C[omp]ute

From: andrew cooke <andrew@...>

Date: Thu, 10 Apr 2025 19:36:05 -0400

i bought a cycling mirror (the "take a look" compact model that is
sold on amazon) and tried it today.  here are my first impressions (i
am trying to order them from specific to general):

- it's very well made for something so light and seemingly delicate.
  the mount on my glasses was secure, the adjustments easy, nothing
  moved out of adjustment (even on a road bike on santiago's bumpy
  roads), the mirror was clear and undistorted, and - most impressive
  of all - it was absolutely solid.  no wobbling or shaking.

- i use prescription glasses - i cycle in the same glasses i use all
  day.  the mirror mounted on the left arm (here we ride on the right)
  and takes up the top left corner of the glasses frame that i see
  when i look out of left eye.  in other words, it couldn't be higher
  or further outboard without being blocked by the frame or out of
  focus (i am short sighted).

- when i cycle there's not a single position (angle) that i hold my
  head at.  when i am more tired, or going faster, my head is lower.
  when paying attention to my environment, or climbing, my head is
  higher.  this means that there is not one "perfect" adjustment for
  the mirror (which is flat, not convex): i needed to choose the head
  position (angle) at which i would adjust the mirror for the best
  view.

- even at this optimum position i cannot see directly behind me.  my
  cheek/shoulder is in the way.  to see directly behind me i need to
  move my head slightly (look slightly to the left).

- and even with my head turned, i cannot see the road if it curves
  away to my right (conversely, if the road curves away to the left i
  don't need to turn my head).  so on winding (mountain) roads it is
  useful maybe 2/3 of the time.

- the mirror is only visible in my left eye (obviously).  sometimes
  that doesn't seem to matter - my brain switches to using just that
  eye if i want to look behind me - but sometimes it does, and it is
  hard to focus / understand without closing the right eye.  this
  seems to depend to some extent on the ambient lighting.

- the mirror blocks my left eye from looking in that direction (again,
  obviously).  this can be important at junctions since it makes it
  harder to see traffic coming from the left.  sometimes my brain
  switches to the right eye and there's no real issue, but sometimes
  it doesn't.  again, it seems to be lighting dependent.

- (if you have visual migraines) the mirror feels annoying like a
  visual migraine, in that there's something in your field of view
  that seems "wrong".  after a three hour ride i was starting to feel
  the hint of a headache from this.

- i suspect the three issues immediately above will all improve with
  practice.

- perhaps because of the need to angle my head i didn't feel like the
  mirror was an improvement over my ears.  in fact, my ears are
  better, in that they can hear cars round corners.  and one of the
  things i learnt was that my ears are pretty damn accurate - i would
  hear something, look in the mirror to check, and get confirmation of
  vehicle type and position / distance.

- on the other hand, on descents, or with headwind, when there's a lot
  of wind noise in my ears, the mirror did feel more useful.  in that
  sense it complements, rather than replacing, hearing.

- the moments when i was surprised by something in the mirror were
  when vehicles i had not heard or seen started to pass me.  they
  appeared in the mirror just before they appear in peripheral vision
  (this did not seem to be particularly useful information).

- it was kinda cool to see cars drop away behind me when descending
  quickly.

- i was self-conscious about using the mirror, but in practice i don't
  think anyone much noticed.  it reminded me of how i felt (many years
  ago) when i first used lycra - very self-concious, but noone else
  cared.  also, despite what i've seen in some online images, the back
  of the mirror is a neutral grey.

- i still look behind me before doing anything particularly risky.
  the mirror doesn't really replace that.  maybe it would with more
  practice?

- my overall reaction to the mirror is simiar to how i expect i'd feel
  about varia: it provides a little extra info, but it's not really
  useful / actionable.  and they're both kinda nerdy.

- the one place i can think of where the mirror might be critical is a
  fast right fork (where i ride straight on / left).  after a near
  miss there last week i am considering simply stopping until things
  are clear.  i will ride there on my next ride - maybe the mirror
  will mean stopping is not necessary?

- the main conclusion from all this - for me - was that, above all, i
  *really* rely on car drivers not killing me.  i don't see a way round
  this - the mirror doesn't change things much.

- my second conclusion is that i should get some of those "cat ears"
  to reduce wind noise, given how useful my ears are.  and i bet they
  are less geeky to wear (they don't *look* like cat ears...)

andrew