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PostPosted: Tue Mar 20, 2007 7:50 pm 
Retro Guru
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Joined: Mon Jan 29, 2007 2:14 pm
Posts: 373
Location: Oxfordshire
apologies Macscheen, that seatpost thang looks cool, never seen it before
breezer or ritchey did a low tech version (height-right?), not quite the same tho!


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PostPosted: Tue Mar 20, 2007 8:03 pm 
Old School Grand Master

Joined: Wed Jun 29, 2005 11:18 am
Posts: 15807
Location: near cwmcarn
kona kid wrote:
apologies Macscheen, that seatpost thang looks cool, never seen it before
breezer or ritchey did a low tech version (height-right?), not quite the same tho!


breezer hite-rite.


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PostPosted: Tue Mar 20, 2007 8:08 pm 
BoTY Winner
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Joined: Tue Apr 04, 2006 6:39 pm
Posts: 2568
Location: Durango CO, USA
Macscheen wrote:
I would love to put a set of spinergy or similar on but they are either not compatible with disks or the bolt thru front hub.


Not true. Spinergy made disc compatible Rev-X Roks for a year or so late in their production. I've actually seen a couple pairs on ebay recently. They didn't go cheap.


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PostPosted: Tue Mar 20, 2007 9:09 pm 
Retro Guru

Joined: Fri Apr 28, 2006 8:42 pm
Posts: 783
Location: Brighton
I think doing this will kill your wheel.

With rim braking there's no extra stress transmitted between the rim and the hub. It's the rim/tyre that's turning and it's the rim that you're applying the force to. If you use a disc brake you're applying the stopping force at the hub and then asking the wheel to transmit that braking force to the moving rim/tyre.

This is the same stress that pedalling applies, but in reverse. The key difference is the amount of force you can create with a brake is far greater than the force you can generate by pedalling, unless you go by the nickname of "link-snapper". Brake from 30MPH to zero and time it, then accelerate from zero to 30MPH and time it. That's the difference in energy!

Force = Mass x Velocity, but rotating mass is equal to the square of a static mass. I think that means (thinks back to GCSE Physiscs) - quite a lot of force.

Now, probably (only probably) your tyre will lose traction before you apply a force that destroys the wheel, but I get the impression that these wheels suffer from a gradual stress weakening that results in catastrophic failure - applying this kind of force will make that happen much more quickly.

Help, I'm turning into Sheldon Brown....


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 Post subject:
PostPosted: Tue Mar 20, 2007 9:25 pm 
Old School Grand Master
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Posts: 4776
Location: No brakes? Way to commit soldier.
Yeah, what he said.


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PostPosted: Tue Mar 20, 2007 9:43 pm 
Dirt Disciple

Joined: Thu Mar 15, 2007 12:43 am
Posts: 35
Location: Lakes
scant wrote:
spin (tri spoke) did a disc brake wheel in around 96~
shimano later copied it, disc rotor slides onto the spline & lockring holds it in place.


AIR there is a very early Hope disc hub also had splines.

I wouldn't run a Tioga disc with disc brake. As has been pointed out the braking forces are totally different and the Tioga disc isn't the strongest of things. i used to watch JMC destroy them rather quickly...


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 Post subject:
PostPosted: Tue Mar 20, 2007 10:53 pm 
Old School Grand Master

Joined: Wed Jun 29, 2005 11:18 am
Posts: 15807
Location: near cwmcarn
[quote="terryhfs"]...but I get the impression that these wheels suffer from a gradual stress weakening that results in catastrophic failure - applying this kind of force will make that happen much more quickly.
quote]

or in summary, disc drives were sh,te :lol: :wink:


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 Post subject:
PostPosted: Tue Mar 27, 2007 8:10 pm 
BoTY Winner
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Joined: Tue Jul 05, 2005 6:29 pm
Posts: 975
Location: NorCal, USA
I actually heard of one case where someone built a T-disk with disc brakes.

Don't do it.

It's already been said, but in the case of the guy who managed to build the wheel with disc brakes....the force of the braking ripped the Kevlar away from the hub/flange.

Total loss in short order.


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 Post subject:
PostPosted: Tue Mar 27, 2007 8:40 pm 
Dirt Disciple

Joined: Sat Jan 27, 2007 8:45 pm
Posts: 13
Thanks for all the replies - you have convinced me that it is a stupid idea!!

I spoke to the guy from Tag wheels and it turns out that his mag wheels will add 5lb to the bike so going to stick to the Crossmax XL's.


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 Post subject:
PostPosted: Tue Mar 27, 2007 8:49 pm 
B.o.T.Y. Winner / Gold Trader
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Joined: Thu Oct 27, 2005 11:00 am
Posts: 5223
Location: York
just out of curiosity that is an image I would love to see.................I mean, was he going down hill at the time to find this out or just to the end of the road and back when all of a sudden he found himself sat a few inches off the floor.

:lol:

like I say, expensive lesson :?


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