# Is double front disc brake becoming common?



## ivantcs (Jan 22, 2008)

I've seen a few recently. Will it be more common next time?
https://www.togoparts.com/showroom/viewpic.php?srid=4&file=20080909123914043.jpg
https://i137.photobucket.com/albums/q215/wilson413/2833467779_f0b3457379_b.jpg


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## William42 (Oct 29, 2006)

no

for a variety of reasons. Weight, absolutely unnecessary, worse clearance, just more things to go wrong. Bikes you see with those on them are dumb.


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## nnn (Feb 1, 2005)

Yep it's just a few silly bikes built to look 'cool' even though they just look silly. I don't ever see double disc as becoming the 'norm'.


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## HOFFMAN223 (Aug 24, 2004)

Ummm..... no.


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## TrickyRCAF (Jun 18, 2008)

I am intrigued to think some riders perhaps don't get enough stopping power with a single rotor.


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## Gemini2k05 (Apr 19, 2005)

TrickyRCAF said:


> I am intrigued to think some riders perhaps don't get enough stopping power with a single rotor.


I am intrigued how some riders can be so retarded to put 2 rotors on the front


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## KingCrimson (Jun 26, 2008)

Are they actually riders, or are they just damn smart marketing guys who, somehow, can't get us to shut up about their bikes until some rich guy notices and buys one?


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## Berkley (May 21, 2007)

That first bike has a double rear shock (useless) and the second has what appear to be dual 220mm rotors (also useless). 

What kind of riding could you possibly do that requires two 9" Discs in the front?


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## Uncle Cliffy (Jul 7, 2006)

A friend of mine used to work for Risse racing and they had a customer that HAD to run dual front brakes... I guess he weighed around 300 lbs and used to burn up rotors every couple weeks or something.

This was back in the day of HFX-mags though...


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## Djponee (Dec 20, 2006)

ya, i would flip every second if i used dual discs


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## d_m_b (Jun 8, 2007)

Berkley said:


> What kind of riding could you possibly do that requires two 9" Discs in the front?







so...what is that fork? travel...9"? i like the little potted plant; nice touch.


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## Djponee (Dec 20, 2006)

d_m_b you need the gatorbrake 12" rotors for that


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## mark03 (Jan 17, 2008)

unless you weigh a shitload, your not going to have enough traction to use that much braking power.


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## frisky_zissou (Jun 4, 2006)

I think we will see a trend in that as brakes get more powerful, smaller rotors will be used to give better modulation and pure stopping power won't be lacking due to more impressive calipers.


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## zahgurim (Aug 12, 2005)

This is what happens when people that don't actually race/ride DH decide to design DH bikes.

nonsensical crap...


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## Jerk_Chicken (Oct 13, 2005)

Hah, I love how that first pic is mine, but they put their tags on it like it's theirs. It even still has my exif data on it.


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## essenmeinstuff (Sep 4, 2007)

never seen dual disks on a real bike.


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## dd13 (Oct 6, 2005)

camo rims look pretty sick


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## Jim311 (Feb 7, 2006)

If one is good... two must be better!!


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## Ithnu (Feb 16, 2007)

Jim311 said:


> If one is good... two must be better!!


That makes sense in the bedroom too


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## SHIVER ME TIMBERS (Jan 12, 2004)

one time at 230 and then armour and backpack weight of 245....Hayes Mags stopped me easy....no need for 2 fronts


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## stylie (Jan 6, 2007)

dual front dics may have a place in the future if the weight can be reduced but for now it is about as retarded as running a dual rear shock


















over rated at this time even though credit has to be given to those who are trying too hard to create something worthwhile


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## LoozinSkin (Jun 29, 2004)

you'd see less bikes of these dual rotor bikes is you spent more time riding the trails and less time surfing pinkbike


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## ducktape (May 21, 2007)

Bugger the dual shock, but I do like the frame!


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## Sim2u (Nov 22, 2006)

Quick answer...No, of course not.

But, just like all and or many fashion designers who make and design clothes that are essentially functionless and unwearable to 95% of the worlds population, so to do some companies like to show their creativity in making some hell-beast MTB that is essentially unridable to many...but it looks interesting.



ivantcs said:


> I've seen a few recently. Will it be more common next time?
> https://www.togoparts.com/showroom/viewpic.php?srid=4&file=20080909123914043.jpg
> https://i137.photobucket.com/albums/q215/wilson413/2833467779_f0b3457379_b.jpg


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## William42 (Oct 29, 2006)

stylie said:


> dual front dics may have a place in the future if the weight can be reduced


what? why? 1 weighs less then two, and you have enough power to throw yourself over the bars with one finger at 250 lbs with plenty of brakes out there these days, codes, saints, formula the ones all spring to mind, and the new stroker ace should be fine for that too. Why on earth could you desire more?


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## stylie (Jan 6, 2007)

William42 said:


> what? why? 1 weighs less then two, and you have enough power to throw yourself over the bars with one finger at 250 lbs with plenty of brakes out there these days, codes, saints, formula the ones all spring to mind, and the new stroker ace should be fine for that too. Why on earth could you desire more?


alright then, if weight isn't an issue whith everyone trying their best to get their ride to or under the 40 lbs mark, then I don't have an argument so I will restate why a dual disc front fork is unreasonable. because we are not hitting speeds of 60+ mph on a regular basis. A dual front would have some benefits if the speeds we hit were higher then what we are hitting these days but as I see it now a single rotor in the front stops just fine at currrent speeds.
But perhaps in the future we will start hitting some of those old school scary-fast speeds and will need the extra braking control to slowdown before we do a Kennedy off the side of a bridge.... or a clif in our case


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## Jayem (Jul 16, 2005)

It's F-ing retarded, plus there's a better way to acheive the same results. Shimano experimented with this a few years back; They made a disc brake where there were actually two brake tracks that were side-by side, so essentially one rotor, but two brake tracks attached, and then the disc brake had 3 pads, one on each side, and one sandwitched in the middle. The only problem with this arrangement was that it was too powerfull. Otherwise, it allows you to flip yourself over the bars much easier without all the added weight of two entire brake calipers and rotors. Not only that, but new vented rotor setups like the hope Motos allow you to push brake performance further, without the dumb weight and complexity of two calipers and rotors.


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## essenmeinstuff (Sep 4, 2007)

stylie said:


> alright then, if weight isn't an issue whith everyone trying their best to get their ride to or under the 40 lbs mark, then I don't have an argument so I will restate why a dual disc front fork is unreasonable. because we are not hitting speeds of 60+ mph on a regular basis. A dual front would have some benefits if the speeds we hit were higher then what we are hitting these days but as I see it now a single rotor in the front stops just fine at currrent speeds.
> But perhaps in the future we will start hitting some of those old school scary-fast speeds and will need the extra braking control to slowdown before we do a Kennedy off the side of a bridge.... or a clif in our case


Dirt bikes are heavier and much faster then we would ever be on a mtb, and they do just fine with a single disk up front. Its just marketing hype to fools.


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## remember1453 (Aug 20, 2007)

i guess i'm just getting old but I was wondering the other day when one of the detailed descriptions on one of the mail order site said "max rotor size=8 inch" and I thought to myself, "there are rotors larger than 8 inches now?"


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## jdude (Apr 19, 2004)

dd13 said:


> camo rims look pretty sick


ditto!


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## Sim2u (Nov 22, 2006)

Yeah there are...surprisingly. But various compnaies are trying to milk the market and or just push the envelope on what is posible. Kind of like a fashion show really...


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## TLL (Apr 28, 2008)

Jerk_Chicken said:


> Hah, I love how that first pic is mine, but they put their tags on it like it's theirs. It even still has my exif data on it.


Three words: Cease and Desist.


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## stylie (Jan 6, 2007)

essenmeinstuff said:


> Dirt bikes are heavier and much faster then we would ever be on a mtb, and they do just fine with a single disk up front. Its just marketing hype to fools.


I agree with you on the whole hype thing but understand, I am personally not a fan of the whole dual disc thing. I was just pointing out why sometime in the future there might be a need for it. Look at street bikes, they run 2 big a$$ duals up front due to the speed they are designed to carry. That is why I said there might be a need for duals in the future. But as it stands now.... it just dosen't have a market, unless you want to try and break the world's speed record. THEN, there might be a need for it.


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## patico_cr (Apr 19, 2017)

Let's bring this thread back to life. 
Brakes have been the topic of the week in my LBS, and I started the discussion about the possibility of 2 front discs, just like it's done on some motorcycles.
I really believe a twin front brake setup could be useful for cooling purposes, not for better stopping power. There's plenty of power in current systems. But overheating is quite the issue today. 

If you normally need 4 "brake powers" apllied by your front caliper, you'll be aplying 4 "heat units" on a single disc.
Having 2 calipers, each disc can receive 2 "brake powers" and 2 "heat units" and perform the same. 
It would mean less heat and a lower chance of warping or glazing of the brake parts and even fluid boiling.

Of course, both calipers activated by a single lever is the most plausible option. Probably with a bigr main cylinder and a specially designed hose.

Other setups could be tried as well, with some learning curve implied. 

I'd be happy to try a setup like that.


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## shwinn8 (Feb 25, 2006)

I can only see dual front brakes being useful maybe for the world record attempt style speed speed runs


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## 006_007 (Jan 12, 2004)

My judgement was correct ignoring this thread 9 years ago.......


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## Mountain Cycle Shawn (Jan 19, 2004)

The purpose of dual disc brakes is to have exceptionally good modulation and power at the same time. If you know how to use it and you have a brake with great modulation, it can be used as a traction control device in the corners. Especially slippery corners. I use this technique on a dirt bike and while driving the canyons in a sports car, and it works very well.


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## LarryFahn (Jul 19, 2005)

Maybe the morons on 29" DH bikes will need them to slow down their wagons.


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## SHIVER ME TIMBERS (Jan 12, 2004)

the only reason to have 2 rotors up front if you are over 250 lbs and are a rookie starting out....

even if you are a beginer going down steep hills riding your brakes (which causes a lot of heat).... if you have a great brakes on 8 inch rotors you don't need 2 front rotors


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## LarryFahn (Jul 19, 2005)

I'm over 250 and all I need are my Hopes. No issues there. Even back in '07 my Code's were full of power! This is just a stupid discussion. Fahn


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## Bigjunk1 (Sep 17, 2016)

Front brakes effect steering in corners adversely. The rear is important when cornering.


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## RAKC Ind (Jan 27, 2017)

Shouldn't be on your brakes in corners anyway. But front brakes also cause weight shift forward more and possible oversteer. So have to compensate.

I know riders who never use rear brakes. Hell a friend of mine needs to repair/replace his rear brakes, just don't work now, still faster than me. On front brakes only.

Sent from my XT1565 using Tapatalk


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## alexbn921 (Mar 31, 2009)

nope. End of thread.


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## Mountain Cycle Shawn (Jan 19, 2004)

SHIVER ME TIMBERS said:


> the only reason to have 2 rotors up front if you are over 250 lbs and are a rookie starting out....
> 
> even if you are a beginer going down steep hils riding your brakes (which causes a lot of heat) if you have a great brake on 8 inch rotor you don't need to front rotors


The last thing any biginner needs is 2 brakes on the front.


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## zooey (Oct 31, 2016)

How about some middle ground? Take this old Shimano prototype for example:









Story goes that test riders claimed it had way too much power, and tried all sorts of ways to reduce the friction, including contaminating the pads and rotor with grease/oil, in order to ride/race on it. It was even water cooled. Someone said there's a 3rd part that acts as a brake pad between the 2 rotors, but I can't personally verify that.


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## EddyKilowatt (Aug 10, 2007)

Dual brakes if it happens will be about energy dissipation, not braking power.

I don't weigh 250 and ride twisty 5000' descents, so I have no opinion on whether heat dissipation with current brakes needs improvement.


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## patico_cr (Apr 19, 2017)

zooey said:


> How about some middle ground? Take this old Shimano prototype for example:


I had read about that double disc prototype, but hadn't seen a picture until you posted it.
What I understood as that 3rd part, is a pad that goes in the middle of the caliper, and between the 2 rotors. 
Is that black piece a water sprinkler? 
Talk about complicated designs.

As far as I see, this design would provide more power (not what we are looking for), 
but the heat would still be concentrated in one single caliper.


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## zooey (Oct 31, 2016)

So vented rotors and liquid cooling (see radiator) do little for heat dissipation. Having it all in 1 unit is much more complicated than changing a hub and fork for another brakeset, with no less clutter and maintenance issues to deal with. *learns something new*


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## nakkers69 (Apr 22, 2017)

I'd be interested in linked braking and/abs tech as it develops. 

Twin discs seems like a waste of material over any perceived benefit. 


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## Flamingtaco (Mar 12, 2012)

patico_cr;13139809As far as I see said:


> The caliper would absorb less heat, as the rotor has approximately twice the volume and surface area, which results in a lower average surface temperature. If the pads are not significantly smaller than those in a single friction design, they will have a increased sink and thermal transfer surface (four pads Vs two), further reducing the amount of heat that makes it's way into the fluid via the piston.
> 
> Buuuuut... all of this can be addressed in a single rotor design, as Shimano has shown. The fins on their pads can be improved significantly (ex. Kool Stop pinned pads for Zee/Saint), as can those on the Icetech rotors. Heat capacity can be increased through higher rotor volume. Material composition can be improved to imcrease thermal conduction (stainless steel is a low thermal conductor).


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## patico_cr (Apr 19, 2017)

nakkers69 said:


> I'd be interested in linked braking and/abs tech as it develops.


ABS is difficult, but not impossible. Useful? Right now, I don't think so, but I could be wrong.

Linked front/rear braking has been used to some degree of success by major motorcycle manufacturers. ABS has been in that segment a bit longer and has worked better. Sadly, like another fellow poster cited above, ABS has proven to be not so useful for loose terrain conditions, and some purist bikers are against it for 'reasons'. That's why some brands has an ON/OFF switch for this function.

If the manufacturers would like to drip this tech to MTBs, it would require a lot of study and careful development. It must be small and ligth, and and quite resistant to weather and falls and crashes.

There is another problem I see with the development of ABS brakes for bicycles.

Let's say BMW designs a brake system for their GS1200 motorcycle, that includes ABS and linked braking.
Before hand, and engineer knows the dimensions of the bike, it's core and expected running weight, suspension leverage, tire sizes, braking system components and characteristics (levers, caliper, rotor and pads sizes, hose lengths, friction coefficient, etc...), rider/pillion expected riding position, and probably more variables that I don't recall.

Well, the ABS system does it's basic monitoring: compare front and rear tire spinning speeds. As they go out of a certain threshold, the ABS activates. Before it acts, it must take into account the feedback provided by a lot of sensors regarding suspension settings, current speed, throttle position, actual weight, bike inclination and leaning, etc. All this stuff is processed by the ECU and/or ABS computer, and orders the mechanical section of the ABS system to react differently depending on the situation.

There are simpler designs than this one I just described, but there will always be a high degree of complication involved.

*Basically: each motorcycle model must have its ABS brake system tuned specifically for that bike. 
*

As we all know, bicycles are assembled a-la-Frankenstein, and set up differently for each rider. Rider weight means a LOT compared to the bicycle weight, and riding positions vary drastically during a normal ride. 
There can be 1000's of different combinations of factors.

Taking the most simplistic approach to ABS, (tire rotation monitoring only) the bike should be equipped with:
- An ABS sensor in each wheel, paired with a special rotor design for the sensor to read.
- A system of valve actuators to open/close the brakes as needed.
- A whole lot of brake hoses. 
- A computer to do the monitoring and actuate the ABS.
- Brake lever sensors and or fluid pressure sensor to tell the computer the brakes are being activated. 
- Wiring
- A lasting power source.

Another problem that this system would need to face, is mud contamination. I'm sure I'm not the only one who has fallen into a mud pool that covered half his tires.

I believe ABS can be done, but as I said in the beginning of this post, requires a lot of work and careful thinking.

In case it's developed and tests prove it works fine, introducing it to the public will be hard. I'm sure there will be a lot of people against it, just like when front suspension was being introduced. Only time would decide it's fate.


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## patico_cr (Apr 19, 2017)

Flamingtaco said:


> The caliper would absorb less heat, as the rotor has approximately twice the volume and surface area, which results in a lower average surface temperature....


I agree with you. However, I believe more thermal dissipation could be achieved by two calipers and tow rotors. One on each side of the fork.

I also agree with what you said about rotor size and manufacturing materials.

I've reading a lot about brake systems recently, and along all the opinions I've read in this forum, I see double discs have a poor future in the MTB/DH scene.

In the other hand, road bikes might find double disc setup useful. The tendency is to provide those bikes with the smallest discs and calipers, ans still be able to dissipate a lot of heat. Maybe......


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## lazarus2405 (Jul 16, 2011)

patico_cr said:


> In the other hand, road bikes might find double disc setup useful. The tendency is to provide those bikes with the smallest discs and calipers, ans still be able to dissipate a lot of heat. Maybe......


And convince roadies to accept twice as many spinning silver death blades in the pro peloton? :lol:


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## alexbn921 (Mar 31, 2009)

Heat dissipation and thermal loading can both be handled by an appropriate sized single rotor on both mountain bikes and road bike. Road bike are usually moving much faster and will dissipate heat at a greater rate. There simply isn't enough energy in bikes to overcome the best brakes on the market. The only exception would be tandem riders. But then your talking about 2X the weight. Dual rotors will never happen.


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## Flamingtaco (Mar 12, 2012)

patico_cr said:


> I agree with you. However, I believe more thermal dissipation could be achieved by two calipers and tow rotors. One on each side of the fork.


Of course it can. My point was that we don't particularly need that second rotor. 203's front and rear, long pad calipers, finned pads, we have the components right now that can handle almost everything you can throw at a bike. For those few that are lucky enough to have crazy huge altitude drops, there aren't enough people wanting that much heat management to justify the mfg of double rotor hubs at this time.

Check the e-bike scene. It'll probably show up there at some point.


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## Mountain Cycle Shawn (Jan 19, 2004)

Flamingtaco said:


> Of course it can. My point was that we don't particularly need that second rotor. 203's front and rear, long pad calipers, finned pads, we have the components right now that can handle almost everything you can throw at a bike. For those few that are lucky enough to have crazy huge altitude drops, there aren't enough people wanting that much heat management to justify the mfg of double rotor hubs at this time.
> 
> Check the e-bike scene. It'll probably show up there at some point.


Tandems. Some of those guys use both rim and disc brakes.


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## Flamingtaco (Mar 12, 2012)

Mountain Cycle Shawn said:


> Tandems. Some of those guys use both rim and disc brakes.


203's front and rear are pretty stout, but if you'd prefer power, even Santana's 10" rotors can't beat a 2.45x larger 622mm rim for brake torque. I don't get running both, though, when you can just run rim brakes for power, and add a drag brake to manage descents.

Maybe it's a reliability thing? I've read a few blogs where tourers talked about carrying a full set of components with them while traveling regions where bike shops didn't exist.


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## patico_cr (Apr 19, 2017)

Flamingtaco said:


> I've read a few blogs where tourers talked about carrying a full set of components with them while traveling regions where bike shops didn't exist.


I read somewhere, of a group of tourers that never used hydraulic brakes for the same line of thought. It's much easier to service a mechanical disc brake (cable and pads) than an hydraulic that might pop a seal and develop a leak in the middle of nowhere.

I'm not a tourer at all, and sometimes, I'd like to carry on my backpack everything that could fail in the middle of a trip: basically, a full bike.


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## gckless (Aug 25, 2016)

Flamingtaco said:


> Check the e-bike scene. It'll probably show up there at some point.


I'd be willing to bet they will figure out a way to recoup energy on the downs before they put double rotors on there. Which in turn could mean smaller battery packs. Win-win.


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## barebike (Jan 4, 2018)

I have a recumbent tandem with a 16 inch front wheel assembly. I didn't think about the heat dissipation issue until having multiple tire failures on my solo recumbent with 20 inch front wheel. I bike in mountainous terrain and after a painful crash I realized how serious the tandem's small wheel issue was. I am in the process of modifying the front fork to accommodate dual front discs to virtually eliminate this issue. This tandem is a downhill screamer, aerodynamically speaking, and with this modification it will be much more safe.


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## jajst35 (Jan 14, 2011)

Have you found any front hubs having dual sided 6 bolt disc brake mounts?
I just had a rigid (upright) tandem fork modified for this application & I'm in process of searching for hub. Hoping to find a dyno hub.
Agree with above, not necessary but for only a few needs: mountain tandem, backup & serviceability for mechanical disc breaks on long descents.


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## barebike (Jan 4, 2018)

I had a dual disc hub created since I could not locate one. I purchased 2 identical standard single disc front hubs and had a machine shop splice them together by sleeving and bonding them.


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