Schlumpf Mountain Drive

[jb]

Does any one familiar with the Schlumpf Mountain Drive know if there are always four planet gears in the gear drive as I have one with only two, which seems a bit odd. There is the holes for another two.

Their web site info always shows four.

I'm just wondering if its been the victim of the lightweight brigade bodging society.

[Brucey]

I've only ever seen pictures, but the pictures I have seen have always shown four, not two gears.

cheers

[Cunobelin]

Email Schlumpf?


Ps did you know that Schlumpf is also a




My wife takes great delight in referring to the Smurf drive on my trikes

[jb]

It appears that this might be a drive designed for hand cranking (The Reha - version) - Less friction and less torque imput.

So, not suitable for peddaling, glad I took a look before buying .

[Brucey]

It appears that this might be a drive designed for hand cranking (The Reha - version) - Less friction and less torque imput.

So, not suitable for peddaling, glad I took a look before buying .

Ah, that makes perfect sense.

I wonder if you could upgrade it by adding more gears?

cheers

[jb]

The gear spindles look like they are press fitted, I can't see Schlumpf suppling them separately.
I may ask them just in case though.

[Slowroad]

Was going to write a post asking if anybody had used a Schlumpf Mountain drive, what did they think of it and what sort of price are they? Then saw you were already talking about them. Can you shed any light?
Cheers!

[jb]

Well I haven't used one yet either, but there about £500 new. They are well made but seem to have a bit of drag when in direct drive from just twiddling it by hand. You wouldn't want to use them on a normal bike I don't think, but for special purposes they seem a good answer. I was going to use it on my hub geared folder as I've found it & myself in some hilly country on occasion.

[hercule]

I had one on a recumbent trike. There was definitely some drag turning the cranks by hand in direct drive or underdrive, but how much an issue this was in real life is hard to say. One major issue I had though was with the gearing: it served a purpose, getting a very low gear for steep hills, but the overall range was significantly below direct drive's range (this was using an 11-32 cassette). I don't remember the numbers, but a smooth progression down the gears meant going from the 32T cog to the 11T cog in one go when engaging underdrive, and the opposite going up. Hitting the change button often meant going from a slightly too high gear to one that turned your legs into a blur if you didn't shift the chain as well.

Despite these issues, it did seem a well made piece of equipment. Mine didn't cost £500 though... Prices have clearly gone up quite a bit!

[hexhome]

Was going to write a post asking if anybody had used a Schlumpf Mountain drive, what did they think of it and what sort of price are they? Then saw you were already talking about them. Can you shed any light?
Cheers!

You will find quite a lot of info on Brompton forums.

[Tigerbiten]

I've the High Speed Drive, not the Mountain Drive, on my recumbent trike.
I've mated it up with a Rohloff back hub.
I think it's a good combo for a bent trike, but an expensive one, due to the range it gives you.
The Rohloff is a 7 speed hub with an internal 2.45x step-down to give you 14 evenly spaced gears.
Match it up with an external 2.5x step-up HSD and you end with 21 usable gears for a full 1300% range, try 10"-130" when in touring mode.
I like the Rohloff as it's easy to drop/climb the 7 gears needed when shifting modes.

The HSD has almost no extra drag with working in normal mode, but you can feel a little bit more when in overdive mode.
But as I tend to only use the overdive mode downhill and/or with the wind behind me, its not that much of a killer.

[Cunobelin]

I've the High Speed Drive, not the Mountain Drive, on my recumbent trike.
I've mated it up with a Rohloff back hub.
I think it's a good combo for a bent trike, but an expensive one, due to the range it gives you.
The Rohloff is a 7 speed hub with an internal 2.45x step-down to give you 14 evenly spaced gears.
Match it up with an external 2.5x step-up HSD and you end with 21 usable gears for a full 1300% range, try 10"-130" when in touring mode.
I like the Rohloff as it's easy to drop/climb the 7 gears needed when shifting modes.

The HSD has almost no extra drag with working in normal mode, but you can feel a little bit more when in overdive mode.
But as I tend to only use the overdive mode downhill and/or with the wind behind me, its not that much of a killer.

My experience is very similar

The trick is to set up the bike so that the mostly used gears are in the "neutral mode" and then select the Schlumpf to extend the range to where you need it

[Slowroad]

Thanks very much for such speedy responses!
Sounds like something to bear in mind but not for immediate consideration.