Nimbus (disc brake) Oracle MUni

[Nurse Ben]

Yeah, the retrofit is the big deal, though now KH has an external disc hub crank set that is really the true retrofit because you don't need to change hubs; yes, MountainUni was first.

Disc brakes are good, I have four set ups, two on the 125 mm Oregon Hub and two on the 100 mm Oracle hub.

Kris added some very insightful comments on this thread: http://www.unicyclist.com/forums/sho...t=93166&page=4

Note that he suggests getting a more powerful brake vs getting a bigger rotor.

Also, he suggests that Maguras would be a better choice for unis that get thrown down a lot in super tech DH scenarios. This comment gives me mixed feelings as I have broken a Magura hydraulic slave fitting from a rock hit and two levers from rock hits, so lever wise it's a push in terms of durability, and it seems to me that having a brake exposed on two sides is more risky than having one exposed on one side...

One comment that I'd make is that having crank mounted disc brake is not only easier to retrofit, it is also easier to remove/adjust, and you will have a stronger wheel. Not that I have had any wheel failures with the Oracle hubs, but the disc brake side spokes are very steep.

[danger_uni]

Originally Posted by Nurse Ben

Yeah, the retrofit is the big deal, though now KH has an external disc hub crank set that is really the true retrofit because you don't need to change hubs; yes, MountainUni was first.

Disc brakes are good, I have four set ups, two on the 125 mm Oregon Hub and two on the 100 mm Oracle hub.

Kris added some very insightful comments on this thread: http://www.unicyclist.com/forums/sho...t=93166&page=4

Note that he suggests getting a more powerful brake vs getting a bigger rotor.

Also, he suggests that Maguras would be a better choice for unis that get thrown down a lot in super tech DH scenarios. This comment gives me mixed feelings as I have broken a Magura hydraulic slave fitting from a rock hit and two levers from rock hits, so lever wise it's a push in terms of durability, and it seems to me that having a brake exposed on two sides is more risky than having one exposed on one side...

One comment that I'd make is that having crank mounted disc brake is not only easier to retrofit, it is also easier to remove/adjust, and you will have a stronger wheel. Not that I have had any wheel failures with the Oracle hubs, but the disc brake side spokes are very steep.

Re my comment, above, about vulnerability of the brakes. Yes there are pros/cons to each. There's no difference in vulnerability of the lever between disk or rim brakes, and the caliper is probably in a less vulnerable position with a disk brake, tucked behind the crank and with no brakeline over the tire. It's just that with trials riding if you jump up a sloping rock surface and slip (a common enough scenario), you're uni usually instantly goes sideways (along with yourself) and grinds its way down the sloping rock surface. Not a good situation for a disk rotor if it's on the side facing the rock.
And with super tech DH - I can imagine a rotor getting dinged if you chuck your uni into a rock garden, but I should admit it has never happened to me so far (damage to rotor).

[MuniAddict]

Unlike maggies, which have an adjustment to bring the pads closer to the rim to compensate for wear, I can find no such adjustment for the Oracle's [bengal] disc brake. Only adjustment I could find is a small screw in the lever but that only changes the lever's up/down position. It doesn't move the pads closer to the disc. If there is such an adjustment, please let me know. Thanks!

[Nurse Ben]

Terry,

The Bengal is a basic disc brake, most disc brakes are designed to have a small tolerance and thin pads that wear slowly, so no adjustment is needed like on a magura. There are some high end brakes that have a measure of pad adjustment, but in my experience it is not necessary.

If you have rubbing, look first to see if the rubbing is in specific places on the rotor, in which case you may just have a rotor that is slightly out of true. They pads will often rub momentarilly after going through water or snow as they shed the moisture and any grit they pick up.

[JacobSpera]

You can move the position of the brake mount holder to the left or right very slightly. I did this with disc brake i have. there is still a slight amount of rub but nothing that is bad, (at least I do not think its bad).

Loving disc brakes sooo much! Its like you can actually use them and still be in control.

[unigami]

Christmas came early for me this year, and I'm excited to offer some first impressions of my new Nimbus 26" Oracle!

First, a bit of background...I started riding in 1998 and was very active for about four years, and then drifted back into road cycling for several years, and then came back into unicycling this summer. In the past my focus has been on building my skills and some distance riding. This year marks the first real experiences that I have had riding muni, and I've really been having such a great time. It's the best! I've been riding a 24" Torker LX with the largest tire I could put on it (1.95) and it functioned fairly well, but I really wanted to get a full fledged muni and I figured while I was at it, I might as well get one with a disc brake.

I debated back and forth between the Oracle and a KH with the crank-mount set-up. I decided on the Oracle because I think the hub mounted disc makes more sense (and just looks better) and because the Oracle is a better value than the KH - with comparable quality. When the Oracle went on sale at UDC at $100 off, I decided to get one now instead of waiting until next spring like I had planned.

First impressions: This is the first "new" unicycle I have purchased since the 700c Semcycle that I bought around 10 years ago. Wow - unicycles sure have changed A LOT since then. The quality of the equipment is amazing! The first thing I saw when I opened the shipping carton was the KH saddle and black graduated Nimbus seat post. Those items alone looked 10X better than the equipment I'm used to. As for the rest of the unicycle, I wasn't sure if I was going to like the red rim of the 26" Oracle, but after I had it out of the box and saw it first hand I was totally happy with the appearance, quality, and design of the wheel and frame. Everything is just beautiful. The only thing that I would want to be different is the color of the brake, being white, but it's not really an issue. The design, decals, color scheme, and quality of the components are all very nicely done and I love it. Oh, the other first impression: this unicycle is much heavier than I expected. That Duro Leopard tire is MASSIVE. I'm definitely going to be putting on something lighter next season.

Assembly: I'm no stranger to working on bicycles and unicycles, so that was no problem at all...install the seat, the pedals, and the brake lever. The instructions are generic and do not refer to setting up the braking system of the Oracle, so that might be an issue for someone that has little experience. For example, I was careful to position the brake lever so that it wouldn't protrude beyond the seat handle and get struck on a drop. I also adjusted the angle of the lever to bring it closer to the seat. Then I noticed that the disk brake was rubbing a bit in one area as I spun the wheel so I did some research and learned how to adjust it. I checked the torque on the cranks and they were fine. None of this was difficult and I actually enjoyed setting it all up but for someone inexperienced it might be more of an issue.

Riding: I brought it to work today and had a short ride at lunch time on a local trail. I was really curious to see how it would feel to ride on that humongous tire and use the brake. I had no problems mounting - I'm used to a 24 but a 26 is so close in size - but once I took off I really noticed a difference in the pedaling effort due to the weight of the wheel. It was a good workout, that's for sure...I'm glad that I stuck with the 165 crank length! On the other hand, the weight of the wheel provides really nice momentum and I was able to roll over some roots really easily, although this trail doesn't have many challenging obstacles on it. (that will come tomorrow). I'm sure that I will get used to the weight and pedaling effort, I think my seat may be a bit too low as well. The Duro tire had a bit of pull on tilted areas of the trail but not too bad, and I adjusted to it quickly. Hopping on that big tire was fun!

Disc Brake: The trail has a nice long sharp descent that I was eager to test the brake on. I fully expected to have a UPD the first time that I used the brake so I practiced with it several times to get a feel for the modulation while I was off the uni and pushing it around, and a little bit when I was riding on the flat. I found it easy to carefully apply just a little bit of brake and it seemed very smooth. No UPD! Then I came to the hill and really had my first experience using it, and it was completely natural and smooth. No problems at all! The brake is going to be very handy on some steep trail sections that I ride on and I'm eager to try it on some sections that I've never been able to ride down.

So that's my little review, coming from a fairly experienced uni rider, but as someone pretty new to muni and very new to the modern equipment that we have now. I'm completely happy with the Oracle and I'm looking forward to my next ride!

[DavidHood]

Originally Posted by unigami

this unicycle is much heavier than I expected. That Duro Leopard tire is MASSIVE. I'm definitely going to be putting on something lighter next season.

Don't dismiss that 3" Duro too quickly. I replaced mine with the Maxxis HighRoller that Kris puts on his new KH26. It did save some weight but my 26" Oracle is still quite a bit heavier than my new KH29. And, since my KH29 (47mm drilled rim) came stock with a Maxxis Ardent 29 x 2.4" tire, I am seriously considering switching my Oracle back to the 3" Duro to differentiate the two rides a little more. I will admit, when I was customizing my Oracle, I was thinking it would be my only MUni so I wanted it to be great for XC as well. But, now that I have my KH29, I want my Oracle set up for tech DH and the Duro is really a very nice tire.

Get a pair of red Deity Compound pedals and one of those new Nimbus Double QR clamps. All I'm missing now is an adjustable seat post and my Oracle will be totally pimped out. Now I just need to pop a spoke on my KH29 so I'll ride it more.

Ditto on the disc brake learning curve. Of course, I knew that when I got my Impulse (sold) 36er. I've gone back to Magura rim brakes on my 36er due to incompatibility with the Schlumpf hub.

[unigami]

Originally Posted by DavidHood

Don't dismiss that 3" Duro too quickly. I replaced mine with the Maxxis HighRoller that Kris puts on his new KH26. It did save some weight but my 26" Oracle is still quite a bit heavier than my new KH29.

I've ordered a Hans Dampf but I'm going to keep the Duro on until Spring to give it a fair trial (and build up my legs!).

I was curious what the weight difference between the Oracle and the KH would be if you take the tire and tube out of the equation. If the weight specs on UDC are accurate the Nimbus Dominator 2 rim is just 160 grams heavier than the KH rim. If you add up all the weights of the seat post, frame, rim, hub, and cranks, the Oracle adds up to be only 68 grams heavier than the KH. Of course the disc brake adds a little too.

I took the Oracle on a 4 mile trail ride this morning and had a blast!