Which carbon disc fork?
 

I mentioned on another thread that I am interested in converting my tandem to a dual disc braking, and thus need to look into carbon disc forks. I'm not going to use a Fatty Aluminum fork on my Calfee Dragonfly, so I'm looking at carbon disc forks.

My present fork is an ENVE 2.0, with a 1.125" straight steerer, and I've been very pleased with it, as have apparently every body else that has one on a tandem, as I've never heard a bit of complaint. Its labeled Not for Tandem Use, but it sure is a great tandem fork nonetheless.

Disc forks tend to be tapered. I've talked to Steve Chang at Calfee, and if need be, Calfee will perform a head tube transplant so that it can accommodate a tapered fork. A 1.25-1.5" tapered steerer must be beefier than an 1.125" straight steerer (which presumably is why disc forks tend to be tapered).

What is available?

Co-Motion has the Carbon Disc Tandem Fork. It is not a disc version of Co-Mo's new all-carbon tandem fork. It has a straight aluminum steerer, and is not particularly light. I could use it right away, however, without having to do a head tube transplant.

http://www.co-motion.com/media/cache...rk_390_470.jpg

Description
This sleek, carbon disc-only tandem fork you always wanted is finally here. Designed specifically for the rigors of tandem use and disc brakes, made just for Co-Motion. It is equipped with mid-fork rack mounts and fender eyelets, and the tire and fender clearance is virtually identical to our steel tandem forks. Includes standard 1 1/8" aluminum steer tube and a durable high gloss finish. Looking to upgrade your current tandem fork? Here are some specs you should consider:

· Axle to crown measurement: 390 mm
· Steer tube length: 350 mm
· Weight: 745 grams
· Fork Rake: 50 mm



The ENVE Road Disc fork is relatively new.

ROAD DISC

Following suit of its predecessor the Cross Disc fork, our new disc compatible road fork has been designed to the same exacting ENVE standards. These standards result in an innovative new fork that addresses the unique challenges of integrating powerful disc brakes to light weight road bikes. At the same time, the Road Disc fork maintains the lightweight, durability, and confidence inspiring handling that ENVE forks are
known for.

WEIGHT........................435g
MAX TIRE CLEARANCE.......28c
STEERER TUBE LENGTH.......350mm
STEERER DIAMETER.........1.25", 1.5" Tapered
RAKE............................43mm
AXLE TO CROWN...................367mm
ROTOR SIZE........................140 & 160mm (W/Adapter) [It could take a 203 mm with adapter, couldn't it?]
FINISH Road Disc Fork..........UNI


Features unique to this fork are, 140mm post style caliper mounts, and ENVE’s integrated disc hosing retention clip.
http://www.enve.com/cache/ProductTyp...20120719095521

Are there any other carbon disc forks to consider?

First off, Santana said that carbon disc forks are not a good idea with road tandems: http://santanatandems.com/Techno/MechVsHydro.html . I'd actually considered the Wound-Up/Co-Motion disc fork until I'd read the Santana comments. One of the Co-Motion forks -- the earlier one that you mentioned is/was manufactured by Wound-Up. I don't know to whom they farmed their newer fork to. YMMV.

Wound-Up will make you a tandem fork with your choice of rake (as long as your choice is 45 or 50 mm) that's a little lighter than the Co-Motion and still with a straight 1 1/8" steerer. The aesthetics of Wound-up may or may not be your favorite, but they do offer black anodization of the aluminum bits which changes the look (for the better, IMHO).

You probably want to look for a fork with similar rake to your current ENVE, whatever that is (40, 43, 45, or 50mm seem to be the options) unless you're looking to change the handling characteristics of your bike.

Ok, our next is the Wound Up Tandem Duo, seen below on a recent Calfee. Nice livery on that Calfee. The carbon crown looks like a carbon piece substituted for an aluminum on a legacy design. The aluminum jacket holding the disc mount also appears cobbled together. It would be hard to part with the ENVE 2.0 fork to replace with what appears to be low end fork just to get a disc.

I emailed Calfee to find out what the rake on my ENVE 2.0 fork is, and to find if every tandem gets the same 2.0 rake, or whether the rake is individualized.

SPECIFICALLY DESIGNED FOR TANDEM RIDERS WHO DEMAND THE BEST (AND LIGHTEST)

Our Tandem Duo forks are compression molded to take greater advantage of our unique fork leg profile. The Tandem Duo also boasts the industry's first filament wound, all-carbon crown. The combination of these two manufacturing processes has created an incredibly high-strength, lightweight fork that dampens vibration better than any of our competitor's forks. We've also included a disc brake option that is, without doubt, the lightest disc brake fork available for tandems. The Tandem Duo is also available for cantilevered brakes.

Tandem Duo - Disc Brake
Steerer OD........700c 1-1/8"
Material.............Carbon
Steerer Length.........300mm
Rake (mm)......45, 50mm
Race Height..... 387mm
Weight Grams..........660





https://www.bikemania.biz/images/pro...fork-duo-3.jpghttps://scontent-a-pao.xx.fbcdn.net/...23242890_n.jpg

I'm going to be ordering a Wound Up Carbon Disc fork for our Cannondale RT2 in the near future. I want to stick with a disc and 203mm rotor for the front. Bryan at Crank 2 said they can make one with a 53 rake that the Cannondale uses.

The Wound Up will certainly be lighter, and its carbon buzz killing, in comparison to the aluminum Fatty fork on the Cannondale. The Fatty lives on, spec'd incongruously on the supposed high end Cannondale Road Tandem 1, only with a 1.5" steerer.

Have you considered the Co-Motion fork in comparison to the Wound Up?

http://i.ebayimg.com/00/s/MTAwMFgxMD..._id=880000500F

You could look at the Whisky Parts Co. #9 (QBP). Tapered and only good for a 185 disc.

The specs from Universal Cycles:

• Includes 15mm RockShox Maxle Lite
• 42mm width between fork legs - 28c tire on 23mm rim
• Compression plug included
• UD full carbon construction
• Rider weight limit - 350lbs
• 5 year Whisky warranty
• S.H.I.S. Clamp Diameter: 28.6
• Crown Race: 39.7
• Steerer Type: Tapered
• Steerer Tube Length: 350.0 mm
• Fork Rake: 43, 49 mm
• Axle to Crown Length: 367 mm
• Front Axle Type: 15mm Thru
• Wheel Size: 700c
• Wheel Mount Center Offset: 0 mm
• Front Hub Spacing: 100 mm
• Brake Type : Disc
• Brake Usage F/R: Front
• Material: Carbon
• Weight: 375.0 g

I have the Wound Up Carbon disc fork. It's been fine for the two years it's been on the bike. Had a non-disc Wound Up before that so I couldn't really tell any difference in how the bike handled although the rake was very slightly different IIRC. I have V-brakes (XTR's) and a rear 203 disc originally and the dual disc is SO much better overall.

That there is a rider weight limit might usually be a concern, but 350 lbs. is huge, and may have been with tandems in mind.

I of course have no idea as to the benefits of a thru-axle, which is the fav apparently in mountain bikes. I looked it up and found this discussion. Sounds like a thru-axle is for heavier duty applications, and thus possibly applicable to tandems.

Thru Axles in Cyclocross: One Mechanic’s Take

The thru axle certainly has a stiffer feel, more control at lower PSI and even helped eliminate brake chatter on the front by making my front end more rigid. In my experience, the added stiffness from a thru axle set-up will allow you to feel more in control when using low pressure in your tires.



I contacted Calfee, and got this response:

Hi Ritter,

Your ENVE 1 1/8" steerer 2.0 fork has a 45 rake. The 73 degree head tube angle , along with the long wheelbase will offer optimum handling characteristic with either a 43mm rake (5.8 trail) or a 45mm rake ( 5.6 trail) fork.

Cheers, Steve

The Fatty name may have lived on, but that fork is definitely a much different design. Look closely, and you will see the typical bladed shaped fork legs, instead of the old beefy round tubes. Cannondale states the fork is manufactured using it's patented OPI process: http://www.cannondale.com/innovation/OPI/

The OPI description has that the aluminum is forged. This must be forged by Dragon Tech, the Taiwan forging company behind Praxis chainrings. As far as aluminum forks go, this must be a really good aluminum fork. This may explain why Cannondale stayed with an aluminum fork rather than carbon. If they have a super duper new one-piece forged fork, why do they saddle it with the unfortunate name of the boat anchor welded fork that preceded it?


Cannondale’s patented 3D forging process allows us to take structures that would ordinarily consist of multiple pieces that would be bolted, bonded, welded or otherwise joined together and turn them into single-piece forged parts.

By forging the pieces from a single block of aluminum, we end up with exceptionally good grain alignment, which makes the parts stronger, and we eliminate excess, overlapping or redundant material, which makes them lighter.

This technology makes parts like the Lefty OPI outer tube/clamp structure, the Lefty OPI inner leg/axle, the OPI one-piece stem/steerer and the Backbone of the RZ120 possible.

thru axle stiffness I thought was more applicable to suspension forks where the two legs benefit from a stronger tie together as they shock. For a rigid fork I don't think the thru axle matters.

FYI, Niner makes a wicked carbon fork for disc, with NO RIDER WEIGHT LIMIT. More than 100g heftier than the enve, so I tend to believe in the strength. And as a rigid mountain bike fork it should be expected to hold up. But the 470mm axle to crown height far exceeds the 367mm for a road tandem, so it will not fit here. And the niner has a tapered steerer tube, so would need the appropriate straight 44mm frame head tube.

Ritchey makes a carbon disc fork, no weight limit immediately apparent. But again the 459mm axle to crown dimension does not work for road tandem.

With a straight 44 mm head tube, the taper will be provided by headset.

But it seems that modern high end bikes have a tapered internal head tube to match the tapered steerer. From Specialized, describing the SL4:

http://static.specialized.com/media/...-head-tube.jpg

TAPERED, SHAPED HEAD TUBE

WHAT Strategically designed head tube on SL4 frames tapers from 1-1/8” at the top to 1-3/8” at the crown and facilitates massive top and down tube junctions.

WHY Increases strength and stiffness for greater steering precision and responsiveness during out-of-the-saddle efforts.

HOW The wider base creates a stiffer, stronger junction, and the gradual transition of carbon fiber from top to bottom eliminates the potential for weak spots due to sharp angles—carbon is at its best when it keeps a smooth line. Uber-oversized top and down tubes “wrap” around the front of the head tube, creating the ultra-stiff “bulges” at the junctions. The design requires a smaller lower bearing (compared to last year’s 1-1/2”) which saves weight.

And here from Parlee:

http://www.parleecycles.com/storage/...=1364174905410

Tapered head and steerer tubes: An innovation derived from the now industry-wide CEN testing protocols; tapered steerer and head tubes are hardly news anymore, however, with our Z5, we pioneered the use of the smaller 1.250” (32mm) inch lower standard over the heavier 1.500”(38mm) inch standard. Riding the bike demonstrates that the 1.250”(32mm) taper provides the ideal balance for a road bike. Strength, safety, performance and lightweight without harshness.

Parlee, like Calfee, obtains its tubes from ENVE, and the 1.5-1.25" Parlee head tube taper matches the ENVE Road Disc Fork. So, if I am to get a head tube transplant, I think that I will be asking about the tapered head tube that Parlee uses, rather than a straight 44 mm head tube.

I see the whiskey fork listing as 397 not 367mm Axel to crown. Right in thier heading. what am i seeing wrong?

A tapered head tube works on a single and maybe on a surgically retrofit tandem. Bit a ground up tandem benefits from a straight 44 head tube because the frame top tube is most often wider than the narrowed top of the taper. some makers in metal had crimped the top tube width down to make the join but with a straight 44 the tubes join square. http://bikeforums.net/attachment.php...hmentid=346415

It's because (IMHO) Whisky's web page is a PITA. My apologies for not specifying that you had to scroll down the page to see the No. 9 Road Fork. The No. 9 Cross Fork is at the top of the page. Hope this helps.

I'm considering changing out the Fatty on my Cannondale to something in carbon when finances allow. The Fatty is kinda unique in its dimensions: 395mm axle to crown and 53mm rake. The closest carbon fork I've found so far is the Enve Cross Disc. It is also 395mm axle to crown, but the rake is a shallower 47mm. IIRC, a shallower rake means increased trail, so the bike should be a bit more stable at speed, though I'm not sure yet if that's needed for the 'dale.

RV, You're after better heat dissipation capacity. But this solution so far seems fraught with compromise:
A dished front wheel and closer spaced hub flanges will give you a less stable front wheel no winding descents. I have two front wheels with different hub flange spacing, and the difference is marked.
Likely more shudder in the front fork with a disc, especially if you go with 1.125" steerer; that will give you less confidence.
Increased rotational weight, albeit close to the hub
More weight in the fork and disc caliper.
And goodness forbid ravaging your frame to alter in a larger head tube. That sounds scary and beyond consideration.

Just as an alternate thought, consider.
I know you love the bling of your rims, but deep section carbon rims have limited heat dissipation capacity, as any carbon rim is limited in this way. And I don't think you get to leverage the deep section capacity of those rims in your terrain with rolling hills and a speed adverse stoker. If you are looking for better heat capacity, either way you'll be getting a new front wheel, dished, 32 spoke at a minimum for disc loads. But you could raise your heat dissipation capacity all that you need by getting a deep section aluminum rim, 18 or 20 spokes. A rim such as the Kinlin XR 300 or 380, or even a rim by Fir if you go that far. All these rims are well tested on tandem platforms in intensive mountains, even on triplets. The heat dissipation capacity is more than up to the challenge. Carefully select rim tape, which is a weak point on warm rims. One of the couple tandems not to have problems on Ventoux (sp) was an all rim brake tandem. With this set up you get to maintain stable steering, no shudder, and likely less weight than the front disc fork solution.

I agree with this 100%. There is a reason Cannondale uses the "Fatty" fork and high spoke count wheels. The front disc puts a tremendous load on the fork. Reviewers of the SRAM road hydraulic disc were saying that they could feel the fork flex under braking on the SINGLE bikes they were testing.... imagine the loads from a tandem. Bending the fork near the end of the blade is much different than applying the force at the crown (rim brake).

I would stick with getting your rear disc back on track (Aluminum Spyre, or other), keep the deep carbon rim in the rear. Get an aluminum rim up front with a nice rim brake and some Swiss Stop Blue pads.

It would be a cheap experiment really. In fact I could lend you my Deep-V / White Industries / CX-Ray front wheel to try out.

I am running BB7 with Hope v2 floating/vented disc front and rear, front fork is the Wound Up Tandem Duo. I do have to open up the BB7's a bit to fit the disc's in, I think you might be able to do that with the Shimano disc shims. I seem to remember another poster had said he was using the Hope Floating Disc (non vented) with standard BB7's and was happy with the performance. The performance of the disc brakes front and rear is fantastic. When I was running a disc and a caliper I was changing disc pads every 6 weeks. I have changed them once since adding the disc up front at the end of August last year. I do a fair amount of steep descending here in Northern California (and have used them on ventoux*) and I do not have braking problems. I am not a good downhiller and most likely overuse my brakes, but I no longer worry if I will have brakes at the bottom of the hill. My setup is a bit heavy, possibly low tech, some times a bit noisy, but they work great. BTW in the past the rear brake was my main weapon on downhills. I was afraid of a heat induced failure if I overused the front brake, I now use both brakes simultaneously.

*Ventoux seem to have become the standard by which brakes are measured. Having ridden it I am not quite sure why. It is a long descent but I did not find it particularly challenging, not much traffic, no stops, no tight turns, not steep at the end, good run out between turns. I think I have ridden a lot of hills that put greater stress on the brakes here in northern Ca, including Montebello which started this thread.

The prospect of doing major and expensive surgery on my Calfee isn't too inviting, and so I might just take you up on the borrow of the front wheel. My ee brake front caliper is a strong brake, and might as well put it to use!

I would certainly stick with the rim caliper on the front. If you want more heat capacity go to a Hope vented rotor on the rear. You may also be able to run the tyres softer to give a bit more head room if you are worried about blowing the front off. We find 100psi sufficient for the 28mm Ultremo ZX (300lb team).

If the test with an aluminum rim is done I would also take the time to explore the option a standard Dura Ace brake. You might get even better performance with a DA (or Ultegra if a DA not available for test) brake. The small added weight between the ee brake and DA brake is very small when compared to the increased weight of a disk brake. DA brake good pads and an aluminum rim will make a good solid safe brake system.

Reputations are nice, but a side by side test with the same bike, same tires, same rims, and even the same pads under the same conditions would reveal the optimum choice for you.

New D.A 9000's have mad stopping power with virtual no flex, using them on new Macchiato, with Hed Jet 6 Wheelset , who needs carbon? The best of both worlds braking, aero, 23mm width!

Ritterview, I have spare set of Swiss stop blues you can borrow as well. They are slated to go on my single bike, once I finish off the current set. They need a little break-in to be perfect, but they are good pads.