disc brake or hydrolic brake?

could someone please help me decide on getting a disc brake or hydrolic brake and give me some pics or reasons why.

Is your question actually Rim Vs Disc brake? Most disc brakes are of the hydrolic persuasion.

well yeah my bad i am just not very educated on brakes for muni. just looking to get one. so i dont have to blow out my leg muscles every time i go down a hill.:smiley:

Can someone tell me what advantages rim brakes have? Are they cheaper, lighter, less prone to breakage?

Are new, standard Kris Holm hubs compatible with disc brakes?

In other words, if I were to get a new KH26 what would it take to put disc brakes on, how much would it cost vs. rim brakes?

I understand the advantages to disc, including performance, less problems with wheel being true etc, but in practice has anyone had experience with both and can they tell me they much prefer disc?

First, the KH disc brake system is not dependant on a hub mounted disc. The KH and Nimbus hubs are compatible. The rotors are connected to the new spirit cranks.

Second, all new (2012) KH unis should have the caliper mount on the frame and come with new spirit cranks. In fact, they should already be set up with a disc brake system. If not, it’s not a 2012. To set up an earlier uni with disc brakes, you would need a bearing holder caliper mount, I recommend the MountainUni caliper mount. You would also need a set of spirit disc cranks, a caliper and 160-180mm rotor, a caliper mount adapter for your 160 or 180mm rotor, and some way to mount the brake lever to the seat.

If you’re in the market for a new uni, get a new KH with disc brakes already set up.

Pros and cons: the biggest reason for me is that with my custom Surly conundrum frame, I can swap out my 29", 26" and 24" wheels as needed, they all have rotors, cranks and pedals set up on them so it’s a quick swap.

I live in the PNW where wet weather is very common, disc brakes work when wet, rim brakes are variable. In muddy conditions, rim brakes get gummed up, disc brakes often don’t. Last, for me, the braking power is very consistent with disc, less so with rim brakes.

Rim brakes work fine unless they get wet.
Rim brakes are limited to a set “contact area”, but you sorta get around that by trying different pads and keeping them well adjusted.
Rim brakes require more adjustment at initial set up and over time.
Rim brakes tend to rub as your wheel flexes from side to side.

Disc brakes require a special crank or hub and caliper mount, so initial set up cost is higher if you are adding them to an existing uni.
Disc brakes can run rotors as large as 230mm, so they can be very powerful.
Disc brakes are not significantly affected by wetness.
Disc brakes are easy to adjust and maintain.

You don’t need disc brakes, you don’t really need brakes at all, but they do save your legs and give you more control. At this point, given that there are two different disc brake systems available, it would make more sense to invest in disc brakes.

I have three hub munted disc brake systems, they work very well, nothing fiddly, but you do need to change out your hub, so wheel rebuilding costs should be factored in unless you build your own wheels. My recommendation is to just get the wheel rebuilt and use a hub mounted rotor system. This is the standard in the mountain bike industry, it works with any crank and any frame, but it won’t work for a geared hub, yet.

Enjoy :smiley:

I’m in a similar situation, deciding if I should get a disc or rim brake to retro-fit my QX 24. During Grischa Muni Challenge I spoke with some of the top riders about this topic.

David Weichenberger (the legend ;)) mentioned that disc brakes are nice to have but the extra braking power compared to rim brakes is not really necessary except maybe when you ride geared (note that he rode brakeless for a long time). Ziga Sternad (2nd in DH this year) rides his Schlumpf hub together with a rim brake and told me that he tried disc brakes but didn’t like them so he stuck with his trusty magura. Jogi from Triton frames rides and enjoys both but pointed out a weakness of disc brakes which is not mentioned very often: during long and brake-intensive descents they can get too hot (damaging the rotor and pads).

The consensus was that even today, a rim brake is a valid option and even preferred by some riders. So I guess, that’s what I’m getting.

Right, that’s why automobiles, trucks, race cars, motorcycles, and downhill mountain bikers all use rim brakes :roll_eyes:

Rim brakes get just as hot as disc brakes and the pads are prone to overheating, which causes quick wear and melting because they are just rubber, whereas disc brakes can be set up to have more braking surface by using a larger rotor, the braking surface (rotor) can be cooled though ventilation and material composition, and the pads can be made of a variety of meterials to optimize cooling vs stopping power (friction).

I’m running a 200mm rotor on my 36er doing long downhill runs under full brake and it has yet to fade or overheat.

Sometimes it’s more important to think through a “problem” than it is to take accept the opinion of others. I’m sure Yogi has his opinion for a reason, but if disc brakes were no better than rim brakes, then we’d all still be running rim brakes on everything.

What does this mean? Does this mean they come with disc brakes? Or does it mean it’s easy to put the disc brake system on the cranks–or easy to put on the hub? If you want hub-mounted disc brakes on a new KH what does that take?

I think I was wrong, all the new frames will have the tab, I think you’ll be on your own for the rest unless UDC and othe retailers set them up with discs. It’s not a big deal though, I set my surly conundrum with with disc brakes easily. :slight_smile:

But what does set them up mean? My understanding is that the spirit cranks allow easy crank mount of disc brakes, but I am also of the understanding that this kind of mount is inferior to hub mounted discs since damage to the rotor is easier when mounted to the cranks. Am I wrong about this?

If hub mounted disc brakes are better, what does it take to set them up on a new KH? Are the new KH hubs compatible out of the box with discs?

Not sure why you’re under the impression that hub mounted rotors are superior to crank mounted for unis, the technology is a bit too new to make that assumption. I have been running crank mounted discs since MountainUni came up with their system and have never had damage.

Setting them up means getting rotor, caliper, lever and everything connected and adjusted so it works.

Not sure either. I think I read it somewhere, maybe Kris Holm’s book.

For someone with limited mechanical skill, is it hard to do the setup oneself, that is disc brakes on crank mounted KH unicycle?

From my experience, the KH system sets up easier than he MountainUni system, but this is does to the Spirit cranks and how solid they are compared to the Sinz cranks I used the MountainUni.

Other than that, it’s easy to set up, it’s a matter of putting everything together than adjusting the caliper. It may take a little “tweaking” but there are plenty of people here who can help you if you need to go down that road.

Two words: Crank Creep

The other issue is clearance of rotor bolts, which has so far caused a bunch of probelms for folks who are adding them aftermarket, so this could improve with the new KH frame or it could continue to be a problem.

In the bike world, hub mounted rotors are the standard, for unis they work just as well, they are better protected from UPD’s than a crank mounted rotor, and no matter which crank you want to use the hub mounted rotors will work. With the crank mounted rotors you have the choice of one crank, one Q factor, and five sizes.

I know you use the crank mounted rotors, but honestly there is no way they are better and there are obvious ways that they are worse. In only one case is the crank mounted rotors hold sway and that is on a geared hub, otherwise it is a retro fit and as such there are retro issues.

If you would just build your own wheels, then swapping hubs would be easy :slight_smile:

Get the hub mounted rotors, it’s a no brainer for a new uni.

Again, on unicycles, this assumption is too soon. I have not had to adjust my MountainUni Sinz system since I set it (which took a while to get perfect) 1.5 years ago. How are my cranks going to creep when they’re properly butted against spacers? I understand the theory, but in practice, I’m not sure it’s an issue on unicycles.

Another assumption… I DO build my own wheels

You listed disadvantages, I’ll agree with these, but in practice, the crank mounted systems are structurally as good as the hub mounted ones.

None of the disadvantages you listed apply to me, I have exactly the cranks I want in exactly the length I use. I ride hard and crash a lot, I have never had serious damage to my rotor. Much less than rotors on various Mt. Bikes that I have crashed on. On crank mounted rotors, it’s much easier to true them on the trail.

I’m not telling anyone that one is superior to the other, I’m refuting your absolute bias. It seems this happens a lot with you about pretty much every piece of uni equipment you purchase :slight_smile:

‘fat tires are better that thinner tires’, ‘29-er is the best size wheel for muni’, ‘Guni is the way to go’, ‘I don’t like Guni anymore, muni 36-er is the new wave’. Etc. You’re passionate about the equipment you purchase, that’s good.

I’m just trying to give an unbiased opinion about crank mounted discs. I might build a wheel with a disc hub and try it out on my frame, if it works, I may like it. I’m not 100% sold on dished uni wheels, asymmetrical wheel builds on a uni just seems wrong to me. This feeling doesn’t mean I’m right. :slight_smile:

So if I want hub disc, can I use a KH hub? Are they compatible? Does it have to be custom built?

It’s all so complicated, I may just go with the rim brakes.

The only hub disk available now is the Nimbus Oracle (?). If you get the new KH Spirit cranks, you can fit the disk on the crank and you can use any existing ISIS hub. You will have the disk mounted on the outside of the frame.

Disc hubs are being produced by Nimbus (3 styles), Mad4One (2 styles), and QuAx, with more to follow.