________
EQUIPMENT

CX Di2 Live Build with Mark Purdy

Fri, 08/31/2012 - 2:06pm by Andy Shen

Today we're going to do a live build of Mark Purdy's personal CX bike, a LaPierre cyclo-x superlight aluminum frame. Caveats first. This is Mark's personal bike, and he's going to 'drill the shit out of it' to make it all internally routed. He will never sell this bike, and he knows full well he has voided the warranty and he's willing to accept the risk of the frame cracking. He just wants to try to do some crazy shit. So here we go.

And there's hole #1. A wire will go down the stem, into another hole in the steerer tube, and exit here into the downtube. The upper hole will be drilled after the stem height is determined.

Another hole. The wire will exit here, then...

...enter and exit the chainstay.

Shimano's new CX brakes. 

DT R1800 wheels, tubeless and affordable at around $600. 

Brake chatter can be reduced by shortening the length of cable between the hanger and the brakes. Mark is going to use a hanger that bolts to the fork crown (instead of its customary location at the top of the head tube), so he's drilling this hole through (it's a hole for attaching a cable catcher).

That's an aluminum fork crown he just drilled out, not carbon!

There's the hanger installed. Shortening the free cable run will reduce brake chatter.

Fitting the front end, this will tell Mark where exactly to drill the steerer tube and bars.

Finding the location of the upper hole.

Time to drill five holes. Two behind each shifter, one in the middle of the bars leading back into the stem, one on the steerer tube, and here on the seat tube leading to the front derailleur.

Action shot!

The holes in the bars. Mark drilled below the attachment point for the hoods to minimize stress on the bars when he's on the tops or the hoods.

Feeding the wire through the chainstay's going to be tough. Mark'll have to route a guide cable through first, tape it to the wire, then drag it back through. He's expanding the hole to make the process easier.

Spoke too soon. That sucker went right through no problems. Mark is going to use red Sugru to seal the holes. Time to watch the Vuelta stage finish!

Mark has chosen to have junction box A live inside the stem, so he won't be able to adjust the shifting easily once the bike's built. Now he'll build up the rear end of the bike, get the shifting tuned, then complete the front end.

Dedicated Shimano crankset with 46-36 rings. Now you don't have to buy a road crankset and change the rings.

Mark wants to mount the battery nice and low, so he'll install a couple of rivnuts on the downtube. Unfortunately he only has 5mm rivnuts and the mount takes 4mm bolts, so he'll have to grind out the mount.

Two holes for rivnuts, one for the wire.

Popping in the first rivnut.

Grinding down the heads of 5mm bolts so they'll sit flush in the battery mount. If they protrude the battery won't be able to slide in. 

One bolt done, nice and flush.

Ultegra connectors are nice and thin. A 13/64" bit is all it takes.

Mark says the worst is over (we'll see about that). The rear end is all connected, he'll connect the shifters just to make sure everything's working before pressing in the BB.

Pressing in the BB86 cups.

Front derailleur installed, using Shimano's clamp. The clamp is shaped so that the set screw on the derailleur pushes against the clamp instead of the frame.

Fine tuning the shifting with the shifters hooked up but not fully installed. Once this is all set Mark will route the bars and finish the front end.

Bahn mi and bubble tea lunch break!

Normal bike building stuff now, cutting a steerer tube.

With the lower bearing sitting on the fork crown, there's just enough space to slip the fork into the headtube with the wire alongside.

The other end goes into the stem.

Now the fun job of routing the wires through the bars. Mark runs a brake cable through first as a guide. Here he's trying to fish it out of the middle hole.

Tape the end of the wire to the cable and pull.

Plugging in the shifter with the dedicated tool.

Plug the front to the back and it's done. The shifters work, and amazingly the wire crossing from the steerer to the downtube doesn't affect the turn radius at all.

Cabling up the brakes.

These brakes come with 3 different size spacers. Mark is installing a narrower spacer to bring the brake arms in for more heel clearance.

Setting up the front brake. Note the extremely short run of cable from the hanger to the straddle.

Sugru-ing the short runs of wires on the outside.

And that's pretty much it. Kinda cool how the only thing visible coming out of the front end are the two brake cables.

Wrapping the bars with Arundel tape, which Mark finds to be the greatest of all bar tapes.

And she's done! Mark just needs to add sealant and seal the tires, add pedals, and he's done. Thanks for following along.

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To me, for a work like this
By: altair
Thu, 03/27/2014 - 1:17pm

To me, for a work like this you need some basic knowledge about the bikes and some above average knowledge in mechanics. And a lot of experience and guts to perform them without giving space for errors. Anyways, I appreciate your work and the perfection by which you completed them. Good job.
www.seowebsitenow.com

asked and aswered....
By: Mohamed Tubie
Tue, 09/17/2013 - 4:34pm

asked and answered....

i love this, HOWEVER, how
By: Mohamed Tubie
Tue, 09/17/2013 - 4:25pm

i love this, HOWEVER, how does the wire running from the steerer tube into the down tube not get pinched against the head tube when the bars are turned?

Update?
By: Subspd
Tue, 07/09/2013 - 2:20pm

Guys any updates on how this setup held up? Would like to know if you had any frame problems or other issues. Anything you would have done differently?

simply put
By: Cosimo Pulley
Tue, 10/09/2012 - 9:26pm

That is really effing stupid. I wish I hadn't come here.

Mountain bikes
By: Pierre Brifter
Tue, 09/04/2012 - 11:27pm

Break often-- good news for a $ensei

Alexis must be a financial
By: "Tricky" Dick Fuld
Tue, 09/04/2012 - 8:56pm

Alexis must be a financial services industry lawyer, resenting the fact that he often gets slammed with doc drafting requests on Fridays at 4:30 pm by his d-bag banker cyclist clients (who take off for weekend training camps in exotic locales like Northern Westchester), requiring his working late nights and into the weekend.

Be the client, Alexis. Don't hate the players.

I'm not sure I get your point
By: Sensei
Tue, 09/04/2012 - 8:07pm

Thank you for the somewhat back-handed compliment Alexis. I'm just not quite sure I understand what you're trying to get at. Do you race on a Lugged Steel, 6-speed friction bike with Aluminum box section wheels, Benotta Cellotape and Clip/Strap pedals? If not, then I don't think your arguments hold much water. Using curent technology to build a bike that will be fun to ride (as well as fun to build) doesn't seem hyper-serious to me. I hate to be the one to break this to you, but as long as there has been CX racing some people have taken it more seriously than others. Which catagory you fall into is your choice. Stand tough my friend! Don't let that Type-A, D-bag Banker whom I bilk out of his life savings tell you that you have to take CX seriously. Grow your own balls and go have fun at 7am and let the Type-A's have their "Serious" race at 2pm.

You are right about one thing... Mountain bike are much cheaper and less equipment oriented.
(that was sarcasm, for those who couldn't tell)

Mark, I commend you on having
By: Alexis Housing
Tue, 09/04/2012 - 1:22pm

Mark, I commend you on having found a profitable niche in the market. I'm glad that you're able to take the Type A d-bag banker bike racers to the cleaners putting together equipment that no one in their right mind needs.

CX used to be a vacation from the hyper serious people in the road scene, but now they've discovered that it's an even more equipment intensive sport that they can clamp their neuroses to.

At least there's still MTBing...

I didn't know David Cross was
By: Matthieu Drainhole
Mon, 09/03/2012 - 5:47pm

I didn't know David Cross was also a mechanic

How you like them Swiffer
By: Sham Wow
Sun, 09/02/2012 - 8:42pm

How you like them Swiffer dusters? Are they vertically stiff, statically compliant?

dreaded internet curse from
By: monorchid conconi
Sun, 09/02/2012 - 8:16pm

dreaded internet curse from dedicated user. must. find. esc.

http://lmgtfy.com/?q=sugru
By: Rinieri Bartape
Sun, 09/02/2012 - 6:46pm
then there was the sugru
By: monorchid conconi
Sun, 09/02/2012 - 6:43pm

what is that stuff? Sugru? the red-clay thing on the outer housing of the crankshaft hole?

i skipped as soon as i saw the bubble tea. wtf is that stuff?
By: monorchid conconi
Sun, 09/02/2012 - 6:40pm

i mean, i wanted to try it but it sounds way too gay. bubble tea? the don ho show? tiny bubbles? dude, my favorite part was the hula dance at the end when all the old white people got up and swirled it around and laughed at themselves for taking too much enjoyment from their protestant minnesota lives, retirement in tucson notwithstanding.

Then I saw this

What is it they are advertising in the subway now? It looks like an advertisement for guns. Because Sometimes Diplomacy Fails. They are like the Lance Armstrong-Paul Ryan Moonlighting do-over with Willis and what'sername Candace or whatever to sit in and pose for the cameras.

What was her name? Seriousy. It was Maddie on the show, and he was Dave. Bruce was Dave. Candace Bergen? No. Priscilla Presley? No. The other one. What's her name?

Gun adverts in New York City. Disguised as a TV series poster, something to influence you to stay in on a weeknight and sit on a couch.

position?
By: Lorenzo Saddlebag
Sun, 09/02/2012 - 2:10pm

That's a lot of drop for a cross bike.

A few more answers.
By: Sensei
Sat, 09/01/2012 - 12:57pm

Amerigo, none of us have seen this crank before. It's new this season and just became available a couple of months ago. 36T may be a bit on the low side for some people. And it's quite possible that I'll move up to a 38 or 39 if necessary. It may suprise you to learn that I can turn over a 46T. You are welcome to stick with your 44 and be content with the knowlegde that my weiner is also bigger than yours.

Although I appreciate Chubby referring to my mid section as "Beefy", the reality is that there is much more gristle than meat.

Amerigo come on, man, look at
By: Chubby Chaser
Sat, 09/01/2012 - 3:08am

Amerigo come on, man, look at that last photo. The dude's packin some beefy midsection, he needs all the 36x28 he can get.

Weight
By: Arno Rivnut
Sat, 09/01/2012 - 3:03am

Did you weigh the removed material from the holes you drilled? I'm wondering if there is also a weight advantage to this set up...
P.S. DI2 has been proven in the worst cross conditions by the few that did run it last season.

shimano cx cranks -- really?
By: Amerigo Lorica
Sat, 09/01/2012 - 2:45am

I've never seen any cx rider run those cranks, mark really?

36t is too small to be useful in any circumstances and 46 is too big to push unless you are Jan Ullrich or the badger or Ryan Trebon. There is a reason why everyone uses standard road cranks and runs rings between 39t and 44t.

hot chicks in bikini's in mud
By: P. Ervert
Sat, 09/01/2012 - 1:33am

hot chicks in bikini's in mud = good. purdy in mud = not good.

Why?
By: Sensei
Fri, 08/31/2012 - 9:35pm

...don't you trust Di2 in the mud? I'm interested to hear the reasoning for it. Is it based on some past experience or just good ol' paranoia of things we don't understand? I don't mean that sarcastically. If anyone has a legitimate concern then I'd love to assuage it. Yes, I just used the word "ass-wage"

Holy Shit!
By: Sensei
Fri, 08/31/2012 - 9:06pm

I actually CAN store a pencil in my beard. Maybe that will become my new "thing". And what do you mean by "smug"? This is the same face that god gave me and he don't make no junk!

Beutifiul bike but
By: Jules Sealant
Fri, 08/31/2012 - 9:05pm

I wouldn't trust D12 in the mud

Aren't you afraid that the
By: Asshat Kornhole
Fri, 08/31/2012 - 9:00pm

Aren't you afraid that the bike is going to randomly fall apart like the Bluesmobile?

Why do you always make that
By: Asshat Kornhole
Fri, 08/31/2012 - 8:57pm

Why do you always make that smug expression like you have a secret whenever Andy takes your photo? And is that beard good for storing pencils?

A few answers...
By: Sensei
Fri, 08/31/2012 - 8:51pm

A.) I did check the hanger alignment, as we do on every new build. Andy didn't take a pic probably because it's not a very interesting thing to see. There were a lot of steps that weren't documented simply out of practicality. But for what it's worth... the hanger was square from the factory.

B.) Will the wiring inside the steerer/Head/downtube wear on the wiring when I turn the bars? There is a lot of space in between the steerer and Head tubes. Plenty of room for the wiring to move freely without rubbing. But as a precaution against it I wrapped that section of wire with electrical tape. There is still a slight chance of something rubbing to the point of wearing down the insultion and causing a short. But I'm not worried about it. If it happens then I'll replace the wire and do what's necessary to prevent the next one.

-Sensei

Purdy drills a smart hole.
By: Black & Decker
Fri, 08/31/2012 - 8:38pm

Purdy drills a smart hole.

Hanger
By: Schiatta Headset
Fri, 08/31/2012 - 8:32pm

Do you check the hanger alignment. I've never seen a new frame show up with the hanger perfectly aligned. You go through so much trouble to make everything perfect. An out of align hanger will not give as nice of a shift as one that is aligned.

Trying to understand:
By: mikeweb
Fri, 08/31/2012 - 8:11pm

So, the shifter cable routes inside the bars to inside the stem to inside the steerer tube then out the steerer tube directly into the down tube? How are you accounting for the movement of the steerer tube, excess cable in the space between the steerer tube and the downtube (frame)? Won't there be too much friction in there that may damage the cable? But perhaps that frame has a large enough opening between the head tube and down tube...

I'm sure you're on top off all that. A very nice setup.

Your Grandmother...
By: Sensei
Fri, 08/31/2012 - 7:35pm

... Gave me these glasses. She's a kick-ass broad!

I don't mean to sound
By: Rayan Cable
Fri, 08/31/2012 - 6:49pm

I don't mean to sound alarmist, but my grandmother has had those same eyeglasses since 1957.

Nice Ride!
By: Benedetto Tigweld
Fri, 08/31/2012 - 6:33pm

I'm impressed with having the wiring come through the handlebars and the stem! Mark, does this mean we will be seeing you at SICX?

Kevin S.

bull riding
By: joshs
Fri, 08/31/2012 - 2:47pm

hey mark, how many rodeo's would you say you have participated in? and would you say you are better at the timed events or the "rough stock" comp?

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