Recumbent suspension

DIscuss anything relating to non-standard cycles and their equipment.
User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 8 Jun 2011, 3:49pm

Father Jack wrote:... would like Recumbent bike, but wondering if any type of suspension is needed? Either rear or full? Also I'd want it set quite hard I think. But prefer none if it's not needed. On road only. Like the Vortex + but the price
You need to work out whether you are after a trike (slower, lower but more stable) or a bike (significantly faster than a trike). Horses for courses, but it would narrow the field down a bit!
"42"

Father Jack
Posts: 237
Joined: 4 Apr 2011, 10:07pm

Re: Recumbent suspension

Postby Father Jack » 8 Jun 2011, 11:27pm

I didn't know a trike would be slower, although I thought the extra tyre would increase rolling resistance, thought the lower position would help with aerodynamics. So a two wheel recubent is faster?

User avatar
[XAP]Bob
Posts: 16945
Joined: 26 Sep 2008, 4:12pm

Re: Recumbent suspension

Postby [XAP]Bob » 9 Jun 2011, 12:38am

Yes - although not infinitely.

The Aero position helps into headwinds and at speed, but you get the same on a bike...
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

byegad
Posts: 3232
Joined: 3 Sep 2007, 9:44am

Re: Recumbent suspension

Postby byegad » 9 Jun 2011, 8:36am

Father Jack wrote:I didn't know a trike would be slower, although I thought the extra tyre would increase rolling resistance, thought the lower position would help with aerodynamics. So a two wheel recubent is faster?


A trike is easier to ride slowly up hill. A recumbent bike 'encourages' you to keep up a good pace. The extra wheel not only adds 50% more rolling resistance but can also be responsible for extra drag due to poor tracking, one of my trikes came with poor tracking and putting that right added 1mph to the average speed over a 20 mile ride. In terms of absolute top speed, down hill, it added more like 5mph.

There is an aero penalty to the extra wheel on a trike, for a start spokes cause drag and then the cross section of the trike itself is a deal wider too.

The difference, in my experience is around 8 to 10% faster on a recumbent bike of equal weight than on a trike.
"I thought of that while riding my bike." -Albert Einstein, on the Theory of Relativity

2007 ICE QNT
2008 Hase Kettwiesel AL27
2011 Catrike Trail
1951 engine

User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 9 Jun 2011, 9:21am

Father Jack wrote:I didn't know a trike would be slower, although I thought the extra tyre would increase rolling resistance, thought the lower position would help with aerodynamics. So a two wheel recubent is faster?
IME a recumbent trike is about 10 to 15% slower on journey times than a recumbent bike - comparing similar types (e.g. touring or 'race'). Tyre drag + aero drag (to quote ICE 'to be fast on a recumbent trike you need to be reclined' - both front wheels are out in clean air, on a bike the rear wheel is in the shadow of the front) + extra weight (which gets you on hills - where you really can loose time).
"42"

Father Jack
Posts: 237
Joined: 4 Apr 2011, 10:07pm

Re: Recumbent suspension

Postby Father Jack » 9 Jun 2011, 10:09am

ok probably looking at a two wheeled bent then. Any recommendations, my road bikes have 23/35/28mm tyres as I quicker rolling.

User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 9 Jun 2011, 11:22am

Father Jack wrote:Any recommendations
Try some :wink:
If in Scotland then Laidback, South of London: London Recumbents - based in Dulwich Park, so good for tryouts but limited stock - or Future Cycles in Forest Row. Anything in-between, for the largest collection of S/H 'bents this side of the channel, DTek (no web site 01353 648177 - just remember it's only Kevin, and he does take breaks :wink: )
FWIW, and this is just a thought, it might be worth trying a couple of trikes - with different seat heights - to get the feel for the recumbent position before trying a bike (where you need to balance via the steering).
Have fun!
"42"

zoxed
Posts: 175
Joined: 25 Aug 2010, 1:18pm
Location: Darmstadt, Germany
Contact:

Re: Recumbent suspension

Postby zoxed » 9 Jun 2011, 12:06pm

Father Jack wrote:...I thought the extra tyre would increase rolling resistance, thought the lower position would help with aerodynamics...


As a trike owner I always wondered about that, but surely for the same weight of (rider + bike/trike) the rolling resistance would be the same: more wheels but less weight on each ? (less weight = less tyre deflection = less resistance ?)

zoxed
Posts: 175
Joined: 25 Aug 2010, 1:18pm
Location: Darmstadt, Germany
Contact:

Re: Recumbent suspension

Postby zoxed » 9 Jun 2011, 12:12pm

squeaker wrote:...both front wheels are out in clean air, on a bike the rear wheel is in the shadow of the front)...


This is true (except in the case of a delta it is the rear wheels !!). So I guess wheel disks/thin tyres are even more useful on a trike than a bike. (And the side-wind effect would be less of a problem on a trike than a bike.)

(I am mostly a trike rider by choice (Kett), but sometimes use a bike for speed: I would love it if my trike was a closer speed to my trike, and then I could drop the bike :-))

User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 9 Jun 2011, 2:03pm

zoxed wrote:but surely for the same weight of (rider + bike/trike) the rolling resistance would be the same: more wheels but less weight on each ? (less weight = less tyre deflection = less resistance ?)

In my consulting days, the standard 'get out of jail' was to mutter something about 'non-linear effects' (e.g. there is some rolling resistance with no load, and the resistance is not directly proportional to the load) - I'm sure that applies here :lol:
"42"

User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 9 Jun 2011, 2:03pm

zoxed wrote:but surely for the same weight of (rider + bike/trike) the rolling resistance would be the same: more wheels but less weight on each ? (less weight = less tyre deflection = less resistance ?)

In my consulting days, the standard 'get out of jail card' was to mutter something about 'non-linear effects' (e.g. there is some rolling resistance with no load, and the resistance is not directly proportional to the load) - I'm sure that applies here :lol:
"42"

hercule
Posts: 969
Joined: 5 Feb 2011, 5:18pm

Re: Recumbent suspension

Postby hercule » 9 Jun 2011, 6:09pm

zoxed wrote:(I am mostly a trike rider by choice (Kett), but sometimes use a bike for speed: I would love it if my trike was a closer speed to my trike, and then I could drop the bike :-))


A fairing has made an appreciable difference to my Trice (DF riders disappearing rapidly in the mirror on downhills!) but would be a bit trickier to fit to a Kett. It's not quite cured my longing for a fast bent bike, though... :roll:

User avatar
squeaker
Posts: 3554
Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Recumbent suspension

Postby squeaker » 9 Jun 2011, 7:10pm

hercule wrote:A fairing has made an appreciable difference to my Trice (DF riders disappearing rapidly in the mirror on downhills!) but would be a bit trickier to fit to a Kett.
IIRC LeeW of BHPC reckoned that a significant tail fairing was worth about 2mph at race speeds on his Trice 'S'....
"42"

UpWrong
Posts: 810
Joined: 31 May 2009, 12:16pm
Location: Portsmouth, Hampshire

Re: Recumbent suspension

Postby UpWrong » 9 Jun 2011, 9:35pm

As others have said, bikes are faster than trikes so if you want comparable times to a road DF then a recumbent bike is a better bet. Even so, the chances are that you will be slower going up hills and faster going down them and around the same on the level depending on conditions.

With regards to suspension, generally more desirable on a recumbent although larger wheels, a mesh seat and wider tyres reduce the need. Good, lightweight suspension tends to cost more money.

You could do worse than buy a Bacchetta Giro which has different seat options and a wide range of adjustment. Then after a few months and a couple of thousand miles you might have a better idea of what you want.

markg0vbr
Posts: 58
Joined: 5 Apr 2010, 9:00pm

Re: Recumbent suspension

Postby markg0vbr » 9 Jun 2011, 11:35pm

squeaker wrote:
Father Jack wrote:I didn't know a trike would be slower, although I thought the extra tyre would increase rolling resistance, thought the lower position would help with aerodynamics. So a two wheel recubent is faster?
IME a recumbent trike is about 10 to 15% slower on journey times than a recumbent bike - comparing similar types (e.g. touring or 'race'). Tyre drag + aero drag (to quote ICE 'to be fast on a recumbent trike you need to be reclined' - both front wheels are out in clean air, on a bike the rear wheel is in the shadow of the front) + extra weight (which gets you on hills - where you really can loose time).

also distance comes into it the farther you ride the less difference in speed there is, i put it down to comfort, not having to balance and stop as often.
then there is touring, i am faster on the trike over long distance with a full load then i ever have, on df or bent bike.