I purchased a pair of Arlen Ness mirrors for half off.
Perhaps it was because they were flat instead of convex glass.

I was a bit surprised because it wasn't mentioned on the packaging but I put them on and in between snow days have been riding around town.
I don't ride any faster but my nose doesn't look as big.


Does anyone have a strong opinion on this? Anyone try both and end up preferring one or the other?
Saw a Dead Head sticker on a Cadillac, a little voice...

 

I had a single convex mirror on my apes. It was a 4" diameter piece made for UTV roll bars. Very well made and fit perfectly on the 1 1/4" bars. It was serviceable, but the convex shape wasn't my favorite. The cars in the left lane right at my flank and just behind looked like they were 10 yards back.

When I changed bars, I bought a pair of Ebay mirrors with flat lenses. The view is much better. The new mirrors have a slight blue tint that is kind of cool.

 

 

Convex.

 

Day 3 of riding with the flat (planar or "unit magnification") mirrors vs. convex mirrors.

The day after I installed the planar mirrors I noticed my car had “Objects in Mirror Are Closer Than They Appear" on the passenger side but not the driver's side, so I looked it up.

According to DOT §571.111 Standard No. 11:

S5.2.1 Each passenger car shall have an outside mirror of unit magnification.

VS5.3 Each passenger car shall have an outside mirror of unit magnification or a convex mirror installed on the passenger's side

And

S10.1 Each motorcycle shall have either a mirror of unit magnification or a convex mirror (we are only required one).

Since the weather was beautiful for January in the Rockies, I did a few reasonably controlled tests using my Dyna and my car. I put on one of the OEM convex mirrors and one of the planer mirrors.

While increasing the "field of view", convex mirrors also increase distance estimates significantly. More variance in distance and spacing estimations as well as "time-to-contact" estimations.
The further away the object is the greater the overestimations resulting in increasingly false recognition of distance .

Eye-to-mirror distance has a substantial effect on the degree of overestimation caused by convex mirrors.
Longer eye-to-mirror distances (like my car's passenger-side mirrors) lead to more overestimation than shorter distances ( my motorcycle passenger-side mirrors).
This of course reduces the false spacing estimations on motorcycles over similar distances in cars because the mirrors are closer.

With my friend riding behind my car at a varying distances and speeds, I usually felt like I could easily merge on the passenger side (convex) but not the driver's side. On the bike with the convex on one side and the planar on the other, I had the same mistaken judgment. It was spooky when I really paid attention to the difference in perceived distances in a reasonably controlled test of flat vs. convex on both my car and motorcycle. If it were a video game I would have crashed and burned.
I imagine that with experience the distortion is subconsciously factored in, but it was still significant.

I really like the planar mirrors so far.

The first thing you notice is that when you see part of a car in your mirror and the rest of the car next to you, it is the same damn car!
Like some seats make you feel like you are sitting "in" the bike as compared to sitting "on" the bike, the mirrors had the same effect. Rather like I was really "in my surroundings".

The planar mirror also gives much greater depth of field. I was aware of cars several blocks behind me, and could even see the horizon.

Using the mirrors with flat glass was far more active. I noticed that I unconsciously rocked my upper body laterally a little when looking in the planer, so my instincts were satisfied that I didn't miss anything. By adjusting my line of vision, I looked for the blind spots.

But my favorite aspect was that things just looked real.