Internal Gear BB (not retro)

[Err]

Does anyone make an internal gear bottom bracket? I have been ruminating on internal gears today and saw this mentioned re the orange belt drive p7. Think it was mentioned as not being available rather than being available though.

I do like fiddling with bikes, but a sealed drivetrain would be pretty cool, no mess etc.

Also why couldn't orange just enclose the beltdrive to keep muck away?

some pics here.

http://www.singletrackworld.com/article.php?sid=2554

 

[hamster]

Do you mean the Schlumpf mountain Drive? You tap a button in the crank centre to change between high and low...

http://www.kinetics.org.uk/html/mountain_drive.shtml

 

[Err]

Well, this is more speculation than actually looking for something to buy.

Wonder if you could tap that button with your toe whilst riding

I'm just thinking that it would be a better location for internal gears than the rear for weight distribution.

 

[Err]

I'm basically thinking why can't you stick a rohloff speedhub style thing in the bb area rather than the hub?

 

[Rsmith]

I believe Voodoo, (I think), are in the process of making one with a bb integrated Shimano Alfine hub.

 

[one-eyed_jim]

I'm basically thinking why can't you stick a rohloff speedhub style thing in the bb area rather than the hub?

That's more or less what Nicolai do. You need some way to manage the higher input loads at the bottom bracket though, which is one reason the Nicolais use a secondary drive.

 

[one-eyed_jim]

Wonder if you could tap that button with your toe whilst riding

With your heel. But yes, it's easy to change gear while riding: you just need to freewheel for a second. There are extension plates than fit along the cranks that give you a bigger target to aim for.

I used to have a Schlumpf in my Brompton, but it went AWOL.

 

[Andy B]

http://www.diamondback.co.uk/sabbath.aspx
Also
http://www.srsuntour-cycling.com/SID=si ... d=59&sno=2

 

[FairfaxPat]

sealed drive

The Schlumpf Mountain Drive in front combined with the Rohloff 14 speed rear hub or the Shimano Nexus 8 speed rear hub with a fully enclosed chain should do the trick. I have discussed this type of setup with my friends around here, and the only downside to it is that a chain is 98 percent efficient while planetary gearsets like the Rohloff or the Nexus are rated at about 94 percent efficient. I am not sure of the energy loss associated with the Schlumpf BB, but it is sure to be a greater geartrain loss than the 2 percent a chain sucks up. That being said, however, the fully enclosed, dirt free chain that doesn't shift laterally, along with the sealed gearsets should be maintainence free for a long time.

 

[messiah]

This is my four year old Nicolai. It has the Rohloff mounted in the frame and I run it with very low gears, equivalent to a 20 x 34. Great for winching up mountains to enjoy the long descents. Bit of a pig round a forest XC trail through.

It's not perfect, but it's a bike and it's brilliant fun.