Can speed-drive be used on the left side or for reversed operation?

Do I need a mountain-drive, high-speed-drive or a speed-drive?

If you prefer mountain-drive, high-speed-drive or speed-drive, depends on whether you want higher gears (higher speed) or lower gears.

mountain-drive reduces speeds by a factor of 2.5. With mountain-drive there is normally no overlap between gears.

mountain-drive enables you to climb steepest hills with your bike. If possible, take a slightly bigger chainring (2 or 4 teeth larger) to get higher gears as well as lower ones.

Please check, if there is space enough for the chainguard.

speed-drive makes the chainring spinning at a higher rate. This means, that a 38 tooth chainring, if speed-drive is engaged, works like a 1.65 times larger one (63 tooth chainring). If you have a 44 tooth chainring, with speed-drive engaged this chainring would equal a huge 73 tooth chainring.

That's why speed-drive is often used for fast bikes like recumbents, or folding bikes, where it compensates for the small rear wheel.

We now offer a new version of speed-drive, the model s-d 08, that comes with extremely small, exchangeable chainrings of 27, 28, 30, 32, 34, 36, 38, 40 or 42t.
This equals 45 up to 69t. in high gear mode!

You can easily calculate the rollout of your specific bike, when going to -> technique -> calculation

Please do not hesitate to contact us, if you need an advise for your best gearing system!

Does speed-drive fit my bike?

speed-drive fits all bikes with standard bottom bracket.

Please note, that speed-drive always comes without chainstay. There is no torque lever.
You need a special milling cutter to prepare the bottom bracket. This tool is available as accessory, in most countries, we have milling cutters for hire.

For tightening, please use the box spanner of tool set "installation and maintenance", which can be combined with a torque wrench and gives best resultats and very easy operation.

I'd like to fit two chainrings.

No problem. The housing of speed-drive is made of hardened steel and the spider is part of the gear housing. Fit one chainring to the left, one to the right side of the spider with a washer of 2mm between spider and one of the chainrings.

Can I replace a triple chainring set by speed-drive?

Yes, you can. There is no space problem, as speed-drive mostly comes with a very small chainring.

Indeed, please consider, that this combination normally doesn't make much sense, as you get a huge number of gears with many gears overlapping.

Does speed-drive fit the Brompton folding cycle?

Yes. We deliver a set of special spacers for the Brompton installation. Please note, that also the lockring on the left side is of special shape for the Brompton. Please always mention, that speed-drive will be installed into a Brompton to make sure, that we send the correct set-up.

Does speed-drive fit the Birdy folding cycle?

Yes. Please check the chainline (distance from centerline of frame to the middle of the chainring), as the Birdy maker Riese+Müller recently changed the design.

Older Birdies with a chainline of approximately 56mm can be combined with a special version of speed-drive with a 10mm longer axle. The newer models have a chainline of approximately 50mm, which allows to use the standard version of speed-drive. In this case, the chainring is fitted to the right side of the spider.

Please do not forget to order two trouser protection rings, as the Birdy needs them to prevent the chain from jumping off the chainring when being folded.

BTW: We deliver chainrings for the speed-drive with up to 53 teeth. Trouser guards for all sizes are available.

Can I use speed-drive for my bike with EBB (eccentric bottom bracket)?

Yes. We now offer a special version of speed-drive for EBB. Please inform us of the outer diameter of the eccentric part of your EBB, and we send the adequate piece. You don't have to chamfer nor tighten anything. Just mount it the same way as your standard EBB.

The only restriction: make sure, that the clamping mechanism is strong enough to hold the reaction torque, that is excerted by every planetary gearing system.

Can I fit speed-drive into a bike with closed chainguard?

Yes. Please make sure, that the speed-drive is in direct contact with the bottom bracket shell. No other parts must be clamped between speed-drive and b.b. shell..

Can speed-drive be used with a fixed wheel cycle?

Yes. From summer 2009, all our gearing systems come with a symmetrically machined clutch, that allows to transmit full torque in both directions.

Can speed-drive be combined with a coaster brake?

Yes. All types of speed-drive can be combined with a coaster brake.

Can speed-drive be used on the left side or for reversed operation?

Yes. From summer 2009, all our gearing systems come with a symmetrically machined clutch, that allows to transmit full torque in both directions. Reverse operation or left hand operation requires a left hand nut to hold the unit in the bottom bracket. The standard nut has a right hand thread!

Can speed-drive be used on a tandem?

Yes. Please check, if the rear gearing system is strong enough for tandem use.
If using it on a recumbent trike, please put the crankarms at 90 degree from each other, to prevent from peak load.

The unit always has to be installed at the stokers position and the chain between captain and stoker must be on the left side. Otherwise, both riders don't pedal at the same rate.

You can use the same crankarm (that comes with the chainring attached) on the left side as before.

Can I combine the Rohloff Speedhub with speed-drive?

Yes. Please notice the minimal chainring and rear cog size of 36/15 and 38/16, stipulated by Rohloff. This is important, if you are pedalling with extreme force or the application is a tandem, transportation bike, rikshaw or the like.

For all other applications, there is no limitation of minimal chainring size on a speed-drive.

The Rohloff hub has a wide chainline of about 54mm. Please fit the chainring to the right side of the spider, if combining it with a Speedhub. Or use the 10mm longer axle to meet the chainline accurately.

Can I use my own crankarms?

Yes. Our axles have standard square ends. No modification of the cranks needed. Please consider, that the right crankarm doesn't need a spider, as the chainwheel rotates at a different speed. The right crankarm looks like a left one, but has a right hand thread for the pedal.

If you are looking for a different crankarm design or length than the ones we offer, please contact a tandem dealer. Tandems use similar crankarms at the front position.