Bicycle Mechanics - Grease on Threads?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Grease on Threads?

rdtompki
05-12-09, 11:20 AM
The manual that came with my tandem recommends putting grease on bolt threads before reattaching stems, etc. I find this strange since for larger bolts in automotive-class applications grease is specifically not recommended due to a tendency to exceed the recommended torque. Are we talking the case of a steel bolt and aluminum threads (the typically bicycle situation)? If so wouldn't some other sort of anti-seize compound be preferred?

neil0502
05-12-09, 11:33 AM
ParkTool's pages on torque and fasteners. May be generally helpful, here....

http://www.parktool.com/repair/readhowto.asp?id=88

AND

http://www.parktool.com/repair/readhowto.asp?id=89

AND

http://www.sacskyranch.com/antiseize.htm

I think you can rarely go wrong using anti-seize ... particularly in a dissimilar metals situation like you describe.
wrk101
05-12-09, 11:36 AM
+1 Anti Seize is a must whenever you have dissimilar metals.

Doohickie
05-12-09, 11:44 AM
Anti-seize is the reason for putting grease on the threads.
cbchess
05-12-09, 11:52 AM
I put grease on every metal to metal connection on my bike -so yes every bolt.
SJX426
05-12-09, 02:05 PM
check this out: http://www.raskcycle.com/techtip/webdoc14.html
DannoXYZ
05-12-09, 02:20 PM
The manual that came with my tandem recommends putting grease on bolt threads before reattaching stems, etc. I find this strange since for larger bolts in automotive-class applications grease is specifically not recommended due to a tendency to exceed the recommended torque. Are we talking the case of a steel bolt and aluminum threads (the typically bicycle situation)? If so wouldn't some other sort of anti-seize compound be preferred?Where did you get that? Torque is bolt-tension and torque-specs are given assuming machine-oil is used on the threads. This prevents thread-friction from contributing to the resistance on the torque-wrench. You want to be able to read true bolt-tension, not friction in the threads. The highest-tensions used in cars tend to be head studs, wheel and spindle nuts. Oil is always used on those threads before torquing to spec (grease or anti-seize also lubricates and prevents excessive friction in the threads, especially the larger bolts with higher tensions).

Check out this info sheet from one of the largest manufacturers of anti-seize: http://www.permatex.com/documents/tds/Automotive/81343.pdf .Specifically the "Directions for use" section, line #6.

Also Engine Builder - proper head bolt use (http://www.enginebuildermag.com/Article/1126/perfect_engine_sealing_starts_with_proper_head_bolt_use.aspx)