Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Bottom bracket upgrade question: PRESS-FIT system size 86.5 X 41

Search
Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Bottom bracket upgrade question: PRESS-FIT system size 86.5 X 41

Thread Tools
 
Search this Thread
 
Old 08-03-20, 09:36 AM
  #1  
Erik_A
Senior Member
Thread Starter
 
Join Date: Sep 2008
Posts: 513
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Likes: 0
Liked 8 Times in 3 Posts
Bottom bracket upgrade question: PRESS-FIT system size 86.5 X 41

I have a Basso carbon frame that needs a crankset upgrade. The original crankset is a Miche "EVO Max" with 24mm bearings on both sides. Basso said that the frame is compatible with BB 72 SHIMANO or any other brand with PRESS-FIT system size 86.5 X 41 - axle diameter 24mm.

Would I need to extract the original cups out of the frame and install a new BB? Since Shimano also uses 24mm bearings on both sides, would any Hollowtech II crankset work, or would it need to be specific for Pressfit?

Thanks in advance!
Erik_A is offline  
Old 08-03-20, 09:39 AM
  #2  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,355 Times in 862 Posts
Isn't Shimano using a 24mm tube spindle.. covet high end ? Dura Ace..


no guarantees..
fietsbob is offline  
Old 08-03-20, 10:59 AM
  #3  
davidad
Senior Member
 
Join Date: Feb 2009
Posts: 6,660
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 582 Post(s)
Liked 171 Times in 138 Posts
All of shimano"s cranks have a 24 mm axle. They usually have a 25mm bearing with an insert for the final fit.
davidad is offline  
Old 08-03-20, 11:40 AM
  #4  
cpach
Senior Member
 
Join Date: Oct 2009
Location: Mt Shasta, CA, USA
Posts: 2,143

Bikes: Too many. Giant Trance X 29, Surly Midnight Special get the most time.

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 533 Post(s)
Liked 312 Times in 236 Posts
You can use whatever Shimano HT2 crank in that BB.
cpach is offline  
Old 08-03-20, 12:51 PM
  #5  
Erik_A
Senior Member
Thread Starter
 
Join Date: Sep 2008
Posts: 513
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Likes: 0
Liked 8 Times in 3 Posts
Wow - Thanks everyone! I appreciate the advice!
Erik_A is offline  
Old 08-03-20, 03:26 PM
  #6  
Erik_A
Senior Member
Thread Starter
 
Join Date: Sep 2008
Posts: 513
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Likes: 0
Liked 8 Times in 3 Posts
I tried to install a Shimano Hollowtech II double crank. If I tighten until there is no lateral play, than the crank arms rub the edge of the press-fit BB shell. Would a spacer of some kind between the bearings and the crank arms work? Maybe something like the spacer that comes with Shimano Hollowtech II triple crank, though that might be too thick. Any ideas?
Erik_A is offline  
Old 08-04-20, 02:25 AM
  #7  
trailflow1
Senior Member
 
Join Date: Jan 2015
Posts: 443
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Likes: 0
Liked 21 Times in 17 Posts
Originally Posted by Erik_A
I tried to install a Shimano Hollowtech II double crank. If I tighten until there is no lateral play, than the crank arms rub the edge of the press-fit BB shell. Would a spacer of some kind between the bearings and the crank arms work? Maybe something like the spacer that comes with Shimano Hollowtech II triple crank, though that might be too thick. Any ideas?
Can you post a picture ? Is it rubbing the bb or the frame ?

Have you seated the spindle all the way through ? did you tap in it with a mallet ?

Shimano HT road cranks are not meant to have spacers. I've read success stories of using 0.5mm shims on occasion. But you need to be extra careful adding more spacers because the more you add the less spline surface there is for the left crank arm to grab onto. And could lead to the arm coming loose and damaging the splines. Adding more than 1mm spacers i would not recommend.

could you modify the bb cups ? i think that solution while not ideal is better than a crank arm falling off.

Last edited by trailflow1; 08-04-20 at 02:28 AM.
trailflow1 is offline  
Old 08-04-20, 02:38 AM
  #8  
smashndash
Senior Member
 
Join Date: Feb 2018
Posts: 1,410

Bikes: 2017 Specialized Allez Sprint Comp

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times in 247 Posts
“Evo Max integrated bottom bracket with sealed bearingsFor use with spindles of 24mm diameter & Shimano Compatible“

Looks like Evo Max and Shimano should be interchangeable. Could you post a video on youtube?
smashndash is offline  
Old 08-04-20, 07:45 AM
  #9  
Erik_A
Senior Member
Thread Starter
 
Join Date: Sep 2008
Posts: 513
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Likes: 0
Liked 8 Times in 3 Posts
Would a thinner spacer or dust seal like this help:


Wheels Manufacturing 24mm BB Spacer Pack

https://www.amazon.com/Wheels-Manufa...2Aentries%2A=0

Erik_A is offline  
Old 08-09-20, 05:18 PM
  #10  
Erik_A
Senior Member
Thread Starter
 
Join Date: Sep 2008
Posts: 513
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Likes: 0
Liked 8 Times in 3 Posts
I figured it out! I needed a wave washer on the non drive side between the Evo Max BB cup and the bearing. That pushed the bearing out so that it was the correct width. No spacer was needed.
Erik_A is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.