SRAM announce new 9-speed hub gear

340% range, and evenly spaced ratios, according to a German bike mag... UPDATED

Posted by Peter Eland on Thursday 29 Sep 2005

The German cycling magazine Aktiv Radfahren is reporting that US-based component manufacturer SRAM is about to launch a nine-speed hub gear, the 'i-motion 9'. The Aktiv Radfahren story says that the hub will be on sale mid-2006, to complement the existing i-brake and i-Light (hub dynamo - new to me, too).

The overall range is said to be 340%, wider by a notch than the Shimano or Sunrace Sturmey alternatives (both just over 300%) and the ratios are apparently very evenly spaced (comparable with Rohloff, they say). The current prototype weighs around 2300g. There will be a one-piece aluminium shifter and brake unit also incorporating a bell.

Thankfully the new hub gear does away with the protruding clickbox of other SRAM hubs.

Suggested gear combinations (presumably for full-size wheels) are 33 to 38 tooth chanrings and 18 to 22 tooth sprockets.

First to be introduced will be a coaster brake version (for the German market) followed by disk brake and i-brake compatible models.

There's a small picture currently on the Aktiv Radfahren homepage.

Nice to see SRAM (who took over historic German hub gear manufacturers Sachs some time ago) joining the 'new generation' of hubs from Shimano and Sturmey. We'll try to get a test on one ASAP.

Thanks to Robin Commander for the tip-off. Update 29.9.05: picture from SRAM added: SRAM i-Motion 9 hub prototype


Posted by Ben - Kinetics (ben@kinetics-online.co.uk) on Wednesday 2 Aug 2006
I heard that rumour at IFMA - it'll be interesting to see in the metal - curious whether it's a whole new hub, or a modified Sachs design.

The iLight has been out for a year or so - nothing special...

 
Posted by Ben - Kinetics (ben@kinetics-online.co.uk) on Wednesday 2 Aug 2006
I heard that rumour at IFMA - it'll be interesting to see in the metal - curious whether it's a whole new hub, or a modified Sachs design.

The iLight has been out for a year or so - nothing special...

 
Posted by Ben - Kinetics (ben@kinetics-online.co.uk) on Wednesday 2 Aug 2006
Nuts ;-)

 
Posted by Miles (mileshellon@hotmail.com) on Wednesday 2 Aug 2006
Keep taking them Ben....

What about the news item on the Aktiv site just before the new SRAM???

Miles

 
Posted by Peter Eland (peter@velovision.co.uk) on Wednesday 2 Aug 2006
That's an auto shifting hub - there's a mechanism inside which uses centrifugal force to work out when to change gear automatically. Says it's not intended for cycle enthusiasts, more clueless beginners (I paraphrase :-).

There's a somewhat similar device from the USA, http://www.lrbike.com/ , though this new one does have the advantage of being fully enclosed. For cyclists who are used to using gears properly these things generally feel rather crude - some of the more sophisticated computer-controlled auto-shift systems are definitely better.

 
Posted by Peter Eland (peter@velovision.co.uk) on Wednesday 2 Aug 2006
Incidentally, does anyone have a copy of BCQ 12 they can look up? Page 21, according to Stephen Bach's splendid index. I remember featuring a proposed nine-speed hub gear design with fairly wide range and even ratios... but don't have my copies to hand to look it up. Would be intersting to see if the range figures match up with SRAM's.

 
Posted by David Hembrow (hembrow@theusualplace) on Wednesday 2 Aug 2006
Yep, I've got it.

The ratios in the article are as follows:

1 2.667 : 1 27.7%
2 2.080 : 1 27.7%
3 1.629 : 1 27.7%
4 1.275 : 1 27.5%
5 1 : 1 27.5%
6 1 : 1.275 27.5%
7 1 : 1.629 27.7%
8 1 : 2.080 27.7%
9 1 : 2.657 27.7%

Overall: 706%

Personally, I think the closer ratios of the SRAM hub are a little more practical.

Having said that, I've just done up an old series 1 Moulton, which has a Sturmey Archer FW four speed hub. That has ratios about 27% apart too, and they're noticably nicer to ride with than the wider AW 3 speed hub on another of my bikes.


 
Posted by marten gerritsen (info@m-gineering.nl) on Wednesday 2 Aug 2006
about to launch? There were two bikes on display at the IFMA!

 
Posted by Will (vwcatbus@verizon.net) on Wednesday 2 Aug 2006
340% works out to about 16.5% steps, so a 22T cog would be like a 10-12-14-16-19-22-25-29-34?

 
Posted by Miles (mileshellon@hotmail.com) on Wednesday 2 Aug 2006
Wonder if they'll bring out an automatic version...
http://tinyurl.com/a5h2c

Miles

 
Posted by Miles (mileshellon@hotmail.com) on Wednesday 2 Aug 2006
Peter,

So that's a hub weighing about the same as a hub gear to change a derailleur, right? :)

Miles

 
Posted by PeLu (peter.ludwigATliwest.at) on Wednesday 2 Aug 2006
How does it came that everybody assumes that the 5th is direct drive?
Anyway, I'm tempted to buy the German magazine (available end of month) to get more information.

Good that it comes in a coaster brake version first.

 
Posted by Will (v) on Wednesday 2 Aug 2006


 
Posted by Will (vwcatbus@verizon.net) on Wednesday 2 Aug 2006
Because 22-26-30-35-41-47-55-64-75 and 7-8-9-10-12-14-17-19-22 don't work for me.

 
Posted by Eric Moss (eric.p.moss@gmail.com) on Sunday 10 Sep 2006
I asked SRAM about availability, and they said it's "not for the American market". Sheesh. Any mail-order shops in Europe/UK that have it yet? I'd like to get one and some repair parts while I'm at it.


 

 
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