Who rides what?

[Beltdriver58]

Originally Posted by Alan

I was checking out the Civia Bryant just a week or so back and it's a very cool bike. IGH and belt drive mean external simplicity, minimal maintenance and lack of greasiness, and that really appeals to me. But as you mention, the gear ratios are a compromise. I really like the wide range of my mountain bike's 3x7 gears. I know some people have cobbled double rings in front of IGH rears but that loses the nice belt drive and still needs some sort of dynamic chain tensioner. So, I've never heard of such a thing but I was wondering, has anyone ever seen an internal multi-speed bottom bracket?

Another option is the NuVinci n360. I took a test ride on one at Joe Bike on Hawthorne. They are doing cool belt drive builds with an aluminum frame Stop Cycles bike Proletariat. It has smoother transitions. I'm not 100% on the system because I haven't done that much research. I have read blogs where mountain bikers were using it for steep climbs applying a lot of torque with no slipping or failures. Comes in a little higher in price than the Alfine 8, but cheaper than the 11. One issue I have with the NuVinci is the shifter. It does not allow for any other options in mounting or any compatibility with other manufacturers.
Check it out:
http://www.joe-bike.com/commuter-bik...s-proletariat/

[Beltdriver58]

For anyone interested in belt drive bikes, this is the ultimate. If I had a second job and no bills:
Introducing the......Tout Terrain Metropolitan

[Alan]

Very nice hardware, indeed, but I dream of Rohloff for my ultimate IGH bike, and it still doesn't have the wide range I like in derailleur gears. That's why I want that unobtainium compound front gearbox...multiply all my rear ratios!

[q`Tzal]

Originally Posted by Alan

That's why I want that unobtainium compound front gearbox...multiply all my rear ratios!

Yeah, they call that the Schlumpf high-speed-drive
http://www.schlumpf.ch/hp/schlumpf/antriebe_engl.htm

I only have the regular speed drive, 1:1 to 1:1.65, but I have it paired with the NuVinci N360.
Quite ashamed of how long it took to finally put the whole bike back together; life ya know.

It is sweet and once I got into the groove of the heel shift (which is easy) and stopped babying the N360 shifting was amazing! Echos of that feeling when you first had the training wheels removed and realized your parent was no longer holding your bike up.

Pics later if interest creeps up.

[Beltdriver58]

Originally Posted by q`Tzal

Yeah, they call that the Schlumpf high-speed-drive
http://www.schlumpf.ch/hp/schlumpf/antriebe_engl.htm

I only have the regular speed drive, 1:1 to 1:1.65, but I have it paired with the NuVinci N360.
Quite ashamed of how long it took to finally put the whole bike back together; life ya know.

It is sweet and once I got into the groove of the heel shift (which is easy) and stopped babying the N360 shifting was amazing! Echos of that feeling when you first had the training wheels removed and realized your parent was no longer holding your bike up.

Pics later if interest creeps up.

Sweet. I did not know such a system existed. It may cause some havoc in the Gates proprietary world. Where were you able to acquire your uber Swiss Sclumpf speed drive?

[Alan]

Originally Posted by q`Tzal

Yeah, they call that the Schlumpf high-speed-drive
http://www.schlumpf.ch/hp/schlumpf/antriebe_engl.htm

I only have the regular speed drive, 1:1 to 1:1.65, but I have it paired with the NuVinci N360.
Quite ashamed of how long it took to finally put the whole bike back together; life ya know.

It is sweet and once I got into the groove of the heel shift (which is easy) and stopped babying the N360 shifting was amazing! Echos of that feeling when you first had the training wheels removed and realized your parent was no longer holding your bike up.

Pics later if interest creeps up.

Mmm! Sufficiently advanced technology. Sweet, indeed. So, yeah, I guess I actually had heard of the Schlumpf drive back when you mentioned before. And I've heard of that "life" thing, too...maybe I'll get around to it, someday.

The 3x7 derailleur gears I like are 48/13 high (3.7 ratio), 28/30 low (0.93) on 26" wheels for a nominal range of 25.2 to 96.0 gear inches (~400% range). Ideally I'd go a little below that and several cogs above it, so maybe 20-120 gear inches, if I had my druthers. I'd sacrifice high-end gears before low-end. Anyway, I'm curious about the range you're running, and gear inches make it easier for me to compare.

And heck yes, pics would be great! Especially the drivetrain, and a detail of the heel shift lever. Does it ever get kicked by mistake?

[q`Tzal]

For those who have asked here are some shots of my bike with a focus on the drivetrain. Posting in groups of 4 because that's what the forum allows.


Finally got around to a test ride longer than 100 feet. I rode up to the DMV to get my driver's license renewed; about 6 miles total. Having been raised on British humor the ridiculous insanity of the system provided me with laughs and many confused stares while waiting in line.

[q`Tzal]

[q`Tzal]

Originally Posted by Beltdriver58

Sweet. I did not know such a system existed. It may cause some havoc in the Gates proprietary world. Where were you able to acquire your uber Swiss Sclumpf speed drive?

I went to the USA portion of dealer list on their site and started closest to home. Citybikes Workers Cooperative does not have the install tool and really had no interest in doing the work; they were only too happy to have me take my money elsewhere. The next closest is in Seattle but their selection was limited. It suddenly occurred to me to just ship my frame to someone who had experience doing this properly. That someone is Cycle Monkey in Albany, CA. I would definitely recommend their work as superb. Turnaround was ~24 hours; I got the tracking number for the return only a couple of hours after I verified that it arrived.

Originally Posted by Alan

I'm curious about the range you're running, and gear inches make it easier for me to compare.

Speed Drive with 27t sprocket NuVinci N360 with 17t sprocket.
This is outside the recommended range for the N360.
From the NuVinci N360 Datasheet:
"Sprocket Ratio 1.8:1 Minimum
(16/29, 17/31, 18/33, 19/35, 20/36, 21/38, 22/40,
larger chainrings can be used without exception)"

27/17 is ratio of ~1.59. So I have been gentle with it in direct drive on the Speed drive. Most, >97%, of the time it has been in over drive so the input to the ratio is 44.55/17 or 2.62.

Sheldon Brown's Internal Gear Calculator shows a gear inch chart that needs a 90 degree rotation to make sense:
Low: 21.4 - 77.2
High: 35.4 - 127.4

I only lost 0.8 on the bottom end and gained 9.6 on the top end.

Originally Posted by Alan

... the heel shift lever. Does it ever get kicked by mistake?

I feared this as well. The force required to actuate this button seems to have been the subject of a great deal of high quality thought. I can only say it seems just right. Not so tight that you can't shift with your foot but tight enough that glancing tangential bumping have not accidentally caused a shift; the smooth round profile allows side to side contact to simply slide off. Very well engineered.

[Alan]

Very cool! The silhouette of the chain loop relative to the frame is really nice...low profile, high ground clearance. I see the Speed Drive's button in both positions in the last two photos, thanks. The gear range is simply fantastic...600%! I think I might use lower ranges a bit more than you and Nuvinci's 1.8:1 minimum sprocket ratio worries me a little; I wonder how many actual failures they've seen and just how much torque abuse it will withstand? The graphic hill gauge is trick; is it helpful?

Is that an Airzound on left handlebar? And a Thudbuster LT seatpost? It looks larger than I remember them.

Anyway, thanks, helpful stuff.