Found: Outrageous 64g Dura Ace Derailleur

64g Dura Ace Derailleur

There are self professed weight weenies out there who bolt on the lightest weight parts they can find, and then there are theses guys – dare we say light weight artists? Found over on the Light-Bikes forum, this stunning 64g (!) derailleur is the product of a duo who go by the handles of FastDad and Cola Wheat. What started life as a spare Shimano Dura Ace 7800 rear derailleur weighing a rather portly (comparitively) 180-190g, was morphed into the show stopper seen above complete with a carbon b-spring. Yes, a one-off carbon spring.

Check out the details, next.

 Original Dura Ace Derailleur

Tuned Dura Ace Derialleur

Based on the looks of things, Stefan who goes by FastDad is quite handy with a Dremel – this is part of where the art comes in. Not only was he able to get the weight down to a very impressive 69g before handing it off to Cola Wheat, but the lines of the cutouts are beautiful. By just looking at it you’d have a hard time figuring out it was done by hand. At the top is an exploded diagram with every stock piece weighed, with the modified versions and the addition of the first cage below.

Tuned Dura Ace Derialleur 2 Tuned Dura Ace Derialleur 1

The final result from Stefan is impressive enough as it is, but it gets better.

Carbon Spring

After the hand off was made to Cola Wheat, Thomas started his magic by building a carbon fiber b-spring! Thomas actually goes into pretty great depth on the creation of the spring which weighs just over 1g.

10g Cage 64g Dura Ace Derailleur 2

In addition to the beautiful anodizing, Thomas also provided the new Tron-esque derailleur cage and pulleys. Total weight for the entire cage is 10 grams.

64g Dura Ace Derailleur 3

All said and done you have a functional derailleur that weighs less than half of the original. I don’t want to know how many hours went into this thing, and I certainly don’t want to be around if it ever gets ripped off by an errant stick, but it sure is nice to look at.

Nice work.


Quinn - 05/29/13 - 2:51pm

but how durable is it?

Mr. P - 05/29/13 - 2:53pm

Nerdiness at it’s finest. I love it!

Nice one FastDad and Cola Wheat!


mike creed - 05/29/13 - 3:04pm

You guys. This is what its about…thanks for making it.

Haywood - 05/29/13 - 3:10pm

nice work guys.

dwiz - 05/29/13 - 3:15pm

another item that while gaining lots of attention from the weight weenies of the world..but i ask you these questions:
how durable is this flimsy thing gonna be?
how AVAILABLE is this thing gonna be?
how much of a pain in the ass is servicing/repairing/parts/pieces gonna be.

is this gonna be one of those items where you can ride it a dozen times then have to replace and or service the crap out it……….one word for ya’ll—-SILLY

Steve - 05/29/13 - 3:21pm

Great art of work !!!!!

Dillao - 05/29/13 - 3:24pm

If that doesn’t get your wheels turning… you’re probably a triathlete.

M.C. Slammer - 05/29/13 - 3:25pm

It’s art… Some get it, some don’t. It’s remarkable not only for it’s appearance, but for the level of skill and craftsmanship applied. Some aspects sport go beyond the utilitarian.

sardinian rider - 05/29/13 - 3:32pm

Find yourself spending a gazilion of euro for a swank-a-drool rear derailleur and see it crumble apart at the very first bad@ss chain crossing.

vectorbug - 05/29/13 - 3:50pm

I love it. Are they taking orders?

Rob M - 05/29/13 - 3:53pm

dwiz, you do realize this is a one-off custom, right? Don’t worry, it won’t make it’s debut on your 2014 Cross Check… silly is right.

Mindless - 05/29/13 - 3:57pm


martin - 05/29/13 - 3:59pm

It wouldn’t work as the first half decent bump you get there is nothing to stop it from throwing the chain!!! ( you have to have an inner chain guide plate! )…..

David French - 05/29/13 - 4:03pm

When my EuroMillions numbers come up, I’ll take a green one!

bin judgin - 05/29/13 - 4:04pm



ant1 - 05/29/13 - 4:16pm

can’t spell silly without ill. this thing is badass.

bbb - 05/29/13 - 4:19pm

I don’t care about the weight, function and durability.
I just can’t take my eyes off those jockey wheels.

Lou - 05/29/13 - 4:20pm

1. It’s a one off. It took like 6 months to complete by the parties involved.
2. Durability is irrelevant. If it makes it 1/10 of a mile then it has succeeded in being one of the most ridiculously light “functional” derailleurs ever built.
3. And who knows, a lot of stuff on bikes is there for a “what if” scenario. Chain catchers, chain tensioners, lawyer tabs, derailleur guide plates, etc. I bet this thing gets a lot farther than you would imagine.

David - 05/29/13 - 4:29pm

A Weight weenie exercise just married up with an artist.
Gorgeous execution, yet it really too pretty to risk a ride with it.
And what about that scale, 4 decimal place accuracy on a gram?

satisFACTORYrider - 05/29/13 - 4:31pm

that. is. badass.

Your Face - 05/29/13 - 4:35pm

That DOES NOT look like a campy seatpost. Why bother?

Chris - 05/29/13 - 4:41pm

Not something I would ever want but I appreciate the workmanship that went into it. The over sized pulley bearings are actually kind of interesting though not having an inner cage plate seems like a sure fire way to get a dropped chain at the first bump.

myke - 05/29/13 - 5:06pm

That is money right there!

Marc Gibeault - 05/29/13 - 5:12pm

Incredible work.
Imagine halving the weight of a part already so light while still being functionnal.
And they didn’t start with a cheap overweight derailleur, it’s already top-of-the line!

ds - 05/29/13 - 5:18pm

Incredible. And high tech should always look like art. Question of total devotion in every domain !

What kind of bearing are in the huge jockey wheels of the 64g ? Needles ?

Congratulations and continue !

Andrew - 05/29/13 - 5:19pm

only having a one sided cage is not a big deal at all, Sunrace did it for a long time with no problems. Believe it or not Sunrace drivetrains actually worked pretty well, their spirit line had some cool design features like top normal front derailleurs (that one was weird), the no outer plate RD, and the cable pinch bolt on the RD was sometimes located ‘inside’ the derailleur, it was very elegant and worked well too.

Andy - 05/29/13 - 5:28pm

Does it actually work? and any performance degradations?

Dex - 05/29/13 - 6:14pm

By far the best component tooling I have ever seen. To know this was done by hand with a Dremel makes it that much more impressive. The carbon spring and anodization shows just how far the creators were willing to take the weight and style issue to the max. Serious kudos very well done!

generalee - 05/29/13 - 6:17pm

i want jockey wheels like that!

aaron - 05/29/13 - 7:10pm

I dont care about the weight, I just want it.

A. - 05/29/13 - 7:57pm

I think this may void the Shimano warranty. Think twice before doing this at home.

ACE - 05/29/13 - 7:59pm

Will this last through an entire race?Who cares if it snaps before you take a left turn. Its pretty and light and and Ive got too much money.

WV Cycling - 05/29/13 - 8:16pm

I’m betting Shimano follows little weight-weenie projects like this behind the scenes to see whether they can improve and copy anything these guys do.

Never said that they would copy or even use the work, but I’m sure they like watching what others are doing for inspiration.

greg - 05/29/13 - 8:46pm

Beyond the functionality aspect, it is also a great design and style exercise. Like a show car that is kinda drivable- it could be a sign of things to come. Wouldn’t you want a derailleur that looked like that but was still bulletproof on your bike? I certainly would.

mk - 05/29/13 - 9:15pm

My singlespeed setup is still lighter

CtoF - 05/29/13 - 10:06pm

Love it!!! I would love to see it mounted on a bike with a black and red KMC chain running through it. THAT’S HOT!

jim - 05/29/13 - 10:14pm

a thing of beauty!
just enlarge the outer diameter of the pulley guide to match the chain.. you’ll have an instant chain guide/cage.
nice work!

Joshua Murdock - 05/30/13 - 12:41am

Possibly the coolest bike part I’ve ever seen. Wow. That really is incredible. Good work!

The Goats - 05/30/13 - 1:21am

Stunning! Big thank you to these guys for being devout (and crazy : ) enough to take it to the end.


The Goats

JCL - 05/30/13 - 1:32am

Just to be complete and to show their dedication and savvy, they also designed a special tool for the “special” jockeys !!!

mountguitars - 05/30/13 - 3:43am

love it or hate, this is such a sick build!

MaLóL - 05/30/13 - 4:53am


Gravity - 05/30/13 - 7:18am

^ – Is that English?

NASH - 05/30/13 - 8:07am

@epo pusher. Metal on metal is fine if there is lubrication between the surfaces, jockey wheels are not a high load part such a wheel bearing.

The general name for this type of design is a bushing and is not commonly associated with (deleted).

CXisfun - 05/30/13 - 8:50am

@epo pusher: isn’t your chain/cassette/chainring combo metal on metal? Did that only last 10 minutes then epically fail?

Loki - 05/30/13 - 9:51am

Gorgeous, interesting and inspirational. Kudos and thanks to the mad men who made it.

ABW - 05/30/13 - 10:07am

Amazing. Makes me so happy that “tuning” a bike now has a definition more like that of the automotive/hot rod world, where you take what you have and make it work better/lighter/more attractive/etc. rather than taking what you have, throwing it in the recycling bin, and buying the next expensive part. Tuning should never be confused with upgrading.

Kark - 05/30/13 - 11:36am

@ epo pusher. you’re a fool. Metal on metal is commonplace in moving and rotational parts. e.g. bearings, sintered bronze or alum bushings, gears, sprockets etc.

perhaps think before you post nonsense and hypothetical gibberish.

ride - 05/30/13 - 11:52am

So many haters.if you have love for the design and plain awesomeness of bikes then you understand why they took so much time to make dosnt matter if it literally never shifts a gear.for all of you haters keep taking your whip in to someone else for service and shut your mouth.meanwhile people like us will push the envelope of of standard issue gear just to finish and say.damn.that’s sick.also I doubt that this is much if any less durable then a normal DA derailleur.I guess everyone should stop making concept bikes because they are not practical….Lets tell Reynolds to stop using carbon “spokes” on the rzrs because they are not practical.lets tell thomson to stop machining from billet because its time consuming.lets tell k edge to stop retrofitting di2 to work with xtr to have a electronic mtb drivetrain.lets stop the use of tapered head tubes and 30 mm spindles and thru axles because the old stuff worked fine.lets tell the guys who built the lightest road bike in the worls that they wasted their time.

ride - 05/30/13 - 11:54am

Xx1 cassette?lame right?

Slow Joe Crow - 05/30/13 - 1:19pm

It looks amazing and Fairwheel should put one on display, but only Germans could be that obsessive about this.

DaleC - 05/30/13 - 1:34pm

EPO pusher – the crankshaft and camshaft bearings in my Checvy V8 are “metal on metal” and they had made it a pitiful 203,000 miles.


Swangarten - 05/30/13 - 1:39pm

@ride- Dead on.

This thing is beautiful. Nice work.

Rick - 05/30/13 - 4:46pm

Beautiful…a real work of art!!!

mike - 05/30/13 - 4:46pm

i still see lots of metal that could be removed. Get out the dremel!

Colaweizen - 05/30/13 - 5:05pm

i’ am one of the constructors for this fantastic RD. Firstable i’ll said many thanks for your great comments. About durable, i’ll mean that it is each of the original RD when not better. All parts are selfmade! It was the first one lightweigt part……

Wijask - 05/30/13 - 6:27pm

Even though I’m a Campy rider and not to much of a weight weenie, this derailleur I would would put on almost any road bike. Just for the swag alone. Then I’d boast the weight and wish for one made for or by campagnolo and bragging rights.

Steve M - 05/30/13 - 6:53pm

Damn that is a bunch of work and quite beautiful. As for the jockey wheels. The bushing /bearing is relatively large due to the big through hole. The friction should be relatively high due to the reduced lever arm. With the large bushing diameter the ‘race’ will have to rotated much faster than if it was the traditional size. There is a reason bike wheels have smallish hubs/bearings/axles.

Jeffrey Barton - 05/30/13 - 6:56pm

The red makes even cooler iooking I would love to get one how can I .

peter wessell - 05/30/13 - 9:19pm

shimano should employ these people asap! beautiful work!

MissedThePoint - 05/30/13 - 10:34pm

Unique art and craftsmanship vs engineering intended to be mass produced. I like.

ThatGuy - 05/30/13 - 10:37pm

Does it bother anyone else that the final number was rounded incorrectly?

JimmyZ - 05/30/13 - 10:54pm

they should have made a gearbox instead.

Iso - 05/31/13 - 12:10pm

Well done!
Rolhoff makes really heavy (sturdy as well) internal geared rear hubs,
they should dispatch one asap to these guys.

Vladimir - 05/31/13 - 12:56pm

I think it’s still no big deal. I want to repeat in the part that does not involve annodizing. Dremel have. The hands also have. There is experience in facilitating a more simple things:

MissedThePoint - 05/31/13 - 3:54pm

Sub 100g pedals coming up next?

Kevin - 05/31/13 - 7:04pm

What a lovely piece of work, and probably not fragile at all, despite what many might think.
I bought a book many years ago called “Fahrradtuning” in German, with loads of examples like this where components were reduced to 30 or 40% of their original weight using a file or dremel. The only material removed is the low stress material. Look how much metal is being used just to support the word “Dura Ace”, because even on the original the corresponding back plate has already been hollowed out. Correct application of file or dremel will improve stress flow and remove stress concentrations in the part making it lighter AND stronger. If you don’t believe me then double butted spokes are the easiest example of this lighter and stronger concept.
The most interesting question is why components as high end as Dura Ace don’t come off the production line like this ?? Are they just saving the weight reductions piece by piece for next year and next year?

JimmyZ - 06/01/13 - 9:05am

I’m getting older, so seeing someone furiously drilling, filing and grinding away on a part to lighten it, only to have the part break under machining, is more gratifying than porn to me.

Bikinbobs - 06/02/13 - 11:11am

Embed it in acrylic and either place it in a time capsule here on earth or send it into deep space on the next interstellar launch as representing 21st century mankindtechnogeekery.

Ashok Captain - 06/02/13 - 11:51pm

FastDad and Cola Wheat,

Greetings from India. That reworked rear mech is utterly B R I L L I A N T – S U P E R G O R G E O U S!

There seem to be a few (few!) places that can still be drilled. And I was mentally Photoshopping the mech to see what it would look like in ‘stealth black’, green (dark and fluo-lime), gold, blue, pink (tribute to the Giro).

And Bike rumor, thanks for passing that around : )



FastDad - 12/01/13 - 6:43am

Hey there,

I can tell you that the RD is still running without any problem 😉


Glenn - 07/12/14 - 8:11pm

I’d like to see what you could do with a steel lugs. Watch out Hetchins! Very impressive. You are an artist and superb craftsperson. Grand ingenuity. – Glenn

Dave - 11/19/14 - 2:19pm

Just stumbled on this. Very pretty. For those of you commenting why Shimano doesn’t do this its because they know it will not be as stable or consistent as their production version. Back in the 90s when CNC boutique was all the rage Shimano answered exactly this question on a sign in a display case full of their CNC prototypes.

Simply put Shimano said we have CNC machines too. We use them for prototyping to determine the best final design before making their forging tooling for production. Forged parts are far stiffer and stronger than machined billet.

Machining a part post forging removes the hardest material at the surface removing significant strength and stiffness. This one off might work for one guy but at the volume Shimano produces it would be a warranty nightmare. Trust me I was a warranty tech during that CNC craze in the 90’s. A lot of CNC parts makers didn’t survive past a few years because they made pretty stuff but Shimano made robust stuff that worked.

Jason Christenson - 01/25/15 - 3:44pm

were can i get one

William - 08/06/15 - 8:43pm

Great job

Are you planning to sell kits?
Have you tried making it on a SRAM?


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