D-Plus: First Ride and Run

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by Byron on Apr 04, 2012 at 4:09 AM

D-Plus Gully

Spotting locations for the photos – Photo: Dan Holtz Photography

After posting the latest D-Plus photos, reader Brian Fung asked

Diggin’ your new ride. Curious – besides, being a custom project, were you looking for certain ride qualities when you approached Davidson? You planning to rock it come this fall for CX season?

Yes, rock it! Also, now that I’ve got more time to write about the topic, the D-Plus is a pursuit of passion. It’s the result of a decade of thinking about modal/cross bikes by Mark V, with the work of a Bill Davidson and his crew.

Like the music a band plays, the influences are many and when you combine the talent of a master builder with someone who’s obsessed with the bike, good things happen. As another trusted source on the project said

Master Builder and OCD types were made for each other. Like Internet dating in 1989. If you were there, it was a guaranteed a match.

And the D-Plus is one hot date, in materials, and build. Check the annotated photo below with a full-rez version and more notes on Flickr.

D-Plus Gully

Annoted with notes – click through for full size.

If you’ve followed us for a while, the D-Plus is a progression from the Modal and Hotspur. The Modal is an S&S coupled Ti bike with Paragon dropouts that toggles from fixed, single, geared, and internal. The Hotspur is a Ti racing bike made with Feathertec tubing and a Reynolds carbon rear. Both bikes were intended to prove Ti is a relevant material, in a market flooded with carbon.

We’ve been discussing a Cross version of the Hotspur with modes like the Modal since I got back into Cross 3 years ago. The D-Plus has even larger diameter Feathertec tubes and Paragon track tips with a derailleur hanger.

In an earlier post, I said the bike is built to fight.

It’s also has soul. It’s made here in Seattle, a city of makers and those that believe in what they do.

D-Plus Gully

Front end

First Ride and Run

Between Bill, Mark, and me we’ve ridden thousands of bikes, are very picky, know what we like, and don’t. Also what works where we ride and race. This bike is tuned to the high-end and wound up tight. As expected with the Feathertec tubing, BB OS, 44 mm head tube, and tapered fork, it rides as a modern Ti racing bike should. It’s a stable platform when you’re twisting it around a race course.

Dismount, remount, into a tight turn; down, and up a flyover, the D-Plus will go where you point it. Most importantly, it’s got the “springy” Ti ride.

The ride qualities Brian asked about in the quote above are best expressed in trust. I trust this bike completely to not let me down and perform as I expect. Sharing the same qualities as the Parlee CX-H, the tail doesn’t wag the dog. In other words, the front end isn’t waiting for the rear to catch up, or the fork to stabilize. The parts are interconnected and track true. It also doesn’t shudder.

D-Plus Gully

Classic decals

On one of my Cross workout rides, there’s a transition from grass to concrete that’s always very harsh. Carbon bikes shudder across the section while the D-Plus just glided across it, as if the bump was a mole hill.

If You Have to Ask

As built and spec’d, the D-Plus costs about $10K USD. Detune the spec and knock thousands off the price or weld it in steel and expect ~3k. That’s a price that should encourage an enthusiast to line up at a local race with a handbuilt bike.

If you’re interested, start talking to Mark V and Bill at Davidson Bicycles.

D-Plus Gully

Standard and Ultralight Gore derailleur cable systems plus an inline barrel adjuster to tune the XX rear derailleur

Is that it?

We call this bike the D-Plus because of all the +1s it has. In keeping with Mark’s style, the spec is subtle. The more you look, the more details you’ll notice, like the mud-free, cable-guide routing. Second in importance to the stiff, springy, sure-footed ride is the Paragon slider derailleur hanger.

slider bitches

Modal Derailleur

Depending on the course and my mood, this bike can race single speed or geared. In the winter and/or off season, I can throw down with it in fixed-gear mode. Put fenders on it, 25s, and it’s a rain bike too.

Finally, cause I know you’ll ask, for Pacific Northwest dirt crits with barriers (jungle cross no more), disc brakes aren’t needed or desired. When the industry delivers lightweight and intregrated hydraulics we’ll talk about that more. Until then, we’re not interested.

Racing weight is 17 pounds with nothing crazy light or sketch.

Timing

The bike was timed to the Seattle Bike Expo where it got good buzz and my first ride after SXSW, I had no indication that the Trek Domane was being released, but did say this on Twitter

Memo! Re: Flexy Carbon bikes aka Fondo bikes. Steel & Ti naturally absorb road shock without elastomer gimmicks. Weigh ‘bout the same.

The latest developments in carbon are to make it flexy for Fondo riders, an aging demographic. Well, to those Fondo riders who may want something more suited to them, spec’d and built how they want, check out a bike maker near you. Inquire about steel, Ti, and carbon. Those materials are more relevant to the ride you want and the ride of the D-Plus.

Influences

We’re riffing on the work of Tim Rutledge, Bob Parlee, Gary Klein, Matt Chester, and others with this bike, including the Surly Cross Check. Also thank ENVE Composites for the wheels.

Interested?

So we’re curious about what you think. Does this bike interest you? How would you built up your own custom project?

Find more about it here:

and the #makebikes on G+ and Twitter.

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Comments: 4

Rear facing dropouts with a SRAM 10s mountain derailleur sounds positively hateful, though at least you didn’t try to work fenders or discs in there. I guess your open chain retention is the secret to making it work, letting you derail it entirely.

But would you really rather be able to singlespeed it sans-tensioner for one race a year than be able to easily mount full fenders w/ buddy flap so you can ride it socially in winter? The idea of a bike being ‘modal’ with different wheels + accoutrements has tons of merit (Shamrock has built some good ones recently) but the particular modes you and Mark have fixated on seem ridiculous.

Ridiculous? You hold the chain, pull them wheel out, do the same to pop it back in—we’re using Monkey Nuts to bring the wheel back a bit and also ensure the alignment is on. In 2 x 10 mode with a road derailer, a second less.

If holding a chain for 2 seconds concerns you, then def not the system for you and the trade off for 3 modes is “clumsy axle egress.” Note that it’s a custom bike, so you can build it with a vertical dropout. 2 generations prior to this bike, the Modal used another type of Paragon dropouts that had a swappable hanger. See that here

http://www.flickr.com/photos/huggerindustries/1808077361/

This tip was chosen for it’s greater simplicity and less space needed inside the chain stay and this is race bike. I can see your disagreement with the choice, but it’s far from ridiculous, it’s a solution to a design direction we chose and it was done for more than one race a year.

It’s also got fender mounts in the seat stay bridge and where the shift reverser boss is on the down tube. My concern about that setup is zero. That’s probably cause I’ve squeezed fenders in race bikes and wrestled with wheels so much. Also, another reason I run tubular or tubeless with a can of sealant in a jersey pocket.

@byron

Hotspur has regular Paragon dropouts. the “Modal” S&S bike has the Paragon “slider dropouts”. 

slider dropouts are cool if you run a rear disc or if when you run ss or fixed, you don’t need to re-tension the chain often, eg you don’t have a dual-sided hub with different tooth count cogs/ss freewheels. downside is more weight, complicated rear end geometry, and slow retension for chain.

if you run a rear disc and almost never need to re-tension chain, then standard vert dropouts with an eccentric bb would be my choice. downside is limited range of tension (ie probably must swap chain if cog swap) and clumsy to reposition the eccentric.

discs weren’t part of the design spec at all.  and it is disc brakes that would allow different wheel sizes to be used. if discs were specified, no bike that i have a hand in designing would have horizontal dropouts. aligning mechanical disc brake calipers is one of my least favourite activities, and horizontal dropouts means you basically are doing that all the time.

frankly, if such a thing as strong (yet light) forward-facing horizontal dropouts with a derailleur hanger in titanium existed, that might have been my choice.  but they don’t and it’s partially related to its material properties. singlespeed riders like the track end style more.

yes they make wheel swaps more time consuming, but that’s a trade-off for function, strength, and light weight.  in the end, it just isn’t that difficult.  i’ve been using such dropouts on bikes for almost 8 years touring, racing, commuting. if you’re thinking about versatility, that’s just one bike that toured through the Japanese Alps, ridden in Angkor Wat, and raced with Mario Cipollini.

Surly was the first larger manufacturer to use them in the modern era, and it hasn’t exactly hurt their sales.

the D-Plus was designed to simultaneously be a great CX and SSCX bike; social riding with fenders was a little lower on the priority list.

Got so many bikes, I get them mixed up. Mark is right, it’s the modal with the sliders and I corrected my comment above.

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