Wheeel circumference for 650 X 23 Kenda Koncept tire

[Harryo]

Does anyone have an accurate wheel circumference for the
Kenda Koncept 650 x 23 tire, for a speedometer caibration. I
know I can do a roll-out measurement but I am just too lazy!

Harry Jiles

 

[Tom Sherman]

harryo wrote:

> Does anyone have an accurate wheel circumference for the
> Kenda Koncept 650 x 23 tire, for a speedometer
> caibration. I know I can do a roll-out measurement but I
> am just too lazy!

Harry,

The actual rolling diameter will depend on the rim used,
inflation pressure and load on the wheel. However, a good
approximation would be the bead seat diameter (571-mm) plus
twice the nominal width (23-mm) for a diameter of 617-mm and
a circumference of 1938-mm.

This brings up a second question - will the tight frame
clearance on a Baron be sufficient for this tire - or did
you get a highracer?

--
Tom Sherman - Quad Cities (Illinois Side)

 

[Harryo]

Tom Sherman <[email protected]> wrote in message news:<[email protected]>...
>
> This brings up a second question - will the tight frame
> clearance on a Baron be sufficient for this tire - or did
> you get a highracer?

I picked up a new Bacchetta Corsa, on Thursday, Tom. I still
have the Baron but the highracers have intrigued me for a
while. I went up to the Bike Rack, in St. Charles, and rode
the Corsa for about an hour, and was even more intrigued, so
I brought it home.

It is an interesting bike and I'll have more to report about
it's performance, compared to a lowracer, after I get some
miles on it but it is definitely an efficient and fast bike.
Also, I don't exactly what it weighs but by hefting it, it
is substancially lighter than the Baron. I suspect it will
be faster when climbing on very hilly roads.

Harry Jiles

 

[Mike Schwab]

Tom, I did the flatest 1 mile strech of nearby road to set
my odometer for my EZ-1. The smallest size in the manual was
20*1.75 for 1502 mm. This is the size of the rear wheel, but
the pickup was on the front wheel, 16*1.75. After 1 mile
read 1.29 miles. Changed number to 1100. Returned to
starting point, 0.94 mile. Changed number to 1160, redid
mile, came out at 1.00 miles. How well does this match the
theoritical circumference?

Tom Sherman wrote:
>
> harryo wrote:
>
> > Does anyone have an accurate wheel circumference for the
> > Kenda Koncept 650 x 23 tire, for a speedometer
> > caibration. I know I can do a roll-out measurement but I
> > am just too lazy!
>
> Harry,
>
> The actual rolling diameter will depend on the rim used,
> inflation pressure and load on the wheel. However, a good
> approximation would be the bead seat diameter (571-mm)
> plus twice the nominal width (23-mm) for a diameter of 617-
> mm and a circumference of 1938-mm.
>
> This brings up a second question - will the tight frame
> clearance on a Baron be sufficient for this tire - or did
> you get a highracer?
>
> --
> Tom Sherman - Quad Cities (Illinois Side)

 

[Tom Sherman]

Mike Schwab wrote:

> Tom, I did the flatest 1 mile strech of nearby road to set
> my odometer for my EZ-1. The smallest size in the manual
> was 20*1.75 for 1502 mm. This is the size of the rear
> wheel, but the pickup was on the front wheel, 16*1.75.
> After 1 mile read 1.29 miles. Changed number to 1100.
> Returned to starting point, 0.94 mile. Changed number to
> 1160, redid mile, came out at 1.00 miles. How well does
> this match the theoritical circumference?

Now that I am fully awake, I realize that it should be the
nominal width of the tire plus the bead seat diameter, so
Harry's Corsa tire is approximately 571-mm plus 23-mm for a
diameter of 594-mm and a circumference of 1866-mm. I was
just trying to make Harry feel faster than he is. [1]

For the EZ-1, assuming a 47-305 tire, it would be 305-mm
plus 47-mm for a diameter of 352-mm and a circumference of
1105-mm. The actual diameter is likely larger due to the
tire not having a true semi-circular cross-section when
inflated and its true width differing from 47-mm.

[1] This is why it is always a good idea to dry a diagram,
but I was too lazy.

--
Tom Sherman - Quad Cities (Illinois Side)

 

[Tom Sherman]

harryo wrote:

> Tom Sherman <[email protected]> wrote in message news:<[email protected]
> berlin.de>...
>
>>This brings up a second question - will the tight frame
>>clearance on a Baron be sufficient for this tire - or did
>>you get a highracer?
>
>
> I picked up a new Bacchetta Corsa, on Thursday, Tom. I
> still have the Baron but the highracers have intrigued me
> for a while. I went up to the Bike Rack, in St. Charles,
> and rode the Corsa for about an hour, and was even more
> intrigued, so I brought it home.
>
> It is an interesting bike and I'll have more to report
> about it's performance, compared to a lowracer, after I
> get some miles on it but it is definitely an efficient
> and fast bike. Also, I don't exactly what it weighs but
> by hefting it, it is substancially lighter than the
> Baron. I suspect it will be faster when climbing on very
> hilly roads.

Harry,

Let us know how the Corsa rides over wonderfully maintained
secondary roads of DeWitt, McLean and Piatt Counties (the
deterioration in pavement quality as one leaves Champaign
County for Piatt County is quite noticeable in places).

--
Tom Sherman - Quad Cities (Illinois Side)

 

[Ben Fox]

Mike,
Didn't know that you got "bent" welcome to the dark side.
Ben Fox
"Mike Schwab" <[email protected]> wrote in message
news:[email protected]...
> Tom, I did the flatest 1 mile strech of nearby road to set
> my odometer for my EZ-1. The smallest size in the manual
> was 20*1.75 for 1502 mm. This is the size of the rear
> wheel, but the pickup was on the front wheel, 16*1.75.
> After 1 mile read 1.29 miles. Changed number to 1100.
> Returned to starting point, 0.94 mile. Changed number to
> 1160, redid mile, came out at 1.00 miles. How well does
> this match the theoritical circumference?
>
> Tom Sherman wrote:
> >
> > harryo wrote:
> >
> > > Does anyone have an accurate wheel circumference for
> > > the Kenda Koncept 650 x 23 tire, for a speedometer
> > > caibration. I know I can do a roll-out measurement but
> > > I am just too lazy!
> >
> > Harry,
> >
> > The actual rolling diameter will depend on the rim used,
> > inflation pressure and load on the wheel. However, a
> > good approximation would be the bead seat diameter (571-
> > mm) plus twice the nominal width (23-mm) for a diameter
> > of 617-mm and a circumference of 1938-mm.
> >
> > This brings up a second question - will the tight frame
> > clearance on a Baron be sufficient for this tire - or
> > did you get a highracer?
> >
> > --
> > Tom Sherman - Quad Cities (Illinois Side)

 

[Mike Schwab]

iIf you are calculating diameter, you need to count tire
width for the top and bottom. 305
+47+47=399*3.1415926=1253.5, still a bit of a difference
from road testing

Tom Sherman wrote:
>
> Mike Schwab wrote:
>
> > Tom, I did the flatest 1 mile strech of nearby road to
> > set my odometer for my EZ-1. The smallest size in the
> > manual was 20*1.75 for 1502 mm. This is the size of the
> > rear wheel, but the pickup was on the front wheel,
> > 16*1.75. After 1 mile read 1.29 miles. Changed number to
> > 1100. Returned to starting point, 0.94 mile. Changed
> > number to 1160, redid mile, came out at 1.00 miles. How
> > well does this match the theoritical circumference?
>
> Now that I am fully awake, I realize that it should be the
> nominal width of the tire plus the bead seat diameter, so
> Harry's Corsa tire is approximately 571-mm plus 23-mm for
> a diameter of 594-mm and a circumference of 1866-mm. I was
> just trying to make Harry feel faster than he is. [1]
>
> For the EZ-1, assuming a 47-305 tire, it would be 305-mm
> plus 47-mm for a diameter of 352-mm and a circumference of
> 1105-mm. The actual diameter is likely larger due to the
> tire not having a true semi-circular cross-section when
> inflated and its true width differing from 47-mm.
>
> [1] This is why it is always a good idea to dry a diagram,
> but I was too lazy.
>
> --
> Tom Sherman - Quad Cities (Illinois Side)

 

[Tom Sherman]

Mike Schwab wrote:

> iIf you are calculating diameter, you need to count tire
> width for the top and bottom. 305
> +47+47=399*3.1415926=1253.5, still a bit of a difference
> from road testing

If we assume that the inflated tire is semi-circular in cross-
section, then distance from the bead seat to the apex of the
tire is the radius of that semi-circle, or half the tire
width. So we add the diameter of the semi-circle to the bead
seat diameter to approximate the overall diameter of the
inflated tire.

--
Tom Sherman - Quad Cities (Illinois Side)

 

[Mike Schwab]

Actually, most tires have max width a bit farther out than
the rim. So I am going with road trial results and not
worrying about theoretical size.

Tonight I rode on our SBC monday night ride, with Ben Fox
and several other members. I chatted for a while with Ben.
As out of shape as I am, I am kind of suprised that I am
able to use top gear on this EZ-1 and getting about 14-16
MPH on level ground. And I find the lowest gear so low I
cannot use it even on a uphill, For starting on flat or
slightly uphill, I am using the small in front and 3rd or
4th in rear. As I was chatting with Ben, I got the
impression that switching to a bigger front gear or smaller
rear gear won't be very much difference or make that much a
difference.

So my thought was to have someone to cut a Bottom bearing
socket from a frame, weld it in between existing crank and
rear wheel, run a chain from the front geears to the small
gear of this, then another chain from the large gear in the
middle to the gears on the rear wheel.

Alignment and ctaking up hain slack will be critical. Has
anyone done this? any parts kits? Problems someone ran into?

Tom Sherman wrote:
>
> Mike Schwab wrote:
>
> > iIf you are calculating diameter, you need to count tire
> > width for the top and bottom. 305
> > +47+47=399*3.1415926=1253.5, still a bit of a difference
> > from road testing
>
> If we assume that the inflated tire is semi-circular in
> cross-section, then distance from the bead seat to the
> apex of the tire is the radius of that semi-circle, or
> half the tire width. So we add the diameter of the semi-
> circle to the bead seat diameter to approximate the
> overall diameter of the inflated tire.
>
> --
> Tom Sherman - Quad Cities (Illinois Side)

 

[Tom Sherman]

Mike Schwab wrote:

> Actually, most tires have max width a bit farther out than
> the rim. So I am going with road trial results and not
> worrying about theoretical size.
>
> Tonight I rode on our SBC monday night ride, with Ben Fox
> and several other members. I chatted for a while with Ben.
> As out of shape as I am, I am kind of suprised that I am
> able to use top gear on this EZ-1 and getting about 14-16
> MPH on level ground. And I find the lowest gear so low I
> cannot use it even on a uphill, For starting on flat or
> slightly uphill, I am using the small in front and 3rd or
> 4th in rear. As I was chatting with Ben, I got the
> impression that switching to a bigger front gear or
> smaller rear gear won't be very much difference or make
> that much a difference.
>
> So my thought was to have someone to cut a Bottom bearing
> socket from a frame, weld it in between existing crank and
> rear wheel, run a chain from the front geears to the small
> gear of this, then another chain from the large gear in
> the middle to the gears on the rear wheel.
>
> Alignment and ctaking up hain slack will be critical.
> Has anyone done this? any parts kits? Problems someone
> ran into?

Err, like this? < http://www.ihpva.org/incoming/2002/s-
unset/Sunset001.jpg >, < http://www.ihpva.org/incoming-
/2002/sunset/Sunset005.jpg >.

A bike with a very strong resemblance to this one was
spotted on the Capital City Century last year.

--
Tom Sherman - Quad Cities (Illinois Side)

 

[Mike Schwab]

Ben's is similar. Yes, the idea is the same, two chains with another
set of gears in the middle. The EZ-1 has 2 square straight bars from
front to rear. Near where the idler roller is
http://www.easyracers.com/ez_1_sc.htm

Tom Sherman wrote:
>
> Mike Schwab wrote:
>
> > Actually, most tires have max width a bit farther out
> > than the rim. So I am going with road trial results and
> > not worrying about theoretical size.
> >
> > Tonight I rode on our SBC monday night ride, with Ben
> > Fox and several other members. I chatted for a while
> > with Ben. As out of shape as I am, I am kind of suprised
> > that I am able to use top gear on this EZ-1 and getting
> > about 14-16 MPH on level ground. And I find the lowest
> > gear so low I cannot use it even on a uphill, For
> > starting on flat or slightly uphill, I am using the
> > small in front and 3rd or 4th in rear. As I was chatting
> > with Ben, I got the impression that switching to a
> > bigger front gear or smaller rear gear won't be very
> > much difference or make that much a difference.
> >
> > So my thought was to have someone to cut a Bottom
> > bearing socket from a frame, weld it in between existing
> > crank and rear wheel, run a chain from the front geears
> > to the small gear of this, then another chain from the
> > large gear in the middle to the gears on the rear wheel.
> >
> > Alignment and ctaking up hain slack will be critical.
> > Has anyone done this? any parts kits? Problems someone
> > ran into?
>
> Err, like this? < http://www.ihpva.org/incoming/2002/s-
> unset/Sunset001.jpg >, < http://www.ihpva.org/incoming-
> /2002/sunset/Sunset005.jpg >.
>
> A bike with a very strong resemblance to this one was
> spotted on the Capital City Century last year.
>
> --
> Tom Sherman - Quad Cities (Illinois Side)

 

[Tom Sherman]

Mike Schwab wrote:

> Ben's is similar. Yes, the idea is the same, two chains
> with another set of gears in the middle. The EZ-1 has 2
> square straight bars from front to rear. Near where the
> idler roller is http://www.easyracers.com/ez_1_sc.htm

Mike,

The Easy Racers chain tensioner could be used in conjunction
with a jackshaft for a step-up gear. Be aware that the
jackshaft will see large loads so the connection to the
frame needs to be substantial.

Due to the relatively thick walls and frame material (1018
Steel IIRC) of the EZ-1, any competent welder would be
able to attach a jackshaft mounting. However, the easier
way to obtain wide range gearing would be to add a SRAM
DualDrive hub (this would work with the existing rear
derailleur and cassette.

You should realize the danger of hanging out with Ben Fox.
Ben has an advanced case of recumbitis [1] that is
contagious. I believe he caught it from a bike he purchased
from an alt.rec.bicycles.recumbent regular who suffers from
the same disease.

[1] A disease that leads to the constant purchasing and
selling of recumbents in the elusive search for
perfection.

--
Tom Sherman - Quad Cities (Illinois Side)