Stripped crank arm threads -
#1
Full Member
Thread Starter
Join Date: Aug 2020
Posts: 237
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
Liked 151 Times
in
96 Posts
Stripped crank arm threads -
Crank arm removal threads are badly stripped on a Stronglight 106 (1980) crank arm. Removal tool pulls straight out when trying to remove the crank arm. I pulled the crank using a 3" three-leg puller. Can the crank arm threads be re-tapped to the larger Stronglight threading used on earlier crank arms? Is there a helicoil option for this application? Or, should I just resort to using the above mentioned 3-leg puller in the future?
TIA
TIA
Likes For James1964:
#3
Old fart
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,784
Bikes: Several, mostly not name brands.
Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3587 Post(s)
Liked 3,400 Times
in
1,934 Posts
Several companies, including VAR and J.A. Stein, offer crank arm repair kits that that cut a 24mm extractor thread and suitable self-extractor bolts and/or tool for removing the arms. They are not cheap, so for a one-off job, check around with local shops t see if they have the tools. E.g.:
Likes For JohnDThompson:
#4
Full Member
Thread Starter
Join Date: Aug 2020
Posts: 237
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
Liked 151 Times
in
96 Posts
Thanks for this info. I've bought other tools from J A Stein and should have thought of them. Stein's extractor system cuts a 24 x 1.5 mm thread - yet another crank arm extractor tool.
#5
Old fart
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,784
Bikes: Several, mostly not name brands.
Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3587 Post(s)
Liked 3,400 Times
in
1,934 Posts
As does VAR's. If you let a shop do the work with their tools, you can have them install self-extractor mounting bolts, so you won't need yet another extractor tool. Both VAR and Stein include those with their crank repair tool kit.
Likes For JohnDThompson:
#6
Friendship is Magic
Join Date: Nov 2010
Location: Sacramento, CA
Posts: 22,984
Bikes: old ones
Mentioned: 304 Post(s)
Tagged: 0 Thread(s)
Quoted: 26402 Post(s)
Liked 10,374 Times
in
7,203 Posts
...the Stein setup comes with several pieces/parts. One of those pieces/parts works as the extractor, once you get the new threads cut. I have one, but I wouldn't have bought one for just a single use. The insert thingies that you can install to reduce the new threads you cut back down to a standard crank puller are somewhat difficult to come by, but a few of them come with the tool. But it you have the tool, you don't need the inserts.
I guess it depends on how attached you are t o that Stronglight crank, or whether you think maybe you'll use the Stein puller again.
__________________