abreichenbach

I have some questions about the Schlumpf mountain drive, if you have any knowledge about this obscure part, I'd appreciate your help! I've looked in many places and can't find much information at all or the info was 3+ years old.

1. How it does with internal hub vs derailleur. I've heard some people describe a drag, power loss, whining and/or wobbling when the Schlumpf is engaged, but I don't know if they were using internal hub or not, or whether these problems could be attributed to internal hubs. Or whether the Schlumpf has gotten better over the years. One person described it as "compression", which the rider eventually gets used to when peddling smoothly, whatever that means.

2. If an internal hub is not used, should just a rear derailleur be used, or do some setups also include a front derailleur.

3. How reliable it is, do many fail, do parts break or wear out within 10,000 miles of loaded touring riding, if so what spare parts I should bring if I go on tour with it.

4. Should I use a LBS that has experience in the Schlumpf mtn drive installation, or can any bike mechanic with several years experience do it with the supplied instructions.

Thanks!

dabac

Some care needs to be taken when coupled to an internally geared hub. The reduction in the Schlumpf crank can give you enought torque to overload and break stuff.

Well, the chain-and-sprocket drive is one of the most efficient drives known to man (when in decent trim), so I suppose that an ultra-alert rider might be able to feel the losses caused by the conventional cogs and disengaging. There will be small bits spinning at quite a rate, so some noise may well be generated.

That doesn't make sense, that's a phrase commonly used for riding bikes with rear suspension. Can't see how the Schlumpf would interfere with that.

You can run the schlumpf with double chainwheels up front, which would require a FD. Needs some care in figuring out ratios though, to avoid repeated values as much as possible. The strength of the Schlumpf though is usually held to be the ability to use encased drivetrains.

They have a fairly solid reputation for durability, and excellent service when something has broken. For that distance you'd need a new chainwheel somewhere down the line, and maybe a new shifter "button".

SInce he runs a rental deal for the chamfering tool required for installation it makes sense to assume that installation is within reach for anyone with a bit of skill and an ability to follow instructions. There are accessory manufacturers who insist on having the frames shipped to them instead, which schlumpf apparently don't consider required.

abreichenbach

Hey, thanks for the info!

What about large gear jumps when the shifter button is used? It seems like the jump would be rather big, according to the calculator on the schlumpf website https://www.schlumpf.ch/Kettenschaltungen_engl.xls. Like 30-40 inches (with a 44t chainring, 11/34 cassette, and 2.1 tire circumference, to yield a total gear in range of 14-105 which is the gear range I dream of).

Like I'll be riding in 58in gear, engage the shifter button, then all of a sudden be in a 23in gear. Or maybe I'm not understanding correctly how the schlumpf works.

Dr.Deltron

You've got it correct. It can be disconcerting to drop so drastically.
I have the Schlumph on a Greensdpeed GTX that also has a Sram 3x9 rear hub.
If I'm in HI on the Schlumph & LOW on the 3 speed hub, I have to shift both together to keep the change from being so drastic.

When I first got it (used), I thought something was amiss. I got no resistance from the pedals, even after shifting the shift levers to HI.

Turns out I was going downhill with the Schlumph in LOW!
1st gear is about a 9" gear!

...and that helps when I've got the 8yr old on the rack/seat and the twins in the Burley trailer.
(about 350 lbs total)

I don't have a front deraileur, but have been told that it can be done. The greenspeed would need a new boom that has the deraileur post. It's supposed to be preferable to using the internal 3 speed hub, as they're not intended for loaded touring on a recumbent.

I also have a friend that has a Greenspeed GTO that has the Schlumph SpeeDrive coupled to the Rohloff 14 speed hub.

So far we have roughly 3,000 miles on said equipment and no glitches or problems, so far.
But that's only 1/3 of the miles in your question though.

As for what to carry for in-a-pinch fix-it?....Your VISA card!

Last note, if you get the Schlumph, also get the paddle flappers. They go between the pedal and the crank, and make it much easier to shift your Schlumph.

abreichenbach

If engaging the schlumpf does require large gear jumps of 40 inches...um...I imagine if I'm not real quick with the rear shifting after engaging/disengaging the schlumpf, I'd fall over or panic or at the very least have a very awkward riding experience. I've always been very kind and methodical with my shifting, one at a time, every second or so, there's never been a huge importance placed on a super fast shift in the rear to prevent from falling over or having a very awkward experience.

I don't know, I'm fairly new to cycling, I only go on tours and only in the last 3 years. I really don't have many riding skills, for instance I'm still working on my cadence and being able to ride the white line in busy traffic and not get too nervous while fully loaded

Maybe learning how to do a lightening fast shift in the rear is something I could learn to do?