On Sep 6, 7:27 pm, (Don Pearce) wrote:
On Thu, 06 Sep 2007 16:27:41 -0700, Andre Jute
wrote:

Techieporn for you.

My Trek Navigator L700 "Smover"
Bicycle with Automatic Gearchange and Electronic Adaptive Suspension
delivered by Shimano Di2 Cyber Nexus Groupset

a photo essay by André Jute

http://members.lycos.co.uk/fiultra/B...igator%20L700%...

My Trek is the 3400 - nice sensible road bike. Looks very similar to
that, but without the chain guard. Doesn't have all that dodgy brake
stuff, either. A reasonably heavy stop (say from 20mph in 5 seconds)
only needs to dissipate 3kJ at 600W, which is no problem at all to
dissipate in a pair of wheel rims.

d

--
Pearce Consultinghttp://www.pearce.uk.com

Those brakes aren't dodgy, Don, they're hyper-competent; what I forgot
to add is that they have a built-in modulator. They stop the one-
eighth of a ton of me and the bike and light touring gear from thirty
kph in 11 feet. I know, because I chewed up a pair of tyres while I
practiced that one to perfection. But I agree with you, for casual use
those roller brakes are overkill.

However, you missed the point of the chain guard and the roller
brakes: it isn't just that the brakes are better, and the chain guard
civilized; what matters is that the totally enclosed brakes and the
totally enclosed chain guard make it an allweather bike -- or that
they are put on there because the specification is for an all-weather
bike. Unlike rim brakes, roller brakes are immune to rain.

Of course, a bike like that, in its primary market, The Netherlands,
is intended and taken into one's family as a permanent fixtu it is
not supposed to wear out. Rim brakes in the sort of daily commuter use
a Dutch city bike gets will wear out a pair of rims every second
year, a dangerous business because it isn't always possible to tell
when the rim is worn so thin by the brake blocks that it collapses the
next time you hit a bump in the road.

Finally, rim blocks are dirty and throw off black stuff, not much chop
on a daily commuter bike (which is what my Trek "Smover" pretends to
be whenever the designers glance at the marketing brief).

So, you see, my Smover's specification is quite consistent with the
bike's supposed purpose, and even more so after I patched up overly
sporting ergonomics. I bet your 3400 was sold to you as a "leisure"
bike. I don't suppose either of us uses a bike as heavily as your
median Dutch officeworker.

Andre Jute
Impedance is futile, you will be simulated into the triode of the
Borg. -- Robert Casey