K2 / Proflex Riders Group

General => Tech Forum => Topic started by: orange on November 14, 2006, 08:27:36 am

Title: 856 swingarm weak spot??
Post by: orange on November 14, 2006, 08:27:36 am
Is he right about that? If so does it apply to my 855 polished swingarm and my black XP-8 swingarm?

http://cgi.ebay.co.uk/OFFROAD-PROFLEX-856-NEW-ODS-ELASTOMERS-girvin-k2_W0QQitemZ170049727814QQihZ007QQcategoryZ22679QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Title: Re: 856 swingarm weak spot??
Post by: micah on November 14, 2006, 12:33:57 pm
funny you should mention... I was just reading this post on MTBR...

http://forums.mtbr.com/showthread.php?t=244271
Title: Re: 856 swingarm weak spot??
Post by: orange on November 14, 2006, 05:48:36 pm
ooh. First I've heard of this. I wonder if that's why they went to the longer carbon swingarm for the x57's...
Title: Re: 856 swingarm weak spot??
Post by: Colin on November 14, 2006, 09:41:59 pm
Extra welding on late 856's and XP series bikes, see my previous postings

Col.
Title: Re: 856 swingarm weak spot??
Post by: orange on November 15, 2006, 02:37:09 am
In a related query - why is there an extra little patch of welding on the drive side of the swingarm on top near the cable insert - doesn't seem immediately obvious to me why that's there. It's long and thin (say 40mm by 10mm) and polished smooth.
Title: Re: 856 swingarm weak spot??
Post by: shovelon on November 15, 2006, 09:28:13 am
I have seen that same type of crack at the dropout on San Andreas frames. A little weld takes care of the problem. Both sides are vulnerable, but easily repairable and reinforcable.

Title: Re: 856 swingarm weak spot??
Post by: shovelon on November 16, 2006, 02:10:01 am
Quote
In a related query - why is there an extra little patch of welding on the drive side of the swingarm on top near the cable insert - doesn't seem immediately obvious to me why that's there. It's long and thin (say 40mm by 10mm) and polished smooth.


I checked my 856 swingarm, and it also has that welded patch. I assume that the drive side may flex under power, and the hole for the derailleur cable just makes it a weak spot.