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1986 Trek 770 restoration or run?

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1986 Trek 770 restoration or run?

Old 01-13-20, 03:03 PM
  #1  
alexihnen 
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1986 Trek 770 restoration or run?

I picked up this 1986 Trek 770 recently and later discovered that the seat lug is cracked. It appears that a previous owner jammed in a too-large seat post. The paint is roughed up about everywhere and the components are an incredible mish-mash.

So...is it restoration worthy, or do I run away?

Actually, the options are 1) attempt a restore myself or 2) send to someone else to restore.




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Old 01-13-20, 03:08 PM
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I might have a seat lug for it.
From a 1987 400 531 frame, 21"? frame

You can look in the Trek Brochures and see if the frame angles are the same or close.

https://www.vintage-trek.com/TrekBrochures.htm

Last edited by dedhed; 01-13-20 at 03:11 PM.
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Old 01-13-20, 03:32 PM
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I remember seeing a forum member treat an identical crack by simply drilling a small hole at the end of the crack to stop it.
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Old 01-13-20, 07:44 PM
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+1 on the hole at the end of the crack. Rdie it-you'll like it!
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Old 01-13-20, 09:36 PM
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My guess would be to drill a hole at the end of the crack like others have said. It seems like as long as the seatpost was the correct size, the seatpost clamp bolt would prevent it from getting any worse.
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Old 01-13-20, 11:12 PM
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There's no harm in drilling it and riding it till either it cracks worse, or nothing happens at all. Easy decision.
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Old 01-14-20, 04:53 AM
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If you drill the hole a little lower and carefully file down to it, no one will ever know...
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Old 01-14-20, 05:36 AM
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If the object were to keep a beater operational a short time, then drilling a hole would be fine.

Assume the @#$%^ idiot who rammed in the oversize post has abused the bike beyond your imagination. Ramming in an oversize post is really hard to do. You are going to find one problem after another. There is no cure for idiocy.
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Old 01-14-20, 07:55 AM
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I would go with the vast majority of opinions voiced here...Drill&Ride..I'll add enjoy, very unlikely it will have a catastrophic failure.
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Old 01-14-20, 08:29 AM
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Oh BTW, Nice find!
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Old 01-14-20, 10:11 AM
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Originally Posted by alexihnen View Post
Huh - I guess the lugs were the same across the lineup? I'll take some measurements.
JohnDThompson was a builder at Trek for a good while. He may know the answer off the top of his head.
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Old 01-14-20, 10:14 AM
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Originally Posted by 63rickert View Post
If the object were to keep a beater operational a short time, then drilling a hole would be fine.

Assume the @#$%^ idiot who rammed in the oversize post has abused the bike beyond your imagination. Ramming in an oversize post is really hard to do. You are going to find one problem after another. There is no cure for idiocy.
It might be from a proper-sized post that was not inserted far enough and then ridden. Also note that these could have been ordered as frames and then equipped as the buyer wished. It's the same materials and dimensions as a 760 frame, but with different paint and decals.
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Old 01-14-20, 02:03 PM
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+1 on drill, restore and ride. Enjoy the bike, it's meant to be ridden!!

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Old 01-14-20, 03:40 PM
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Originally Posted by USAZorro View Post
It might be from a proper-sized post that was not inserted far enough and then ridden. Also note that these could have been ordered as frames and then equipped as the buyer wished. It's the same materials and dimensions as a 760 frame, but with different paint and decals.
Sure, that sounds plausible. Correct post would be 27.2 and 27.4 is not common.

Either way the bike has been abused. Abuse is seldom isolated. To easy to see a project that snowballs. A full and correct repair with new lug, new seat tube, new paint, easily exceeds imaginable value of bike. Who would want to take on that frame repair? Start over with a more promising frame.

If the only object is to cruise the neighborhood have at it.
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Old 01-14-20, 04:01 PM
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Originally Posted by 63rickert View Post
Sure, that sounds plausible. Correct post would be 27.2 and 27.4 is not common.

Either way the bike has been abused. Abuse is seldom isolated. To easy to see a project that snowballs. A full and correct repair with new lug, new seat tube, new paint, easily exceeds imaginable value of bike. Who would want to take on that frame repair? Start over with a more promising frame.

If the only object is to cruise the neighborhood have at it.
Agree with your sensibilities here. Wouldn't mind hearing what John says about the drill and file strategy. If the crack hadn't gone past the lug, I would have much more faith than in this instance. When I discovered what appeared to be a hairline crack in the seat-tube of a Raleigh Competition that I was already preparing to have modifications made to, and which I was also intending to repaint, gugie was able to braze a reinforcing band on it. That was pretty unobtrusive in that instance, but for a bike with original paint... considerably less so, I'd think.
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Old 01-14-20, 05:03 PM
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Looked around. Have the BB shell, brake bridge, DT mounts, headtube & lugs.
Didn't find the seat cluster lug. I must have turned that into a keychain and gave it to someone.
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Old 01-14-20, 05:11 PM
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That break is nothing, and I'd be more concerned of the barf tape. 💀
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Old 01-14-20, 05:12 PM
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Drill and ride. That was one of the best non italian racebikes back in the day. Concor saddle?
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Old 01-14-20, 05:17 PM
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Weld of glue the post in and enjoy...no need to ever take it out again...
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Old 01-14-20, 07:09 PM
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Unfortunately it's not worth a ton of money. Fortunately, you own one of the best riding bikes ive ever swung a leg over. Just ride the heck out of it.
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Old 01-14-20, 07:28 PM
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Originally Posted by GrainBrain View Post
I remember seeing a forum member treat an identical crack by simply drilling a small hole at the end of the crack to stop it.
Precisely what I would have recommended. Drill it, and ride the %#$@ out of it.
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Old 01-14-20, 08:11 PM
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Originally Posted by USAZorro View Post
Also note that these could have been ordered as frames and then equipped as the buyer wished.
The subject bike has primarily Shimano bolted to it, rather than the Campag as noted in the catalog, so this is a strong possibility.

Originally Posted by USAZorro View Post
Wouldn't mind hearing what John says about the drill and file strategy.
Ahem ( JohnDThompson ) cough!
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Old 01-14-20, 08:33 PM
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Originally Posted by NoControl View Post
Precisely what I would have recommended. Drill it, and ride the %#$@ out of it.
Agreed.

I have a 560, same frame, IT IS ONE OF THE BEST RIDERS I'VE EVER OWNED. They are just awesome riders.
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Old 01-14-20, 09:41 PM
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Originally Posted by mechanicmatt View Post
Agreed.

I have a 560, same frame, IT IS ONE OF THE BEST RIDERS I'VE EVER OWNED. They are just awesome riders.
The 760 & 770 had a different frame then the 560. In '86 the 560 had a main triangle of Reynolds 531 and forks and stays of chrome moly. The 760 and 770 had 531 main tubes, fork, and stays. In '86 the 560 & 760 shared geometry and the 770 had shorter wheelbase and slightly steeper angles.
In previous years the 760 & 770 were the same frame, while the 560 had a longer wheelbase, slacker angles, and used Reynolds 501 for the main tubes.
I have an '85 560 and an '84 760. Totally different riding frames. The 760 is much more lively, imo. I haven't ridden one of the later 560's built with Reynolds 531.

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Old 01-15-20, 10:02 AM
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Originally Posted by Hobbiano View Post
The 760 & 770 had a different frame then the 560. In '86 the 560 had a main triangle of Reynolds 531 and forks and stays of chrome moly. The 760 and 770 had 531 main tubes, fork, and stays. In '86 the 560 & 760 shared geometry and the 770 had shorter wheelbase and slightly steeper angles.
In previous years the 760 & 770 were the same frame, while the 560 had a longer wheelbase, slacker angles, and used Reynolds 501 for the main tubes.
I have an '85 560 and an '84 760. Totally different riding frames. The 760 is much more lively, imo. I haven't ridden one of the later 560's built with Reynolds 531.
I have a cherry (no exaggeration) ‘84 braze dated 760 that was intended for the ‘85 season but sat until ‘86. It has the steep geometry, same frame as the 770 confirmed by the Trident fork crown and “through the stay” RD cable. Excellent riding bikes and worthy of restoring if at all possible. The full 531c frames are incredibly light, lively and smooth if you can master the twitchy but intuitive geo. I removed the Wolber clinchers for era Mavic tubulars. Awesome bikes.
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