New SRAMi9 hub gear

[lornac]

Saw something about this on web : is it a real rival to Rohloff? Anyone seen or tried one?

[RJC]

Some details on the i-Motion 9 in:
http://www.sram.com/_media/pdf/sram/manufacturers/NewTechSpecifications_MY07.pdf
The quoted weight for the coaster brake version is 2.4Kg, so allowing
~200gms for the internal brake it is about 1/2Kg heavier than a Rohloff.
I think a key factor will be the efficiency in the extreme gears (1,2,8,9). And the price of course.

Robin

[PH]

quote:Originally posted by lornac
 is it a real rival to Rohloff?

No, the range of 340% compared to Rohloffs 525%, isn't enough for a tourer or MTB, not for me anyway.  It's a decent step up from the 300% of the SRAM 7 and the Shimano 8, more than enough for a short distance commuting or town riding.  I agree with Robin that price will be a major factor, but within reason I think efficiency is less important.  You have to remember that the major markets are Holland and Germany, where people often ride heavy bikes at slow speeds in normal clothes.  As cycling becomes more popular, particularly in London, some people will be looking for bikes that fit that same criteria, and a good thing too.

[RJC]

Some more details on the hub:
http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=813

I overestimated the weight as SRAM claim the version without a hub brake will be "less than 2000grams". Still a bit heavier than the Rohloff.
The efficiency of hub gears tend to fall in the gears furthest from direct drive. If the extreme gears get too inefficient it could become that they add extra weight without adding useful gears.

[donkeebrain]

Came a bit late to this one :-)

I imagine the cost of the SRAM hub (especially in Germany) would allow for the fitting of a Schlumpf drive and still be cheaper than a Rohloff...

Now that would weigh more than the latter, but the gear range would be wider and the weight would be more evenly spread.