Hi folks,

This is a specific question directed at those who've done this with this specific bike (or other low bb bike)
I have a 21" 83 Trek 720 that I truly enjoy riding with a huge caveat. I live in the Pacific NW.
I've found that with the 27* 1.25 Michelin tires it's v nice to ride but I can't fit fenders on it.

Part of the ride is that the bottom bracket is kinda low.
I use a wider pedal - the MKS touring pedal of song & story - due to duck like feet.

I'm thinking of using about a 32mm, maybe a 35mm

Has anyone who converted one of these to 700c put fenders on 'em? If so what size of tire could ya fit.

Finally if ya did convert 'em did you squeeze a 135 in there or a 130 or did you actually coldset it (I was debating leaving the option of using the original wheels.

Thanks for any replies folks.

Didn't the 720's come with 700C's originally? That's what my '82 720/28 came with.

-Kurt

According to the vintage Trek site, the 1983 came stock with 27 inch wheels, while the 1982 came with 700C's. Seems weird to me, but thats what the site shows. 1984 has 27 inch wheels too. Ditto 1985. 1986 was back to 700c. Maybe they got a deal on some 27 inch rims???

I would check the geometry on the vintage Trek website.

As far as the pedals, you could look into the extenders, so called knee savers. A guy sells them for a reasonable price on ebay ($19.99). I bought a set from him, they have worked well.

My 1983 720 has 27 1 1/8 tires and fenders. I built this from a frameset in 83. It is a little close at the seat stay bridge. I've thought about cutting the fender in 2 there.
My 1985 720 is all stock. It came with fat 27 1 3/8 tires.
You should have plenty of room with 700c. Just check that your brakes will work.

I did a quite a bit of loaded touring in the late 70s and 80s. For domestic tours (USA), 27s were generally preferred because they were more widely available. If you were in East Monkeybrow Alabama and just burned up your fold-up spare, you could waltz into the Montgomery Wards and grab a 27 off the rack. That would get you to the next town with a shop and some proper tires. On the flip side, trying to find 27s in Europe were equally troublesome.

When I got it it had fenders & 27 * 1 1/8th on it - they did fit & I did keep the tires & the fenders, but I prefer a plusher ride due to the nature of Seattle streets, my bad shoulder, habit of ignoring the grittier sections of my fav trail, & my tender derrière.

GMS - Cool racks - what are they?
Were you able to fit fenders with 27 * 1 3/8 on your 85? Did they change the geometry?

My main question would be regarding the clearance when cornering with a lower BB & such as well as being able to get fenders in with a (dare I say) 35mm tire. I some confidence that the 32 would go.

Far as just cutting the fenders in two, that has occurred to me, but I'm not sure how well that would work as far as keeping the much off. Anybody done that in a mucky climate like this?

Love the pic's I fear mine's probably a bit offensive to some with the "giraffed" up technomic & moustache bars, so I'll spare the critics eyes..

The pewter one has Cannondale racks. I have a set of red Cannondale bags to match.
The red one has the stock Blackburn rack.
I have not tried fenders on the 85 with the 1 3/8 tires. The seat stay bridge is the real problem mounting fenders. If it was a 1/2 higher fenders would fit better. I also thought about notching the fender and moving it above the bridge.
I don't beleive the bb height is that different. Going from 27inch (630mm) to 700c (622mm) rim diameter would only be 4mm bb height change with similar profile tires.

While I lived in Olympia, the front fender on my Torelli was shattered by a stick. My LBS gave me a black Planet Bike from their discard bin & I cut it to make it fit at the fork crown, then zip tied the front piece to my brake bolt. Kept the crud off just fine for several years now & fits better than the original Zefal. Don

You do realize that if you go to a smaller diameter rim, your bottom bracket will be even (incrementally) lower, right?
And what does a low BB have to do with fitting fenders?

Yeah, I have the same questions!

The BB is a derivative issue, smaller wheels would potentially open enough space to install fenders.
The derivative issue would be issues with pedal strike when cornering due to a lower BB.

Please pm me and let me know how this works for you. I have an '84 520 that is going to get 700c wheels as soon as I get the old Nishiki MTB I am working on tour ready.
An aside: I had the exact same 720 touring bike as in the pix, except mine was a 56cm frame. I went from San Fransisco to Yellowstone on it, and had the best vacation of my life. I had another fantastic tour in northern Michigan on it, and rode it off road a bit. Then I was broke when I moved to SF and sold it!!! DUMB! I have been trying to find another one for the last year. Feel free to chat me up.

Venturi95,

Like this one?









Yeah, the seat is a bit low, but it's a bit tall for me. Finally got a set of XL toeclips to fit my big feet...putting 'em on as you read this.





Steve

Surprise, surprise. I gather the change might have had something to do with the switch to cantilever brakes, as the '82 came with sidepulls.

Funny that the later versions for 27" have little clearance though, particularly on the rear rim - GRS, if you're listening, might you be able to check clearance from the bottom of the seatstay bridge to the edge of the rim (not the tire, but the rim)? I'll check my early '82 and see whether Trek did make any particular accommodations for 27"s for the '83 model year.

Take care,

-Kurt

+1

I'm astonished how different the various Trek 720's are, and I'm not even talking about the later bicycle that reused the 720 number in the late 80's. The 720 I bought in the summer of '83 (frame made in '82) looked almost exactly like the one shown, was spec'd with 27" wheels; had the same seatpost cluster (the tops of the stays say TREK on them, right?), same color, etc. I too used 27 x 1 3/8 tires (which were not easy to find!) and even so fenders were not a problem. But mine didn't have cantilever studs. I ran 27" wheels on it until I moved to Germany in early '84, at which point I switched to 700c (wider availability there) which worked fine, but now my rear brake --Suntour Superbes-- didn't have enough reach. I fixed that with a Campagnolo drop pivot bolt.

So I'm afraid what's true of one 720 is not necessarily going to be true of the other. By the way, somewhere on the Vintage Trek site it says specifically that All Trek Bikes have English Threaded Bottom Brackets. Not so: mine came with Italian!

Now you have me surprised - for the second time in this thread. My '82 720/28 came equipped with 700C's (and from what wrk101 read off from the Trek catalog, this is supposedly original spec), and I'm not entirely sure that you can shove 27"s - particularly with 1-3/8 tires - on it - hard enough to shove 25C's with fenders under there in the first place:



Incidentally, which brand of 1-3/8 were you using back then? Michelin?

The Italian BB is a hoot. Makes me wonder how many other 720's have 'em.

Take care,

-Kurt

On the model number, by the way: it's cut into the steerer on mine. The words "Reynolds 531" are stamped onto the tube, and right next to that the 720 was cut on, apparently with a hand-held Dremel tool... all under the paint. So if anyone's unsure what model they have, that's one way to figure it out. The serial numbers also give it away, of course.

Sorry, I don't remember. It's been a few years....

Yeah, huh. Have you checked yours? My 720 looked just like that once. By the way, Kurt, it suddenly occurred to me a few weeks ago, that THAT was why I had that old Sugino Italian BB kicking around, which I was going to trade away... so I decided I better keep it!

I just installed my daughter's 700C front wheel from a brand new Jamis Commuter 3 on my 1983 Trek 720 and the cantilever brake pads alligned perfectly. What a surprise! (I can send pictures if you're still interested.) I thought there was supposed to be an approximately 4 mm offset.

Any thoughts on updating the original Maillard Helicomatic hub to a Shimano 8-speed internal hub?

Well, you can't really see it, but here's a picture...

showing me and my 1982 Trek 720. Resprayed because I hated the original color (it was blistering and rusting anyway), fitted with a Shimano Nexus 8-speed internally geared hub and 700c wheels.

The handlebar is a flat MTB bar, with the Nexus 8-speed twist grip shifter mounted on it, and Origin 8 drop bar ends with the brake levers mounted on them. The end result is similar to a randonneur bar, but with corners.

I don't recall that any 720s were built with Italian thread. I suspect this was a repair from a bunged aftermarket BB installation.

What type of BB shell does it have? The earliest 720s used Cinelli (English thread) shells, later ones briefly had Cinelli shells with "TREK" cast into the bottom (where it usually has "Cinelli"), and finally they used Trek designed shells with cast-in under-the-BB cable guides from Signicast in Milwaukee.

But back to the issue at hand -- what type of brakes does the OP's bike have? The first run of 720s had Gran Compe centerpulls, which should have no problem accommodating to 700C wheels. Later ones had Gran Compe cantilevers, which might be a problem -- try it and see. Even later they had Shimano cantilevers which had a few millimeters of vertical adjustment that might allow 700C wheels.

I put MAFAC tandem cantilevers on my 720, and run 27" wheels. But 700C wheels seem to work, with a bit of goofy angling. Here's a 27" wheel:



And here's a 700C wheel in the same fork:

I converted a 520 from 27" to 700c. As long as the brakes permit the fit, I don't see why not. Put 32mm tires on for a plush ride, and you're on the road.

It's the Cinelli shell, the one that says "Cinelli" on it. Campy cable guides are brazed nearby, I guess on the downtube.

I bought the frame new in June or July 1983. I recall that the headset (Hattaswan) was already installed. As for the BB, the most valuable piece of information I can share is that I don't remember anything in particular about it until much later: I remember discovering, ten or twelve years ago, that my BB was Italian. I was very surprised. This fact leads me to suspect that the frame came with the BB already installed. If I put it in myself, which is not unlikely, then I used something that was lying around the bike shop where I was working at the time. I most certainly did not (re)tap the BB shell (I would remember that!); did the original bike shop --in Vienna VA-- do this? I don't know; if they did, they did not tell me (I would remember that too!).

Canti post are mounted high for maximum leverage with 27s. (at least on my ’84) Wide 700s may work OK. but narrow 700 rims just don’t work with the brakes as the pads are moving more down than inward. Not completely accurate to say they “Don’t work.”, but not well enough for me.

OP,
Don’t worry about cornering clearance. As my son’s racing coach said, “If you are pedaling in corners you‘re going too damn slow.” I use MKS Grip Kings with pedal extenders. No problem.

Recently I was given (Yes, given!) a low mileage 21” 1984 Trek 720 Frame/Fork. Included were brakes, BB, Spidel headset and XT FD. The original owner, an old friend, hadn’t ridden it since being badly injured in a crash while touring England on it in 1989. BTW she had a pretty good idea what it was worth, having turned down several offers for it, but gave it to me to keep it “in the family”.

Love the bike with its long stays. Specially drawn for Trek by Reynolds, an inch longer than anyone else could buy. I tried to buy some from Trek, no luck. Ride quality is noticeably better than any of my other 531 framed bikes. I’m sure it also flexes more from pedaling forces. But I’m in agreement with Jan Heine that a certain amount of what he calls “planning” actually improves performance.

I’d often wondered why they were only made for 3 years. But the previous owner said it was a bit too flexible when carrying a lot of gear. Fortunately I have a couple of bikes with beefier frames for that sort of riding, so built it up as a comfortable "Day Tripper”. It’s interesting that the 728 came first. Was it intended as a serious tourer? Do they have low rider mounts? Seems the 720 should have been built with Reynolds Tourist weight tubes like my Jack Taylor. I've wanted a 720 since they 1st came out but I probably would have been happier with a 728 but hey, free bike, can’t be choosy. Single eyelets seem lame for a touring bike, my '77 Centurion ProTour had doubles.

Also tire clearance is marginal for modern touring rubber. She kept the wheels with their '80s 700-32 Specialized Touring II tires. They actually measured just over 25mm wide. My new 700-25 Michelins on another bike are actually a bit wider on similar rims.

The more I learn about these bikes, the more I wonder. For a frame in production only three years, there's a lot of variety-- no two frames seem to be the same!

My '82 had double eyelets (good for serious touring) and caliper brakes (not so much). Despite what the catalog says, it was built for 27" wheels. But even with 700c wheels I have a hard time finding the best balance between fat tires and fenders.

Could someone remind me the difference between a 720 and a 728? I've heard a 720 was a complete bike, a 728 just a frameset; but mine is definitely a 720 (model number dremeled on the steerer) and sold as a frameset.

The 520 was a big hit with the touring crowd, and 25+ years later it has maintained its reputation as one of the most desirable touring bikes. I imagine the people at Trek saw the 720 being out-competed by a cheaper bike, so they discontinued it as redundant.