IRD QB-75 Bottom Bracket (First posted April- 9-2014 at 08:31 pm)
IRD QB-75 Bottom Bracket (First posted April- 9-2014 at 08:31 pm)

 IRD QB-75 Bottom Bracket, cups removed During a recent ride I noticed my Bottom Bracket was cooked. A good ol' Shimano UN-73. This is the first time a bottom bracket dies on me like that. At least It took me to Ukiah, CA (another ~50 miles away) and then the next morning another ~50 miles of very gentle riding to Healdsburg where I was picked by the wife.

I replaced my broken Bottom Bracket with an IRD QB-75. I liked the fact that it is a "cartridge" design but has sealed bearings you can access and potentially lubricate by carefully lifting the seals with a needle and replacing them back after injecting grease. That is what I did when I was using my old Mantis Flying V and Klein Attitude frames, both used pressed-in bottom brackets and never had an issue with that lubricating method.

The sealed bearings read Tange Seiki on raised letters and IRD website confirms they are mde by Tange Seiki.

 IRD QB-75 Bottom Bracket, sealed bearings Both alloy cups are replaceable, they come with English thread cups but IRD makes cups to fit Italian threads so the same cartridge can be use on bikes with Italian threads. The body is also alloy and the spindle is plated and hollow CrMo. The box comes with Instructions, that's right installation instructions! The one I bought for exactly $40 from American Cyclery in San Francisco came misprinted on the shell as a 118mm, the box had the correct size printed, 113mm. My frame uses 68x113. Walking out of the shop I noticed the 118mm printed on the shell, walked back in and the mechanic measured it and it was indeed a 113mm. I measured back at home just to double check before installation. It installs with the same tool used for Shimano cartridge bottom brackets. As an added bonus it is very light at 235 gms for my 68x113mm

I abuse my bottom bracket a lot. Riding brevets on the rain and many mixed terrain rides on very questionable weather. I'll try to remember to update this post after I have some significant use out if it. My average yearly mileage is about 5000 miles, probably 3500-4000 for that bike. The Shimano lasted me maybe 4 years... I think. Construction seems very good but only time will tell.

(First posted April- 9-2014 at 08:31 pm)

Write a comment
  • Required fields are marked with *.

If you have trouble reading the code, click on the code itself to generate a new random code.