One Piece Crank to Modern Conversion?

smyrna45 said:

I have an old Schwinn World 10 speed with a cotterless (not one piece)
that has begun to give a tell-tale klunk on every revolution. I am
about to try to get the tools together to pull the crank and was
wondering if it is possible to convert the beast to a modern sealed
cartridge type? Do these things come in different sizes and screw
threads?

If the bottom bracket shell is threaded, it will be a standard
ISO/English thread, any normal bottom bracket will fit.

See: http://sheldonbrown.com/harris/bottombracket

If it's the larger, unthreaded shell as commonly used for one-piece
cranks, we've got some very nice adaptor bushings that will allow you to
install a standard ISO/English bb.

See: http://sheldonbrown.com/harris/opc

Sheldon "Can Do!" Brown
+-----------------------------------------------------------------+
| I'll be traveling in France and England throughout the month |
| of June. I hope to remain online, but don't know what sort |
| of 'Net access I'll be able to get... |
+-----------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

smyrna45 said:

I have an old Schwinn World 10 speed with a cotterless (not one piece)
that has begun to give a tell-tale klunk on every revolution. I am
about to try to get the tools together to pull the crank and was
wondering if it is possible to convert the beast to a modern sealed
cartridge type? Do these things come in different sizes and screw
threads?

If the bottom bracket shell is threaded, it will be a standard
ISO/English thread, any normal bottom bracket will fit.

See: http://sheldonbrown.com/harris/bottombracket

If it's the larger, unthreaded shell as commonly used for one-piece
cranks, we've got some very nice adaptor bushings that will allow you to
install a standard ISO/English bb.

See: http://sheldonbrown.com/harris/opc

Sheldon "Can Do!" Brown
+-----------------------------------------------------------------+
| I'll be traveling in France and England throughout the month |
| of June. I hope to remain online, but don't know what sort |
| of 'Net access I'll be able to get... |
+-----------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Sheldon Brown said:

If it's the larger, unthreaded shell as commonly used for one-piece
cranks, we've got some very nice adaptor bushings that will allow you to
install a standard ISO/English bb.

See: http://sheldonbrown.com/harris/opc

This link doesn't work for me. However the following does:

http://sheldonbrown.com/harris/opc.html

--
Benjamin Lewis

Basic Definitions of Science:
If it's green or wiggles, it's biology.
If it stinks, it's chemistry.
If it doesn't work, it's physics.

smyrna45 <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

I have an old Schwinn World 10 speed with a cotterless (not one piece)
that has begun to give a tell-tale klunk on every revolution. I am
about to try to get the tools together to pull the crank and was
wondering if it is possible to convert the beast to a modern sealed
cartridge type? Do these things come in different sizes and screw
threads?

Your subject line and the text of your message contradict each other.
Does the bike have one-piece cranks or not?

In either case, it's a possible, and easy, task. If the bike has
one-piece cranks, BMX shops sell a converter that allows you to put a
conventional sealed BB in your bike's frame. One can be seen here:
http://sheldonbrown.com/harris/opc.html

If it's got cotterless cranks, then replacing the bottom bracket with
a sealed cartridge is a straight-across swap. Your bike has English
threads (the most common), which means that you'll just have to get a
cartridge with the right length spindle.

Here's a couple pages that may help:
http://www.parktool.com/repair_help/FAQrCarm.shtml
http://www.parktool.com/repair_help/FAQcartdg.shtml

Jeff

Sheldon Brown said:

If it's the larger, unthreaded shell as commonly used for one-piece
cranks, we've got some very nice adaptor bushings that will allow you to
install a standard ISO/English bb.

See: http://sheldonbrown.com/harris/opc.html

Although I have used such contrivances in the past, to mate road bikes
to BMX bikes in the pursuit of mongrels, I think they are generally a
bad idea. It's like using special washers to allow modern fork ends a
better fit on 5/16" axles. Better yet is to use the superior
component for which the American shell is designed.

A beautifully chromed tubular chromoly crank like the Redline Flight
http://www.danscomp.com/products/CRANKS/451060.jpg would be a far
better aesthetic match for a vintage Schwinn than anything with a
cartridge BB.

It seems like the best and most cost-effective solution would be for
the OP to use one of the cup-and-cone press-fitted conversion kits
such as you show on your OPC page. That would allow the use of any
old square taper cranks (often free, with an old bike thrown in
besides!) while taking advantage of the free-spinning, almost
indestructible OPC-type bearing assembly and a relatively trustworthy
nutted spindle.

Chalo Colina

I said:

Quoted message said:

If it's the larger, unthreaded shell as commonly used for one-piece
cranks, we've got some very nice adaptor bushings that will allow you to
install a standard ISO/English bb.

See: http://sheldonbrown.com/harris/opc.html

Chalo Colina demurred

Quoted message said:

Although I have used such contrivances in the past, to mate road bikes
to BMX bikes in the pursuit of mongrels, I think they are generally a
bad idea. It's like using special washers to allow modern fork ends a
better fit on 5/16" axles. Better yet is to use the superior
component for which the American shell is designed.

If you're speaking of one-piece-cranks, that would be a downgrade for
this application, which is a bike with a double chainring.

It's true that those cranks are very strong and easy to service, but
they're heavy and it isn't possible to get modern pedals to fit them.

Quoted message said:

A beautifully chromed tubular chromoly crank like the Redline Flight
http://www.danscomp.com/products/CRANKS/451060.jpg would be a far
better aesthetic match for a vintage Schwinn than anything with a
cartridge BB.

Heavy-duty, high-end BMX cranks like that are a good choice for riders
who are very hard on equipment, and who can tolerate long cranks (it's
hard to find such things shorter than 175 mm.

For most riders, especially of geared bikes, they're major overkill.

I haven't tried it, but I would be skeptical that a multiple chainring
setup on such a crankset would run as true as on a good forged crank/spider.

Quoted message said:

It seems like the best and most cost-effective solution would be for
the OP to use one of the cup-and-cone press-fitted conversion kits
such as you show on your OPC page. That would allow the use of any
old square taper cranks (often free, with an old bike thrown in
besides!) while taking advantage of the free-spinning, almost
indestructible OPC-type bearing assembly and a relatively trustworthy
nutted spindle.

That might be the cheapest way to go, and it may be what he has now.

Unfortunately, these bottom brackets only seem to come in very long
lengths, which provide unacceptable chainline with most newer cranks.

The Truvativ adaptor bushings we recently got in are quite a lot nicer
than the more expensive ones we previously had, and they give great
versatility, because they allow any modern crankset to be used...if he
wanted, he could go with Dura-Ace 10 speed, or, if he wanted something
resistant to medium-calibre firearms, Shimano Saint...

Sheldon "Not Everybody Needs A Hummer" Brown
+-----------------------------------------------------------------+
| I'll be traveling in France and England throughout the month |
| of June. I hope to remain online, but don't know what sort |
| of 'Net access I'll be able to get... |
+-----------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

You are right Jeff about the subject line. Sorry about that. I am
really a newbie at this. The bike has a cotterless crank (not one
piece). It has aluminum crank arms attached to a square ended shart
through the bottom bracket with bolts. The aluminum crank arm is of
course threaded and had a plastic screw in protector cap, which
unfortunately I could not get out without destroying the cap and a few
threads on the crank as well - ouch. My LBS guy told me a quarter
works pretty well on them when I bought some other stuff there today,
but mine were just too frozen in I guess.

Unfortunately I am not sure I can even use a crank puller on it now,
but I may be able to clean up the threads enough.

The partial destruction was at least useful in letting me understand
how a crank puller works. Its a beater bike I picked up from a thrift
store for $8 to learn on and get in shape with. I recabled it, threw
on new tires and tubes. I've only been riding a few months since
giving it up as a kid, but I am getting in shape and learning a lot
too, which I hope to apply when I finally spring for that new road
bike. It was carrying me 25 miles a day for two months until the knock
started. , I have grown rather fond of the old bike though and dont'
want to mess it up too badly.

The bottom bracket is indeed threaded and measures very close to 35
millimeters in diameter. The spindle appears to be to be 145 mm long.
I managed to unscrew it and look inside, as far as the crank arm would
let me until I get a puller. I also tightened it up enough to stop the
klunking, but I know it should be disassembled and greased. I was
considering getting a new bottom bracket, and thus my question. Now,
that I may have messed up the threads too much on the aluminum pedal
to use a puller, I may especially want to go with a new setup.

Thanks for the replies all. I think I see it all much more clearly
now. I will check out Sheldons links.

(Jeff Wills) said:

smyrna45 <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

I have an old Schwinn World 10 speed with a cotterless (not one piece)
that has begun to give a tell-tale klunk on every revolution. I am
about to try to get the tools together to pull the crank and was
wondering if it is possible to convert the beast to a modern sealed
cartridge type? Do these things come in different sizes and screw
threads?

Your subject line and the text of your message contradict each other.
Does the bike have one-piece cranks or not?

In either case, it's a possible, and easy, task. If the bike has
one-piece cranks, BMX shops sell a converter that allows you to put a
conventional sealed BB in your bike's frame. One can be seen here:
http://sheldonbrown.com/harris/opc.html

If it's got cotterless cranks, then replacing the bottom bracket with
a sealed cartridge is a straight-across swap. Your bike has English
threads (the most common), which means that you'll just have to get a
cartridge with the right length spindle.

Here's a couple pages that may help:
http://www.parktool.com/repair_help/FAQrCarm.shtml
http://www.parktool.com/repair_help/FAQcartdg.shtml

Jeff

smyrna45 <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

You are right Jeff about the subject line. Sorry about that. I am
really a newbie at this. The bike has a cotterless crank (not one
piece). It has aluminum crank arms attached to a square ended shart
through the bottom bracket with bolts. The aluminum crank arm is of
course threaded and had a plastic screw in protector cap, which
unfortunately I could not get out without destroying the cap and a few
threads on the crank as well - ouch. My LBS guy told me a quarter
works pretty well on them when I bought some other stuff there today,
but mine were just too frozen in I guess.

<much snipped>

OK, I've got a better idea of where you're coming from. Don't worry
about the plastic dustcaps in the crankarms- they're really only there
to give cosmetic protection for the threads. The threads are there
for the puller.

If you've mangled a thread or two on the crank- don't worry about it.
I've removed arms with half of the threads gone- it's a matter of
getting the puller seated all the way into the crankarm before trying
to pop the arm off. If the threads are really mangled, find someone
with a Bicycle Research TC-8 tool, which cleans up the threads nicely.
It's illustrated here:
http://www.parktool.com/repair_help/FAQcrkarm.shtml

As to the spindle, I suspect you have a "nut-type" spindle as opposed
to a "bolt-type". They're interchangeable, but the measurement is
different. Both are measured from the end of the tapered flat section-
on the bolt-type, this is the end-to-end length, while on the nut-type
you need to subtract the protruding bolt ends. It's probably best to
dissassemble the works and take the old spindle with you when you go
to buy the new bottom bracket.

Jeff

smyrna45 said:

The aluminum crank arm is of
course threaded and had a plastic screw in protector cap, which
unfortunately I could not get out without destroying the cap and a few
threads on the crank as well - ouch.

Quoted message said:

Unfortunately I am not sure I can even use a crank puller on it now,
but I may be able to clean up the threads enough.

Try it -- I bet you'll still be able to use the crank puller. Thread the
puller in slowly, backing it off occasionally if you hit a sticky point.
You won't likely mess up the steel threads on the puller with your
aluminum crank, so you're not going to lose anything by trying to pull
the crank.

Quoted message said:

Its a beater bike I picked up from a thrift
store for $8 to learn on and get in shape with. I recabled it, threw
on new tires and tubes. I've only been riding a few months since
giving it up as a kid, but I am getting in shape and learning a lot
too, which I hope to apply when I finally spring for that new road
bike. It was carrying me 25 miles a day for two months until the knock
started. I have grown rather fond of the old bike though and dont'
want to mess it up too badly.

I'm glad you're enjoying it. And there's nothing wrong with a little
sentimental attachment to an old bike. At least I hope not.... :^)

Quoted message said:

The bottom bracket is indeed threaded and measures very close to 35
millimeters in diameter. The spindle appears to be to be 145 mm long.
I managed to unscrew it and look inside, as far as the crank arm would
let me until I get a puller. I also tightened it up enough to stop the
klunking, but I know it should be disassembled and greased. I was
considering getting a new bottom bracket, and thus my question. Now,
that I may have messed up the threads too much on the aluminum pedal
to use a puller, I may especially want to go with a new setup.

Your bottom bracket klunk may have been caused by maladjustment. Your
hardware may be in fine condition. It's hard to tell without looking at
the bearing surfaces. At any rate, there may be no need to replace the
stuff. Pull it apart, clean and inspect, and you may just find that
everything is hunky dory. In which case you simply regrease and
reassemble. I recommend replacing the ball bearings any time you have
the BB apart, since they're pretty cheap and readily available.

--
Dave
dvt at psu dot edu

On 8 Jun 2004 09:29:19 -0700, [email hidden] (Jeff Wills)

Quoted message said:

OK, I've got a better idea of where you're coming from. Don't worry
about the plastic dustcaps in the crankarms- they're really only there
to give cosmetic protection for the threads. The threads are there

They're also good for retaining loose spindle nuts, so you don't
lose them; of course, if they're that loose, losing a 20 cent nut
isn't going to be among your worst problems.
--
Rick Onanian

Sheldon Brown said:

The Truvativ adaptor bushings we recently got in are quite a lot nicer
than the more expensive ones we previously had, and they give great
versatility, because they allow any modern crankset to be used...if he
wanted, he could go with Dura-Ace 10 speed, or, if he wanted something
resistant to medium-calibre firearms, Shimano Saint...

The problem you're left with is the same problem that blights all
threaded-BB frames: Either you can have a decently large spindle, or
you can have reliable and cheaply replaceable bottom bracket bearings,
but not both. The American shell gives plenty of room for both, if'n
you don't waste it by using a threaded BB.

I wonder about Saint cranks, and why anybody would want them,
especially in the single-ring or double-plus-chainguard varieties. To
me they look to offer less durability and less configurability than
most BMX 3-pc cranks, almost as much weight, and double to quadruple
the price! For those who simply *have* to have a "gruppo", I
suppose...

Has anybody else noticed that all the Bullseye-ripoff cranks produced
by Shimano cost _at least_ what Bullseyes did, when Bullseyes were
made by hand, cottage-industry style, in California? It must be nice
to make thousand-percent margins on a design you stole from somebody
else!

Chalo Colina

On 8 Jun 2004 09:29:19 -0700, [email hidden] (Jeff Wills) wrote:

much snipped

Quoted message said:

OK, I've got a better idea of where you're coming from. Don't worry
about the plastic dustcaps in the crankarms- they're really only there
to give cosmetic protection for the threads. The threads are there
for the puller.

If you've mangled a thread or two on the crank- don't worry about it.
I've removed arms with half of the threads gone- it's a matter of
getting the puller seated all the way into the crankarm before trying
to pop the arm off. If the threads are really mangled, find someone
with a Bicycle Research TC-8 tool, which cleans up the threads nicely.
It's illustrated here:
http://www.parktool.com/repair_help/FAQcrkarm.shtml

Many thanks guys. I will go ahead and give the puller a try. I think I
will see if I can clean the threads up a bit by hand first. I will let
you all know how it comes out.

I am not sure why the whole idea of how a puller worked threw me at
first. I was somehow convinced by looking at pictures of the tool
itself that it went into the bottom bracketand pulled the guts out of
there. After I got the cap off, I could see what things were about.
Now with your help I think I can successfully do it right next time.

One follow-up question if I may - How are you supposed to get the
plastic caps out the right way? I want to know for the next time. As I
said its an old Schwinn World bike and they were threaded chrome-
plated plastic with a large slot in the middle large enough to get
about 1/3 of a quarter in.

According to Sheldon Brown <[email hidden]>:

Quoted message said:

medium-calibre firearms

Calibre good, derailleur bad? 🙂

---
Lars Lehtonen

smyrna45 <[email hidden]> wrote in message news:<[email hidden]>...
<snip>

Quoted message said:

One follow-up question if I may - How are you supposed to get the
plastic caps out the right way? I want to know for the next time. As I
said its an old Schwinn World bike and they were threaded chrome-
plated plastic with a large slot in the middle large enough to get
about 1/3 of a quarter in.

I went to Schwinn School back when there was such a thing.
The Official Schwinn Approved Crankarm Dustcap Removal Tool was a
nickel from your coin purse.

Jeff

Just a follow up to close the thread. I got a Park crank puller and
cleaned up the threads as best as I could. Unfortunately I could never
get the puller to seat into the messed up threads. Fortunately, I was
able to get the other (non-messed up side) crank arem off with the
puller. I loosened the bottom bracket from both sides and was able to
pull the assembly out. Nothing broken. I lubed the bearings and races
good and re-adjusted it. Works fine now. When and if I decide I need a
new crank arm, I will worry about getting the other one off. Thanks to
all who gave advice.

On Tue, 22 Jun 2004 21:27:03 -0400, smyrna45 <[email hidden]>

Quoted message said:

Just a follow up to close the thread. I got a Park crank puller and
cleaned up the threads as best as I could. Unfortunately I could never
get the puller to seat into the messed up threads. Fortunately, I was
able to get the other (non-messed up side) crank arem off with the
puller. I loosened the bottom bracket from both sides and was able to
pull the assembly out. Nothing broken. I lubed the bearings and races
good and re-adjusted it. Works fine now. When and if I decide I need a
new crank arm, I will worry about getting the other one off. Thanks to
all who gave advice.

Well the repack didn't last long but I finally got the stripped crank
arm off with my Park puller. I got it started as best as I could and
then tapped it lightly with a hammer. Then I could turn it a few more
fractions of a turn and tap it again. I was able to seat it all the
way with that method and it cleaned up the threads and pulled the
offending crank arm.

Closer inspection of the axle spindle and the bearings revealed that
they were pretty well pitted. I am currently looking at both sealed
bottom brackets and a new spindle/cups/bearings. I know the sealed
units are a lot easier, but being cheap, I will probably go with whats
cheapest for this old clunker.

The old spindle is 124.5 mm, and of course a 68 mm width on the BB.
Shimano makes a sealed unit in both a 68x122.5 and 68x124.5, but the
122's seem to be easier to find. Is the 2 mm really going to make that
much difference?

I also bought a new crank, by the way, and it fits on the old spindle
but the chain rings stick out too far, because the old crank had about
12 mm of indentation before the crank seats. It looks like a 113 mm
would fit the new crank just right, but I may for historical purity
keep the old crank on if I get the right spindle length.