1985 trek 660 question
06-09-14 | 08:17 AM
#1
Thread Starter
Senior Member
Joined: Sep 2008
Posts: 8,888
Likes: 2,967
From: Elwood Indiana
Bikes: they change so much I'm tired of updating this
1985 trek 660 question
Picked up this frame yesterday, and I'm searching around and figuring out some things about it. One question though, whats the 72 on the inside of the rear dropouts refer to? thanks.
__________________
Semper fi
Semper fi
06-09-14 | 09:10 AM
#2
Extraordinary Magnitude
Joined: Aug 2009
Posts: 14,085
Likes: 2,140
From: Waukesha WI
Bikes: 1978 Trek TX700; 1978/79 Trek 736; 1984 Specialized Stumpjumper Sport; 1984 Schwinn Voyageur SP; 1985 Trek 620; 1985 Trek 720; 1986 Trek 400 Elance; 1987 Schwinn High Sierra; 1990 Miyata 1000LT
Could it be the intended Head Tube Angle (unlikely for on the rear dropouts) or the BB drop?
21" and under had a 72 degree HTA, the BB Drop for all sizes was 7.2.
21" and under had a 72 degree HTA, the BB Drop for all sizes was 7.2.
__________________
*Recipient of the 2006 Time Magazine "Person Of The Year" Award*
Commence to jigglin’ huh?!?!
"But hey, always love to hear from opinionated amateurs." -says some guy to Mr. Marshall.
Commence to jigglin’ huh?!?!
"But hey, always love to hear from opinionated amateurs." -says some guy to Mr. Marshall.
06-09-14 | 09:33 AM
#3
Old fart
Joined: Nov 2004
Posts: 26,402
Likes: 5,333
From: Appleton WI
Bikes: Several, mostly not name brands.
That's the seat stay/chain stay angle. Those investment cast, socketed dropouts needed different angles for different frame sizes and chain stay lengths. That wasn't an issue with the traditional tabbed dropouts, which could accommodate almost any angle.
Other manufacturers of investment cast dropouts used a separate piece for the seat stay socket to accomplish this:
Other manufacturers of investment cast dropouts used a separate piece for the seat stay socket to accomplish this:
Last edited by JohnDThompson; 06-09-14 at 09:37 AM.
