chain was save-able.  The other was not.  Both bikes had vines growing through the back spokes.

I had to sand off the rust to ID the beyond hope chain as an IG31.  The side plates were cracking at the rivets, probably from interference fit stress winning over rust weakened steel.

There are so many thorns in the area that I started running sealant after I got 5 punctures in one day and got tired of patching.  The GT's last owner's solution was ridiculously heavy inner tubes and a Mr. Tuffy puncture liner.  I don't know where he found these tubes, they might be as thick and heavy as one of my road bike tires.  Pictured above is one of the tubes with all of the air pressed out, next to one of the ultralight tubes I used to run in the 970SHX, when it used to weigh 23 lbs.  Even with a steel frame and rack and fat rhyno-lite rims, the 970SHX still weighs less than the GT and Diamondback, both of which have aluminum frames.