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Restoring a 1983 Trek 720

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Restoring a 1983 Trek 720

Old 07-07-22, 08:47 AM
  #26  
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Originally Posted by 52telecaster View Post
My 1985 720 takes a 6 speed no problem but it came with 5.
There were 6's which have the same distance between sprockets as Regina 5's. Those 6's require 126 mm hubs unless you go with a radical and possibly risky dishing.

There were SunTour "Ultra-6's" for which 6 sprockets were spaced close enough together to fit into the same space as a standard 5-speed. Those can use a 120 mm hub.

From SunTour and others there were 7's with spacing to fit into a 126 mm hub, and some others which were a little too wide and needed 128 mm hub spacing.

So to the OP: measure the spacing between your rear dropouts (inner face to inner face). Most likely it's 126 mm, but it's worth checking. It's nearly 40 years old and could have had a lot of bumps and bruises in that time. It's also worth doing a string test to get an indication of whether the rear triangles are evenly offset.
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Old 07-14-22, 04:48 PM
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Originally Posted by Road Fan View Post
There were 6's which have the same distance between sprockets as Regina 5's. Those 6's require 126 mm hubs unless you go with a radical and possibly risky dishing.

There were SunTour "Ultra-6's" for which 6 sprockets were spaced close enough together to fit into the same space as a standard 5-speed. Those can use a 120 mm hub.

From SunTour and others there were 7's with spacing to fit into a 126 mm hub, and some others which were a little too wide and needed 128 mm hub spacing.

So to the OP: measure the spacing between your rear dropouts (inner face to inner face). Most likely it's 126 mm, but it's worth checking. It's nearly 40 years old and could have had a lot of bumps and bruises in that time. It's also worth doing a string test to get an indication of whether the rear triangles are evenly offset.
Turns out to be 128mm. Also, I used the string-test for checking alignment of the rear triangle and it looks fine.

I could buy a new rear wheel built to the correct size, but I don't see how to confidently find a freewheel that would work.
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Old 07-14-22, 05:22 PM
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Old 07-17-22, 10:50 PM
  #29  
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I built mine up as a 9 speed but no matter how you set yours up I think youíll find it to be a very sweet riding frame. I was surprised how light feeling and responsive it is for a touring frame.

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Old 07-18-22, 05:36 PM
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very nice. Are those 27" rims, or 700c? thanks for the note.
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Old 07-18-22, 06:21 PM
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Originally Posted by pjw77 View Post
very nice. Are those 27" rims, or 700c? thanks for the note.
I don't know about his bike but my 720 has 700c with 35s and fenders. Very comfy ride.
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Old 07-18-22, 09:00 PM
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Originally Posted by pjw77 View Post
very nice. Are those 27" rims, or 700c? thanks for the note.
Thanks. They are 700. I have 28ís on them only because I had them but would like to eventually go with wider tires.
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Old 07-18-22, 09:02 PM
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Originally Posted by badger_biker View Post
Thanks. They are 700. I have 28ís on them only because I had them but would like to eventually go with wider tires.
Did u have any issues getting the brakes to work?
Btw, I wish mine looked as good as yours!
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Old 07-18-22, 09:14 PM
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Originally Posted by 52telecaster View Post
Did u have any issues getting the brakes to work?
Btw, I wish mine looked as good as yours!
They matched up fine with the rims but felt mushy or soft at first. I tweaked the angle of the straddle cable so they grabbed before my levers ran out of play. Pretty good now.
I had it powder coated so it isnít fair to compare with an original and I donít have the nice head tube paint to match the decal like from the factory.
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Old 07-18-22, 10:02 PM
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Originally Posted by badger_biker View Post
They matched up fine with the rims but felt mushy or soft at first. I tweaked the angle of the straddle cable so they grabbed before my levers ran out of play. Pretty good now.
I had it powder coated so it isnít fair to compare with an original and I donít have the nice head tube paint to match the decal like from the factory.
Mine feels a little soft while it's doing tons of stopping. It really is a terrific bike. After years of a bob Jackson world tour I'm going to be touring on the 720.
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