RiddleOfSteel

Thank you! I enjoyed our conversation yesterday (I am responding to this late), and am immensely pleased with the bike. And while I didn't ride it last night (too tired for some reason, but that ended up being for the better), I aim to do so today.

For everyone listening/reading, Dfrost and I share the Carefully Crafted Vision gene/inclination, as well as the desire to sense and feel the ephemeral and ethereal characteristics of a frame/completed bicycle. It can be arduous, and seemingly obsessive to others (and I certainly, at least, fully own it), but because we are so inclined and because we can, we engage in it and are able to recognize and appreciate other's creations as well. Sometimes it takes building and/or riding other bikes to confirm suspicions or intuitions. Other times it takes re-riding a bike in question, albeit after some time and thought, to realize why we did or liked something in the first place. It's a very tangible and often non-linear process, but in addition to the physical benefits riding it can bring, there is joy and a continued mental acuity brought along as well.

mhespenheide 

Thanks for documenting your long and well-though-out process. The end result rocks. Or at least looks like it rocks.

I have my own ideas rumbling through my head about a carefully crafted vision for a 650b-42mm XXL bike. And I'm moving to Seattle next month. I may have to ask if I can come check yours out...

RiddleOfSteel

Haha, you're welcome. It does rock. I was able to pick up an acceptable-enough stem (and by that it's the overall color, bolt layout, and visual condition) in the needed 110mm length. Used. Still looking for normal looking carbon bars in 42cm width, which will really help things out of the saddle. Lastly, I'll need to more aggressively toe in the pads front and rear. They make quite the noise on steep descents or moderate (or more) stopping/slowing efforts. There's some fork shudder as well upon moderate application in the ~7-12 mph range. The comfort is great, the speed is great, the look is great, the braking power is great, and the gears are really helpful with all sorts of medium to steep gradients.

sdn40

Did I miss something or are you not putting spacers under your adapter ??

RiddleOfSteel

No spacers. They bulk up that "steerer" section too much, as far as diameter goes. Like a super thick turtleneck sweater or poofy scarf wrapped around a skinny person--out of balance. The stem holds perfectly (it held perfectly before when there were also no spacers to help support it).

RiddleOfSteel

Well I went and did it. I gathered a groupset around a bought-for-$5 11-speed cassette. Since Reading Is Hard for Riddle, I thought it was "just" an 11-28T cassette, but after buying a R7000 105 11-32T cassette and having the $5 (6800 Ultegra) weigh a fraction less (all of this, while cleaning up both), I saw "32T" on the Ultegra cassette and then it clicked, "Oh, those big cogs do look quite similar in size." Honest moments, folks. BTW, the 105 cassette is something like 17g more than the Ultegra, so if you don't want to pay Ultegra money for a wide-range 11-speed cassette, R7000 is here to save the day.

Anyway, cassette stories aside, we're here for the rest of the groupset, right? Right. Sitrep: 53/39 front rings mated to an 11-32T 10-speed cassette yield me a great gear range and look the business, but a few recent observations of the hills around the greater Seattle area (via car this time) had me wanting to put my lowest ratio right near 1:1, which I sort of consider a "touring standard" low gear (after many a catalog perusal). Those 15-20% grades do not mess around, and I'd like to do all of this with a double while not pruning a ton of top-end speed capability.

Enter the wallet, I mean, uh, Dura-Ace's gorgeous 9000 generation. Much thought, again, went through my head, as well as much deal hunting. Pay to play for the only bike in the fleet, the most capable and best looking and riding bike ever built (by me)? Dream groupset for a long time? Ease of shifting now that I've had my fill of downtube shifters? Yeah, let's do it. Get some of that good gloss black AND gloss/polished silver, and drop weight even further. In the end, I couldn't be happier! 50/34 on the front and 11-32T in back. Near 1:1 low gear and still good top end (ran the gear-inch calcs and they assured me I wouldn't top out at a snail's pace). Final weight (unloaded)? 22.5 lbs



Yup, love the way it looks! Matching (free, left over) Hello Bicycle (a local bike shop) water bottles give a great stealth bomber look and manifest the full hydration carrying capability of a top-flight touring bike of this period.


These STI levers feel great to operate, as they should, and for whatever reason, have quelled the massive buzz generated by the mini-V's (the old Tektro levers really had you feel it). Koolstop pads have eliminated squealing, which is GREAT because that drove me nuts.


Who knew Dura-Ace 9000 came with a band clamp and spacer setup that accommodated a 28.6mm seat tube diameter? Crankset (which is so beautiful), Dura-Ace BB, and this FD were all Recycled Cycles finds. Love it!


To handle more chain and look proportional on a 1) wide gear range 2) large-size 3) touring bike, I ordered 6800-generation Ultegra GS rear derailleur cage pieces (inner and outer, same gen as DA 9000) to swap onto the Dura-Ace unit. Weight went up a little, as to be expected. Dura-Ace cage is fully carbon and smaller. I swapped over the Dura-Ace pulleys and silver cage stop peg. The swap is a straightforward process. Allen keys and a Philips screwdriver. Shifts like butter, and the derailleur has enough room to handle a 34T large cog easily, from what I can see.

RiddleOfSteel

Shifting is sublime with the Dura-Ace setup. Front derailleur setup is a little fiddly, but once dialed, is good to go. Epic and instantaneous small-to-big-ring shifting, I must say. Like, wow does it shift right now. And with the chain at this length, I can run big-big and small-small without blowing things up or dragging the cage. Good for brain fart moments when I'm tired. The low ratio is really nice to have when you just don't feel like hardman'ing it at the end of a ride. Or the middle.

Another photo to show things in the low ratio.


Clouds surrounding the Olympic Mountain range made for an early 'sunset'. Gorgeous as always.

Dfrost 

Even a pump!

canopus 

Nice. Made me pull the trigger on some 42s as i was looking at them and wondering if they would fit my '84 720 that has been waiting to be built. I converted my '81 710 to 650B and while the 38's are nice on it, I wanted something wider to use my 700c's on it.

RiddleOfSteel

Thanks, man. Depending on the 42s, they'll measure differently. My Soma 42s are on the small side(39-39.5mm wide), which helps, and should help with fitting them under your 720, which has slightly less vertical clearance (my friend's '85 720 as in-person experience) but should clear other places easily enough (my friend has run true 40mm tires).

Road Fan

You can make an estimate based on adding the bead seat diameter to double the measured tire width. There are sources of error: the thickness of the tread and sidewalls, the inflated shape of the tire, the elasticity of the casing, the effect of the actual rim width, exactly how the bead latches onto the bead and hooks, and how the air volume between the beads deviates from that of a simple circular geometry.

But after that calculation I measure with my metric tape, and it’s usually as close as I can trust. I think the biggest error there is whether I can actually use a tape or yardstick as if it is a caliper. A rollout measurement should be more accurate, but I haven’t done that. To be accurate you need a good approximation of Pi, such as 3.14159. Since that is 6 decimal places, it’s at least good to 1 in a million, far better than our measurements can be.

Bottom line is, I’m happy with this calculation and do not need better accuracy. If you do feel you need better, I would say, think about how good you need it to be, and for what purpose?

As far as “floatation,” I’m not sure, but I guess it’s related to the 15% sag built into the Frank Berto/Jan Heine chart you can access on the Compass site. If you use the Berto pressure settings based on tire width, the basis for sag will be (again my best guess) 15% of the tire width. Therefore the sag for a 30 mm tire should be more than for a 25 mm tire. As well, the pressure should be lower for the wider tire and the contact area will be greater for the same rider and bike.

But I’m not sure what all this means. My 1984 Trek 610 is now wearing Challenge 32 mm (actually 31 mm fwiw) Strada Bianca at 67 psi front and 70 psi rear. It’s based on the pressure calculator on the Silca site, and it feels good on pavement which is less than perfect. And I cannot precisely measure diameter but the clearances are all good, though not generous. I haven’t seen where elastic lateral rim deflection, which sounds like spokes are loose, causes occasional rim rubbing.

canopus 

I got my tires in today and mounted them. On my Mavic A719's which are 19mm, these Soma 42's measure 40.5mm in width and the same in height above the rim @ 70psi. They clear every thing on my '85 720 (no rocks allowed) but are snug at the fork cantilever mount (have to force them in) and are a little tall in the rear to clear the fender mount and the dropout. I still need to pull the '84 720 down and check it but they should be the same. I can probably run fenders in the rear but it will have to go over the bridge (custom Woody's maybe) and the front would have to be a partial, just to the crown.

All in all though I will be happy to get them on it to ride it. Thanks for the inspiration.

RiddleOfSteel

Sweet stuff, man. I don't know if you plan to ride them at 70 PSI, but I would drop that nearly in half to obtain the absolutely epic benefits of their comfort while not losing speed. I'm more or less at 35 PSI for the front and 38 PSI (maybe 40) for the rear, as an optimal setting. 40/43 F/R is also a good starting point (and just let them ease out air over a week or so to slightly lower pressures). I would be the first person to tell you if the "same speed as 700x23 tires" claim was rubbish, to any degree. Smooth is (or certainly can be) fast!

[PS: I run 62/68 PSI F/R or so on my 33mm Somas (same tire, just smaller, 29mm actual width) and 32mm Panaracer Paselas and those pressures perform well for me]

************

As a minor update, I went back to the lightweight aluminum bars I had picked up for cheap. Why those bars? 42cm CTC width vs the carbon bars' 40cm CTC width. 2cm, eh? Yeah. BIG difference. All the low to medium speed turning/cornering issues, where it felt like my input at the bars was very much fighting the tires (hardcore scrubbing and wheel flop) in addition to any out-of-the-saddle work having my upper body (at the handlebars) and my lower body (legs/feet pushing on the pedals) out of sync. Muscles memory all out of sorts or at least "dealing with things" at best. After a few months, popping the 42s back on the 620 was a complete return to normal! Bikes are an ecosystem, everyone. Every day I learn more (aka it smacks me in the face) and I appreciate it!

Speaking of appreciation, and I knew it'd happen: Returning to aluminum means I lose that sweet, sweet road buzz absorption of carbon bars (through the hands). Sooooooo, if anyone want's to trade 40cm Zipps for 42s, and are local, I'm all ears!

Schlafen

What about carbon stem with alloy bars?

RiddleOfSteel

Carbon stems tend to be bulky, rare and expensive. Weight savings over a good alloy stem tends to be nonexistent as well--stem walls and clamping areas need to be really thick for the same strength. A good alloy stem will be svelte in form, light, and naturally suited to the job (of clamping things) thanks to it being metal. A carbon bar is a much larger object and doesn't have to clamp onto things (just be clamped), which allows it to be made thinner (wall thickness). Good alloy bars end up around 250g, good carbon bars around 200g or just under. You'll never get that difference from a stem swap (good alloy to good carbon). There's also the sheer distance from stem clamp to brake hood, which is physically longer, both along the bar itself and 'as the crow flies.'

Schlafen

Was referring to vibration dampening. May be a good trade off if you can find one that you like.

I've used self amalgamating tape in the past for rough alloy bars ( heavy vibration, mostly were 31.8mm bars ) under the bar tape and that seemeed to cut some of it out. It's worth a try as it only costs a few coins per roll. If it's not overlaped it doesn't make the tape too bulky either.
25.4/26mm bars are pretty flexible regardless of material, especially with a quill, so not using any on my nitto b135aa's 45cm at the moment.

RiddleOfSteel

I know/knew you were implying vibration dampening. Make any material known for certain comfort qualities into a solid brick and one is going to not have a comfortable outcome. A carbon stem's shaft wall thickness is considerable, as is the area that clamps the steerer as well as the bars. It's being made into a brick. Aluminum (a soft metal with inherent comfort if built to that end) stem's shaft walls are very thin, as are their areas around both steerer and bar clamps. Svelte form matters, to me, proportionally with these vintage frame tubes' thinner outer diameters. Vintage Cannondale or Klein? No problem with a beefier looking stem. I don't think you heard me on the cost factor as well, or weight.

Some padding under the tape at the levers is something I have considered. I don't need or want it elsewhere as the padding is good on the tops and I simply spend a lot of time on the hoods.

A slender alloy bar mated to a quill stem (especially of unknown height above the headset) is a completely different vibration-damping (and resulting comfort) scenario and is not comparable to a 1 1/8" steerer + 31.8mm clamp stem + 31.8 clamp bars, especially with 45cm width bars vs the 40 or 42cm ones being used and discussed here.

Schlafen

Extralite and Darimo make slender carbon stems but they cost ridiculous ŁŁŁ.

Initially I have considered it as well, but, 25.4mm carbon bars are too flexible for a 195lbs rider, so I'm fettling with quill height instead, you're right about that lol. Takes a bit ot trial and error to get the right stem height.

RiddleOfSteel

Yeah, crazy prices for considerable and needed engineering effort into a very demanding component. Carbon bars are a nice, "big" visual bang-for-your-buck, IMO, in comparison to stems or other components. I had a 26.0mm carbon bar years ago. It was an older profile, and that was early in my bike exploration (this 620 is one bike in a line of literal dozens before it), thus my knowledge and sensitivities were not what they are now. I believe it did well, but it wasn't as obvious (then) as switching frame materials. This during a period of running 23mm Gatorskins at 110 PSI and extreme saddle to bar drops on much too small frames. There has been considerable learning since then, more happening now, and still more to go.

ThermionicScott 

I just got caught up on this thread. Always fun watching a build take shape... and then change direction.

BTW, a couple months ago you mentioned your new tires having a weird coating. That's probably the mold release from making the tires. Some folks will lightly sand the tread of their new tires so that they can corner aggressively from the get-go.

Jasongrace313

Man, it is an absolute beauty Riddle. Great work!

RiddleOfSteel

Thanks, man. I just swapped the standard butyl inner tubes for some Vitorria latex ones in 700 x 30-38 size. Advertised at just 105g for these huge tubes, two of the three I ordered were 103g each, and the last one was just 95g. In all, it was a 134g savings, which is considerable for $14 (on sale) tubes. Even better, the weight lost was at the outermost rotational point of the wheel. The bike is sniffing around 22.25 lbs now (even with the 40g bump in handlebar weight).

The 620 without frame pump, a water bottle, and a saddle bag, in this post-powder coat configuration (with the 42mm tires), has always seemed a bit unsettled. I mean, it's dead stable, but it's like putting weight in a pickup bed to get the rear suspension to chill out a little. I figured any improvements with the latex tubes would be "quiet" ones. Indeed they are. It rolls a little better, sounds a touch different, climbs out of the saddle with a different sound, and feels more eager to spin up. The valve stems are gloss black, so, you know, just when you thought this bike couldn't get any more black, here we go. Looks great, IMO.

I'm basically at the point to where if I can find some good, light, carbon bars in 42cm for the same price or less than the 40cm ones I have now, that will make the bike perfect/complete. The aluminum ones are doing fine, though I will need to add some padding where the current tape is too thin/tired to offer padding.

canopus 

I keep thinking about a tubeless setup then I start adding it all up vs the cost of tubes and just think, I’m old and slow, rubber does just fine.

52telecaster

Your build is killer and inspiring. I have an 83 620 taking shape in 650b. Nowhere near as cool as yours but u inspire me.

tricky 

I've been considering carbon bars for a while, but it scared me a little bit with it being such a vital part. I guess if the considerably taller and higher mileage @RiddleOfSteel can honk on them and be fine then so should I. I could probably drop a half a pound or more by swapping out the giant flared gravel bars I have on my Lemond Poprad. You're splashing out for parts is contagious!