Mountain Biking - Putting discs on a bike

I'm looking to get disc brakes on my 03 garyfisher big sur. It obviously is the big sur w/o the discs. What all do I need, because I know I need more than just the discs

Hubs (or just a new wheelset), calipers, rotors, discs, pads and longer cables.

I'm looking to get disc brakes on my 03 garyfisher big sur. It obviously is the big sur w/o the discs. What all do I need, because I know I need more than just the discs
disc specific hubs (have flanges)

caliper mounting capabilities on fork/frame

...that's about it! :)

disc specific hubs (have flanges)

caliper mounting capabilities on fork/frame

...that's about it! :)


what do those flanges look like? sorry, I'm not familiar with disk brakes...

I'm looking to get disc brakes on my 03 garyfisher big sur. It obviously is the big sur w/o the discs. What all do I need, because I know I need more than just the discs


everything above, plus since you have a fisher you need to get a disc brake kit, your dealer will have to order it for you. Many forum members have this wheelset and its served them well so you might want to look at it since you need new hubs. http://www.pricepoint.com/detail/12012-365_SHIXS3-3-Parts-75-Wheelsets/Shimano-XT-M756-Disc-Wheelset-w_-Sun-Rhyno-Lite-Rims.htm
These are 6 bolt hubs, which I think all brands use except for shimano, correct me if I'm wrong.
Shimano has a proprietary system to affix the discs to the hubs.

These are 6 bolt hubs, which I think all brands use except for shimano, correct me if I'm wrong.
Shimano has a proprietary system to affix the discs to the hubs.
Shimano still has both out there and not all brands used the ISO 6 bolt standard (remember Coda 4 bolts and Rock Shox 3 bolt systems?) :lol:

About how much longer will the pads last compared to regular pads

It will all depend on your riding style. My last set of disc pads lasted about 1 1/2 months. My set before that lasted about 8 months. I'm riding much more aggressive now though and a lot of the riding has been in poor conditions.

Keep in mind that pads usually cost around $25 a set (so $50 for front and back).

How often are you supposed to change your regular pads.

Again, that will depend. It was extremely wet around here last month and I was riding every day through streams, muck and mud. I had new pads on the bike (regular V-brake) and they only lasted a few weeks. Other pads have lasted a few months.

There isn't any time interval on when you are supposed to change pads...just change them when they are almost worn out. The time interval will depend on how you ride, weather conditions (pads generally wear faster when wet), and how often you ride.

Whenever they are worn down about 1/2 way is a good time to replace them.

What I'm trying to ask is, will discs pads last a lot longer than regular pads?

What I'm trying to ask is, will discs pads last a lot longer than regular pads?
Depends on which ones you get

So what are the advantages of discs

So what are the advantages of discs
They have more power and modulation than v-brakes and have much better stopping power than the v-brakes in wet and muddy conditions.

Down side is that if you do very aggressive riding six inch discs will overheat very quickly

Down side is that if you do very aggressive riding six inch discs will overheat very quickly
Not always the case. Besides it's hard to develop flow if you're jamming on the brakes every ten seconds. Unless you're downhilling or doing some really extreme FR 6" rotors will be plenty for most of us here

Worst case scenario, what if I overheat the disc brakes? Will I just warp the rotor, kind of like you would in a vehicle if you do 90 mph and floor the brake?

No. They'll simply become ineffective. Braking is the dissipation of energy, which causes the energy to be released as heat. When your rotors are too hot, they will no longer be able to dissipate energy, therefore they won't work very well, or not at all. Worst case, the hydraulic fluid could boil, and plastic parts on the caliper could melt. The boiling isn't an issue with cable operated discs. It's unlikely you can generate that much heat.

No. They'll simply become ineffective. Braking is the dissipation of energy, which causes the energy to be released as heat. When your rotors are too hot, they will no longer be able to dissipate energy, therefore they won't work very well, or not at all. Worst case, the hydraulic fluid could boil, and plastic parts on the caliper could melt. The boiling isn't an issue with cable operated discs. It's unlikely you can generate that much heat.


In order to do the above you are going to have to really be moving though. I have been running disc brakes for a while and have only had a couple of very minor cases of brake fade. Unless you are riding true downhill courses you should be fine with 6" rotors. I have done some very technical 6 mile xc downhills and never had a problem. These were not true "downhills" though.

In order to do the above you are going to have to really be moving though. I have been running disc brakes for a while and have only had a couple of very minor cases of brake fade. Unless you are riding true downhill courses you should be fine with 6" rotors. I have done some very technical 6 mile xc downhills and never had a problem. These were not true "downhills" though.

I was only answering his question. I think it's unlikely that the average single rider can cook disc brakes to the point they don't work. I'm told by the owner of a tandem recumbent trike that his brakes glowed red hot after slowing from 96km/h. But they still slowed him down. We run 8 inch discs on our tandem, and they're nearly fade-proof. My only concern about swapping to Magura hydraulics is that the rotors are slightly smaller. Even then, they should hold up fine. Anyone that overheats 6 inch discs on a regular basis needs to look at either their style, or the terrain, as it shouldn't ever really be a problem.

Oops, wasn't actually trying to correct you, just adding to it. Sometimes hard to tell these things on a forum. :)

Exatriate - you might be interested in this as well. :)

It's all good. I really want the Magura brakes to work with my XT rotors. I've never been a big fan of warranties anyway...

Most of the time getting products warranteed (sp?) is more trouble than it is worth anyway, especially when dealing with companies as large as Shimano. Hugi on the other hand, I can't get over how great their customer service is! (Slightly off topic but I give them credit whenever I can.)

Another misunderstanding. Magura won't honor their warranty if I use Shimano discs.