Unicyclist Community

Go Back   Unicyclist Community > Unicycling Discussion > General Unicycling Discussions

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 12 votes, 4.92 average. Display Modes
Old 2010-03-01, 06:00 PM   #16
Max_Dingemans
Pedal Pedal Crash
 
Max_Dingemans's Avatar
 
Join Date: Oct 2002
Location: Minneapolis, MN
Posts: 1,401
Send a message via AIM to Max_Dingemans
John, I think you missed something. The cranks they're currently using come in both square and ISIS, in a large variety of sizes. http://www.sinz-racing.com/drivetrain_home.html
Max_Dingemans is offline   Reply With Quote
Old 2010-03-01, 06:02 PM   #17
rob.northcott
Mainly XC Muni
 
rob.northcott's Avatar
 
Join Date: Aug 2004
Location: Dartmoor, England
Age: 50
Posts: 2,886
Quote:
Originally Posted by johnfoss View Post
The biggest drawback on your current model is the square taper cranks. As a disc brake is kind of a high-end add-on, it would seem much more likely to appeal to the users of splined hubs these days. Hopefully you have an ISIS version in the works.
Quote:
Originally Posted by Mountainuni1
wide range in sizes from 115-180mm square taper & 135-180mm ISIS lengths at an affordable cost
Sounds like they've tried it with both.
__________________
"Hedgehogs - why can't they just share the hedge?" (Dan Antopolski)

"I would absolutely recommend a 29er to anyone who didn't prefer a larger or small wheel." (Mikefule)
rob.northcott is offline   Reply With Quote
Old 2010-03-01, 06:29 PM   #18
MuniAddict
UniGeezer - Not "2" Tired
 
MuniAddict's Avatar
 
Join Date: Aug 2006
Age: 63
Posts: 14,624
Looks interesting, but I'm wondering if this braking system is better than the magura hydraulic rim brake, or just another equally good option. For me the HS33 provides an extremely powerful and sure stopping force, and you can modulate the braking very precisely. It also seems that if the wheel became tweaked, the disk would "wobble" just as the wheel would, making it less effective with the high/low spots.
__________________
Happy Birthday Terry! Every year you get cooler, younger and unicyclier!
Be our muniprohpet for many years more.
-Dani Buron


Website
Videos
Facebook

Last edited by MuniAddict; 2010-03-01 at 06:34 PM.
MuniAddict is offline   Reply With Quote
Old 2010-03-01, 06:40 PM   #19
Tirving
Post Muni
 
Tirving's Avatar
 
Join Date: Oct 2009
Location: Portland, OR, USA
Age: 44
Posts: 837
Quote:
Originally Posted by MuniAddict View Post
Looks interesting, but I'm wondering if this braking system is better than the magura hydraulic rim brake, or just another equally good option. For me the HS33 provides an extremely powerful and sure stopping force, and you can modulate the braking very precisely. It also seems that if the wheel became tweaked, the disk would "wobble" just as the wheel would, making it less effective with the high/low spots.
Wouldn't the same be true for rim brakes? If the wheel is not true.... I get rubbing of my pads.

Plus.... I'm pretty sure the axle would have to be bent for it to affect the rotor as it is attached to the cranks, not the wheel specifically. Maybe I'm seeing this wrong but for the rotor to wobble, the crank would also have to wobble..... right?
Tirving is offline   Reply With Quote
Old 2010-03-01, 06:49 PM   #20
Nurse Ben
XC Muni
 
Nurse Ben's Avatar
 
Join Date: Jul 2008
Location: Northern Cascades, USA
Age: 54
Posts: 4,644
Other than some occassional rubbing with a rim brake, it's hard to see an advantage to a disc, but as a gear whore I feel the call...

One thing, I don't want to weld anthing onto my Ti frame that won't be relevant down the road. However, I do have a Nimbus frame kicking around that would be okay for a little weld.

Why not a bolt on bracket? More saleable for sure.

As to abuse, the location of the disc is likely a safer place than all the brake hose and such on a rim brake, as my recent bent steel braided hose can attest.

Heat will be insignificant with a steel disc, maybe with aluminum it might be an issue. Keeping in mind that we're not doing emergency stops or traveling at bicycling speeds, there should be a lot less heat build up than on a bike. Socks and shoes should be fine protection.

I wondering how much sensitivity you can get from the disc, that's a lot more braking power than a rim brake
Nurse Ben is offline   Reply With Quote
Old 2010-03-01, 07:08 PM   #21
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
schlumpf....

Quote:
Originally Posted by munirocks View Post
I would love to test these but my main unis are KH, so they would require another brake mount. I do have a nightrider too, though.
Schlumpf compatibility would be awesome. Will that be possible?
if Schlumpf uses conventional isis cranks, then yeah. its the whole idea of using cranks for the brakes, you don't have to modify wide hubs or geared hubs.
kb1jki is offline   Reply With Quote
Old 2010-03-01, 07:20 PM   #22
jtrops
Unicyclist
 
Join Date: May 2008
Location: Longmont, Colorado
Age: 51
Posts: 2,299
I think it makes perfect sense for a road going uni. There seems to be a lot of worry about hitting the disc with you foot/ankle, but in all of the time I've ridden bikes I can't remember ever hitting my foot/ankle against the chainwheel. I like the idea of a mount that bolts on, or maybe an endless band like the way road bike brake levers mount.

I think you could expect better modulation with a disc brake on a 36'er than a rim brake. If you think about it there is more leverage between the rim and the disc, and so you should be able to get finer control; although, not stop as quickly. I also like the idea of using a cable brake rather than a hydraulic. The cable brake would allow for a simple drag lever in line with a standard brake lever so that you could have the best of both worlds.
__________________
"A properly ridden unicycle is like an object in orbit: constantly falling but never landing." -Diogenes
jtrops is offline   Reply With Quote
Old 2010-03-01, 07:20 PM   #23
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
I was thinking of having an adaptor made that would screw onto the crank arm like a freewheel on a trials bike crank. It would then allow you to use standard 6 bolt rotors.

My fist thought was that people would rather have a standard disk rather than a oddball disk that may or may not work properly with various calipers. You loose a point there

But

You found a readily available crank in almost all usable sizes for unicycling where you would need a brake and allow the use of other (bike) cranks without modification to be used. +1

Are you planning on making various sized rotors? I would be curious to see if 203mm rotor would feel similar on a 36er as a 160 would feel on a 26.


One suggestion I would make right away though would be to make the rotors compatible with Hayes, Magura, and Avid calipers, as far as I understand it they need a slightly wider braking surface than the Shimano calipers but the braking surface looks very wide so those calipers you mentioned might just be the ones tested and confirmed to work with the disk. Am I right?[/QUOTE]

when we modified a cheap crank for the prototype and bolted on a 160mm 6 bolt rotor, the bolts were 1mm away from the bearing holders -too close. when we decided to use 104mm bcd cranks with 160mm rotors, the bcd was too close. we're using 180mm rotor, and may also make a 203... but this is a drag brake. this rotor should work with all calipers, as it did with shimano. we need the feedback before we build every option. These are the most common usable standards out there. I'm glad you like the idea.
kb1jki is offline   Reply With Quote
Old 2010-03-01, 07:31 PM   #24
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
Quote:
Originally Posted by GizmoDuck View Post
Looks really nice- I think Disc brakes are the way to go especially for bigger wheels. Do you find it gets hot and is there a risk of burning your ankles on the brake? Also, what exactly are you patenting? The concept of attaching a disc brake to a bicycle crank has been discussed before, and at least one other prototype has been made, but this is the nicest I've seen so far.
The disk is an inch closer to the leg because it's outside the frame, but it's unlikely to touch the leg while riding. if you rest your leg against it in an other circumstance, after taking it to sunday river... well the risk is your own. how many people have hurt themselves on a chainring while riding their bicycles? you should be fine... but that's the feedback we're after. the last discussion of brakes on a crank was the prototype for this.
kb1jki is offline   Reply With Quote
Old 2010-03-01, 07:42 PM   #25
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
Quote:
Originally Posted by rob.northcott View Post
I would think the main problem with that would be that the Schlumpf ISIS axle has no stop for the crank, and apparently because of its design it can't use a spacer as a crank stop like other ISIS uni hubs, so you'd need to choose a crank that goes on just enough to get the disc close to the frame without hitting it. But as the OP says it works with square taper (which of course has no crank stop either) then presumably he's thought of a way round that.

- For use as a drag brake on a big wheel, is there enough metal there to disperse the heat on a long descent?

- How wide does that setup end up? It's hard to imagine from the side view, but it seems like it would end up with a big Q.

- I'd also be afraid of dropping it on a rock and bending the disc like somebody else mentioned, but that's a problem with discs on bikes as well - although unicycles do tend to get dropped more often than bikes. If I go out for a bike ride and drop the bike on the ground, it's pretty unusual. If I go out for a muni ride and DON'T drop it, it's pretty unusual.

Rob
We haven't thought our way around the lack of a crank stop spacer, just spacers between the mount and caliper as the square taper wears, remove spacers... There is no extra metal to disperse heat on the disk, but the crank seems like a great heat sink. as far as Q, it's the same as a chainring on a bicycle, conventional. Am... the seat and pedal seem to keep the disk away from the ground on crashes, however rocks could reach up and smack the disk, what can be bent can be unbent -kinda. I haven't had to hammer it flat yet, or even bend it yet.
kb1jki is offline   Reply With Quote
Old 2010-03-01, 07:48 PM   #26
johnfoss
North Shore ridin'
 
johnfoss's Avatar
 
Join Date: Apr 2002
Location: El Dorado Hills, CA
Age: 57
Posts: 17,055
Quote:
Originally Posted by Max_Dingemans View Post
John, I think you missed something.
Sorry about that. I seem to be having trouble editing my posts. Sometimes the edits won't "save" and there seem to be coding issues. That previous post should have had paragraph breaks in it, but they didn't get coded in...

Anyway, I think what Terry was saying could still apply, but not from wheel tweaking. A bent wheel would screw up rim brakes but not a disc. To do that you'd have to bend the disc, which is also a possibility if you have hard knocks against rocks. But could a disc brake be easier to straighten out?
__________________
John Foss
www.unicycling.com

"The miracle is this: the more we share, the more we have." -- Leonard Nimoy
johnfoss is offline   Reply With Quote
Old 2010-03-01, 07:50 PM   #27
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
Quote:
Originally Posted by mikepenton View Post
Not only that, the centre of the pedals would be offset towards the side of the brake, possibly giving an uneven-feeling ride.
I imagine that it is significantly heavier than any rim brake?
(sorry, I'm being negative - it's a great idea and a simple solution to the desire for a disc brake)
We'll submit one for review! the cranks go on evenly, the part that holds the disk on is slightly outboard of the frame, yet still inboard of the person. hydraulic rim brakes are not light, if any weight penalty for a disk is a trade off for consistency if the rim isn't perfectly true, the rim surface is beat, if the wheel is covered in whatever... smooth, predictable, reliable.

a negative opinion to start is the most credible opinion once changed!
kb1jki is offline   Reply With Quote
Old 2010-03-01, 08:03 PM   #28
kb1jki
Unicycles on my mind...
 
kb1jki's Avatar
 
Join Date: Sep 2008
Location: North of Boston, MA
Age: 46
Posts: 877
Quote:
Originally Posted by MuniAddict View Post
Looks interesting, but I'm wondering if this braking system is better than the magura hydraulic rim brake, or just another equally good option. For me the HS33 provides an extremely powerful and sure stopping force, and you can modulate the braking very precisely. It also seems that if the wheel became tweaked, the disk would "wobble" just as the wheel would, making it less effective with the high/low spots.
if you bent the axle, then maybe the disk brakes would be effected, but that's the least of your issues in that event. HS33's are great, but host the same issues that all rim brakes do. when you heat the pads, they glaze the rim, when you wobble the wheel, or goo the rim up with something, or get it wet, it's not as consistent as a disk brake.
kb1jki is offline   Reply With Quote
Old 2010-03-01, 08:27 PM   #29
skrobo
jumps stuff
 
skrobo's Avatar
 
Join Date: May 2006
Location: Corpus Christi TX
Age: 30
Posts: 4,430
Send a message via AIM to skrobo
as far as the problem you guys are suggesting, look at your frames. the majority of all nicks and dings on mine are about 8" up from the axle... and the ones that are closer are very small and because i did something completely out of the ordinary. the pedal and crank are like a big guard for the majority of the disc, but i wouldn't suggest crank grabs on that side.

it is a very original, simple, and useful idea, i like it, but i do have to question etching the name into the disc. it seems that the disc would be very reasonably priced, and significantly easier to produce without that.
__________________
><> Unicycle For Christ <><
MY VIDEOS
World Record
94cm Highest Hop (rolling)
308cm Longest Hop (10 feet)
210cm Static Flat Gap
skrobo is offline   Reply With Quote
Old 2010-03-01, 08:36 PM   #30
Mountainuni1
Unicyclist
 
Mountainuni1's Avatar
 
Join Date: Aug 2008
Location: Pembroke, MA & Stowe, VT
Posts: 239
Send a message via Yahoo to Mountainuni1
Smile

Quote:
Originally Posted by johnfoss View Post
Ulikely. For those of us who knock our ankles into cranks (we've all done it, right?), remember the disk is behind that, so probably impossible for actual ankle or leg contact. Except in a crash. That's where heat could be a factor, bringing you closer to the experience of motorcycling! Having the disc on the outside of the frame is of course not the optimum way to do it. You have that problem of possible rock strikes and off-centered-ness. But the reality of the situation is that building a system for inside of the fork would involve a lot more custom work, and would be quite a bit more expensive. The idea here is to bolt and weld something onto an existing unicycle rather than having to buy a whole new one. The biggest drawback on your current model is the square taper cranks. As a disc brake is kind of a high-end add-on, it would seem much more likely to appeal to the users of splined hubs these days. Hopefully you have an ISIS version in the works. From the tone of the OP, it sounds like you're ready to gear up for a major production run once testing is over. Sounds great! Just remember to have a realistic idea of the size of your market.
The pictured 29er is an ISIS hub, so we're ready for both versions, and I definitely understand the volumes, and potential market. Thanks for the feedback John, and words of encouragement!
Mountainuni1 is offline   Reply With Quote
Reply

Tags
arrived, brakes, disc, mountainuni, mumpitz


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Disc brakes on a uni Pigs on Unicycles General Unicycling Discussions 16 2009-06-17 09:13 PM
disc brakes on a uni zachjowi General Unicycling Discussions 13 2006-08-04 06:10 AM
disc brakes on a uni zachjowi Just Conversation & Introduce Yourself 6 2006-08-02 06:52 PM
disc brakes nb General Unicycling Discussions 14 2003-02-16 10:45 AM
Disc Brakes Scott Bridgman General Unicycling Discussions 0 2001-11-07 03:41 AM


All times are GMT. The time now is 10:31 AM.


Powered by vBulletin®
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright © 2001-2016 Gilby
You Rated this Thread:
Page generated in 0.11469 seconds with 14 queries