RiddleOfSteel

In my non-quest to go at least toe-to-half-a-toe with Roger M in the bikes-as-scaffolding game, and thanks to my friend and enabler @ctak whose search alert for bikes in/up to 62cm (or whatever it happened to be, maybe just "Davidson Impulse" as he has a splendid example in 60cm), I was presented with an eBay listing of a "62cm" Impulse for sale in the SW. One look and I said, "This thing ain't no 62cm bike. It's even bigger than my 64cm Impulse." I asked the seller to help me with size measurements as some Photoshop scaling between the seller's photos and my own of my former Impulse had me at about 65cm CTT. Knowing the Impulses in the catalogs came in even cm increments, it was either a 66cm (maybe) or a custom. The seller stuck his tape measure on the top of the BB shell, ran it to the top of the seat tube, and took a photo. 25", which after some conversion put the frame in the 65-65.5cm range. Good to know I was hunting closely with my measuring from afar. The top tube length looked reasonable and there was a bucket load of 7400 Dura-Ace on the thing.

The Buy It Now price was a little north of a grand and there was a bidding option. I figured this thing would go for at least $800 easy (and clear a $325 reserve-not-met starting bid amount), because it's an Impulse, a Davidson at the very least, in a rare size (for us tall guys, it's gold), and it has great components in great shape. I keep the browser tab open for a few days. No one is watching/interested in this. I decided to wait until a day or two left before throwing in a bid. Didn't want to start anything too early and get people's attention--at least that was the thinking. Just inside of two days or so and a bid goes up. Dang. I put a max bid number that's below my final selling price guess of $800, click bid, and then see what pops up. Auto bid for $10 more than the other guy and I think, "Aw man, here we go, watch this start to go up and pass my max." I already have enough bikes in my place (and ones I like), so this would be a sure-why-not thing--no running after higher bidders. Well, shoot. I won the thing!

I had been missing my former Impulse, even low-key contemplating reaching out to the buyer now that I'm a little smarter and have an Innicycle headset that could take up the saddle-to-brake-lever drop in an aesthetically-pleasing manner. Having running the big tire line for a while, and really enjoying its benefits, once a road bike guy, always a road bike guy. My Impulse was telepathic in how it responded in all situations, and you know, nostalgia and memories get to talking and here we are. Knowing that Davidson made a 66cm Impulse, and having passed on a Drew'ed 66cm while having my 64cm, this is a Grail Impulse for me. Lotta hype to live up to!

Seller photo:


Looks great, doesn't it? Sure, we have junked bottle cages, a roasted saddle at a bad angle, electrical tape that's a bit too liberally applied, a possible replacement hood incorrectly installed on the right Dura-Ace brake lever, and a flipping Sun CR18 replacement rim laced to a 7400 rear hub. Between that, the method of measuring, and the ad copy, I could tell the seller likely wasn't the original owner (which is fine, happens all the time) or much into bikes. He did insist he would seek out advice in how to package it correctly, and it came...embalmed.

If you like miles of plastic wrap and a yard of packing peanuts, he's your guy.


Super aero disc wheels. For free!


Loosely assembled, now with more exposed wires (ran along the bottom of the down tube and the fork blade).

RiddleOfSteel

Packing bikes can be tricky, if not difficult. Everything protrudes and is subject to getting bent or broken. If not a bike enthusiast or an hour or so's worth of research and planning of how to pack it optimally, it's even more difficult. The frame being intact was the important part for me. As I would be inexperienced with packing things unfamiliar to me, we had my bike. And honestly, there was a lot of good in it. Load locking it in the super huge Specialized box would have helped, but there was a lot of honest effort, and the plastic helped any damage from abrasion. As with anything, there are bumps along the way, and we had a few here. In all, very minor and all correctable. The fork was undamaged and nothing came out of alignment.

Levers were turned in a bit oddly, but hey they're protected. That loose brake lever hood is actually the original 7402 hood! It's been stretched from sitting like that for so long--more evidence this bike has been unused for a long time in addition to other things, which I'll get to below.


This bent somehow. Maybe in packing or moving it around beforehand, or shipping. It's a dollar and I've already cut and removed it, and have a replacement ready to install.


The rear dropout was closed slightly, cracking the paint. It took little effort to open it back up to be able to slide a wheel in. The paint crack is barely visible. Likely got bumped in transport somewhere.


The 7400 "8-speed" rear derailleur is, outside of the parallelogram, nearly frozen in its pivots. Baffling. It took a lot of effort just to spin the anchor bolt to remove it when addressing the dropout situation. For something that looks this good, it's in a bad way, unfortunately. The below photo shows what happens when you're so distracted with how difficult it is to mount a derailleur that you forget the cable and housing are on the inside of the rear triangle and you bend/break the very pretty barrel adjuster. Sigh...


This is a 110mm long, full-meal-deal 225mm tall Technomic stem absolutely buried in the steerer. It should clean up pretty well I think. Lots of nearly solid grease making things look concerning.


At this point, there is a lot of interesting going on with this bike. Much maintenance neglect from whomever owned and did or didn't ride it. It's a shame, but I am the guy--one of many--to get it sorted out. It's my bike now, and it's an Impulse, and in my size! And unlike my former Impulse, this one's white paint is a gorgeous pearl/metallic and it looks wonderful...in indoor lighting. I have my work cut out for me with all the petrified grease and rear derailleur, and removing the adhesive residue, but it's worth it for many reasons. Do I have hopes and dreams and memories willing this new-to-me bike (or really, frameset) to the level of greatness that my 64cm Impulse achieved? Very much so.

The bike has been disassembled already, which was a very good decision, but I'll get to that tomorrow / the next post, along with all the geometry and weights, which are stories in and of themselves.

bulgie 

Congrats, nice score.

I worked there when this was made. I can confirm that everyone who worked there was highly motivated to do our best. Bill D never pressured anyone to go faster, the emphasis was on quality.

I forget when the larger frames went to OS (1-1/8") toptube, '90-'91 maybe? So yours (1" TT) is older than that, let's say late '80s. Tubing really is Prestige throughout, but some tubes were in thicker gauges commensurate with the size. I don't remember for sure but possibly as thick as 1.0/0.7 for the DT, 0.9/0.6 for the TT. It's still light for a 66, but not stupidlight. We had some good racers on them (by "them" I mean 66 cm Impulse) and even with the 1" TT, strong guys were OK with the amount of flex. Definitely a road bike though, not a sprinty crit bike. You already know this though since you had an Imp previously.

Rear stays and steerer are the same as smaller frames. Blades are the thicker of the two Prestige choices at 0.9 mm — same as Columbus SL, lighter than Reynolds 531. Plenty flexy for a comfy 66 cm road bike despite the stiff crown and short blades, short rake. Actually come to think of it chainstays might be one tenth thicker than the small frames got, but there weren't many choices in Prestige c-stays.

I'm guessing you'll find the steerer does not have a TANGE stamp in it. If it does, that means Tange made the fork. D used Tange-built forks on early Impulses, but at some point we brought the fork production in-house. Nothing wrong with the Tange-built forks, they're nice, but a D-built is better IMHO. We got so good at making forks that we were able to sell batches of them to a couple other builders who didn't want to make their own. Great, we perfected the steel road bike fork just in time for it to be obsolete!

All the above is from fallible memory so no guarantees as to accuracy.

Ride and enjoy!
Mark B

jamesdak 

Awesome find, congrats! My Impulse was a mess when I found it too and is now one of my most favorite rides. Can't wait to follow this one as you sort it out.

OutnBack

Great looking Davidson! Have you determined how wide a tire will fit?

ctak

Intriguing cellophane pack job. Glad it arrived unscathed

bulgie 

Don't read this if you only want skinny tires on your road bike!

That's the problem with an Impulse — and so many other '80s and later pro-level or pro-wannabee road race frames. Chainstays, brake bridge and crown limit you to about 28-29 mm tires, maybe 30 if you hold your tongue right. That's enough for a lot of people, but I'm a clydesdale ex-racer who likes comfort too much. So my similar custom Davidson is probably going to get a 650b conversion one of these days. Luckily for me, my crown is wider than the "MER" crown on the Impulse. The MER is stylish if you only want skinny tires, but it's so narrow that even 650b conversion will not allow much wider.

I indented the chainstays on my "Big D" and currently run Challenge Parigi-Roubaix that measure a bit under 30 mm, but they almost rub on the brake up top.


The clearance in front is even a little less, but I don't have that picture.

There was some tolerance* in the brake bridge height, so individual Impulses might have a little more or less vertical room in back, but the forks were pretty close to exactly the same height on all the thousands we made, we had the process dialled in quite precisely. Clearances are equal F&R, or a little more in back due to the bridge tolerance, never less in back that I know of.

Useless trivia someone might like: The tolerance in the bridge height was to allow us to use pre-mitered bridges. We had them in 1 mm length increments, and you'd choose the longest one that would fit in the jig. The jig had some up/down adjustment range, basically because it doesn't matter much (unlike fork height, which affects the bike's geometry). The jig could go down to the same height as the fork, or a bit higher to allow the bridge to snug up to the stays without any gaps. A strong joint there is more important than the exact height.

Custom bikes got the bridge custom-mitered to an exact length, but that's time consuming and we were trying to get the Impulse to a better price point, with the same performance. Examples of cost-cutting that didn't hurt the performance one bit: main triangle tubes came to us pre-mitered at both ends by Tange (very precisely I might add). Stays came out of the box from Japan already slotted, with the right side stays nicely flattened for chain/freewheel clearance, and cut to length, BB end mitered. Tange was more efficient at that stuff than we were and hardly charged anything for the extra processing they did, so it was a no-brainer. How clean and polished the Prestige tubes were was a sight to behold, no other bike frame tubing I ever saw was so shiny. Even the insides of the tube looked polished. They were a dream to work with. Reynolds and Columbus tubes always had some brown oxide coating that had to be sanded off before brazing. True Temper came close, because those were seamed tubes that were ground after welding to make the seam disappear, but their grinding was coarser than the polish that Tange put on Prestige.

Combined with our brazing method, which left almost zero spatter or brunt flux anywhere, the bikes were very aesthetically-pleasing at every stage of production. The rows of shiny polished Prestige frames hanging from racks was a sight to behold. Wish I'd taken pictures.

Mark B

Chombi1 

Yup!, I always ask people that ship bikes to me to remove rear dropout adjuster screws as they wil always get bent up, during shipping and maybe even damage the rear dropouts.
And yes, the Davidson usually have minimal clearance between rear brake bridges, fork crowns and tires, which limits your choice of tire sizes. The biggest tire I can fit on my 1983 Davidson are 23mms......

RiddleOfSteel

Thank you for your wealth of information in general but especially on these Davidsons! Love it! If the Dura-Ace on it is original, and that's more than a possibility, that puts it as a late-80s build. If the hubs are original to the build, then it's a 1989 as the rear hub is a one-year-only Dura-Ace 8-speed Uniglide freehub. This is the second 1989 hubset/wheelset I've had the pleasure of owning. 7400: It follows me around, I swear.

Fork is a Davidson unit as you guessed (me, too, but I'm just a guy ):

RiddleOfSteel

Thank you! I bought my 64cm Impulse as a frameset with a more modern Record headset. It took a few setups and wheelsets before I found the magic combination of C24 wheels (10-speed in this case) and Vittoria Open Corsa 25mm tires (that measured more like 27mm).

Thank you as well! Between what I've briefly fit to this frame (before leaving for a very busy Sunday this morning), the brake calipers I plan on using (preview in the reply to bulgie above), and what @bulgie has said, 28mm MAX on this particular frame. Clearance is very tight everywhere. The Dura-Ace 9000 calipers (like the 6800 and 5800 versions of its generation, and newer generations) have Shimano officially stating 28mm as the maximum tire size, and they ain't kiddin'. I remember my 64cm Impulse having more reach required and thus a few mm more vertical clearance available. Regardless, If I want to make 28s work on this, and I really do for the extra comfort while still retaining speed capability, they can't be "big 28s" or anything. They'll have to play by the rules.

RiddleOfSteel

Prior to bike disassembly, I weighed the whole bike just to find out what I was starting with. Like my 1982 Trek 720 before it, this Impulse weighed...a lot. 25.2 lbs with cages and pedals. This is a bike flush with 7400 Dura-Ace, quality components, and a race bike's geometry (aka not a touring bike that's longer and heavier duty). It should really be around 23 lbs given that it's a Prestige-tubed Impulse with top shelf parts. Is someone adding lead??? Meanwhile, my YUGE 68.5cm Fuji with it's 4000g frameset, bigger gearing and tires, and fenders, weighs barely more at 25.6 lbs with cages and pedals. So I thought either there was a big jump in tubing heftiness from my previous 64cm Impulse (around 3000g for frameset, which includes the headset, as all my "frameset" weights include), that there was hidden lead, or that I simply had some heavy components on there. I had taken the wheels on and off of it, and noticed they were a bit heavier than I thought they should be.

I kept the wheels on the bike as I took everything else off, piece by piece. The bike started to get lighter, lighter to an encouraging degree. And by the time I took off the wheels--the purposefully last items to be removed--and lifted up the frameset, it was instant confirmation that I didn't magically have a Miyata-inspired 66cm frame. 3,225g! This bested my "ideally low" guess of 3,250g, and my "oh boy it may be more" fallback of 3400g. ~200g over the next size down makes sense to me given my and ctak's various frameset pairings (mine a size up from his). For another reference point, my former 67cm Davidson Signature, an in-the-saddle long-distance specialist of a frame/bike, came in at just 3,120g. Another 100g to put some meat on the bone to take the frame from softer to punchier is perfect. The same thing happened with my 720 vs 620. ~350g more on the 620 meant a much punchier yet still comfortable bike. Partner in wine vs. partner in crime.

Time for some measurements:

HTA: 75.0°
STA: 73.0°
ST: 66.0cm CTT
TT: 59.5cm CTC
HT: 240mm
CS: 410mm
FC: 595mm
Fork rake: 37mm (calculated via CAD)
Trail: 53mm (calculated via CAD)
BB drop: 70mm (+/-)
Stack: 643mm (calculated via CAD)
Reach: 399mm (calculated via CAD)

I calculated 56mm of trail on my 64cm Impulse, but I'd have to have the frame back in my hands to better measure it today. 53mm of trail is sort of a no mans land for me on other bikes (620, '74 Paramount) as the lower speed steering felt funny, but Specialized has long used it on their race bikes and there are a number of factors that go into "just a number" trail figures. If my 64cm Impulse was actually a 53mm trail bike, then I'll have no issue with the 66.

RiddleOfSteel

And to follow up with my stating that disassembly of the bike was a good idea, it was. A very good idea. There was considerable petrified grease and really gummed up threads all over the bike. I have had that before, but usually on bikes that looked in rougher shape. This bike spent it's last stint in the Phoenix area for however long, so anything resembling rust or gummed up stuff seems out of place. Still, the bottle cage bolt threads had slight rust on them, which I at the time thought might portend other less than stellar findings.

Thankfully, everything that could unscrew from the frame actually did so without trouble. The BB threads were a dream to work with as, once I broke the cups loose, they spun out by hand as easily as they could. The plastic dust shield/tube for the BB spindle inside the BB shell was practically sealed against the shell itself. Lots of smelly old grease, and I had to use a small screwdriver to gently pry and unstick the shield from the shell, then push it out with a seat post as the diameter matched the shield well enough to push it out without much more hassle.

Well...you'd think an Arizona bike would have everything pretty dry inside but nope! The shell was showered with a lot of wet dirt and some rust bits. I did a bit of shop towel trying in the down tube, seat tube and chain stays, using the small screwdriver to lightly scrape any clinging dirt and/or rust from the inside of the tubes to get an honest gauge of the condition. Thanks to the dirt having collected and stopped at the base of their tubes, at the BB shell, that was where the corrosion was on the tube. Looking further into the tubes, it got a lot better and quite quickly. The base of the BB shell is in great shape. My conclusion is that I've seen considerably worse, and that this is in the range of acceptable to me, albeit on the more interesting end of it. The steerer was also somehow a touch wet when I took the fork out an hour ago (the bike disassembly was last night). And BTW, the 7400 headset was heavily indexed. Of course. I'll have to inspect it to see if that's salvageable.

So in the interest of some disclosure, here are some (top notch, lol) photos. Nothing I found will deter me from riding the bike or loving it less. Steel oxidizes, and I found plenty of evidence that gives me confidence in the frame. But seriously, people, take care of your bikes!!

The harbinger:


This was after a lot of cleaning and brushing away. More orange-colored friends! Also, look at that beautiful paint!


Mostly cleaned up BB shell. Looks good.


You can see the chain stay corrosion concentrated at the BB shell, but within about 10mm, the tubes are grey.


Blurry look at the down tube innards. Some texturing due to dirt collection at the BB shell, but it cleans up quickly enough.


The base of the seat tube seemed to get the worst of it. Probably a good bit of stuff from the top of the pre-mitered downtube that was making a roof over the BB shell. Also, as you can see, the BB shell threads are in really good shape.

jamesdak 

I wound up with Campagnolo Eurus wheels on mine sporting Continental GP 4000S II 700 x 25 tires. A true size 700 x 27 tire may fit but it would be close. While these feel wonderful in use I wouldn't call it one of my really light steel bikes. My 55cm with 8 speed Ultegra parts weighs in at 20 lbs 13 ozs as in this picture. Still when I look at the other steel bikes lighter than this one they are running more modern components, lighter wheels, etc. so these Prestige frames must be respectably light. For sure this is one bike I am constantly considering "upgrading" with a modern groupset but it works so well as setup that I'm almost afraid to mess with it.

mountaindave 

Sweet find! Subscribed

RiddleOfSteel

I am definitely a proponent of when one finds a combination that works well with a bike, to stick to it. Sometimes that combo is happened upon more accidentally, other times it's through swapping components in and out. My first building up of my former 64cm Impulse had me considering selling it. Wheels were of plenty good quality, but didn't do much for the bike, and neither did the apathetic but decently-regarded tires. Vuelta Corsa Lit wheels were light but a bit harsh upon impacts. It took the C24s and Vittoria tires to complement the street fighter nature of the frame and make a formidable bike. The Ultegra Di2 helped a lot as well (and I still miss it). This Impulse will get the kitchen sink thrown at it: Dura-Ace 9000 and RS81 C24 wheels. I have one GP4000s II tire in 28mm, and need to find another. The bike should be in the low 20 lb range, employing some rough mental math. I still need to take a closer look at the 7400 headset. Maybe it will get a preliminary/test ride build first just to give an idea before fully committing to 9000 (which is still complete and on a different bike).

rando_couche

There may be a lot of crud, but my oh my, that is some SWEET metalwork inside the BB!

Rocket-Sauce 

Nice Score ROS. So... how are you going to build it up? Is that modern Dura Ace caliper on the for a hint of things to come?

RiddleOfSteel

Thanks! That caliper is indeed a hint of what I plan on building it with. In an above post I briefly mentioned that I may do a sort of proof-of-concept build with different spare parts to get an idea for the bike before completely disassembling a fully functioning bike (with that Dura-Ace on it) and changing parts over. There are a few irons in the fire right now, and I just added another today (changing parts from one bike to another to sell the other--special case/request). The merriment of bike build chaos continues.

RiddleOfSteel

Well, it's been, uhhh, a few weeks since the last post. Much has happened since then, including a lot of work, that has taken up much of my time. The Impulse has actually been together for most of those weeks--sorry!--but first, a photo of the completed frameset:



This was one of the build photos I took (below). Most of the 'cast' (components) shown are on it, but a few had to be switched out. The Grand Prix 4 Seasons radially trued/mounted great, and it was very tight as far as clearance all around--particularly the under-brake-caliper region, and in the case of the 9000/6800/5800 era (and newer) of brake calipers, the specifying of a 28mm tire maximum is not conservative. For whatever reason, the front GP tire had a side wobble to it that had it brushing the inside of the fork blade (also a 28mm max tire scenario). So sadly, I had to switch those tires out for my true-25mm 700x25 Vittoria Corsas. The DA9000 brake calipers felt spongy from the lever, which I took as these were going to be pretty grippy. I decided to save them for another build. I did sneak one 9000 component on there, the front derailleur, and it looked quite at home.

RiddleOfSteel

It turns out that the change from the bigger black wall 28s and Dura-Ace 9000 brake calipers was the most perfect thing that could have happened to the build and overall composition. The gloss black elements--seatpost, stem, bars, bottle cages, rim beds (Open Pros), and front derailleur--were playing very nicely off the white paint, and the polished silver was looking great, but the aesthetic levity (and color) that the tan wall Vittorias added was the key. A lithe, tall, spaced-out 66cm frame now has the whole wheel assembly to match. Wonderful!

Final weight: 22.1 lbs / 10.05 kg with bottle cages and pedals. After this photo, I dropped the stem height 1/4" since on the very brief test ride, I wanted a little more weight over the front to tone down the steering before that evening's ride to Bike Works for volunteering. This lunch time photo shoot and subsequent 1 mile test ride was all I got before riding 18 or so miles round trip that evening, through the city and up and down steep hills. As always, a smart move.

The Bontrager carbon seatpost (one can find lighter carbon and aluminum examples, but 232g is more than fine) and this particular Prologo saddle were a great comfort aid as I tacked city streets with 25mm tires, on a road/race frame. The bars, at 42cm CTC, are technically my preferred width, but the classic drop profile and lever position meant the recess at the base of my palms was displaced outwardly, thus giving me an effective 44cm bar or so. Out of saddle efforts, especially with gloves on (hands can slip around in them slightly), were not the most natural; and in my experience, that fogs my ability to get a full and/or true idea of the characteristics of the rest of the frame/bike. Thankfully, I had dialed in the saddle position (per my measurements I've had for a while now) and my trusty (and timeless) q-factor Chorus cranks were on the bike.

As for the ride, it didn't take long for the Impulse to live up to its name. Yes, 25mm (vs 42mm) tires do impart an urgency to the movement of the bike, as does the tight wheelbase, but where as my very good Trek 1.5 frameset (when built) gives a responsive but stable ride characteristic, the Impulse, well, instigates by its very nature. The steering is nuts. Fast. Light. Ready to go wherever. NOW. Secondary steering happens easily with the simple weighting of one set of sit bones or the other. Load up the chassis either in the saddle or out, and feel it coil and spring back. It wants to go. Extremely enthusiastic, and so much so that it goads me into just sending it into traffic. Like the feeling you get when gearing up to overtake someone in a car on a two-lane road (before an oncoming car appears), this is that when asking/encouraging you to put the power down and shoot a gap, or just hammer it down a hill or along a flat or punch up a short hill out of the saddle. It's a bad influence, but in a good way.

Like my former 64cm Impulse, this frameset will take any power you put down, BUT! will not murder you for such capability. It never feels harsh. My 65cm Medici Pro Strada was a jackhammer, and only 25g heavier. This is the magic of the Impulse and/or a properly designed and built frame. I think the 64cm Impulse I had was a little punchier, but that's what smaller frames feel like compared to bigger ones, and this 66'er is no slouch. A bumpy set of streets over the course of a ride will fatigue the body more quickly (than a bike with larger tires), as will below-40° temperatures, which is to be expected. Thus, I will test how it does over a 24 mile loop I've done.


Looks even better in real life than in these photos, but isn't that true for many bikes?


I was able to get the right side brake lever hood to shrink back enough to be plenty useable (and stay in place enough). Nothing beats Dura-Ace 7402 brake levers for beauty and feel, for me. The road rash will always be sad to see, but they feel as wonderful as before to use.


The only short reach calipers I had on hand were these lovely 6600-era Ultegra calipers along with some single-piece (but fully adjustable!) pads. Their particular sheen actually matched the other silver components' sheen very well. But for chuckles, the "cheap" pads did pretty well! Still, this isn't the king 7800 Dura-Ace / Kool Stop setup, but I have remedied that!


The 9000-era Dura-Ace front derailleur adds immediacy to big ring upshifting, which is right in character with the frame. Its gloss black and overall design tie with the other gloss black elements, so it is staying. It's also a ridiculously light front derailleur. I don't know how they do it.

And as for the crankset, a 50/34T arrangement is total propaganda / ego stroking if you want to ride in the big ring when at cruising speed. This, compared to the traditional 53/39T combo. Working the 53T up front means running up the cassette in the back a bit and hoping you're not stressing the rear derailleur.


Thankfully there is enough chain for this 7800 unit to work with, and man is it so good to be back with my favorite silver derailleur. Others do a great job as well, but none are 7800s. It was also operating over my favorite cassette range, 11-28t, and that is also something to get used to after having a 34-32t low combo. I have to slowly re-harden up..

TPL

Previous owner must have been a downhill racer

RiddleOfSteel

We have a few detail shots to show. Just the usual from me here...

I must say, the graphics are in much better shape, as is the paint, than my 64cm Impulse. I am very grateful for this.


Can't be 33 years old without some scrapes, I suppose.


I had this saddle on my last Impulse, and my 620. For good reason!


The biggest bummer about this frame, the front-and-center top tube paint damage. Take care of your top tubes, people!


So, here's a outside-photo preview of the evolution of this bike. I found used gloss black Dimension 40cm handlebars to give me a theoretical 42cm handlebar feel, lift my hand position up a cm or so, and give better hand/palm access to the brake levers. The handlebars follow Nitto's M151 bar profile and intended orientation pretty well. I shaved 10g off the old bars (just for fun weighing here) at 312g IIRC. Secondly, I obtained my favorite brake calipers--7800-era Dura-Ace (Mr. Broken Record over here)--and swapped the metal-shard-infused pads for some Kool Stops I had. And lastly, in another Recycled Cycles visit, a pair of nearly-new Rene Herse Chinook Pass 700x28 tires were being offered for decidedly less than the price of one new one, so why not see what the fuss is about? Dropped another 15-20g a tire (from the Vittorias) and I end up with a at-present 21.9 lb bike. Sub-10kg steel without exotic (though very nice) components. Oh, and a note about the RH tires: They looked a little shy in width for 28s (claimed approximate 28mm width on huge 20mm wide internal rims..) and sure enough, they measured 25mm on the nose. Just like tires back in the day!

We've had a number of days of rain, so I've been unable to get out and test ride this updated setup. Alas, we had a dry day today and it looks that way for the next week. A hair warmer as well. Night riding in the mid- to upper-30s is not ideal, though plenty enjoyable in and of itself. I'm really happy to be rocking the top-dog 7800 calipers, and I am confident that the raised brake lever position will help longer distance ride comfort/fatigue. No problems with accessing/using the shift levers--a much shorter reacquaintance window than before, to the point that STIs feel like cheating a little. That's hilarious. Hoping the narrower bars feel better and maybe tone down the very eager steering a touch, though I will say, I love the way it sticks it into a turn--very confidence-inspiring, and you just rail it through.

I honestly--as stated far above--had plans to have an initial/interim build (as shown above, more or less) before having that assumed inevitable confirmation of worthiness lead to a full Dura-Ace 9000 build. This is a Grail Road Bike/Frame for me. It goes no higher. It has the size, it has the looks, it has the proportion, it has the character. As such, it is worthy of modern componentry, to me. But I have absolutely fallen in love with the glittering silver spokes, hubs, crankset, everything, as it plays off all the other colors and components. I ran around in my head, trying to figure out how to get that same look, just with a 9000 build. But nothing glows like 7400 hubs. A more elegant crankset is nigh on impossible to find. You see where this is going. So I am staying with this composition. A 9000-era build, one that would take this bike to the 20 lb mark or below, will be for another bike. "Local Man Can't Quit Vintage." May it ever be so.

I will get some updated outside photos soon, do not worry. For now, another indoor shot.

Fredo76

Nice build. I think you got the aesthetics just right. Do you know the angles? My 66cm frame (not a Davidson) is 75/75, with a wheelbase of 39.5".

RiddleOfSteel

Thanks! Post #11 has a ton of measurements and stats, but 75°/73° HT/ST.

RiddleOfSteel

Ok, back on the case of the big Davidson. Much time and thought has passed in these three short (and still cold and wet!) months. I've built it with Shimano 105 (5800 generation) and ridden it around briefly before disassembling it and putting those components (back?) on my '08 1.5. Consistent to my observations, the 1.5 handles really crummy streets surprisingly well thanks to its carbon fork, something that the Impulse really isn't interested in doing thanks to its steeper head tube angle and general on-kill demeanor. That and it's nearly half a pound increase in frame weight over my former 64cm Impulse frameset. The Impulse with a traditional quill stem and bars does not fare anywhere as well over crappy roads as a stem-conversion-with-carbon-bars setup (which I had with the 5800 groupset), the modern/converted setup doing well to close the considerable gap in impact mitigation, much to my relief.

The 1.5 and Impulse share their capacity for tires, which stands at a firm 28mm width maximum. If I want to handle poor road surfaces, I have a pair of bikes that can do that. Still, I've been a bit down on the Impulse, and sub-30mm tire bikes in general, as getting kicked around on bad roads immediately around me is a pretty big discouragement. Just eight to ten miles ride away is the other side of the lake, with far fewer stoplights/signs and much smoother roads. This is what makes small tires a practical reality, at least in my mind. I have realized that I can't figure out what to do with the 1.5's paint job, as well as the fact that I did not buy the Impulse to only put decent components on it. I also did not buy (and get delivered) matching Dura-Ace brakes for my modern 9000 groupset only to never pair them with their shifters, let alone the rest of the groupset just because said groupset was on the 620 or Trek FX where those brakes were V-style.

So we're going full send Glam Roads road bike here. A true successor to my Di2-equipped 64cm Impulse, just with sublime mechanical 9000 generation shifting. Heck, the graphics on it are silver and black, just like 9000 so you know it's meant to be.

Testing the setup a little bit ago with 5800, stem conversion, and the wheels/tires I'll use here--the Stormtrooper look is a winner for sure:


Taking @joejack951 's Innicycle headset from my Trek 620 and installing it here. This is a mockup (aluminum bars and Tiagra STIs) to ascertain how much I'd need to cut the shaft to have a flush look while achieving the desired 50mm saddle-to-brake-lever drop that I run. 15mm is the number. The wheels are placeholders, but the saddle and seatpost are in their respective positions again. And as of this posting, I've made the cut to the shaft and am waiting for some touchup paint to dry before installing it. Such a beautiful piece that is a BREEZE to work with and install. Once installed, the jewelry adornment will begin. Will it get as low as 20 lbs? Who knows. I am excited to build it, though!