Pros/Cons to outer vs inner disc brakes?

[bouin-bouin]

@jaco_flans

The disk has to be used to the right of the mount, so if you want to use inboard with a KH, you need a D-brake, same if you want to go outboard with a Qu-ax.

The distance is different for the D-brake and the KH mount. For example, if you put a KH Spirit setup with a D-brake, you’ll need spacers. The D-brake as the right spacing to be used with an inboard disk setup.

I’m using 1mm washers on my KH36 + D-brake (original design) + disc on Spirit cranks; but I have a lot of rub, even after changing pad material so I just bought Milan’s frame with disc tab to solve it, waiting to receive it

[bristlecone]

@Vertigo

Hmmm, that’s interesting. How was it packed? I’ve been thinking about how to deal with this. Almost every website I find about packing a bike says to take the rotor off. Recently I found Scott Wilton’s description of how he packed his 36er with a disc brake. I think I’d do something like this. I suppose if the rotor does get bent I just won’t use the brake.

The wheel (24") goes diagonally in a suitcase, and I have clothing against the rotor side. Could be that fortune favors the foolish, but I’ve probably gone on 10-15 flights like this by now.

[pierrox]

@jaco_flans

@pierrox;1662382

Dumb question: on a KH frame, meant for an outboard rotor when designed, can you install an inboard rotor?

The disk has to be used to the right of the mount, so if you want to use inboard with a KH, you need a D-brake, same if you want to go outboard with a Qu-ax.

I’m resurrecting this thread as I might build a wheel when my Schlumpf hub moves from my KH24" to the 29". Since I’ll need a hub for the 24", I was thinking “Hey why don’t I get a Nimbus hub with inboard disc”. But re-reading this 4 page thread, I’m realizing I won’t be able to use the tabs on the KH frame with an inboard disc, correct? The only way would be to put the caliper upside-down, yes?

I’ll probably stick to the out-board disc then.

[Eric_aus_Chemnitz]

@pierrox

… I’m realizing I won’t be able to use the tabs on the KH frame with an inboard disc, correct? …

Yes

@pierrox

… The only way would be to put the caliper upside-down, yes? …

Don’t do that. The caliper is not designed to withstand abuse in this direction.

[Siddhartha_Valmont]

@pierrox

The only way would be to put the caliper upside-down, yes?

@Eric aus Chemnitz

Don’t do that. The caliper is not designed to withstand abuse in this direction.

And what about just having the caliper on the front of the uni instead of at the back ?
The caliper would be in the correct side and still proper side up !

[Eric_aus_Chemnitz]

@Siddhartha Valmont

And what about just having the caliper on the front of the uni instead of at the back ?
The caliper would be in the correct side and still proper side up !

Also wrong direction of braking force. It would push the caliper away from the frame instead of against the frame.

Edit:
For this, look also at this thread: http://unicyclist.com/forums/showthread.php?p=1660740#post1660740

[Siddhartha_Valmont]

@Eric aus Chemnitz

Don’t do that. The caliper is not designed to withstand abuse in this direction.

Right, I always forgot…

But… (time for another ugly paint drawing) …what if the Oracle hub is mounted with the disk on the same side as the KH tab ? Wouldn’t the PM adapter work on either side of the frame tab ? (after all the bolts do not care about the way they are installed and the PM adapter is threaded all the way thru…)

[Eric_aus_Chemnitz]

@Siddhartha Valmont

Right, I always forgot…

But… (time for another ugly paint drawing) …what if the Oracle hub is mounted with the disk on the same side as the KH tab ? Wouldn’t the PM adapter work on either side of the frame tab ? (after all the bolts do not care about the way they are installed and the PM adapter is threaded all the way thru…)

Then you would have to mount the caliper upside down, so that its mounting holes are on the frame side of the rotor. But I don’t know how well calipers withstand forces in the opposite direction they’re designed for. Personally I wouldn’t try it, but it could possibly work. Has anybody done this so far?

[saskatchewanian]

Some calipers work with the disk spinning the opposite way and others don’t. I think the biggest factor is how the pad is held in place. Some brakes would eject the pad or jam if they get a lot of backwards pressure. There are some trikes and custom dual disk bikes that run one of their front brakes “backwards”, so it has been done, I’m just not sure about on unicycles.

All that aside, I don’t think you can use the tab on the frame that way anyway. The mounting surface needs to be nearly centered over the bearing and the thickness of the tab would put the caliper way too far inboard without some pretty substantial modifications. If you want an inboard disk I would just get an adapter, or if you are dead set against adapters get another tab welded on the other side of your frame.

[pierrox]

Not dead-set. It was more a “what if” since I like the idea of inboard and the idea of welded tabs. Outboard has been fine so far too.

[lobbybopster]

Non-conventional caliper mount position

@Eric aus Chemnitz

Then you would have to mount the caliper upside down, so that its mounting holes are on the frame side of the rotor. But I don’t know how well calipers withstand forces in the opposite direction they’re designed for. Personally I wouldn’t try it, but it could possibly work. Has anybody done this so far?

Ok, I guess this would count, I have a Coda caliper operating in the opposite position it was originally intended. Dont know how to link this. Pictures @Schlumph hubs general discussion, page101, post #1507 and with over a year of riding this way, no problems with the way it brakes or with the caliper. I had to do it this side for clearance of the torque arm on older schlumph hubs.

[kunstrasen]

How about those bike trial guys? They have brake forces also in backward directions. I know Hope is doing a special trial brake however the attachment is still PM:

Brakes - Trial

So I guess the trial bikes do not have special tabs on the frame.

[vookash]

@lobbybopster

Ok, I guess this would count, I have a Coda caliper operating in the opposite position it was originally intended. Dont know how to link this. Pictures @Schlumph hubs general discussion, page101, post #1507 and with over a year of riding this way, no problems with the way it brakes or with the caliper. I had to do it this side for clearance of the torque arm on older schlumph hubs.

It is here: Schlumpf hubs: general discussion - #1531 by lobbybopster

[lobbybopster]

Picture link

@vookash

It is here: Schlumpf hubs: general discussion - #1531 by lobbybopster

Thanks Vookash

[Reeny]

Reversing the frame and riding it back to front seemed like the lesser of 2-evils, until I noticed that the Magura brake mounts would be on the front of the fork legs.

The slot for the seat post clamp could be hidden by tape or a sleeve, but those mounts for rim brakes are going to be ugly at the front in full view.

[MrImpossible]

@Reeny

Reversing the frame and riding it back to front seemed like the lesser of 2-evils, until I noticed that the Magura brake mounts would be on the front of the fork legs.

Reversing the frame doesn’t really accomplish anything, anyway. The brake would still have to be mounted upside down or something.

I’ve been thinking through the same things because I would like to replace my old 26" Oracle frame with something that has proper disc tabs, and a little more clearance. The KH just doesn’t make sense. What alternatives are there? A 27.5" QX frame? Or Mad4One, which is what I’m leaning towards.

[LanceB]

The new Mad 4 One frames I’ve seen recently are really nice!

[bouin-bouin]

@LanceB

The new Mad 4 One frames I’ve seen recently are really nice!

Last M4O frames have both disc tab for inner and outer setting

[Tony_Black]

Brake adapter forward

I have tought About it And I think it wouldnt work, I Will try it in week but you Will have to have brake upside Down, which is pretty weird;)

[lightbulbjim]

@MrImpossible

Reversing the frame doesn’t really accomplish anything, anyway. The brake would still have to be mounted upside down or something.

I’ve been thinking through the same things because I would like to replace my old 26" Oracle frame with something that has proper disc tabs, and a little more clearance. The KH just doesn’t make sense. What alternatives are there? A 27.5" QX frame? Or Mad4One, which is what I’m leaning towards.

The newer Oracle frames have welded caliper mounts and (I believe) more tyre clearance then the original ones. Available in 26 or 27.5 if you want more vertical clearance. Might be tricky to find in your part of the world though…

Linky: http://www.unicycle.uk.com/unicycle-parts/frames/frames/nimbus-oracle-disc-unicycle-frame.html

Edit: Just noticed that the 27.5 frame isn’t listed in that link. Might not be available separately yet I guess.