Ode to UN55 BB

[hendrich]

Ode to UN55 BB

The UN55 turns and turns
Nary a click nor a flutter
Runs smooth as butter
Tough as nails and doesn’t cost the farm
With a square spindle that works like a charm
Some say too heavy and must be hollowed
But others revere it as hallowed
Ignored over miles and miles of fun
Rest in peace UN55 knowing a job well done.

[leftpoole]

Available in most sizes on Amazon!

[hendrich]

Available in most sizes on Amazon!

Strange, not Amazon in US. Most US bike shops and a large distributor (Universal Cycles) is out of all english threads. The shimano web site says UN300 is the replacement and US shops do have those in stock. So, not sure, but seems UN55 is no longer being made.

[John Saxby]

Mike, I found a 73 x 118 UN 55 at The Bike Doctor in Saskatoon -- so I'm now future-proofed, I hope 

I also found out that the splines of my Park BBT-32 tool doesn't quite mate with the notches on either my current or my new UN 55 -- so it's back to the Bike Doctor to get a Shim PRO Cartridge BB tool.

Nicely poetic requiescat, BTW.  The sceptic in me expects that whatever replaces the UN 55 will be less durable and/or more expensive...

Cheers, J.

[Danneaux]

The sceptic in me expects that whatever replaces the UN 55 will be less durable and/or more expensive...

Seems likely, John.

I'm still a fan of Phil (Wood, no relation) bottom brackets (and hubs!) after many years. I have several with more than 32,000mi/515,000km that are still spinning happily and smoothly despite use in all weather. Given the service life, their initial cost works out to a pretty reasonable annual value compared to shorter-lived, less expensive units.

Keep in mind I am a low-torque, high-rev spinner rather than a masher. This might contribute to longer BB lifespans as well.

Best,

Dan.

[Mike Ayling]

Hi Dan

Check your miles km conversion.
That pesky decimal point strikes again!

Mike

[Andre Jute]

Love the interno-onomatopeic rhyme of "hollowed" and "hallowed", Hendrich.

+1 for your sentiments about the UN55.

[Aleman]

I also found out that the splines of my Park BBT-32 tool doesn't quite mate with the notches on either my current or my new UN 55

I'm glad I'm not the only one that just found this out when building my Raven Twin My original Shimano tool (must have had it for nearly 30 years or more) fitted the free cup of my new UN55, but not the retained side  So I ordered another tool ... and that fits the retained side, but not the free cup!! Whisky Tango Foxtrot!

Oddly enough my original Shimano tool fitted both sides of my wife's 25year old BB, bit only one side of the new one!!

[John Saxby]

Update on the removal tool:  Found the required item at a local bike shop, the Park BBT22 

[hendrich]

Update on the removal tool:  Found the required item at a local bike shop, the Park BBT22 

This is strange, the Park BBT-32 and -22 service the same BB's having 20 splines. I have a -32 which has been used on Shimano (and other) BB's. Do you think your -32 was defective, or are you suggesting that the pattern is somehow different on newer BB's?