View Single Post
Old 06-25-23 | 10:07 AM
  #61  
dddd's Avatar
dddd
Ride, Wrench, Swap, Race
15 Anniversary
 
Joined: Jan 2010
Posts: 9,809
Likes: 1,783
From: Northern California

Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.

Originally Posted by mpetry912
I have heard the square taper interface likened to "a landing craft going up on a beach"

where the tapers match and the running torque goes up, that's enough

come back and re-visit after 50 miles

on Campagnolo cranks in good condition that turns out to be about 220 in/lb

the Stronglights are so soft it is hard to tell but I'd start wth 150 in/lb and again re-torque after 50 miles.

should be clean. To grease or not to grease is up to you

great pics from Chas on the details of the spindle to arm interface

/markp
I'm wondering where it became seemingly "common knowledge" that these Stronglight crankarms were "soft". I know I've heard this before, but I've straightened Stronglight crank spiders, and the slender, material seemed to resist my efforts comparably to other brand's top-tier offerings.

And I've never stripped any of their pedal eyes, nor found either arm to bottom out at the end of the spindle on any of the quite good number of Model 93's I've worked on.

I do believe though that the material is dimensionally thin, for light weight, so I always respect the stated dry assembly procedure that I learned that at the Wheelsmith shop (a comparable Shimano crank is beefier around the taper).

At the very least, it can be said that the appropriateness of the manufacturer's bolt torque spec will very much reflect (i.e. be dependent on) whether or not grease is used on the tapers as well as on the threads. When "dry" is specified, parts should be very clean of any residual grease.
I've never had a corrosion problem of note on the tapered surfaces of a Stronglight crankset.
Note also that the bolt caps are intended to prevent loosening of the bolts, though a bit of Loctite is a good substitute.

Last edited by dddd; 06-25-23 at 10:12 AM.
dddd is offline  
Reply