RiddleOfSteel

Decals update: So I sent an email with pictures (some you see above) to Velocals stating that the brown of the decal didn't match the photo's brown (not to mention, the head tube's brown) and asked if there was anything we could do to remedy it (to whatever degree). I did some color sampling in Photoshop (not that they couldn't, but I took the initiative) and listed them in the email. I'm just trying to help. At any rate, they got back to me quite quickly and we're (aka they're) cooking up a solution. I wish the original seat tube decal was still present as it would have made this not even a problem, but here we are, and we are working towards a solution that will benefit not only me, but future buyers.

*****

In other good news, I took the 720 to a friend's place last night, netting nearly 20 miles total. Occasional sprinkles, and mostly wet ground on the way over, it did supremely well. Smooth, solid, quiet, but still playful when you want. The 170mm cranks help quell the power pulses more noticeable with the leverage that 175s provide, but on the flats and most anywhere, it's just smooth pedaling and efficient progress. I made sure to do a few digs out of the saddle, starting "behind the gear" and seeing if the frame laid over and played dead (or tired) like my 510. It didn't. I mean, I knew it wouldn't because I'd ridden it before, but still, great news. I will see how my knees like it tomorrow (2 day delay checkup), but they aren't hurting today, and that's a good sign.

The 720 is a Grail Bike for many reasons, and I am only adding more. If you want the classic Trek look without the canti brake hassle, 1982 is your year. If you want the look with the cantis, 1983. And if you want the techier looking in-house lugs with all the Peak Touring Bike braze-ons, then 1984 and 1985 are your years. You can't lose with any of them!

52telecaster

As a former mechanic in a shop that sold trek, when old bikes came in for service it was clear to me that trek was the Pinnacle in the lug era. Certainly why I recently picked up an 82 620. Working on old trek stuff always felt like a visit to a golden age.

squarenoise 

A gentelmen and a scholar. That's great to hear they're so receptive to making tweaks.

I'm having the same experience with my 520. Very stable without feeling like an anchor.

polymorphself 

This should be on a t shirt. Poignant and concise.

RiddleOfSteel

An update on the seat tube panel decal:

I received what I thought was several "color chips" (via email communication) and those chips ended up being three different brown decals! There must have been a miscommunication, but whatever, I had three to choose from, which I was very thankful for. Two decals, though darker than the one I had originally applied to the frame, were still firmly in the red-brown camp, and not committedly brown-brown like the head tube. Thankfully, the third decal was actually brown-brown, and a hair darker actually. Given this 720's 40 year old paint, chance for sun/UV to do it's work, and for the very enthusiastic metallic flake, the head tube's brown, IMO, is "allowed" to be whatever it wants. The fact that the Velocals' brown is essentially the same is just the best. Total win.

As to any future use of that brown decal in their catalog, it won't replace the "Dark Brown Metallic" offering (SKU "Trek330"), but may become a "Chocolate Brown Metallic" offering. And to be clear, "Trek330" was never labeled as a replacement for the 720's seat tube decal (or any other Trek model that was the taupe/brown combination). I had simply chosen the only one that was metallic brown which also happened to look, in the photo, quite close to what the 720 would have originally had.

I'll need to send the two extra samples back to them as I don't have a use for them and of course will not be selling them. I let them know that the new dark brown hit the nail on the head and that I was very appreciative that we could get something figured out. I sent photos as well. Today we had some cloud breaks (so grey for the last few weeks--no surprise, but still), and I got out the 720 to take some decent photos for this thread (and future color reference should anyone need it). Enjoy!

Hobbiano 

That looks great.

RiddleOfSteel

Thanks, man.

******

I should also note that I swapped cranks to my trust tripleized 7400 Dura-Ace set. Really nice to have a big 53T for storming down hills . Chain's been shortened an inch but is still able to allow a big-big ring combination without grenading the rear derailleur. I'm fighting saddle position and knee (dis)comfort, which is frustrating. I'll figure it out one way or another, but for now, the big (visual) deal is that I now have a fully OEM looking 720 frameset. The bike is quite rapid--very efficient. Top to bottom an ideal wheel setup, IMO. It's ability to just glide is really something.

jPrichard10 

I grinned reading this whole thread and am also crying on the inside.Why? Because this is one less 25.5" 720 for me to find in the world .

Happy whenever another tall fella finds the right bike, and even happier to see that one more of these bikes is still around and not in a scrapyard.

I hope someday to find my own 720 in size NBA, but this is a worthy build for this frame!

RiddleOfSteel

You know @jPrichard10 I nearly sold this recently. I had photos taken of it, with Superbe Pro down tube shifters and a mint Shimano 5600 GS (long cage) rear derailleur along with new 32mm tan wall Paselas (folding bead, the nice ones). Turns out I can't quit beautiful frames or beautiful builds, even if I could get out of it what I have into it monetarily. I have been dialing in my newer Trek 1.5 (which is a truly amazing bike that gets even better with good wheels and tires) and busy with work, and have not had the motivation to post the 720 (in efforts to 'focus' the fleet). I was (very recently) curious to see if it would hold my 700x42 Somas and it did! First on the wider DT Swiss wheels (as I had cribbed them directly from my 620) and then fully changed over to the 7400/MA2 wheels (which I basically am unable to sell with or without a bike, haha). On the 23mm wide (external) DT Swiss R460 rims, they measure about 39.5mm wide at 35-40 PSI (what I run them at). On the narrower ~20mm external MA2s, they measure right at 38mm. I have to put them in partially inflated as the calipers won't open wide enough.

The look of the larger rubber in concert with the tall frame and tall cockpit setup really helps the overall composition and proportion. As nice as the smaller 33mm Somas and 32mm Paselas are, crummy roads will give one a hard time unless you're rocking a carbon fork, basically (trust me), a steel frame that fits 38-42mm+ tires is the ticket to dealing with degrading infrastructure and coming out smiling on the other end. Thus this was/is the case with the 720. Light, lithe frame, but even 32s at 62/69 F/R had the bike not liking the street I live on (which is particularly bad). The Soma 42s brought that right around.

Steering is slightly affected by the much larger tires. It prefers to track more straightly now, though will exercise somewhat of a tendency to dive into a turn than before (it was more neutral with 32s). Part of this is front end setup (height/reach). The 620 with these 42s is more dive-prone in slow/slower speed corners and can be ambivalent at speeds above that. Always manageable and can be used for benefit. Anyway...the 720 still has great manners, and now it's even better looking and dynamite over the rough stuff.


Front (vertical) clearance is less than the rear, but we do have clearance! Depending on your brake caliper situation with these, this may be enough or may not. Why? Because at speed or in out-of-saddle climbing/accelerating, tire deformation at this size is real. This happened to me, and the solution ended up being to bring the pads closer to the rim (via the caliper's barrel adjuster) which elevate the caliper arms just enough to be out of the Tire Deformation Danger Zone. [With the caliper arms relaxed or not hooked up to the cable, they swing down/droop well below what you see here. Some calipers do this less and new Shimano ones not at all.]


Tons more room back here. No rubbing issues at all, even under heavy out-of-saddle efforts. This bike, with these tires, is remarkably amenable to this sort of effort. Wonderful!

area531 

Thanks as always for sharing the details of your builds, RiddleOfSteel -

A question for you: You cite tire deformation, relative to rubbing interference (or absence, as it were) at the pinch points. Do we know that tire deformation really persists beyond the load affected zone?

I would think, particularly for the rear wheel, that (a) rim deflection with lateral loading, (b) chainstay deflection and twist with out-of-the-saddle efforts, and (c) axle slippage in horizontal drop-outs, would be more significant limiting factors when considering tire clearances.

Up front, the wheel and fork are subject to heavier braking loads, so there may be some radial rim distortion and fork flex influencing tire rub under the caliper. Is your inbound/outbound spoke lacing pattern mirrored between left and right flanges, or identical? This too affects how the wheel distorts under dynamic loads.

All that having been said, maybe the most important take-away here is that the 47cm chainstays aren't getting out of line- something I've always wondered about.

Anyway, if you've given this any thought, it would be interesting to hear more about your observations-

P.S. Just looking at those pictures again. Man, that is one good looking bike, my friend.

Kobe 

As always, another great write up of the process. Good luck with the 728, I hope you decide to keep it.

RiddleOfSteel

Thank you!

Regarding tire deformation, you ask great questions and bring up great points to ponder. It would make sense that the tire really only deforms in the load affected zone, coming back into its "normal" shape quickly, and certainly by the time it gets to the fork crown. I have had plenty of bikes with heavy and very light wheels, brake pads set wider and closer, and have very rarely had brake pad rub (and if I did, it was only in the rear under out-of-the-saddle climbing efforts). This 720 is no exception (thankfully), even with the now-narrower-set pads. Wheels are 7400 hubs laced with DT Swiss Revolution (2-1.5-2) in front and Revolution / Competition (2-1.8-2) (NDS/DS) in back. Standard three-cross lacing. Mavic MA2, 32h rims in good shape.

Slow climbing out of the saddle (10-15% grade, 39-28T gear combo) incurred noise aka rub. Above 12 mph or so would give me rhythmic noise as well. And then of course, bigger power efforts and 18+ mph (out-of-saddle sprinting etc) got it as well.

These Soma tires "true" well in that the take a seat on the rim well and I don't end up with a "wobbly hotdog" when I look at the tire/wheel spinning. There is minimal radial deviation, but a few mm of lateral deviation due to the front wheel needing a little bit of truing in addition to the tire seated 98% perfectly (you get the idea).

Front tire is ~35 PSI (intentionally). Given the large volume, supple carcass, lower pressure, narrower/"normal" MA2 rim width, and the fact that pneumatic tires grow in outer diameter as speed increases (the most extreme examples being NHRA Top Fuel dragsters and land speed record cars before they go to a solid tire/wheel), it makes sense to me that there would be enough of a deformation effect from the rocking from out-of-saddle climbing/accelerating (you can really see the tire shift beneath the rim in these efforts) that it would manifest as tire rub all the way at the fork crown/brake caliper.

I think this is a bit of an edge case given the tire size, composition, and set pressure. I've not run into this issue with smaller tires. And as we've both overtly or tacitly said, there is a lack of rubbing in the rear triangle, even with the long chain stays and thin tubing. That's a very good thing, especially as at my height and weight, I can put a good bit of power into the frame.

Almost posted addition: This being a Trek 720, with a full double-butted 531 frame, I would imagine the fork blades' flex upon loading (under rider power) would also be a factor. That wouldn't explain the near-constant rubbing above X mph coasting/not pedaling, so I think tire deformation still wins out as the culprit, even if it has a few helping hands.

bikemig 

Great thread. I have one of these. I plan on doing a 650b build on mine.

thedriveside

Well, this is a fun thread. 650b conversions on this forum really encapsulate why I love this place...

RiddleOfSteel

@bikemig and @thedriveside 650B would be great, especially as you could do 42s and fenders, though on an '82 720, you'll need a center pull caliper of enough length in the rear as a Tektro R556/R559 won't reach. I'm happy fitting 700x42s (nominal) in this without fenders as I already have a fendered 620. Love these old Treks!

bikemig 

I bought my '82 Trek 720 planning on doing a 650b conversion. Good to know that the Tektro 559s don't work. Their max reach is 73 mm. I figure I'll use a dia compe 750 with a max reach of 78. Do you think that would work?

This is my 720 set up with 32c tires and fenders. I have clearance but not a lot to spare. I'd like to be able to run 650b x 38-42c tires and fenders.

RiddleOfSteel

I think the Dia-Compe 750s should work. I was needing about 3-4mm on the R559s, which would put things right at the end of the reach of the 750s. 650x42 plus fenders will be a cake walk.

RiddleOfSteel

Your wish could be granted!

RiddleOfSteel

Present day update: I determined that the 42s, while good in several ways, were not the most ideal match to the bike. Neither was the triple for my knees, nor the friction shifters. Changed the saddle angle and, well, about half the darn bike. Dura-Ace tripleized 7400 crankset and BB-UN55 for my 9-speed Chorus 53/39T double and matching BB. 7803 triple front derailleur for a sublime 7800 double. My venerable 7700 GS rear derailleur for the beautiful 105 (5600-era) GS one on there. The 11-28T 8-speed cassette gave way to a 11-32T 10s-speed cassette so I could at least have some gearing below my personally-standardized 39-28 low combo. And finally, 7900 10-speed DT shifters, which I've had for a long time, got to replace the lovely but...unsatisfactory...Superbe Pros.

Oh, and finding a very well used pair of Compass Bon Jovi, er, Bon Jon Pass 700x35 tan wall tires at Bike Works--$10 a pop gets you two winter-ridden tires that look like death, and that were apparently on a fixed-gear bike as noted my the intervals of skid areas on the squared-off center section of the rear tire Nearly a half hour sitting on the edge of the tub with a veteran sponge/scotch brite pad, warm water, car wash soap, and a light touch brought both of these tires right around. On MA2 rims, they measure a hair under 34mm wide (55 PSI front, 60 PSI rear), putting it right in between my Soma "33s" (30mm in these rims) and Soma "42s" (38mm on these rims). It ends up being the Baby Bear "just right" size for this particular frame. Enough size/air volume to deal with bad roads well in comparison to the Soma 33s (not enough), but not too large so as to affect steering feel and "pedaling through sand" that could slow down this bike. The Soma 42s did make pretty much any bump nonexistent, but it was at the expense of overall enjoyment. The Compass' proportion the bike well, too.

My test of this setup was last Thursday riding up north to visit some friends for the evening as it was 70° that day. T-shirt and shorts weather! I pushed the bike to achieve the pace I desired and it responded beautifully. Elegant in its rapidity, beautiful in its steering, and a sublime out-of-saddle climber. I'm still breaking in the saddle, and that will be a while longer, but the rest of the bike is perfect, so as far as I am concerned, this 720 will stay as is.

Dfrost 

I will try really, really hard to remember that thought/concept from you!

uprightbent

I too was concerned with too much Brown redoing my 82' 728 2 years ago. Then I went all out Brown due to the Taupe head tube color. Rich old Brown Brooks, VO brown housings which have a light coffee shade to them, Brown Newbaum's cotton tape, and eventual VO Brown leather toe straps not shown in these pics. I love the Brown theme and have received numerous comments. I think even the bamboo cap and sidewalls added to the Brown theme and tempered it a bit. My favorite color theme yet.

polymorphself 

Beautiful. How do you stop that bottle from rattling? Or do you?

uprightbent

They're surprisingly quiet as long as they have some water in them, and the cage has been bent properly. When empty, they give off a hollow tinny sound which is a good reminder for me to refill and keep hydrated since I tend to not drink enough water.

RiddleOfSteel

Well I'll let you take the Brown Crown there--no use in competing, especially since mine is already built (and has been for a bit now) and looks and works just fine for me. It may lack ultimate visual adornment compared to yours, but its componentry is top shelf (in and of themselves) and visually cohesive (always important for me, because of course it is), things that for me make it a pleasure to look at and ride.

wdarner

Addin to a year old post:
I have a 728 built up with Magic MA40 rims which are the same specs as the MA2's. I have been running Continental Grand Prix 4 Seasons in 700c x 28, afraid to go any wider with the narrow rims. This post inspired me to order the Bon Jon Pass tires to try them. Other than having to deflate the tire to get them past the rim brakes, they fit fine and after a test ride yesterday, ride great.

Question to RiddleOfSteel:
Have you continued to ride this setup successfully with no problems? What pressure have you been running? My bike shop advised me against going this wide with these rims to avoid pinch flats, just curious if it has continued to work for you, thanks.