Author Topic: Bastard wind!  (Read 2595 times)

fd3

Bastard wind!
« on: August 26, 2020, 07:28:42 pm »
Got properly buffeted by the turbulence from a bus passing in the other direction yesterday on the commute home.  I was wondering whether the panel believes that a laidback bike would fair better in side wind than a DF.  Furthermore, what are the panel's opinions on a laidback trike in such circumstances?
Strange things are afoot at the circle K.

Re: Bastard wind!
« Reply #1 on: August 26, 2020, 08:06:37 pm »
I'm not at all sure that a 'bent trike would be buffeted but I'm very interested in the thoughts of those with high mileage behind them.
Never knowingly under caffeinated

Kim

  • Timelord
Re: Bastard wind!
« Reply #2 on: August 26, 2020, 08:18:27 pm »
If you're low down, a combination of hedges and the boundary effect protects you from wind somewhat.  That does approximately nothing for being buffeted by passing motor vehicles.

Given a higher recumbent, I don't think there's much fundamental difference to a DF bike.  More relevant I think is whether the bike's geometry is conducive to steering stability under sudden perturbation.  Small front wheels may help somewhat, too.

Trikes don't do the alarming wobble thing the way bikes do, but I don't think they're completely immune to sidewind - it just adds to the camber you're already correcting for.
Careful, Kim. Your sarcasm's showing...

Re: Bastard wind!
« Reply #3 on: August 26, 2020, 08:28:36 pm »
I was out on audaxes in the storms in Feb and March.  My Lightning P38 was virtually unaffected by the strong side gusts. In contrast when on my road bike on audaxes in similarly strong storms  the year before, it was like I’d been wrestling the bike against the winds. My arms were worn out in this latter case. In particular if you went past a gate  between the hedges, you had to brace the road bike for the expected gusts.

Recumbents are so varied though, it will depend on where you sit in relation to wheels, between or on top, size of wheels, and the relative centre of gravity plus the side profile of rider and bike.

So it depends...

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Bastard wind!
« Reply #4 on: August 26, 2020, 08:37:52 pm »
Not in the Fens, where it's flat as hell and the hedges are broken where they exist, and few and far between.  There is a road near me that is 10 miles long, dead straight, and completeley exposed.  I've ridden ten miles into a headwind, and ten miles canted over like a sailing yacht.

I've spent several hours fighting the gusty crosswinds to the extent that I've woken up the next day with aching forearms.  I don't think it would have made any difference riding a DF.  This week I decided to go out on Monday for example to get my online TT league run in the bag. The rest of the week has been shit so far and looks no better for the rest of it.
“Procrastination is the thief of time, collar him.” –Charles Dickens

Wowbagger

  • Sylph
    • Musings of a Gentleman Cyclist
Re: Bastard wind!
« Reply #5 on: August 26, 2020, 08:47:15 pm »
OT, but I recall a very fine afternoon in the Fens a few years back when Kim and I cycled from Mildenhall to Prickwillow Museum with a stonking tailwind. We were dreading the return trip, but holy of holies, the wind was, if anything, even stronger when we came out, but it had turned 180°. We were cycling on the flat (in the Fens?!) at about 30mph.

ISTR that Kim, on her Street Machine, outpaced me marginally on my Thorn, but I discovered that I hadn't changed into top gear...
Bach without a doubt.

fd3

Re: Bastard wind!
« Reply #6 on: August 26, 2020, 11:08:01 pm »
You'd think crosswind would be more manageable on a laidback because wind travels slower near the ground (layers of air and friction).  I'm surprised that buffeting would be easier with a small front wheel, I had expected it would be worse due to lower inertia and gyroscopic forces, though smaller might also mean less sail size.
So, Trikes would experience the same push (maybe less as lower) but you wouldn't risk being knocked over.
Strange things are afoot at the circle K.

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: Bastard wind!
« Reply #7 on: August 27, 2020, 12:52:56 am »
I used to use wheel covers on my Kingcycle all the time with nary a problem, so made some spiffy new ones when I got my Speedmachine.  Got blown one full lane rightwards when descending the north face of Stamford Hill on practically the first commute.  Took 'em off the same evening, never used them again.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Bastard wind!
« Reply #8 on: August 27, 2020, 06:17:24 am »
OT, but I recall a very fine afternoon in the Fens a few years back when Kim and I cycled from Mildenhall to Prickwillow Museum with a stonking tailwind. We were dreading the return trip, but holy of holies, the wind was, if anything, even stronger when we came out, but it had turned 180°. We were cycling on the flat (in the Fens?!) at about 30mph.

ISTR that Kim, on her Street Machine, outpaced me marginally on my Thorn, but I discovered that I hadn't changed into top gear...

Volunteering at St Ives on the last LEL on the day of the bastard winds on the Fens, took me 1h 15 to get there and 45 mins home. I've never done that run so fast again.
“Procrastination is the thief of time, collar him.” –Charles Dickens

andytheflyer

  • Andytheex-flyer.....
Re: Bastard wind!
« Reply #9 on: August 27, 2020, 08:23:54 am »
Not in the Fens, where it's flat as hell and the hedges are broken where they exist, and few and far between.  There is a road near me that is 10 miles long, dead straight, and completeley exposed.  I've ridden ten miles into a headwind, and ten miles canted over like a sailing yacht.
As a teenager, I rode many many miles across the Fens north of Boston.  Wind always came into the route planning.  The worst bit was the 7 Mile Straight through Carrington (actually 5.5 miles) with few hedges and trees.  On a clear day you could almost see from one end to the other.  A southerly wind was on the nose.  Nightmare.

Kim

  • Timelord
Re: Bastard wind!
« Reply #10 on: August 27, 2020, 01:50:53 pm »
OT, but I recall a very fine afternoon in the Fens a few years back when Kim and I cycled from Mildenhall to Prickwillow Museum with a stonking tailwind. We were dreading the return trip, but holy of holies, the wind was, if anything, even stronger when we came out, but it had turned 180°. We were cycling on the flat (in the Fens?!) at about 30mph.

ISTR that Kim, on her Street Machine, outpaced me marginally on my Thorn, but I discovered that I hadn't changed into top gear...

I should stress that in those days cycling on the flat at 30mph was Not A Thing I Could Do.  Indeed, I can't do it for very long now, and I'd struggle to manage it on the Streetmachine.  [Especially if you keep forgetting to pump the tyres up - Ed.]

I've filed that particular ride alongside the Welsh end-to-end with 20 minutes of light drizzle, a tailwind the whole way, and sunburn:  Weather karma comprehensively depleted.

Possibly more relevant to this discussion, was the time that I accompanied Mr and Mrs Bagger on an overambitious ride in more textbook Welsh weather.  The bulk of the comedy/tragedy is documented elsewhere, but it provided a useful illustration of how much rider weight affects handling in crosswinds, with two riders on almost identical bikes having a very different experience.
Careful, Kim. Your sarcasm's showing...

Re: Bastard wind!
« Reply #11 on: August 27, 2020, 04:45:42 pm »
Enjoyed that write up

Re: Bastard wind!
« Reply #12 on: August 27, 2020, 05:39:19 pm »
  I'm surprised that buffeting would be easier with a small front wheel, I had expected it would be worse due to lower inertia and gyroscopic forces, though smaller might also mean less sail size.

I suspect it’s to do with the COG being higher on HRs unless they are very long wheel base. Plus the side wind is acting on a surface area higher above the point of pivot when on a HR. Mostly for smaller front wheel recumbents (of the short wheel base variety) you have the rider and bike COG below the height of the top of the rear wheel.

You steer to the right in a cross wind from the left to correct for when your balance is upset. I suspect the higher up you are the easier it is to shift your balance point over to the right of the bike.  At which point gravity is trying to pull you down that way. You get greater sideways torque the higher up the area the side wind force is pushing against. So if you’re lower down as well as lower wind speeds your balance is not getting upset as much. Not enough to need to steer right to regain your balance.

It’ll also depend on the seat. Quite a few solid recumbent seats have a fair bit of material projecting down from the middle, and that will also catch the side wind. A mesh seat and tube frame not so much.

Plus as surmised much less sailing effect with the smaller front wheel.

Re: Bastard wind!
« Reply #13 on: August 28, 2020, 02:29:51 am »
I'm on a low bent trike.
How much I get affected by a sudden cross gust basically come down to what speed I'm going as the faster I go the lighter the steering gets.
In that respect it very similar to hitting a lump/hole with one front wheel.
So if I'm sub 15 mph a sudden strong gust may only divert me sideways an inch or three.
But the same strength gust when I'm over 30 mph could well divert me off line a foot or more.
I'm never worried about big stuff passing me fast as I'm down in the ground effect zone and most of the air blast is going straight over my head.
At worst I may speed up a mph or two.

Luck .........  ;D

Blodwyn Pig

  • what a nice chap
Re: Bastard wind!
« Reply #14 on: August 28, 2020, 07:11:38 am »
Enjoyed that write up

Yes , so did I, refreshingly descriptive.

Re: Bastard wind!
« Reply #15 on: August 29, 2020, 10:55:56 am »
Touring Holland, me on a Giro 20 with underseat rack & panniers, mate on a Moulton with front rack and panniers. Encountered really strong but fairly steady cross winds on a dijk next to one of the meers. Very scary, trying to cycle straight whilst leant over at a ridiculous angle. My mate coped better on the Moulton. When we got round the corner and had the wind behind us we rocketed along without pedalling for ages.

quixoticgeek

  • Mostly Harmless
Re: Bastard wind!
« Reply #16 on: August 29, 2020, 08:47:53 pm »
Touring Holland, me on a Giro 20 with underseat rack & panniers, mate on a Moulton with front rack and panniers. Encountered really strong but fairly steady cross winds on a dijk next to one of the meers. Very scary, trying to cycle straight whilst leant over at a ridiculous angle. My mate coped better on the Moulton. When we got round the corner and had the wind behind us we rocketed along without pedalling for ages.

It can be an interesting experience that one.

I've had similar cases where I've been riding along canted over quite a bit because of the cross wind, only for there to be a sudden drop in the wind, and you have to correct very quickly...

I've also once, and so far only once, had an issue where the wind hitting a building, blowing down, and then across in the opposite direction, has pushed me sideways so much I've had to do an emergency stop to not fall off. That was scary.

The other common one round these parts is being in the shelter of buildings, passing a gap in them, and being blatted from the side by the stupid strong wind. Great for improving ones bike handling skills, not so great for the blood pressure...

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: Bastard wind!
« Reply #17 on: August 30, 2020, 10:14:38 am »
My worst crosswind was on Route 1 in southern Iceland.
The wind was strong enough to pick up volcanic sand off a rivers floodplain.
Now normally this forms a layer about 3" thick, so even on a bent trike most of it passes under me.
But the way the roads was built on a berm to help clear snow also lifted the top of the sand layer to roughly 18"-24" up as it crossed over the road.
It was sunny and hot, so I was wearing only shorts and sandals.
I ended up sandblasted from head to toe for roughly half an hour as I crossed that rivers floodplain.

Luck ............  ;D

Re: Bastard wind!
« Reply #18 on: August 30, 2020, 11:47:16 am »
I recall an early FNRttC to Brighton where the weather turned at the top of Ditchling Beacon. I was very glad that I chose my coat rather than my cape as after crossing the A27 I watched Tim Pike blown onto the verge in front of me while riding his bent. :o

Thinking about is on a bent you largely have the same side area but a lower centre of mass therefore a wind load that moves you sideways by 10mm changes the angle of the centre of mass against the contact points further.

I am not a recumbent rider, but I wonder if the nature of the saddle makes it harder to move your body weight side to side where on an upwrong you can hunch a shoulder into the wind and move your upper bodyweight to the side as a counter balance.

sprogs

  • from your big sister, Steve.
Re: Bastard wind!
« Reply #19 on: September 07, 2020, 06:17:06 pm »
Hight of cg above ground must be a factor.
Imagine trying to balance a broom on your hand, easy.
Now try it with a pencil.

Kim

  • Timelord
Re: Bastard wind!
« Reply #20 on: September 07, 2020, 06:55:09 pm »
I recall an early FNRttC to Brighton where the weather turned at the top of Ditchling Beacon. I was very glad that I chose my coat rather than my cape as after crossing the A27 I watched Tim Pike blown onto the verge in front of me while riding his bent. :o

I believe that was a Streetmachine, too, which is a pretty stable touring bike.  Unfortunately stability doesn't help you when a crosswind changes faster than you can react.



Quote
I am not a recumbent rider, but I wonder if the nature of the saddle makes it harder to move your body weight side to side where on an upwrong you can hunch a shoulder into the wind and move your upper bodyweight to the side as a counter balance.

Yes, that's the big difference in technique between balancing a recumbent and an upright bike - you can't[1] really move your body-weight to provide steering correction, it all has to come from the handlebars.

Trike riders tend to lean into corners a bit to stay in the seat, if not usefully shift the centre of mass.  This is easier with a more upright seat angle.


[1] Unless you sit forward in the seat, which you can only do if there aren't handlebars in the way and don't mind unloading the back wheel.
Careful, Kim. Your sarcasm's showing...

Re: Bastard wind!
« Reply #21 on: September 07, 2020, 06:58:40 pm »
I recall an early FNRttC to Brighton where the weather turned at the top of Ditchling Beacon. I was very glad that I chose my coat rather than my cape as after crossing the A27 I watched Tim Pike blown onto the verge in front of me while riding his bent. :o

I believe that was a Streetmachine, too, which is a pretty stable touring bike.  Unfortunately stability doesn't help you when a crosswind changes faster than you can react.

I'm pretty sure he borrowed your one for a while - I remember him doing the Dun Run on it.


If it ain't broke, fix it 'til it is...

Kim

  • Timelord
Re: Bastard wind!
« Reply #22 on: September 07, 2020, 06:59:51 pm »
I recall an early FNRttC to Brighton where the weather turned at the top of Ditchling Beacon. I was very glad that I chose my coat rather than my cape as after crossing the A27 I watched Tim Pike blown onto the verge in front of me while riding his bent. :o

I believe that was a Streetmachine, too, which is a pretty stable touring bike.  Unfortunately stability doesn't help you when a crosswind changes faster than you can react.

I'm pretty sure he borrowed your one for a while - I remember him doing the Dun Run on it.

Yes, it definitely knew the way to Dunwich when I firsecond attempted it.
Careful, Kim. Your sarcasm's showing...

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Bastard wind!
« Reply #23 on: September 07, 2020, 08:01:32 pm »
I recall an early FNRttC to Brighton where the weather turned at the top of Ditchling Beacon. I was very glad that I chose my coat rather than my cape as after crossing the A27 I watched Tim Pike blown onto the verge in front of me while riding his bent. :o

I believe that was a Streetmachine, too, which is a pretty stable touring bike.  Unfortunately stability doesn't help you when a crosswind changes faster than you can react.



Quote
I am not a recumbent rider, but I wonder if the nature of the saddle makes it harder to move your body weight side to side where on an upwrong you can hunch a shoulder into the wind and move your upper bodyweight to the side as a counter balance.

Yes, that's the big difference in technique between balancing a recumbent and an upright bike - you can't[1] really move your body-weight to provide steering correction, it all has to come from the handlebars.

Trike riders tend to lean into corners a bit to stay in the seat, if not usefully shift the centre of mass.  This is easier with a more upright seat angle.


[1] Unless you sit forward in the seat, which you can only do if there aren't handlebars in the way and don't mind unloading the back wheel.

I beg to differ, round here you can regularly be bombing along (for your variant of bombing along) with protection from a hedge, which suddenly stops to reveal a bastard crosswind.

It is perfectly feasible to shift the arse and dip a shoulder into the wind as well as steering input.  If you know it's coming you can even anticipate.
“Procrastination is the thief of time, collar him.” –Charles Dickens

T42

  • *** fool in a hurry
Re: Bastard wind!
« Reply #24 on: September 08, 2020, 08:25:55 am »
It is perfectly feasible to shift the arse and dip a shoulder into the wind as well as steering input.  If you know it's coming you can even anticipate.

People who sail might have an advantage here.  Tacking or luffing not advisable, though.

---o0o---

Anent the original question, I remember having a similar chat with a 'bent rider at the start of a PBP long ago.  He said that wind buffeting from traffic isn't so bad, but if it happened to go through a puddle when overtaking the splosh invariably landed on the crotch.
I've dusted all those old bottles and set them up straight.