Why R Single speeds more efficient than multi-gear bikes?

On 5/19/2014 4:50 PM, Frank Krygowski wrote:
On 5/19/2014 4:22 PM, Sir Ridesalot wrote:
In the last few days I've gone on a number of rides. I've
used different bikes on different days. One thing I
noticed is that my single speed seems to be a lot more
efficient accelerating or climbing than what the
multi-gear 27 speed, 18 speed (2 x 9) or the 14 speed
bikes are. All bikes have clean and unworn drivetrains.

So, what is it that make the single speed so much easier
to accelerate and climb? Is it simply the absence of the
extra moving parts such as derailleur pulleys?
Is a fixed gear with the same gear as a single speed even
more efficient to pedal?

Under what conditions do you feel it's "more efficient"?
Surely, it has to be under a very specific set of conditions
- e.g. not a very steep hill, not a very bad headwind.

Keep in mind, your perception could be due to the same
mechanism that makes red bikes faster.



It's a real phenomenon and I notice it when changing between
fixed (winter) and coast (all too brief other)bikes. The
fixed setup seems more snappy, lively. Most probably
psychological since there's no physical explanation and I
use the same class of rims with same tires for both.

That said, there are other differences. A long descent fixed
is drudgery unlike the exhilaration of coasting down.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Per Frank Krygowski:
BTW, 2nd gear on a Sturmey-Archer 3 speed is a direct drive, so the
transmission is just as efficient as a single speed.

Guy at a place I used to work had his bike set up with a Sturmey-Archer
3-speed in the back and three chain rings in the front. And he just
loved that setup.

You could call this guy borderline-morbidly-obese - he was almost as
round as tall - but he was infamous for being able to ride most people
into the ground on weekend rides.
--
Pete Cresswell

On Tuesday, May 20, 2014 7:26:20 AM UTC-4, John B. wrote:
On Mon, 19 May 2014 18:18:35 -0700 (PDT), Sir Ridesalot

wrote:



On Monday, May 19, 2014 4:22:41 PM UTC-4, Sir Ridesalot wrote:

In the last few days I've gone on a number of rides. I've used different bikes on different days. One thing I noticed is that my single speed seems to be a lot more efficient accelerating or climbing than what the multi-gear 27 speed, 18 speed (2 x 9) or the 14 speed bikes are. All bikes have clean and unworn drivetrains.







So, what is it that make the single speed so much easier to accelerate and climb? Is it simply the absence of the extra moving parts such as derailleur pulleys?



Is a fixed gear with the same gear as a single speed even more efficient to pedal?







Cheers



I see that I forgot to include the line, "in the same gear. That is if my single speed gear is exactly equal to the same gear on any of my other bikes the single speed accelerates and climbs better. that's the efficiency I was asking about. Four bikes, three are multigear and one is single speed. All bikes are ridden in the same gear combination for a fair distance. Of the four bikes the single speed is easier to accerate and to climb with until the gear becomes too high for the grade. I'm surprised a5t how steep the grade is for the single speed as compared to the multi gear bikes that I need to ger down on sooner.



Cheers



Out of curiosity, have you weighed the bikes? The single speeder might

actually be the lightest, which might account for it.

--

Cheers,



John B.

(invalid to gmail)

When I first built the single speed before repainting it, I used the exact same parts on it as I did when it was a multi-gear bike. I know that the single-speed with the shorter chain, shorter chainring bolts, one chainring instead of two, one gear freewheel instead of multi cogs on a bigger freewheel body and the lack of derailleurs, shifters and their cables makes for a lighter bike. BUT, the single speed does feel a lot easier to accelerate and climb with compared to the exact same gear when it was a multi-gear.

Cheers

On Tue, 20 May 2014 20:29:44 -0700 (PDT), Sir Ridesalot
wrote:

On Tuesday, May 20, 2014 7:26:20 AM UTC-4, John B. wrote:
On Mon, 19 May 2014 18:18:35 -0700 (PDT), Sir Ridesalot

wrote:



On Monday, May 19, 2014 4:22:41 PM UTC-4, Sir Ridesalot wrote:

In the last few days I've gone on a number of rides. I've used different bikes on different days. One thing I noticed is that my single speed seems to be a lot more efficient accelerating or climbing than what the multi-gear 27 speed, 18 speed (2 x 9) or the 14 speed bikes are. All bikes have clean and unworn drivetrains.







So, what is it that make the single speed so much easier to accelerate and climb? Is it simply the absence of the extra moving parts such as derailleur pulleys?



Is a fixed gear with the same gear as a single speed even more efficient to pedal?







Cheers



I see that I forgot to include the line, "in the same gear. That is if my single speed gear is exactly equal to the same gear on any of my other bikes the single speed accelerates and climbs better. that's the efficiency I was asking about. Four bikes, three are multigear and one is single speed. All bikes are ridden in the same gear combination for a fair distance. Of the four bikes the single speed is easier to accerate and to climb with until the gear becomes too high for the grade. I'm surprised a5t how steep the grade is for the single speed as compared to the multi gear bikes that I need to ger down on sooner.



Cheers



Out of curiosity, have you weighed the bikes? The single speeder might

actually be the lightest, which might account for it.

--

Cheers,



John B.

(invalid to gmail)

When I first built the single speed before repainting it, I used the exact same parts on it as I did when it was a multi-gear bike. I know that the single-speed with the shorter chain, shorter chainring bolts, one chainring instead of two, one gear freewheel instead of multi cogs on a bigger freewheel body and the lack of derailleurs, shifters and their cables makes for a lighter bike. BUT, the single speed does feel a lot easier to accelerate and climb with compared to the exact same gear when it was a multi-gear.

Cheers

It's sort of an interesting question. The bike is probably lighter but
how much lighter does a bike have to be to "feel" quicker?

Maybe a Watt meter or a, say 25 Km TT next Monday and Tuesday to
develop real data :-)
--
Cheers,

John B.
(invalid to gmail)

Per Frank Krygowski:
I'm still thinking it's mostly the red bike effect.

I can definitely feel the diff - but I'm with Frank on the "Red Bike"
effect. And my car runs better after being washed and waxed - there's
just no doubt about that.
--
Pete Cresswell

On Tuesday, May 20, 2014 8:29:44 PM UTC-7, Sir Ridesalot wrote:
On Tuesday, May 20, 2014 7:26:20 AM UTC-4, John B. wrote:

On Mon, 19 May 2014 18:18:35 -0700 (PDT), Sir Ridesalot



wrote:







On Monday, May 19, 2014 4:22:41 PM UTC-4, Sir Ridesalot wrote:



In the last few days I've gone on a number of rides. I've used different bikes on different days. One thing I noticed is that my single speed seems to be a lot more efficient accelerating or climbing than what the multi-gear 27 speed, 18 speed (2 x 9) or the 14 speed bikes are. All bikes have clean and unworn drivetrains.















So, what is it that make the single speed so much easier to accelerate and climb? Is it simply the absence of the extra moving parts such as derailleur pulleys?







Is a fixed gear with the same gear as a single speed even more efficient to pedal?















Cheers







I see that I forgot to include the line, "in the same gear. That is if my single speed gear is exactly equal to the same gear on any of my other bikes the single speed accelerates and climbs better. that's the efficiency I was asking about. Four bikes, three are multigear and one is single speed. All bikes are ridden in the same gear combination for a fair distance. Of the four bikes the single speed is easier to accerate and to climb with until the gear becomes too high for the grade. I'm surprised a5t how steep the grade is for the single speed as compared to the multi gear bikes that I need to ger down on sooner.







Cheers







Out of curiosity, have you weighed the bikes? The single speeder might



actually be the lightest, which might account for it.



--



Cheers,







John B.



(invalid to gmail)



When I first built the single speed before repainting it, I used the exact same parts on it as I did when it was a multi-gear bike. I know that the single-speed with the shorter chain, shorter chainring bolts, one chainring instead of two, one gear freewheel instead of multi cogs on a bigger freewheel body and the lack of derailleurs, shifters and their cables makes for a lighter bike. BUT, the single speed does feel a lot easier to accelerate and climb with compared to the exact same gear when it was a multi-gear.

Probably has significantly lower wheel weight with the tubies, plus they have a different feel, depending on what you're used to in terms of clinchers..

I do believe that pawl engagement/slop, weight, friction from chain angle and a lot of other things about multi-speed drive trains can have an effect on efficiency and perceived acceleration. I think weight and tire characteristics have a much larger effect.

-- Jay Beattie.