From: truesdel@ics.uci.edu (R. Scott Truesdell)
Subject: Diacomp brakes not recommended WAS Re: Putting your bike on a diet
Newsgroups: rec.bicycles
Organization: University of California, Irvine
Date: 28 Jul 92 01:16:16 GMT
Distribution: na
bcc: truesdel

In article <1992Jul25.024833.12021@athena.mit.edu>, jclee@athena.mit.edu (Yogurt brains) writes:
>
> From the wisdom of the net...
>      "How to Put Your Bike on a Diet (Shed Weight)"
>
> (2) Brakes: lighter cantilevers and levers, Diacompe is popular, such as
>             SS5/SS7 levers, 986/987 cantilevers

I recently went with Diacomp 987 cantilevers to shave some weight and
because various opinions were favorable. I regret my decision and will
soon switch to something else (Shimano XT or XTR or something trick like
Paul's Components or Graftons).

Here is why I am dissatisfied:

1. They are engineered wrong. The lever that the stradle cable is on
is over twice the distance from the base of the brake boss as it is
for Shimano. This more than doubles the stress on the brake boss.
I have suspension forks and under moderate braking the brakes would
twist the sliders outboard so that brake shoe toe-in became toe-out!
Until I installed a brake-booster plate I would use the resulting squeal
to warn hikers and uphill-riding cyclists when I was rounding fast
downhill corners. I got so I could play simple melodies by modulating
the brakes! I believe this bad design may lead to brake boss failure.
It definitely reduces braking power.

2. The threaded fastener that is used to adjust the brakes for position,
alignment, and toe-in is even more forward than the cantilevers which
meant I had to design and fabricate the brake-booster myself since no
commercial unit would fit, never mind allow me to remove my front wheel.

3. To shave a few grams they use 9mm hexes on the stadle cable nuts
instead of the more ubiquitous 10mm which means I can't effectively
work on them on the trail without packing another wrench. There go
the weight savings! Instead I have opted to hope for no brake problems
and not take the extra wrench.


Neutral observations:
1. Braking power has not increased nor decreased from my circa 1989
Shimano Deore cantilevers which the Diacomps replaced.

2. While they are SLIGHTLY easier to adjust than the old Shimanos, the
Shimano cantilevers starting in 1991 are just as easy or easier. What
used to be a big Diacomp marketing plus is no longer an issue.


Postive observations:
The individual spring adjusters are a nice touch and, so far, they
haven't moved under use. However, I was disappointed to see that they
are held in adjustment solely by friction.


My experience is compelling me to switch away from the Diacomp brakes.
I am loath to throw away $65.00 but I fear it's the only way I'll be
happy. By the way, I am writing Diacomp with a more detailed explaination
of my dissatisfaction along with supporting dimensioned drawings. They
may answer my concerns with positive reasons for their design decisions
and/or they may re-evaluate their design and encorporate some of what
I have experienced. I figure it's my duty as a concerned consumer to
give this feedback to the manufacturers. May we all benefit.

  --scott