Shorter cranks on Double Vision

[Perry]

I did a Google search to see if any new pertinent information had come to
light lately. All that popped up were posts of mine, expounding the
gloriousness of shorter cranks. I am at least a year into using shorter
cranks (165's) and I positively have no knee pain on my single bike.
The tandem (Double Vision) has 175's and my knee always hurts when we ride
it.
Any new ideas on shortening cranks on the DV? I called Vision and Ricky
Comar said it would cost about $15,000. Machining, R& D, prototypes, etc.
(I have heard that Ricky Comar is not at Vision anymore...)
Perry
bentcajungirl
down to just a
Double Vision
New R-40
Husband's R-44
and still the El Camino.

[Guess Who I Am]

Hello:
if you donot have IPS or splined crank i know of a machine shop that will drill
and tap them out for you.
if intrested please e-mail me back.
Thank you Earl
GRR,RANS V2
Ti Rush,Ti Pursuit

[Perry]

Hi Earl,
I do have IPS. (and I believe they're tapered) Why does that make a
difference?
Perry

"Guess Who I Am" > wrote in message
...
> Hello:
> if you donot have IPS or splined crank i know of a machine shop that will
drill
> and tap them out for you.
> if intrested please e-mail me back.
> Thank you Earl
> GRR,RANS V2
> Ti Rush,Ti Pursuit
>
>

[Don]

Perry, I do not know if the DV is something unique or just uses
regular tandem components. Maybe what I am posting is useless to you.
But hopefully it is not. St. John Street Cycles.
http://www.sjscycles.com/store/vIndex.htm has beautiful Thorn cranks
for front and rear tandems 140-175mm

In the index do NOT look under cranksets. Look under "Chainsets" then
"Tandem chainsets/cranks". I have a triple solo from them in 150mm
and it is very nicely done. I picked the TA rings. Their polish
matches the crank and they are ramped and pinned. Note which are
marked outer, middle, and inner. Please note on pricing, US
customers do not have to pay the value added tax so the listed price
must be reduced by that amount. Also, when I ordered the arms, rings,
and bolts I was promptly informed that what I ordered was considered a
kit so they assembled it for me and greatly reduced the price.
Delivered to my door in Sacramento from Jolly Olde in 9 days from my
order. Nice chaps to deal with. Spot on and all that rot. Good luck.
Don

[Jeff Wills]

"Perry" > wrote in message >...
<snip>
> Any new ideas on shortening cranks on the DV? I called Vision and Ricky
> Comar said it would cost about $15,000. Machining, R& D, prototypes, etc.
> (I have heard that Ricky Comar is not at Vision anymore...)

Yeah, Ricky left a couple months back.

Regarding the cranksets: the IPS system required some special
machining to accomodate the freewheel mechanism. A really good
machinist might be able to set up shorter cranks for IPS- but it's
fairly sensitive. You might want to talk to someone familiar with
machining and bicycles... perhaps Longbikes or Terracycle.

OTOH- ask yourself how often you use the IPS system. If you think you
can get away with captain-only freewheeling (that is, the captain
could coast on his own, but the stoker would be forced to pedal when
the captain pedaled) then you could replace the stoker cranks with
standard, but shorter cranks. That's certainly the least expensive
proposition.

Jeff

[Perry]

Thanks, Don. I just emailed them.
Perry
"Don" > wrote in message
om...
> Perry, I do not know if the DV is something unique or just uses
> regular tandem components. Maybe what I am posting is useless to you.
> But hopefully it is not. St. John Street Cycles.
> http://www.sjscycles.com/store/vIndex.htm has beautiful Thorn cranks
> for front and rear tandems 140-175mm
>
> In the index do NOT look under cranksets. Look under "Chainsets" then
> "Tandem chainsets/cranks". I have a triple solo from them in 150mm
> and it is very nicely done. I picked the TA rings. Their polish
> matches the crank and they are ramped and pinned. Note which are
> marked outer, middle, and inner. Please note on pricing, US
> customers do not have to pay the value added tax so the listed price
> must be reduced by that amount. Also, when I ordered the arms, rings,
> and bolts I was promptly informed that what I ordered was considered a
> kit so they assembled it for me and greatly reduced the price.
> Delivered to my door in Sacramento from Jolly Olde in 9 days from my
> order. Nice chaps to deal with. Spot on and all that rot. Good luck.
> Don

[Prints]

I run 145mm cranks on my trike and I'm a convert. Stopped my knee pain.
Smoother and higher cadence. If it's all in the mind, it worked for me.

MR now supply 155mm cranks on their Swiftlet S2.

Paul W

[Guess Who I Am]

Perry:
i'm sorry they can tap out your ips tapered cranks. the shop is Custom
Machinery in Schiller Park ,il.
if intrested contact Len at:

Thank you Earl
GRR,RANS V2
Ti Rush,Ti Pursuit

[Perry]

There is positively NO WAY I will ever give up IPS. Not until they pry my
cold dead toes from my Frogs. With a big battleship hulking bike like the
Double Vision, there are just too many needs for the IPS.
Perry
"Prints" > wrote in message
...
> I run 145mm cranks on my trike and I'm a convert. Stopped my knee pain.
> Smoother and higher cadence. If it's all in the mind, it worked for me.
>
> MR now supply 155mm cranks on their Swiftlet S2.
>
> Paul W
>
>
>
>
>
>

[Steve Christensen]

In article >, Perry says...
>
>There is positively NO WAY I will ever give up IPS. Not until they pry my
>cold dead toes from my Frogs.


What a GREAT line to be overheard by somone who has no knowledge of cycling.

"Just what were your toes doing on your Frogs?"


Steve Christensen

[Jeff Wills]

"Perry" > wrote in message >...
> There is positively NO WAY I will ever give up IPS. Not until they pry my
> cold dead toes from my Frogs. With a big battleship hulking bike like the
> Double Vision, there are just too many needs for the IPS.
> Perry

:-))

If you're not going to give up IPS, then drilling and tapping the
cranks is just about your only choice. It'll still require a good
machinist to do the deed, but it's not terrible complex.

They'll need to be shortened quite a bit, though, since enough
material needs to be left on the outside of the pedal eye to keep them
from cracking. You'll probably end up with 145mm or 150mm cranks,
kind of like these cranks from DaVinci Designs:
http://www.davincitandems.com/images/xt3.jpg

Mark Stonich has shortened cranks from a variety of sources: here's a
little reading material:
http://mnhpva.org/meetings/July_03/Crank.html
http://bikesmithdesign.com/Short_Cranks/Dotek.html


Jeff

[bentbiker]

Perry, how about a set of crank shorteners from the Hostel shoppe? they
would make the "Q" a little wider, but all in all, a less complicated
and hassle free modification


Perry wrote:

> Hi Earl,
> I do have IPS. (and I believe they're tapered) Why does that make a
> difference?
> Perry
>
> "Guess Who I Am" > wrote in message
> ...
>
>>Hello:
>>if you donot have IPS or splined crank i know of a machine shop that will
>
> drill
>
>>and tap them out for you.
>>if intrested please e-mail me back.
>>Thank you Earl
>> GRR,RANS V2
>> Ti Rush,Ti Pursuit
>>
>>
>
>

[Tom Thompson]

"Jeff Wills" > wrote in message
om...
> "Perry" > wrote in message
>...
> > There is positively NO WAY I will ever give up IPS. Not until they pry
my
> > cold dead toes from my Frogs. With a big battleship hulking bike like
the
> > Double Vision, there are just too many needs for the IPS.
> > Perry
>
> :-))
>
> If you're not going to give up IPS, then drilling and tapping the
> cranks is just about your only choice. It'll still require a good
> machinist to do the deed, but it's not terrible complex.
>
> They'll need to be shortened quite a bit, though, since enough
> material needs to be left on the outside of the pedal eye to keep them
> from cracking. You'll probably end up with 145mm or 150mm cranks,
> kind of like these cranks from DaVinci Designs:
> http://www.davincitandems.com/images/xt3.jpg
>
> Mark Stonich has shortened cranks from a variety of sources: here's a
> little reading material:
> http://mnhpva.org/meetings/July_03/Crank.html
> http://bikesmithdesign.com/Short_Cranks/Dotek.html
>

I'm using a set of Mark's 155s drilled and tapped for triople rings. The
crank and matching rings were about $150. He did a great job.

I've never even seen an IPS-equipped bike, so I can't tell you if these
cranks could be modified to work. I'm sure Mark knows, and could probably to
the machining for you.

Tom Thompson

[Don]

Just trying to learn something here. Is the IPS integral to the
crank? Meaning you buy it all together and have limited choice on
crank length. Don

[Mark Stonich]

"Tom Thompson" > wrote in message >...
> "Jeff Wills" > wrote in message
> om...
> > "Perry" > wrote in message
> >...
> > > There is positively NO WAY I will ever give up IPS. Not until they pry
> my
> > > cold dead toes from my Frogs. With a big battleship hulking bike like
> the
> > > Double Vision, there are just too many needs for the IPS.
> > > Perry
>
> > :-))
> >
> > If you're not going to give up IPS, then drilling and tapping the
> > cranks is just about your only choice. It'll still require a good
> > machinist to do the deed, but it's not terrible complex.
> >
> > They'll need to be shortened quite a bit, though, since enough
> > material needs to be left on the outside of the pedal eye to keep them
> > from cracking. You'll probably end up with 145mm or 150mm cranks,
> > kind of like these cranks from DaVinci Designs:
> > http://www.davincitandems.com/images/xt3.jpg
> >
> > Mark Stonich has shortened cranks from a variety of sources: here's a
> > little reading material:
> > http://mnhpva.org/meetings/July_03/Crank.html
> > http://bikesmithdesign.com/Short_Cranks/Dotek.html
> >
>
> I'm using a set of Mark's 155s drilled and tapped for triople rings. The
> crank and matching rings were about $150. He did a great job.
>
> I've never even seen an IPS-equipped bike, so I can't tell you if these
> cranks could be modified to work. I'm sure Mark knows, and could probably to
> the machining for you.
>
> Tom Thompson

Some 175s can be retapped to 152s if there is enough material around
the new hole. Usually there is not. I wouldn't use IPS if it was
free, had no extra parts to fail, and didn't add weight. Especially
if the alternative was an end to knee pain.

[Jeff Wills]

(Don) wrote in message >...
> Just trying to learn something here. Is the IPS integral to the
> crank? Meaning you buy it all together and have limited choice on
> crank length. Don

Yes. Vision's Independent Pedaling System inserts a freewheel
mechanism between the crankarms and the chainrings on both the
captain's and the stoker's cranksets. That way either rider can pedal
or coast at their pleasure.

Jeff

[Russ Price]

Jeff Wills > wrote:
> Yes. Vision's Independent Pedaling System inserts a freewheel
> mechanism between the crankarms and the chainrings on both the
> captain's and the stoker's cranksets. That way either rider can pedal
> or coast at their pleasure.

Shades of the Shimano FF (Front Freewheel) system of the '70s. However,
the only FF bike I ever rode, a 1977 Schwinn Caliente that I used to
use, had permanently integrated chainrings and Ashtabula-style crankarms
and BB. It was basically a Varsity with a fancy drivetrain; it also had
the Positron rear mech, Shimano's first attempt at indexed shifting.

FF also had an oddball cluster with a one-way slip clutch on each
sprocket, in case the chain jammed. A flange on the cluster had a
stamped warning that it was for use only with FF.

With FF+Positron, you could shift at any time, but starting off was
awkward if you downshifted while stopped. The Positron also used a
solid shift cable, which tended to break from fatigue, either at the
shifter or at the derailleur. One of today's 7- or 8-speed gearhubs
with a conventional crank would be much better from a shift-at-any-time
standpoint. I'm surprised, though, that Shimano never thought of using
the FF cranks for tandem IPS, whether or not the funky cluster was used.

I still have the old Schwinn, but damage/rust on a seat stay and
worn-out teeth on the big ring have made it unsafe to ride.
--
Russ --kill the wabbit to despam
"No, see, it's not something you 'experience' - it's something that you
posess. You know, that fine 'recumbent butt' - a distinguishing
characterisitic of a recumbent cyclist." -Geoff Adams, on 'BROL

[Jeff Wills]

Russ Price > wrote in message news:<pzkob.65809$Tr4.183512@attbi_s03>...
> Jeff Wills > wrote:
> > Yes. Vision's Independent Pedaling System inserts a freewheel
> > mechanism between the crankarms and the chainrings on both the
> > captain's and the stoker's cranksets. That way either rider can pedal
> > or coast at their pleasure.
>
> Shades of the Shimano FF (Front Freewheel) system of the '70s. However,
> the only FF bike I ever rode, a 1977 Schwinn Caliente that I used to
> use, had permanently integrated chainrings and Ashtabula-style crankarms
> and BB. It was basically a Varsity with a fancy drivetrain; it also had
> the Positron rear mech, Shimano's first attempt at indexed shifting.
>

Not quite- the Calientes of that era had "Positron II". The original
Positron (that was never used on Schwinns, AFAIK) used a dual-cable
system with indexing at the derailleur.

You're right about the IPS being similar to the Front Freewheel
system- almost exactly the same, in fact.

<snip>
> I still have the old Schwinn, but damage/rust on a seat stay and
> worn-out teeth on the big ring have made it unsafe to ride.

So go buy an old Varsity and swap out the drivetrain. It all
interchanges. Old Schwinns never die- they're tougher than
cockroaches.

Jeff Wills (Schwinn mechanic 1979-1984)