[Jersey]

ive been a pretty strong proponent of my XT v brakes for quite some time. i find them plenty powerful, maintanence free and theyre easy to setup, BUT
is it possible to save weight by going with a light disc setup, wheels included?
p.s. my XTs are bone stock

 

[bike_freak]

ive been a pretty strong proponent of my XT v brakes for quite some time. i find them plenty powerful, maintanence free and theyre easy to setup, BUT
is it possible to save weight by going with a light disc setup, wheels included?
p.s. my XTs are bone stock

Yes, Magura Claims something around a 30gram weight saving when going from XT v-brakes to Magura MARTA SL's (per end), not sure on how accurate that is really.

With something like a Hope mono mini, or Magura Marta, with Ti/Alu bolts all around (i am still running stock steel), the seat-ups would probably be lighter. Ofcourse, you will probably add a bit of weight in the hubs, unless you evened that out with something like Stans Alu rotors.

Even if you add a little weight, the performance increase will be well worth it, i admit that well setup V-brakes can be awesome, but my Martas (and most of disc brakes) are just MUCH better then any V-brake, no matter the conditions..

 

[nino]

No...

ive been a pretty strong proponent of my XT v brakes for quite some time. i find them plenty powerful, maintanence free and theyre easy to setup, BUT
is it possible to save weight by going with a light disc setup, wheels included?
p.s. my XTs are bone stock

on brakes alone this might be possible (by spending big bucks on a high-end xc-brake with little rotor)

but don't forget the added weight of disc hubs with sometimes more and heavier spokes. and don't forget the cost of such a wheelset either!

added up alltogether you will always gain 1 pound (ca. 450g) compared to a v-brake.

if you have been happy with your current v-brakes why in hell would you want to spend money and add more weight??? if you want to upgrade and are concerned about weight you might go for something like this:
http://classifieds.mtbr.com/cgi-bin...sults_format=long&db_id=95971&query=retrieval

that's 230g for both ends! so 270g LESS than your current XT, less money spent and still adding power to your brakes.

and don't forget that discbrakes, although en vogue these days, don't have more power than V's! german magazines now rate any disc with small 160 rotor a cx-brake for light riders only. the small rotors suffer from overheating and fading....bigger rotors are cool but even heavier. Discs are ok if you are riding in wet conditions or doing freeride style riding. but then you need big rotors anyway...

think about it!

 

[TechniKal]

Swapping XT v-brakes and levers for a light disk brake such as a Magura Marta will be pretty much an even trade weight wise. Any weight gain you'd see would come from your wheels - where disc hubs are a bit heavier. If you're running a superlight v-brake wheelset, you'll likely gain a few grams.

I don't know about 160mm rotors being for 'cx' use only - seems like crap to me. I know lots of folks - some over 200lbs, who are riding 160mm equipped bikes over gnarly stuff all day and never have a problem with fade or overheating. Maybe bikes in Germany are built differently? I do know that after going to disc brakes, I'd never go back to V's - even if I could knock a bunch of weight off the bike. Disc brakes work better, feel better, and require less maintenance.

 

[nino]

Swapping XT v-brakes and levers for a light disk brake such as a Magura Marta will be pretty much an even trade weight wise. Any weight gain you'd see would come from your wheels - where disc hubs are a bit heavier. If you're running a superlight v-brake wheelset, you'll likely gain a few grams.

I don't know about 160mm rotors being for 'cx' use only - seems like crap to me. I know lots of folks - some over 200lbs, who are riding 160mm equipped bikes over gnarly stuff all day and never have a problem with fade or overheating. Maybe bikes in Germany are built differently? I do know that after going to disc brakes, I'd never go back to V's - even if I could knock a bunch of weight off the bike. Disc brakes work better, feel better, and require less maintenance.

sorry - "little" 160mm discs have less power than a V-brake. this was tested by BIKE magazine. see graphs below where red is dry power, blue is wet power. they tested all brakes on the same roller. the V-brake was just a standard Avid SD on a non coated rim (341 Newtons). ceramic rims would increase dry and especially wet power dramatically! as you can see only the "enduro/freeride" discs offer more power in the dry.

160mm rotors are for lighter riders, or those doing not so stressful rides with their bikes. just throw in a long descent and the small discs are on/over the limit. XTRand XT discs eat up pads like they were some soft cookies, XTR pads bend because of heat...nice!

-agreed - discbrakes are superior in wet/muddy conditions
-discbrakes offer better modulation/feel. however good cables get a v-brake very close in feel.
-definitely not less maintenance! just start with initial setup, durability of pads and cost of replacement parts...a v-brake can be maintained by any rider. a disc is much more complex and needs change of fluids,bleeding and adjusting pads, preparing of frame fittings in order to have them parallel...

 

[TechniKal]

I don't know if disc brakes are more 'powerful' - seems that as long as you can get to the point where the power of the brake exceeds the traction of the tire, then you have all the power you can possibly use. I think neither v-brakes or disc brakes have any problem doing that. And the disc brakes I've used allow better, more consistent modulation before exceeding the traction of the tire.

I agree that v-brakes with fresh cables feel good. Unfortunately, those cables don't feel that way for long.

Initial setup for disc brakes may be a bit harder - but that's debatable depending on the brake and the frame/fork it's being used on. In my experience, disc brakes have required much less maintenance in general use. Pad wear has been better than the v-brakes I've used, and pad changes are super simple compared to V's. The costs of the pads isn't all that much more than decent v-brake pads. I've never had to change fluid. I never have to adjust for pad wear. I never have to change cables. I never notice small variances in the trueness of my wheels anymore... I get the same, consistent feel all the time.

I think v-brakes are great, but I feel disc are a true 'disruptive technology'. They are better in every aspect except possibly weight and price, and both of those detriments are being reduced each product itteration.

 

[Muggsly]

I don't know if disc brakes are more 'powerful' - seems that as long as you can get to the point where the power of the brake exceeds the traction of the tire, then you have all the power you can possibly use. I think neither v-brakes or disc brakes have any problem doing that. And the disc brakes I've used allow better, more consistent modulation before exceeding the traction of the tire.

I agree that v-brakes with fresh cables feel good. Unfortunately, those cables don't feel that way for long.

Initial setup for disc brakes may be a bit harder - but that's debatable depending on the brake and the frame/fork it's being used on. In my experience, disc brakes have required much less maintenance in general use. Pad wear has been better than the v-brakes I've used, and pad changes are super simple compared to V's. The costs of the pads isn't all that much more than decent v-brake pads. I've never had to change fluid. I never have to adjust for pad wear. I never have to change cables. I never notice small variances in the trueness of my wheels anymore... I get the same, consistent feel all the time.

I think v-brakes are great, but I feel disc are a true 'disruptive technology'. They are better in every aspect except possibly weight and price, and both of those detriments are being reduced each product itteration.

I couldn't agree more. Getting a tire to skid can be done with ease no matter the brake setup but skidding does not = stopping. The modulation and level of control with discs far out ways V-brakes. And putting a brake on a machine to test when it stops does not equal real world riding enviroments. In the end the pluses to riding discs vs V's far outweighs the negatives. Just knowing that whenever I pull the lever I will stop no matter the conditions is good enough for me to go disc.

 

[Jersey]

consider this:
im running XT v-brakes all stock and steel canti studs
XT 32h hubs on 517s

would a set of Hugi 240 disc hubs on 28h 517s be roughly the same weight? if so then going with Hope minis (that weigh very close to XTs) would keep the weight just about even.

granted, i love my XTs, but there are certainly times where i can see im pushing them a little too hard and discs would be be superior.

EDIT
so i just added up some #s and:
Hugi 240 disc hubs would save me ~125grams over my non-disc XTs
Mavic 317s are roughly the same weight as 517s plus i could run 28h which would save another ~30-35grams in spokes.
and i could save about ~35-40 grams in removing canti studs
if i can get the Hope minis to weigh less than my XTs than ive saved around 190+grams all together.

does this sound about right?

 

[nino]

consider this:
im running XT v-brakes all stock and steel canti studs
XT 32h hubs on 517s

would a set of Hugi 240 disc hubs on 28h 517s be roughly the same weight? if so then going with Hope minis (that weigh very close to XTs) would keep the weight just about even.

granted, i love my XTs, but there are certainly times where i can see im pushing them a little too hard and discs would be be superior.

EDIT
so i just added up some #s and:
Hugi 240 disc hubs would save me ~125grams over my non-disc XTs
Mavic 317s are roughly the same weight as 517s plus i could run 28h which would save another ~30-35grams in spokes.
and i could save about ~35-40 grams in removing canti studs
if i can get the Hope minis to weigh less than my XTs than ive saved around 190+grams all together.

does this sound about right?

i wouldn't suggest 28 spokes on a disc wheelset.
the rims have the same weight

the DT 240 Disc hubs weigh 148+268 = 416g
the Hope Mini weighs 770g (that's with the 140mm rotor in the back)
total: 1186g

XT hubs weigh 156+370 = 526g
your XT V's weigh 500g
XT levers are 165g
cables ca. 60g
total: 1251gg

overall the DT/Hope setup would be ca. 65g lighter.

BUT

do the math - how much money do you spend to get your bike set up with discs? now invest the same amount in lightweight parts. i'm sure you can save almost 2 lbs by doing so. just think about some lighter wheels and tires in 1st place...

question now is what makes you faster? the discbrake or a 2 lbs lighter bike??? that's up to you.

for me the choice is pretty clear

 

[MightySchmoePong]

In terms of light weight you're probably right.

i wouldn't suggest 28 spokes on a disc wheelset.
the rims have the same weight

the DT 240 Disc hubs weigh 148+268 = 416g
the Hope Mini weighs 770g (that's with the 140mm rotor in the back)
total: 1186g

XT hubs weigh 156+370 = 526g
your XT V's weigh 500g
XT levers are 165g
cables ca. 60g
total: 1251gg

overall the DT/Hope setup would be ca. 65g lighter.

BUT

do the math - how much money do you spend to get your bike set up with discs? now invest the same amount in lightweight parts. i'm sure you can save almost 2 lbs by doing so. just think about some lighter wheels and tires in 1st place...

question now is what makes you faster? the discbrake or a 2 lbs lighter bike??? that's up to you.

for me the choice is pretty clear

I've been running disc brakes on my bikes for the last few years. I recently bought a rigid SS with v-brakes. By _far_ the toughest thing for me to get used to on the new bike was the v-brakes; I've gotten totally spoiled by my discs. Weird but true. I hate the modulation, the feel and on my one of my first rides I hit a stream when the temps were hovering around freezing and.... well you can guess the results.

Even if I were riding someplace that was warm/dry the modulation and control disc brakes provide would be enough.

I swapped my wife over to some Magura Marta's when she got her last bike and she now refuses to ride anything but disc's. She doesn't know squat about the parts on her bike, but she knows she wan't the martas!

Dave

 

[pimpbot]

I dunno, Nino

on brakes alone this might be possible (by spending big bucks on a high-end xc-brake with little rotor)

but don't forget the added weight of disc hubs with sometimes more and heavier spokes. and don't forget the cost of such a wheelset either!

added up alltogether you will always gain 1 pound (ca. 450g) compared to a v-brake.

if you have been happy with your current v-brakes why in hell would you want to spend money and add more weight??? if you want to upgrade and are concerned about weight you might go for something like this:
http://classifieds.mtbr.com/cgi-bin/classifieds/classifieds.pl?db=MtbReview&website=MtbReview&language=&session_key=&search_and_display_db_button=on&results_format=long&db_id=95971&query=retrieval

that's 230g for both ends! so 270g LESS than your current XT, less money spent and still adding power to your brakes.

and don't forget that discbrakes, although en vogue these days, don't have more power than V's! german magazines now rate any disc with small 160 rotor a cx-brake for light riders only. the small rotors suffer from overheating and fading....bigger rotors are cool but even heavier. Discs are ok if you are riding in wet conditions or doing freeride style riding. but then you need big rotors anyway...

think about it!

I agree with the weight gain with discs, but not the power. I got Hopes with 160mm rotors, and weigh about 200 lbs. I'm no lightweight, and ride crazy steep stuff all the time (on what is now a 29 lb bike with winter equipment) and I only overheat the rotors when I know I'm doing something wrong, and keep on doing it anyway. I have to really pound on them to smoke them.

I have to really crank on my LX V-brake to get the same braking power. I have a ceramic front rim with Kool Stop green ceramic pads and a regular rear rim with regular black Kool Stop pads. While they are good, they are not close. I can one finger my Discs all day long, but not my Vees. Maybe I have some setup issue I am not aware of on my Vees, but I don't think so. I've dialed and dialed but this is a good as it gets for me.

 

[Jersey]

yeah i dont know how much i can agree with that graph there.
i ran old school hayes with 6" rotors on my 43lb santa cruz free ride bike and can say that one finger braking and modulation was waaaaay nicer and easier than my XTs
as nice as the XTs are, they cant compare modulation wise. overall power is difficult to determine simply because of the 7" travel fork i was running in the front - brake dive makes for some difficult comparison vs. my SUPER stiff 80mm manitou mars on my XC rig.