Plastic BB thread prep?
09-27-19, 10:22 PM
#1
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Japan
Posts: 106
Bikes: 2020 Trek Domane AL 3, 2019 Giant Escape RX Disc
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 52 Post(s)
Liked 15 Times
in
10 Posts
Plastic BB thread prep?
Just screwed out the square-tapered BB on a bike less than 1 yr old and was surprised to find the threads are plastic. Haven't seen such a thing before. Doesn't seem to have been thread prepped with anything when originally assembled. Should I reinstall it dry or throw some grease, thread locker or something else on it?
09-27-19, 10:34 PM
#2
Really Old Senior Member
Not really needed.
You might want to reinstall by finishing up with the metal DS cup instead.
The plastic gets brittle over time and may not handle the same torque as when new. Seat it 1st.
The question is- Why did you remove it if it's good enough to stick back in?
You might want to reinstall by finishing up with the metal DS cup instead.
The plastic gets brittle over time and may not handle the same torque as when new. Seat it 1st.
The question is- Why did you remove it if it's good enough to stick back in?
09-27-19, 11:10 PM
#3
Senior Member
Eh, the plastic cups on those work fine. Grease is a good idea.
09-28-19, 05:22 PM
#5
Junior Member
Thread Starter
Join Date: Oct 2018
Location: Japan
Posts: 106
Bikes: 2020 Trek Domane AL 3, 2019 Giant Escape RX Disc
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 52 Post(s)
Liked 15 Times
in
10 Posts
Thanks for the helpful replies, all.
Was getting some mild creaking sounds when pedaling with force. Spoke tension and crank and pedal tightness seemed fine, so thought I'd check the BB. Not sure what else would be creaking. Haven't yet had a test ride to see if reinstalling the BB fixed it.
It was super easy to start stripping the plastic BB threads when removing it though the bike is still under a year old. Metal does seem like a better way to go.
It was super easy to start stripping the plastic BB threads when removing it though the bike is still under a year old. Metal does seem like a better way to go.
Last edited by el forestero; 09-28-19 at 05:26 PM.
09-28-19, 08:22 PM
#6
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,093
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4209 Post(s)
Liked 3,875 Times
in
2,315 Posts
I would spread the grease onto the BB shell and not try "throw"ing it on
Andy (who sees such terms as a way to diminish the value and effort of good work)
Andy (who sees such terms as a way to diminish the value and effort of good work)
__________________
AndrewRStewart
AndrewRStewart
