ogre Posted September 17, 2014 Report Share Posted September 17, 2014 reckon they're up to trials love? Quote Link to comment Share on other sites More sharing options...
MartMini Posted September 17, 2014 Report Share Posted September 17, 2014 rb did a design a while ago with ball bearings, dont think the engagement will take the abuse! Quote Link to comment Share on other sites More sharing options...
aener Posted September 17, 2014 Report Share Posted September 17, 2014 Very different design to the bearing clutch hubs, but I don't think they'll stand up to it either. I'd love to be proven wrong and will be keeping a close eye on them, but I'd wager they won't be able to hack it. Not too fussed about the immediacy of engagement - more interested in the lack of noise. Would be a dream come true if I could have a silent hub. 1 Quote Link to comment Share on other sites More sharing options...
niconj Posted September 18, 2014 Report Share Posted September 18, 2014 Would be a dream come true if I could have a silent hub. Hm... I find the sound of an Echo TR freewheel/Hope Trials hub soothing. I wouldn't want it to be silent at all. The instant engagement on the other side... Quote Link to comment Share on other sites More sharing options...
Clerictgm mk2 Posted September 18, 2014 Report Share Posted September 18, 2014 Who needs instant engagement? I ride Hope with 7.5 degrees and feel absolutely no difference between 7.5 and 2.9 on my tryal k-libre 120.9 (shitty freeweheel that lasts without skipping only 1 hour). Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 18, 2014 Report Share Posted September 18, 2014 Looks similar to the Stealth hub. They were a bit hit and miss... Quote Link to comment Share on other sites More sharing options...
isitafox Posted September 18, 2014 Report Share Posted September 18, 2014 Hm... I find the sound of an Echo TR freewheel/Hope Trials hub soothing. I wouldn't want it to be silent at all. The instant engagement on the other side... Drives me insane, slightly dreading the Jitsie freewheel I'm getting as they're supposed to be the loudest you can get. Saying that though at least I know it's working, with a silent hub I'd be scared of putting the power down too hard. Quote Link to comment Share on other sites More sharing options...
niconj Posted September 18, 2014 Report Share Posted September 18, 2014 Drives me insane, slightly dreading the Jitsie freewheel I'm getting as they're supposed to be the loudest you can get. Saying that though at least I know it's working, with a silent hub I'd be scared of putting the power down too hard. Did you say Shimano? Quote Link to comment Share on other sites More sharing options...
Rusevelt Posted September 18, 2014 Report Share Posted September 18, 2014 (edited) Rear hub spins freely like front hub Edited September 18, 2014 by Rusevelt Quote Link to comment Share on other sites More sharing options...
forteh Posted September 18, 2014 Report Share Posted September 18, 2014 Ah sprag clutches, identical to the starter clutch on 99% of motorbikes. Ask the owner of a big single, high torque (read open class supermoto/enduro bike) engine bike how long the starter clutch lasts? Mine completely gave up the ghost after about 7000 miles, it had been slipping for 4000 or so of those miles. I'll stick with my king thanks Quote Link to comment Share on other sites More sharing options...
N.Wood Posted September 18, 2014 Report Share Posted September 18, 2014 Same as the 'anti reverse bearing' on a decent spinning reel. I envisage the hubshell being cracked by the force of the cams. Quote Link to comment Share on other sites More sharing options...
Rusevelt Posted September 18, 2014 Report Share Posted September 18, 2014 Ah sprag clutches, identical to the starter clutch on 99% of motorbikes. Ask the owner of a big single, high torque (read open class supermoto/enduro bike) engine bike how long the starter clutch lasts? Mine completely gave up the ghost after about 7000 miles, it had been slipping for 4000 or so of those miles. I'll stick with my king thanks No moto or bicycle conponent in world will be 100% reliable or failure feel for 100% of it's riding lifetime, but if it provides better performance reliability than the nearest competitor (let's say a Chris King or Hope PRO2), then give it a chance to prove itself. Is Steath the same as this Quote Link to comment Share on other sites More sharing options...
J.KYDD Posted September 18, 2014 Report Share Posted September 18, 2014 Same as the 'anti reverse bearing' on a decent spinning reel. I envisage the hubshell being cracked by the force of the cams. A sprag clutch is similar to a roller clutch, but instead of allowing each piece to roll freely, the cam shaped pieces lock into place when rolled in the opposite direction. Free wheel and the cams barely brush the inner surface of the hub shell, held down by the spring, but pedal and the cams lock into place instantly where ever they are. The other crucial difference is that according to my engineering friends who know a lot more about this stuff than I do, the more torque you place on a roller clutch, the more force is exerted on the hub shell. The sprag doesn’t work in this way, which should mean the absence of cracked hub shells and much lighter overall weight. Quote Link to comment Share on other sites More sharing options...
forteh Posted September 18, 2014 Report Share Posted September 18, 2014 (edited) But as the cam lobes wear it starts to slip, what kills them in motorbikes is the shock loading from trying to bounce a 100mm piston over 12-13:1 compression ratio. I personally can't see them lasting in trials, being a friction device compared to a positive mechanical lock. edit:@ Rusevelt, the design works and is generally pretty reliable, however under certain loads it fails much quicker - in my example turning over a large bore, high compression engine puts such shock loading on the clutch that it soon starts slipping. This is a pretty good analogy for the forces imparted by trials riding. Edited September 18, 2014 by forteh Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted September 18, 2014 Report Share Posted September 18, 2014 The forces have to go somewhere though... Looks like a sprag does try and 'explode' the outer race to me - unless they are using something totally different. Even then the torque has to go into either radial or axial force. Quote Link to comment Share on other sites More sharing options...
laurent Posted September 18, 2014 Report Share Posted September 18, 2014 And the issue is that it could be as dangerous as un chain breakage in case of failure. Freewheel with pawls seems a lot more predictable in that matter. And it is more sensitive to dust or such thing. Quote Link to comment Share on other sites More sharing options...
bing Posted September 18, 2014 Report Share Posted September 18, 2014 I'm not entirely convinced by this design. Like adam quite rightly mentions, the design looks like it would naturally try and break the outer race. Which if the outer race is pressed into a hub shell, it's new hub time if it breaks. It's probably ok for xc useage and BMX racing, but nothing more Quote Link to comment Share on other sites More sharing options...
dezmtber Posted September 18, 2014 Report Share Posted September 18, 2014 If you want to quiten up a hope hub run a little fork lower leg oil inside the freewheel. It shuts them up and keeps them smooth like butter Quote Link to comment Share on other sites More sharing options...
Rusevelt Posted September 18, 2014 Report Share Posted September 18, 2014 (edited) Checkout close up of internals at 01:29 Profile Elite Hub Edited September 18, 2014 by Rusevelt Quote Link to comment Share on other sites More sharing options...
onzatpro09 Posted September 18, 2014 Report Share Posted September 18, 2014 Profile Elite Hub They have something like 204 engagements don't they? But they're pretty expensive... A quick google search reveals that the $450 price tag is about £275. I wonder what the reliability is like?http://www.profileracing.com/estore/product.php?productId=408 Quote Link to comment Share on other sites More sharing options...
Max F Posted September 19, 2014 Report Share Posted September 19, 2014 "Imagine a hub that offered instant, infinite, and silent engagement" No, thanks Quote Link to comment Share on other sites More sharing options...
Rusevelt Posted September 24, 2014 Report Share Posted September 24, 2014 The forces have to go somewhere though... Looks like a sprag does try and 'explode' the outer race to me - unless they are using something totally different. Even then the torque has to go into either radial or axial force. Just remember seeing this prototype on Crewkerz facebook. Quote Link to comment Share on other sites More sharing options...
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