Old 01-11-19, 04:08 PM
  #3  
masi61
Senior Member
 
masi61's Avatar
 
Join Date: Oct 2005
Location: SW Ohio
Posts: 2,215

Bikes: Puch Marco Polo, Saint Tropez, Masi Gran Criterium

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 442 Post(s)
Liked 22 Times in 20 Posts
Originally Posted by dddd View Post
It sounds like the "Phil Wood pressfit bearings" are actually bearings contained in external cups.

It's pretty obvious that external bottom bracket bearings need a certain amount of width to support a durable-enough width of bearing.

The Shimano crankset gives 86mm of spindle length to accommodate that total width of bb shell and cups. That's equal to 68mm of shell plus only 9mm of bearing/cup on each end, and the 9mm isn't something that you can take away from.

How about finding direct-fit bearings with a 24mm ID to press-fit into your bb shell?
I'm not sure if the 76mm (instead of the intended 86mm) outside width of installed-flush bearings would properly support the spindle. But what about if possibly-wider bearings could be installed which overhang the bb shell by at least some of the 5mm deficit on each side? It's a matter then of perhaps finding the "right" bearing for the job, and the ideal bearing would be one which had a widened outer race that allowed for the bearing to be somewhat offset from the bearing's seating area in the bb shell.

As far as re-installing the Klein bb with a 7410 crankset, sounds like an ideal solution as long as you have or can source the appropriate 103mm JIS spindle.
Thanks for your reply. When you say finding he “right” bearing for the job - I did not think that starting from scratch to get all the critical tolerances and dimensions was going to be required since Phil Wood lists it as an option on their website. I would have thought that they had measured the installed outside to outside width for a Shimano Hollowtech road crankset with 24mm hollow axle and outboard bearing cups and been able to revise the bearings maybe running them inside the bottom bracket shell partway. What I have looks like the Phil Wood version of a Shimano Pressfit external bottom bracket. I guess I’ll take some measurements with my metric dial caliper and compare the standard Shimano road/English threaded bb dimension to the Klein 76mm bb shell/Phil Wood external bb cup dimensions.

If the numbers point point to the shell being faced 4mm off each side like he said, I’m just curious to what extent is the facing going to get close to the aluminum tube welds?
masi61 is online now