Road Fan

This discussion started, in my mind at least, with "what will I do with this early 1982 Trek 720 touring frame in my size? I've always wanted to see how they ride."

I have a few SunTour rear mechs and a front mech. The rears: a Cyclone with a short cage, and a smooth outer parallelogram plate, with just the word "Cyclone." The cage plates are fully closed. The back says "BA." The other one has more of a medium length cage which is an open cage on the side away from the rear wheel. It is marked "BL," in white letters on a black background which covers the full length of the outer parallelogram plate. "GT" is marked on the outer face of the lower cage plate. Both derailleurs have phillips limit screws on the long side of the cage. The front is a SunTour XC with a very looonnnng cage which might interfere with the chainstay, so I might not use it. Its cage seems shaped either for a triple or a wide-range double, so that is attractive due to its long cage. No indexing is planned without a total refit.

I've always heard great things about SunTour components but have never used them long-term, usually having built with older Campy or Huret. This long-wheelbase Trek 720 tourer frame will get a SunTour/Huret mix, a SR Apex chainset 46/30, 700c wheels with early Ultegra friction hubs, CR18 rims, 700x30 mm Challenge Strada Bianca tires, and DT friction shifters either Shimano 600 6207 or Huret, perhaps Challenger. The frame, which seems to have good construction and materials, seems aligned ok, but the fork blades are sprung out about a centimeter. It's a little off on a string test, but if it rides even sort of well, I'll get the fork aligned.

Brakes are old Campy Record levers with CPSC Campy sidepull brakes. These are have about 60mm available reach and measure out to 54 mm with the CR18 700c rims. The wheels in the frame look like a tight fit, but I'm imagining the fender radial clearance with some radial clearance below fenders for pebbles to just run through.

After I get it put together with the 700 x 30s I'll try some SKS or spare Honjo fenders to see if it works. I'm not sure there is enough chainstay side clearance, especially with a rear fender also between the 'stays. So I'm not confident this bike will "like" gravel-level tires, but it needs to be tried. I'll be able to test a 27 x 1 ¼ in the front later this week, but I do not have high hopes at this moment.

Can anyone comment on how these frames handle? Keeping in mind this bike has the very long 47 cm chainstays of Treks first full foray into touring, has anybody experimented with a fork designed for pretty low trail? A lot of us have positive experience of low trail 650b and that style of handling, but with a 47 mm chainstay? How might that feel? Jan's Rene Herses are more like a 43 or 44 cm chainstay, so this might be pretty flexy. OTOH it's a small 52 cm frame, so the frame tubes are not very long.

L134 

I am a little lost but my 82 720 is currently equipped with a 700x33 tire on the rear with fenders and there is plenty of clearance. I've got a 30mm up front just because, not because of any limitation. Before the bike was stolen and then frame recovered, I had 35mm tires on it. Looking at an old picture, I did not have it fendered at that time but it looks like I could've. Never tried 38's.

OTS 

Hmmm, well my 720 currently has 27 x 1 ¼ tires that measure out at 31mm. Here are some photos of the front fork clearance, rear brake bridge clearance and finally rear chain stay clearance with the 27's.
I would think dropping to 700 or even 650b you would have more than adequate clearance for 35's

The Golden Boy 

So this is a couple of subject matters that I'm roughly familiar with.

Starting with the 720- the 82 was the odd duck of the litter- built for 700C and centerpull brakes. My 720 is running 700C with Compass/ReneHerse 35s with SKS fenders; you should have no trouble with 32s, and even less than no trouble with 28s. 25s on a 720 sounds obscene.

Regarding 650B- there's been at least 2 people here that have changed over 1982 720s to 650B- but I don't think either of them are posting here anymore.

Regarding derailleurs- The Cyclone sounds like a regular short cage- I wouldn't use it- but if that's in your comfort zone- you know the specs of if it'll work on your crank/cog combo better than I do. The Blue Line RD- it'll get the job done- it was conceived as a touring derailleur- but it wasn't high end.

Regarding the XC- that's absolutely perfect. If'n I were to be building a 720 in a "1985" sort of way, I would go with an XC rear and either an XC or Mountech front.

vmizera

Original owner of 1982 Trek 720, serial number 040291.

Over the years it has been through several iterations.


Came with 27 inch/ 630 mm wheels. Changed to 700c/ 622mm wheels

when 27/630's became rare. Changed to 650b/584 mm when original

fork developed a crack. Replaced with high offset fork that had same

axle to crown height as original. Trail dropped from neutral, mid 50's,

to low 30's. Ride became even more smooth. Able to run 42 mm tires

and fenders without crimping stays.


Have used Cyclone short cage with 13-28 freewheel; works fine.

Larger freewheel will need long cage rear derailleur; any long cage

Suntours will work.


If you go 650B/584mm then the Campy brakes will not reach the rims.

Long reach Mafacs will work.


Bike is currently disassembled and being prepared for its final re-painting.

It is the best purchase that I have ever made in my life.

RiddleOfSteel

Below is an earlier photo of my '82 720. Soma Supple Vitesse EX 700x42mm tires on Mavic MA2 rims. Tires measured 38mm wide and the Tektro R737 dual pivot calipers juuuuust cleared in front. Rear was fine. No dimpling on the chainstays needed. 700x33mm tires (30mm actual, same rims) with fenders worked well.

sd5782 

You mentioned wanting to try Suntour. To get the full experience you might want to try the wonderful ratcheting downtube Suntour shifters. They are highly regarded here.

JohnDThompson 

Or SunTour "BarCon" ratcheted handlebar-end shifters, which were the OEM shifters on the Trek 728.

RiddleOfSteel

Sprint or Superbe Pro Power Control micro-ratcheting downtube shifters would be the ticket. I have a pair of Sprint versions all polished up--need to put them on a bike...

HelpSingularity 

vmizera
If your 1982 Trek 720 came with 27 inch rims then it probably is not a 1982 model. The 1982 models came with 700c rims, as well as center-pull brakes. The 83-85 models came with 27 inch rims and cantilever brakes. If your Trek 720 has center-pull brakes then it is a 1982 model. Cantilever brakes and it is a 83 to 85 model.
And not to get too deep into the weeds but for 1982, and only 1982 Trek called the complete bike the 728. The same bare frameset, was called the 720.

This is all spelled out in the 1982 Trek catalog that formerly resided in vintage-trek.com (RIP)
Time to get off my soapbox.

vmizera

Though appearing in the Trek 1983 catalog as a 27 inch with cantilevers, this Trek 720
was purchased in 1982 at Northford Cycles, North Branford, CT.
The serial number confirms date of manufacture.
Would not have bought it had it not had cantis.

As bad luck would have it, when 27 inch rims and tires became obsolete I wound
up having to de-braze the canti studs anyway in order to fit 700c. Ran centerpulls and
sidepulls that reached the new rims, not impressed, so switched to Sturmey Archer
drums. Been running it as a commuter since.

Remember this purchase being a toss-up between the Trek 720, Miyata 1000
and the Specialized Expedition. Chose the Trek due to being Reynolds 531 and
having 27 inch wheels. Who figured that in a few years time that 27s would be gone,
along with the Helicomatic hubs, Duopar derailleur, Avocet seat, etc?
Only things left from original bike are the venerable Suntour Barcons and
Sugino ATX crank arms.

Thanks to original poster for bringing up good memories from 40 years ago.

Road Fan

Yes, it is all there.

I'm installing 700c, not 27 x 1 1/4.

Road Fan

Are you saying you have this set of shifters for sale? I'd be interested!

Road Fan

If they do not require braze-ons!

JohnDThompson 

Still accessible via the "Wayback Machine:"
https://web.archive.org/web/20221105...trek/Trek3.pdf

RiddleOfSteel

I do not have them for sale, nor do I have intentions to sell them.

HelpSingularity 

​​​​​​I think this is like the car industry. For example you may purchase a 2023 model car right now even though it was still 2022. So even though the car was manufactured in 2022 it is still a 2023 model. Your serial number is at the higher end of the range for 2022 which indicates it was probably built towards the end of the year. With all the evidence presented I would argue that you purchased a 1983 model in the latter part of 1982. So even though it was made in 1982 and purchased in 1982 it is still a 1983 model, as indicated by 27 inch wheels and cantilever brakes.

JohnDThompson 

A clamp-mount version was never offered AFAIK, but as the Velobase entry shows, they can be fitted to other clamp mounts, in this case Huret:

Campagnolo, Zeus, and other Campagnolo-compatible clamps will also work.

Road Fan

You're very welcome! Reactions like that, remembering a favorite bike and what we may have had to do to it, are some of my favorite aspects of this forum!

In the old Vintage Trek site Skip Echert wrote that the date info he can give for Trek frames are the date it was stamped, not necessarily the build date. And that the model years of built bicycles are based more on the year they needed to sell it. Trek felt free to finish a 1982-built frame in 1983 as a 1983 model just for the requirements of merchandising. Most big makers had to adjust the quality of components, to ensure supply. It would have made no sense to specify Campagnolo Super Record chainsets on all 7xx bicycles (as wonderful that might have been, or the SunTour equivalent grade of parts), if the goods cannot be ensured to be available with all their trappings, such as correct competition-grade BB parts. So good-quality parts which will be delivered on-time and not impede production, are necessary over and above the best pats made.

To paraphrase Robert Heinlein, manufacturing is a harsh mistress.

My 720, at least according to my measuring, does not have the angles shown in the Trek catalog, while my 1984 610 does (same frame size). The seat tube is rather more upright, about 75 degrees, and the head tube angle is about 70 degrees, very laid back and typical of a smaller touring frame. So one of my interests is to see how this odd beast rides!

Road Fan

Thanks for the information!

Regarding shifters for my 720, I'll just use my set of Shimano Ultegra EX 600-6207 (post-grain-of-wheat) with clamp band, which I got on my 1984 Trek 610. It is sacrificing its gear for the 720. They are pure friction, a nice shape, and my hands remain familiar with the use of DT friction shifters - Huret, Campy, Simplex, or whatever. As beautiful as those Superbes are, I just need shifters. I could also use a set of banded Hurets. My system will be 6 or 7 speed by 2 chainrings: 46/28 or 30, and 13/26 7 sp Sachs ARIS in the rear. I don't need more at this point.