RiddleOfSteel

Ohhhh, now don't get me started!

ctak

Just ruminating on the plausibility of a 45-miler at night in the pouring rain up/around Cougar Mountain as a backdrop for evaluation of the merits of said technology

RiddleOfSteel

What my friend is getting at is that we did an impromptu 40+ mile ride on Saturday night. What we thought would be a few drops onto wet roads (from earlier rain) ended up being rain of varying intensity for the entire ride. I finally did Zoo Hill, with it's 10-20% inclines. The 26-28T low gear helping pace me up the hill as it was about mid ride and we had done some climbing and wind-fighting beforehand. The long, fast descents were good fun (as good a fun as you can have in the dark, in the rain, with limited visibility and reduced traction and braking ability..), exceeding 30 mph easily, if not more. The cringing came when it was time to stop. Sure, there was the usual "no stopping" upon initial lever squeeze, but that quickly left and we could slow down well enough. The real grimacing was when, upon pad-to-rim contact, hearing the scraping sound of road grime. On a descent. With a stop sign/light at the bottom of the hill.

The ride was a lot of fun, even with the unpleasant conditions. I ended up as wet as my bike. The 620, however, I was figuratively weeping for. 40+ miles in dedicated rain (in the winter time no less) was the gauntlet thrown down, and the grime was everywhere, especially on the brake tracks and side walls. The fenders did there job, keeping water off the frame, but everything else was disgusting. The bike survived, and actually did great. As good as it would in the dry. Stable and gliding on descents (much more so when riding the hoods than when in the drops due to weight balance etc), capable on the ascents, and fun the whole way. A faithful partner.

I spent four hours today cleaning it. Wheels off, tires, off, cassette off, crankset off (and disassembled). Car wash soap for the tires, foaming cleaner and a combination of rags and towels for everything else. Cleaned the chain as well (re-lubed, too).

But before that, there was this sight! Yuck!


The caked-on dirt on top of the rear pads was the cherry on top of the repulsion cake.


Those poor tan walls! You can call me a princess; I'll admit as much when it comes to scenarios like this. Lest anyone forget, I've commuted for years, year-round, including rain and snow--I know how to do this and I know how it goes. It just usually doesn't take this short of time to get things this bad. And as my only bike, with all the pretty parts I like (and would like to keep in good condition for as long as practically possible), you can understand my being taken aback, even if I knew it would happen. I've always liked my bikes pretty, which means dry weather and roads. My winter bikes have heretofore been shod with black wall tires, for obvious reasons. And while it's good to know that I can clean everything in a four hour effort, I'd like to not have to do that on a weekly basis right now. I don't need to HTFU if I don't have to. MA2 rims, T.A. triplizers, 7400 hubs, and 7400 cranks don't grow on trees.

casanewt

So I had been following this thread and its wealth of tips and knowledge since you posted it. Thanks for taking the time to document your journey with this build! I have a few of the long wheelbase 1980's Treks in the fleet(but not a 720) and it caught my attention. I think many of us have dreamed of landing a 1985 620 or a (various years) 720 with the famed 47 CM chain stays. Funny thing happened, I just landed a 1985 720 in the 25.5"(my size) for a reasonable price locally. I won't hijack your thread, but I wanted to chime in that I will be comparing my experiences in my build to yours here.

RiddleOfSteel

Thank you! And congrats on the 25.5" 720 score! If your 720 is anything like my friend's 720 (also an '85, but in the 24" size), there will be tiny differences all over the place (as befitting a 700-level frame over a 600-level). My friend and I noticed extremely small tire clearance differences between the two bikes, as well as a host of frame/cast lug differences. The 620's canti posts seems to sit a hair lower or wider (or some combination) than the 720 as I notice my canti arms' positions aren't as "laid out" or spread out as on my 620--we're both running 700C wheels, though it could be exaggerated by his slightly wider rims. All good stuff. Looking forward to what you find out.

casanewt

I could geek out on these types of details all day long! Thanks again for sharing, and let me know if you want any pictures or measurements to compare our two same year/same size touring kings. Mine came with an odd assortment of component changes including a conversion to caliper brakes, Mountech rear derailleur, 600 double crank, 600 front derailleur, Campy downtube shifters, etc. It has 27" Wolber rims, but not the original Matrix Titans. I am starting to wonder if this was purchased as a frame only and built from there since the parts are fairly period correct. The caliper over canti is weird though. The only OEM part I see so far is the Stronglight headset. I need to get cantilevers back on it and a triple crank/triple front derailleur as step one.

RiddleOfSteel

You're going to have to start a thread on that, simply for posterity (25.5" 720s are so thin on the ground that good pictures existing of them is also a rare occurrence).

Seems like they kept the canti posts instead of cutting them off. Whew. I've seen that on another 720 for sale (small size in this case). Some tragic-level Drewing there.... We'll need pictures for sure!

polymorphself 

These fenders are just beautiful and were the perfect choice for this bike! I've never seen them before but am taking a look now. You really nailed this build!

casanewt

Wow, very different on my 720...

casanewt

Heading into a rabbit hole here, but I am wondering if the above chain stay bridge differences have anything to do with the fact that the 720 does not have the internal cable routing like the 620. The odd thing is that I believe their other frames with internal chain stay cable routing DID have a standard bridge more like the 720. Of course it could have been many other things like the difference in the stay tubing, or just the fact that they used certain bottom brackets for some frames.

From Vintage-Trek.com "Some early and mid 80s bottom brackets were marked with 58TSI or 60TSI. In the early 1980s Tim S. Isaac designed new lugs and a new bottom bracket shell for Trek. The new bottom bracket shell is typically marked with 58TSI (or more rarely, 60TSI). This designation is not part of the serial number but is a model number of the shell. The TSI are Tim's initials. The 58 or 60 refer to the angle between the seat tube and the downtube." My 720 BB is marked with the 60TSI stamp as well as the serial number.

RiddleOfSteel

Seems like the tall frames got the 60 TSI shells--I've had a few of them on my 25.5" Treks.

From another thread, we are informed that the through-the-chain-stay cable routing was pushed by marketing as something cool, even if the cable housing (and/or ferrule) to dropout port interface is rather poor. I personally wouldn't read too much into it. Trek was producing well over 50,000 bikes at this time, and there were variances all over the place. My 620 has a more normal 531 decal and not the 531CS decal like other 1985 620s. The 720's chain stay bridge was a feature of that bike (compared to the 620), just like the tubing, geometry, lugs, braze-on locations etc. By 1986, the internal chain stay cable routing was up and down the entire range of offerings, after being more low + mid level in 1985 (1984 had traditional routing for all bikes).

The Golden Boy 

Keep in mind the 1985 Trek 620 is an ENTIRELY different bike than the 1984/85 720. Tubing, tube lengths, angles as well as most components... this isn't a matter of the 720 being an upgrade package on a 620 frame.

The primary difference here, in this example, is that the 720 has a proper chain stay bridge. The 620 has it cast into the socketed BB shell.

I'm looking forward to seeing a thread on your 720!!! FWIW- I think yours is at least the 3rd 84/85 720 I've seen/heard of with caliper brakes stuck on- which just seems goofy to me. On the other hand, there are people that think that cantilevers have inferior braking power. Oddly, I've never seen an 85 620 with calipers stuck over the canti posts.

casanewt

I definitely understand that the frames are different as well as the components, but the frame differences are intriguing to me. Even when you go back one year to 1984 and see that the 520 and 620 were more similar and only the 720 had the 47CM stays, then Trek changes the 520 into a sport tourer in 1985 and gives the 620 47CM stays. That and the construction differences are really cool to dive in to because they are all going to have different ride qualities.

ctak

+1 re: variances at Trek. I have two 24" Trek 700s from 1986, identical in all areas (including internal chainstay cable routing) but one..

The Golden Boy 

Now THAT is interesting.

That looks like someone used up a spare BB shell just hanging around the place...

So think of the fortunes of 531 at Trek in 1986. 531 was being used on 400 level frames (or more accurately, 400 level frames were being built similarly to 600 level specs). Regardless, I can't think of anyone at Trek thinking of a 700 level frame as being anything but upper level.

casanewt

That is wild for sure. Do the BBs on those actually have different BB codes on them? Regardless, we know by the production numbers that during this period Trek was ramping up big time. The fact that they basically standardized their frame construction across the board gave them the ability to play fast and loose.

Classtime 

The 620 rear triangles could have been brazed by Tange and plugged in at Trek. While the 720s were all Trek. (Man, this thread makes me wish that I kept my '85 620☹️)

The Golden Boy 

That's what John D. Thompson says; and he was there.

Trek really played free and loose with that 'made in USA' thing.

ctak

Both shell undersides look the same as the bb on the '86 760 pictured below, albeit with unique serials. Source: Vintage Trek Gallery - Dave Staublin's 1986 Model 760

casanewt

Well, I might as well keep this going since we are on a roll. As I research more about the 720/728, it is interesting to see the changes on that frame as well. It started in 1982 without cantilever braze-ons and tapered seat stays. Then it got cantilevers in 1983. Then it got the cool cast seat lug in 1984 along with the entire 700 series range. That particular cast seat lug first showed up on the top line 170 race bike in 1983.

RiddleOfSteel

@casanewt you are killing me with all these teaser photos of your 720! Take some whole-bike photos and ones, for sure of the crazy center-pull caliper setup and start a thread--we want to see it!!

casanewt

Here she is in all of her caliper-converted glory!

RiddleOfSteel

Looks like I'll have to find one of those as well. Know that, although all 1984 and 1985 720's were built in 1984, the number slated for 1985, in the 25.5" size, was 75 total. Smaller sizes of course had more examples built--bell curve and all of that--so that's like 1.5 720's per state average. Distributions were very likely not quantity / 50 states, but regardless, you have an incredibly rare bird on your hands. Looks to be in great shape. Enjoy!

L134 

Wasn't somebody looking for 25.5" Treks?

https://orangecounty.craigslist.org/...277965144.html

RiddleOfSteel

Yup. I have been tracking that one (recently, thanks to a friend) along with a now-sold 1985 Trek 670 in Wisconsin and 1989 Trek 660 in the same SoCal area. Both 25.5"--keepin' my ears to the scanner. I may or may not already have a '70s Trek gem--in frameset form--in (very recent) addition to this.