Supported Lejog goes Off topic

[reohn2]

I'm a stand up and be counted right on pro mirrorist (Mirrycycle), obviously you know what we really NEED is more technology

https://youtu.be/7lCQN8DaelY

Technology and fear,should sell well

[Mick F]

http://explore.garmin.com/en-GB/edge/#
Good grief.

[Vantage]

Oh I do hope they upgrade that varia thing so it has a built-in ray gun to zap the tyres of close passing drivers

[Steady rider]

reohn2 » Wed Jan 06, 2016 6:10 pm wrote

but I can't see any scientific reasons for your viewpoin

Mainly to explore if some reasons stack up; not precise figures used below and errors may exist in the calculations and would require research to see how viable or not.

Evidence we know or have some idea about, proportion of accidents due to rear end collisions, 6%-12% say for accidents involving a motor vehicle.
Say for example 100 accidents from motor vehicles, rear end perhaps 10 from 100 in total. In fatality cases could be much higher proportion.

http://www.ctc.org.uk/resources/ctc-cycling-statistics
The general risk of injury from cycling in Great Britain is just 0.05 injuries per 1,000 hours of cycling.

Injury risk possibly one per 20k hours, assumed based on road accidents stats.
Rear end risk, say 10% of accidents involving a motor vehicle. Once in 200k hours cycled. Assume average person cycles 2 hours per week for 50 years, roughly 5k hours. Assume a mirror has a positive benefit in 50% of rear end accidents, equivalent to once in 400k hrs.
Once in perhaps 80 lifetimes of average cycling a benefit could be seen (400/5 = 80), (assuming no added disadvantage of the cyclist riding off road in cases of near misses and end up crashing.)

Disadvantages of mirrors, taking eyes off road on occasions for probably near to 0.3 -0.5 seconds, assumed once per 2 minutes of riding, 5k hrs/ 2 mins = 150,000 times per lifetime. In 80 lifetimes this would be 12 million times, assuming a small disadvantage arises once in 10000 views.

Summary; the added advantage of a mirror may assist in knowing when a motorist is not passing safely, the cyclist can view when they chose, it provides more information of vehicles coming from behind. The potential disadvantage stems from the cyclist having to take their eyes off the road ahead and possibly over estimating the risks and taking evasive action that may result in a fall. It appears that the benefit on average may occur once in 400,000 hours of cycling and the potential small disadvantages occur 1200 times during that time. It appears likely that overall a negative safety outcome may occur in general accident terms. This may not be the case in some circumstances.

[Vantage]

Imo there's too much statistics and science going on here.
I take the view that I don't know what will happen a mile or 10000 miles up the road, an hour or 10 years up the road. I don't count the time I spend watching the rvm any more than I do the cyclo computer speedo, the pink line on the gps or the gorgeous scenery around me.
What I do know for a fact is that a quick glance in the rvm takes less time than swinging my head around for a shoulder check and I'm less likely to let the bike wander of its line also.
The rvm is there to check that traffic IS behind me, not to ensure that it isn't. If I see traffic in the mirror then I know there's traffic behind. If I see nothing in the mirror then that's the time to shoulder check. Simples.

[reohn2]

Steady rider <snip>
I'm now totally confused and will need a lie down in a darkened room..... .......perhaps for a very long time................

[irc]

Once in perhaps 80 lifetimes of average cycling a benefit could be seen

I must be an outlier then. I've had one incident where my mirror probably saved my life as I had to ride off the road to avoid being hit. The only alt being not using a mirror and doing multiple shoulder checks for passing vehicles.

I've had many, perhaps dozens, of incidents where I was forewarned of dangerously close passes. I was then able to move towards the road edge to make the pass safe.

I've been able to maintain my position in the lane while a following vehicle was trying to bully me on to a 9" wide shoulder (at 20-25mph) because my mirror let me see that though the driver was sounding his horn he was maintaining a safe distance behind me.

I've been forewarned several times of drivers starting an overtake on the approach to a blind bend. I could therefore even before the car was past get ready to take evasive action if an oncoming car appeared. Cover brakes, check road edge to see if suitable for riding on to etc.

Many times when needing to change lanes in heavy traffic I've been able to watch for a gap in my mirror without having to lose forward vision for as long as shoulder checks. Then see a gap, quick shoulder check, signal and go.

Loads of big and small benefits.

The scariest moment I've ever had on a bike was when my mirror was broken and I was riding on the narrow shoulder of a busy fast road. A driver wandered off the lane onto the shoulder and went by me around 60mph within about 2 inches. One foot further over and I would have been at best seriously injured. A mirror would have prevented that one.

But you could say that it's only ever prevented one serious/fatal crash. I think all the other benefits are worth it even if a mirror never saves you from an overtaking accident. It's just better driving/riding being as aware as possible of where other road users are and what they are doing.

[Steady rider]

If someone has a hearing problem or is deaf then I may even recommend using a mirror. It also seems possible that helmet wearers when turning their heads to do a shoulder check, will be more affected by wind forces and a mirror may reduce their need for shoulder checks. I can recall being passed by a very long vehicle where a mirror could have been helpful to know just how long it was, probably about 20+ m, it was unusual.

[reohn2]

If someone has a hearing problem or is deaf then I may even recommend using a mirror. It also seems possible that helmet wearers when turning their heads to do a shoulder check, will be more affected by wind forces and a mirror may reduce their need for shoulder checks. I can recall being passed by a very long vehicle where a mirror could have been helpful to know just how long it was, probably about 20+ m, it was unusual.

If we've been on a long tour on the tandem and I haven't been on a solo for a couple of weeks,due to the tandem's long wheel base it's very stable and steady,on getting back on a solo it feels very twitchy for the first mile or so,even my relaxed geometry bikes,feel like that.
I can understand that to some people a bike may feel like that all the time.I know a couple of chaps who've been riding all there lives and who marvel at me sitting up stretching,etc,'without hands',one in particular tells me he'd be terrified to take his hands off the h/bars.
If you ride with a group,PDQ you get to know who the dodgy bike handlers are,some have a job to keep the thing in a straight line with both hands on the h/bars!

People who aren't as flexible as they could be,nervous individuals,people who's bike handling skills aren't up to scratch,older riders,etc,etc could all perhaps benefit from an RVM.

YVMV

[Steady rider]

People who aren't as flexible as they could be,nervous individuals,people who's bike handling skills aren't up to scratch,older riders,etc,etc could all perhaps benefit from an RVM

.

I may see it from an opposite view, older people with poorer eyesight perhaps and slower reaction times, I may advise to keep their eyes on the road ahead. If on the other hand they had neck problems in turning their head, a RVM may be helpful, as you suggest. Perhaps riding with no hands is an area where some research could be of benefit, what precise design provides the best outcome for riding with no hands and conditions (bearings, out of track frames or other aspects, weight distribution etc)? I did try a tandem but found it less stable than my normal bike, not for me.

[reohn2]

I may see it from an opposite view, older people with poorer eyesight perhaps and slower reaction times, I may advise to keep their eyes on the road ahead.

Specsavers? for the optical issues
I can see how a RVM could help with slower reaction times,as such people may not shoulder/lifesaver check as often as they should.

If on the other hand they had neck problems in turning their head, a RVM may be helpful, as you suggest.

Well we at least agree on something.

Perhaps riding with no hands is an area where some research could be of benefit, what precise design provides the best outcome for riding with no hands and conditions (bearings, out of track frames or other aspects, weight distribution etc)?

TBH any bike with any amount of stability should be able to be ridden without hands,if not it becomes a liability,especially when the rider is tired and or the road surface is bad,bad roads surfaces are increasingly the norm in the UK,IME.
When I'm dog tired I want steering/handling that'll 'take me home' and not need constant attention or be knocked off line by that small pothole I might miss,or off camber corner I'm not ready for,a bike that returns to a straight line automatically is the ideal,slack 'n stable front end geometry provides that,and makes for easy no hands riding.It's also another plus for big supple tyres that deform to bad roads and remain stable and straight.
I've ridden with chaps on 23/25mm tyres who've remarked that I ride over stuff they have to avoid or suffer.
RVM's could benefit those poor folks as they need to constantly change line to avoid the joys of UK tarmac,so need to keep an even more vigilant eye on motors approaching from behind

I did try a tandem but found it less stable than my normal bike, not for me.

I can understand tandems don't suit everyone,but after a couple of days riding getting used to one,the stability is far better than a solo due to the longer wheelbase,of course the team have to work together to achieve an equilibrium.Tandems are next to useless with two captains.
They climb slower than a solo,but descend like a stone and corner well enough,and with a strong team on board will drop a solo for dead on flatish to undulating terrain.

[[XAP]Bob]

I'm not sure how/why people think that an RVM is less safe than a shoulder check - you can look at an RVM and maintain peripheral vision of what's ahead - similarly you retain peripheral awareness of what is behind whilst you look ahead.

[reohn2]

I'm not sure how/why people think that an RVM is less safe than a shoulder check -

A shoulder check signals to others that you've eyeballed them,and give a better perspective,first person true view of the road behind.

you can look at an RVM and maintain peripheral vision of what's ahead - similarly you retain peripheral awareness of what is behind whilst you look ahead.

+1

[deliquium]

I'm not sure how/why people think that an RVM is less safe than a shoulder check - you can look at an RVM and maintain peripheral vision of what's ahead - similarly you retain peripheral awareness of what is behind whilst you look ahead.

+1 = simples

[Si]

I'm not sure how/why people think that an RVM is less safe than a shoulder check -

A shoulder check signals to others that you've eyeballed them,and give a better perspective,first person true view of the road behind.

+1

In the same way that keeping both hands on the bars is the best way to keep control of the bike, thus does keeping both hands on the bars rather than signalling increase safety? It all depends on the context.