Discs??

scottgee

Hi,

I know discs have good stopping power but what are the disadvantages/problems with having them. Most bikes have them but for XC/trail is it worth having them or should i stick to rims?
Cheers

Dan67

Its worth having them.

Advantages

in wet conditions braking is much improved. You dont have to worry about wobbly rims so much. You can brake so much later than with disc brakes.

Disadvantages.

They dont have the feel of rim brakes in the dry. Have to worry about aligning the disc correctly or your pads will wear out fast. Also the rotor has to be true enough to not wear on the pads.

Overall they well worth getting

Northwind

Wee bit heavier than rim brakes too. But then to compensate, you can happily dive into deep mud and your brakes won't instantly fill with goo.

I've not ridden with modern rim brakes, my last bike had some anceint shimano kit on which was effective, but not even remotely close to my very cheap tektro hydraulic disc brakes, which are pretty bottom drawer. Less power, less feel, less consistency. On the other hand, I've not met a cable disc brake which I liked more than those old rim brakes.

nicklouse

Northwind
debatable if they are any heavier. in fact often the disc brake frame combo will be lighter than the V brake frame combo.

Northwind

Mmm, I've never actually weighed either so I can't really stand by it, I've done an indirect compare just by feel and there's not much in the business end parts but the cable runs and lever assemblies are also lighter. The standard wisdom does seem to be that rims are lighter though, so it's not just me

dave_hill

I can't think of any disadvantages of disc brakes, whether cable or hydraulic. I wouldn't go back to rim brakes on an MTB if you paid me!

xtreem

One disadvantage on disc brakes: most pads wear quickly,
and it's more expencive if you have to replace some part like caliper, rotor, lever.

supersonic

I don't think you need discs for trundling through forests and XC - even some light trail work. Too many budget bikes are speccing hydros at the expense of good quality forks.

Simplicity and cost of Vs work well for many. Cost equivalent Vs are a lot lighter ;-)

realnumber 1

dave_hill wrote:

I can't think of any disadvantages of disc brakes, whether cable or hydraulic. I wouldn't go back to rim brakes on an MTB if you paid me!

+1
I find I can go so much quicker with disks due to the consistency in them. I was forever fiddling with the V's and used to get a lot of pain in my fingers from pulling so hard on the levers to try and stop in the wet.

supersonic

I see more problems with discs than we ever had with Vs lol!

realnumber 1

I've only had to realign mine once and bend my front rotter back a bit (think I knocked it when crashing). Only had mine since march mind but so far so good
Could depend on the model Sonic or maybe a lot of people are more put off by maintaining them because of bleeding and things?

supersonic

I think both. If not set up perfectly, they can rub and squeak, and when do go wrong, tend to do so in a pretty bad way! Of course when set up properly and bedded in, many pose no problems at all. I think bleeding and pad changes do put beginners off them.

I use Vs on the XC bike, and discs on the Idirve. In the dry the Vs totally out perfrom the discs in every way. But they are very good Vs! (Avid Arch Rival)

realnumber 1

Must admit my deore V's weren't bad in the dry with good pads but in the wet they were terrible for the type of riding I find my self doing.
As you say though if just doing XC and a bit of light trails then the V's would probably do the job in most cases.
I used to hate it when my rim started rubbing on every spin of the wheel though

BOYDIE

I agree not having to true your wheel all the time is good,you can get away with a very slight wobble.

supersonic

The advances in the last few years with discs has been very good. Weight is dropping, open systems have more adjustability (ie free stroke/bite point adjust), maintenance and reliability has improved and cost has come down. Still not enough to convince me to run discs on an XC bike though!

chrisga

I would take more stopping power over a few grammes saved everytime. You may be riding around with too much stopping power for 99.9% of the time but that one time you need it, you'll know it was worth having.
One issue, not so much a disadvantag to disc brakes noone mentinoed so far is that you have to make sure your frame/forks can take them. Some old or perhaps cheaper frames do not have the disc mounts on. My g/f had/still has a very very capable rockhopper but it is the year before disc mounts came as standard. She was fed up of running in to the back of us everytime we stopped in the wet (everyone running discs apart from her) and she didnt. So when she decided the time was right to upgrade to discs it meant a whole new bike :-(

Northwind

Yeah, even with bikes that come in disc and discless forms, like the hardrocks, the rim brake model doesn't always have the capacity to upgrade. That must surprise some people...