Not long ago, I spent an afternoon, cleaning and relaxing all my bikes’ chains at once. During the process, I discovered that my Palo Alto’s bottom bracket’s bearings sounded like gravel. As I had a few years back installed a sealed-bearing bottom bracket, (1) a little frustrating that it did not last long, and (2) very well, time to replace. I just pulled the cranks, and the shell (Italian) is 70mm, and the spindle is 118mm in length.

(A) Any ideas on finding a reliable replacement? Amazon has a Sunlite of those specs, very affordable, but low rating and the reviews describe bearing failure… so back to Square One in short order. A Google Search shows little to nothing, results show a lot of 68mm- and 73mm- shell sizes and a lot of various lengths but mostly far shorter in spindle length (and why, when doing a search on square taper, why are so many “hits” give modern-style BB’s?) Is there a place to turn to for a reliable product?

(B) Maybe 118mm is an unusual size and, moreover, wrong? Via eyeball today, chainline looks fine and the bike has been rideable. Hmm, 12mm gap from the inner chainring seems like a lot. I ask as there’s a recent For Sale by a forum member for a used one, looks good, in 70x113. Well, yeah, it would bolt up but, after that…??? You know, I really should already know, but the difference between 113mm and 118mm units, is that 2.5mm shorter on each side, or 5mm on the drive side only? Kinda embarrassing to ask, but I really do not know.

Oh, data point, 2x6 gearing installation.

Is the BB assymetrical? Longer spindle on one side?

Velo Orange

IRD

you are on your own for symmetrical or offset and taper.

+1 on this. VO typically easier to find in Italian.

OK, more fun; just pulled the cranks for the 2nd time today. Measuring end-of-shell to tip-of spindle (have not removed BB yet), I see symmetrical. Would this imply shorter sizes are as well? Might suggest the 113mm in the For Sale forum is only 2.5mm shorter on each side.

Thanks, but the first place I checked, as they are local-ish. They have Italian, but only 110mm.

Hd not thought of that; plus, I am amidst de-IRD'ing a bike by ditching the freewheel I am not happy with. Just got off the IRD website, OK figured out they want you to buy an English BB and then additional Italian cups (couldn't I just re-use the cups I have?) But they have several BB "series"... all 68mm, so...

OK, had not thought to see if another seller still has in stock the 118mm VO unit that VO itself is out of. Lots of hits, none of the 70x118.

You didn't specify the brand of the 'for sale' BB. Nor what brand you currently have, (may have missed it).

But for most cartridge BBs in the 113-118mm range, they are very close to symmetrical, usually within 1mm of symmetrical.

For the Shimano BB-UN5x series, the data that I've seen for the 118 & 113 is that the difference is; DS 2.5, NDS 2mm.

For others brands, the differences seems to be about the same, equal amount off each side or <1mm, (less than matters).

first check that the "old" BB with the crankset you intend to use gives you the correct "chainline" distance measured from the C/L of the seatube to middle of gap between the two chainrings (on a double) if that checks out then you can shop for a replacement BB unit with the same spindle length. (read this handy cheat-sheet from Sheldon: https://www.sheldonbrown.com/chainline.html)
Don't rule out a Shimano BB (made by Tange, usually) if you can find a low-mileage say UN-52 or better, Shimmy had Ital units offered in many models for many years.
Here's one on eBay that is oddly a "Deore" but if the seller lists it correctly it has correct shell width (70mm) and threading (24x36) for a Ital shell...but be advised that MANY Ital-threaded Shimmy BBs have the Octalink spindle, just to raise your hopes and then dash them!


this one is $59 or BO and it's a 116 mm square-taper (but JIS, I'm sure) spindle: https://www.ebay.com/itm/157115252720

The one in the For Sale ad is Shimano; I have not pulled the old one out yet, so unsure.

I did PM the seller to ask if he'll measure it for symmetry.

This is not enough information
What cranks are you using?
Can you measure the chainline?

Something no one has asked yet and I didn't see in the OP - is it a Campy taper or a JIS taper?

I was going to suggest Phil Wood, but (1) they do not have 118mm spindles in either Campy or JIS tapers and (2) they are out of Italian threaded lock rings (you buy the BB cartridge and the lock ricks separately). Too bad, because Phil stuff, while pricey, last a good long time.

If it is the LL113 Shimano length, these should be 0.5 or 1mm longer on the NDS. Total length is actually 113.5 or 114mm.

If it's a JIS taper, you can get a 116mm length from Rene Herse. Expensive? Yes! But, you'll probably never have to buy another one again.
https://www.renehersecycles.com/shop...-square-taper/

I have something you might want.

PM sent.

If Mr Carter’s solution doesn’t work I have a BB that might work. New, 116mm, Ital threaded, and it says Campagnolo. My disclaimer - it was oddly inexpensive when I bought it for something that is Campy. Also, no width indicated on the shell but IT threading so it should(??) fit a 70mm BB.



PM me if interested.

I'm sure it ^ will fit a 70mm width shell, only problem with that is it has the (hated by me) "Thun" style flanges that require a special tool and the "better" tools have a feature that makes them *less* likely to slip and bash your knuckles, but even then not any guarantee.
After a few bashed knuckles you might decide as I did to always give this style BB a wide berth, but if you can live with them I'm sure the bearings when new are fine and you KNOW the taper will be Campy-friendly

Pretty sure I have a 115-116 Suntour Italian BB in the parts closet, can check when I return next week if you need it. New, as I recall.
PM if interested.

I got a few of those as well, also cheap (for Campag) and I have that tool.
The tool does not slip if you bolt a suitable spacer to the end of the axle to hold it on - extra BB cup and some washers...

EDIT: Oh heck, just realized that with Italian threading, the following does not apply, you can't get a hollow spindle crank in Italian (I think). But good general info:

Yes, that drove me nuts too. Good quality cartridge too, dry weather road riding only.

Generally, internal BB cartridges are superior to old-style cup and cone with bearing cages or loose balls. EXCEPT, once the cartridge starts to loosen up the slightest bit, wear accelerates, because the load is only going into 2-3 balls per side. With proper (original) bearing preload, the rider load goes into almost 180 degrees (half) of the bearings per side. With a cartridge, you cannot readjust the bearing preload to correct this. And you need to, because, while the balls or rollers are quite smooth, the inner and outer races have very fine grinding marks, and during break-in, the surfaces get burnished smooth, the grinding marks disappear, but that also opens up slack in the bearing.

And this is the most important reason why I love (newer) 2-piece hollow-spindle cranks with external bearings (Hollowtech 2 style); Once the bearings burnish in after a couple months of riding, the preload can be restored in 2 minutes by just loosening the left crank arm clamp, retorque the end preload cap, and retorquing the crank clamp bolts. And then, the bearings will often go YEARS without need for readjustment. It's that initial burnish-in that is most the issue. Besides preload, other benefits of this design are:
- external bearings allow larger or more balls, so more durable and smoother feel
- external bearings are farther apart, reducing their load
- external bearings allow a larger diameter spindle that is both stiffer, and lighter
- crank can be removed, even in the field, with no crank pulling tool, using only an allen wrench

Most of these newer cranks are in 4 bolt asymmetrical or symmetrical chainring pattern, and some where you need matching brand chainrings to look right. HOWEVER, if you look hard, you can find hollow spindle cranks in classic 5-bolt spiders on standard bolt circle diameters like 130mm, 110mm, etc.

Any time I need to replace the BB bearings, I upgrade to a hollow spindle crank, if I can find one in classic spider design with bearings included for a good price. The external bearings take a special wrench, I bought a 4-way one so can do many different spline patterns, but my crank uses "ISO External" bearings, which I think is the most common pattern.

Made by SKF (renowned bearing company) in da olde country. Quality.

Although manufacturing tolerances are (generally) better now than they were, in a no-load and zero clearance situation, the axle only contacts the cups and three points (each end), the three being where the three balls contact the cup race (it is is possible that more contact, but that requires the those balls have *exactly* the same amount of space, i.e. none, between their surface and the race, possible, but depends on the manufacturing variences.
With rotation, which three are in contact constantly changes (those tolerances...)
With pre-load, the cup and axle are forced closer together, the balls and cup elastically deform, and you have more that three points.
Too much pre-load and the degree of osculation goes up, and with too much preload, spalling occurs.
So clearly there is a compromise between pre-load and bearing life.
Cartridge bearings don't give the user a chance to make that decision, and for most users that is a good thing.

True. Proper preload adjustment is pretty tricky (even more difficult on quick release hubs). Turning spindle in fingers, any radial slack at all, or very easy spin, usually not enough preload. "Notchy" feel, too tight. Backing off just slightly from notchy and it smooths out, but you can feel all the balls "engaged", I call it when the bearing "sings". You'll know it when you feel it.

I used to run all bearings with just the slightest bit of slack, based on dad's saying that a little loose is better than a little tight. He was a mechanical engineer, but surprisingly, on this, he was wrong. No preload, and spalling comes much quicker, usually the inner race first. Had this happen in both bike and automotive until I read deep dive on bearing theory and manufacturer recommendations. Since using proper preload, drastic improvement in bearing durability, like night and day.

Yes, IRD cranks and BB’s are quality but the freewheels really suck.

And Phil Wood. Phil can supply a cartridge to suit just about any need. They last forever, but they're not cheap.

Yup. I have an ISIS crankset on my winter/foul weather bike. This bike only sees rain and salty roads. I was replacing it's bottom bracket every two years at about $40 a pop. I broke down and bought the SKF one. It's been in there 6 years and it's still smooth. It's already paid for itself.

I neglected to mention Phil. many here are too frugal for them or SKF.

Small chance the IRD Italian thread "cups" shift the cartridge inboard 1mm