Well, I guess its not under much stress.
Don't bmxers occasionally run thier chanring on the left side? This would either suggest that there's a standard for left side drive cranks or the pedals really don't fall off. Since the chain is going to a jackshaft it really wouldn't be a problem to use a BMX crank anyways.
GT has wanted to build this bike for years but Shimano told them their Nexus was a commuter hub and wouldn't hold up. This year Shimano finally came out with the Nexus 8R Sport which is supposed to be lighter, more efficient, and more importantly tough enough for mountain bike user.Originally posted by Village Idiot
A commuter hub on a DH bike
Really? I've never anywhere seen Shimano or anyone else say the Nexus could hold up to real abuse. I've been reading as much on the 8R Sport as I could too, as I'm interested in it for my city bike. Where did you get your mountain-bike-use-OK info?
Umm, would it? Uhhh... no.
keep in mind that the hub is being mounted in the frame in this case, so the only real 'abuse' is comming from the high gearing of pedalling a DH bike without any structural forces.
Uhuh, now, grab a pedal spanner, put it on your pedal, and hold it flat as if your foot was using it as the pedal. Rotate the cranks forward as if you're pedalling forward, whilst holding the spanner horizontal the whole time... what happens?
the bearings in the pedal reverse the torque direction, so the pedals are indeed being 'tightened' while riding.
is my brain, my apologies... I don't understand how that works, and it's too early to think about it, so I'll just accept what you say.
think of the bearing in the pedal as a little gear; when the pedal cage rotates in one direction, the bearing rolls against it rotating in the opposite direction. Thats why the torque is reversed.Originally posted by Rik
i think i understand... let us consider the right pedal, top part of the spindle as the cranks are rotated forward. between the spindle and the top of the pedal is, for simplicity here, a single ball bearing. as the crank is rotated the pedal turns counterclockwise with respect to the spindle. our hypothetical ball bearing on the top of the spindle also turns counterclockwise. this means the ball bearing's top surface is moving "forward", and its bottom surface is moving "backward." in any case the point is that the opposite side of the ball bearing is exerting a torque opposite of that exerted by the counterclockwise-rotating pedal. that is, the torque on the spindle serves to rotate it clockwise. and that is why pedals are threaded as they are.Originally posted by Rik
How will they ever get LBS to carry high-end GT or Mongoose in the US? After Pacific bought them, the only place I saw high-end iDrives in a LBS was in New Zealand. They are going to have to get some pretty good incentive programs and marketing people to get LBS and consumers to buy them again. Any ideas on that very important end of the equation?Originally posted by OddArne
Seems like peope prefer tp discuss pedals and threads over gear box bikes
I saw the most recent GT proto a couple of weeks ago in their Technical Division office, and you wouldn't believe the difference to the first proto shown on the picture. It has a lot of really sweet details, and it seems like the new ID5 is almost finished, so resources can be put into the GBox to have it finalized for production.
Both the G-Box and ID5 instantly struck me as bikes I really, really want to ride, even more than the Mongoose Teocali shown above. But the Mongoose Black Diamond Freedrive, there is one machine you all should have your eyes set on...
I guess you will start to see leaks of the ID5 soon, while the G-Box probably won't be leaked much before InterBike. I know some guys in Southern California will start test riding the G-Box about now, so who knows...
something your probably forgetting is that the freewheel mechanism is now located in the tranny, not the rear hub. So most likely the sprocket is bolted directly to the hub like the disc, essentially making the rear hub as simple and reliable as a front hub. This could make room for true 20-25mm rear axles too.
I thought it over on my ride to work, and I managed to make sense of it in my head... moral of this story: I should think about balls more often.
hmm, that could be fun....maybe a single pulley tensioner for emergency slack could be used...(edit: needs a tensioner anyways, not a concentric pivot...)
im up for that much more of a challenge going down the hill dont you think?
Nicolai managed to mount the primary and secondary drive on the right side however.
I know this has come up before but a chain tensioner is not always needed just because the bike doesn't have a concentric pivot. It just depends on the amount of chain growth and how they want to tackle it.
Does anyone have any photos of how they actually secure the hub?
Whats the deal with the primary and final drive being on the same side of the bike? I figure you could do a brooklyn machine works setup via the disk rotor mounts if you really needed the drive side on the right. seems alot easier to do that unless I'm missing somthing.
