"rBOB" <
[email protected]> writes:
>I have the dual drive with an 8 soeed cassette. It basically
>substitutes an internally geared, three speed, rear hub for the front
>derailleur and triple chainrings and then compliments that with an
>eight speed cassette. This gives you the same number of gears as your
>typical, 8 speed triple. In this case (3 x 8 , or 24 gear
>combinations). There is also a normal derailleur to shift the chain
>among the eight cassette cogs. You shift the derailleur with a
>twist-shift grip, and the internal hub gears with a thumb shifter. A
>nice feature of this system is that you can shift the three internal
>hub gears while at a standstill. That way, if you find yourself stopped
>at a light and in too high a gear, just click down and you are good to
>go. You can see the shifters here:
>http://tinypic.com/9jzjog.jpg
I have the Dual Drive with a 9 speed cassette on my Fiero. Works great, in
my case with a bar end shifter on my USS.
My only gripe is that you can't change the ratio of the 3 hub gears. There
is a lot of overlap within the 3x9 gears, and I needed a lower gear.
With the normal setup of 3 chainrings in front I would just have changed
the smallest ring, giving me a larger range with larger spacing between
gears. Now I had to change the single chainring in front which meant that
the whole set of gears moved down, meaning my top gear is now a bit low.
Something else to get used to: you can use all of the 3x9 gears, no issues
with chainline which you would normally have using the smallest ring in
front and the smallest cog in the back.
>Another advantage is that it=92s a clean-looking design, with one
>chainring and no derailleur in the front. The one-handed operation of
>all the gears is also an advantage, in my opinion. Here is a photo of
>the front chainring, which comes with dual-sided chainring guards on my
>bike:
>http://tinypic.com/9jzjv9.jpg
Yes, that was one fo the things I liked as well: a clean view with no
front derailleur.
It is possible to have multiple chainrings in front as well, to further
expand the range. I have experimented with have 2 chainrings in front
without a derailleur, worked fine.
Can't say anything about durability yet, I've had it for about a year now
and not that many miles. What I understand is that the middle hubgear
needs to be well tuned or the hub will wear down quickly - the little box
has a mrker to adjust that gear.
Roos