Where to get this strange chainring?

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

That's not a crank spider, those five arms are part of the chanring. It
attaches somehow at the BB spindle (I haven't extracted the arm yet to
see how it works).

Anyone have any ideas on this one?...

Convert the Piccolo to being a fixie and add clipless pedals - your son
will then learn to pedal at high cadence!

--
Tom Sherman

Johnny Sunset aka Tom Sherman said:

Convert the Piccolo to being a fixie and add clipless pedals - your son
will then learn to pedal at high cadence!

lmao

He really pedals fast already. He went w/out training wheels the week
of his 3rd birthday, and has been riding a14" BMX bike with a 26/18.
His cadence is impressive, but he can't seem to manage the 180 rpm long
enough to keep up with me on the Piccolo 🙂

He corners like a madman too. I've tailed him on my road bike around a
corner, and he dropped me. He just slid through on his knobbies --
proabably slid 8" off his line and kept his feet on the pedals.

Crazy kid. He turned 4 this week -- got him a Specialized Hotrock 🙂

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

That's not a crank spider, those five arms are part of the chanring. It
attaches somehow at the BB spindle (I haven't extracted the arm yet to
see how it works).

Anyone have any ideas on this one?

I'd look into getting different cranks, but they are probably 155s or
something, so likely to be rare and expensive. Besides, all I need is a
chainring if I can ID this one.

Looks swaged onto the crank, and if so you'll need a new crankset. Many
cheap 1980s "sports" bikes were similar - the big ring was swaged on
although the small ring was bolted on.

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

That's not a crank spider, those five arms are part of the chanring. It
attaches somehow at the BB spindle (I haven't extracted the arm yet to
see how it works).

Could be a swaged (sp?) spider - i.e. the ring and crank arm may be
permanently attached to each other. That is what it looks like to me.
Used to see lots of cranks like that on economy bikes in the 70's. If
that's the case, you'll need a new crank to change the chainring.

Mark

In article <[email hidden]>,

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

That's not a crank spider, those five arms are part of the chanring. It
attaches somehow at the BB spindle (I haven't extracted the arm yet to
see how it works).

Anyone have any ideas on this one?

I've seen cheap bikes with chainrings that are some sort of press-fit to
the crank. That appears to be what is going on here, too, though you
won't know for sure until you get it off.

Quoted message said:

I'd look into getting different cranks, but they are probably 155s or
something, so likely to be rare and expensive. Besides, all I need is a
chainring if I can ID this one.

If I'm right, you're into a new crank. If that photo you posted
accurately represents your Piccolo, then the rear gears are 7-speed
freewheel, and about the best you could do is a 12-x; if you build up a
new freehub-based rear wheel, you could get an 11-x freehub cogset on
the back, putting your son in touch a little more.

I mention it mainly for completeness, but if you're really desperate,
Shimano makes a small-wheel group set called "Capreo" which has a very
special freehub capable of running a 9-tooth small cog. Such a wheel
would probably cost more than finding a new crank/ring.

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Ryan Cousineau said:

If I'm right, you're into a new crank.

Yeah, that's the way it's sounding. I'll get that thing off of there
sometime when the piccolo and my extractor are in the same room.

I see some $22 110BCD 155mm BMX square-taper cranks at aebike.com. The
problem is that I need a road-size chainring so that 20" can wheel keep
up with my 26" wheel, so that means buying a $25 chainring. $50 plus
shipping isn't outrageous for this project...

Does anyone have an opinion on getting an LBS to drill & tap some 175mm
road cranks I have at 155mm? Then I could just use those and he'd still
have his lil' critter crankarms.

Any problems with an extra 20mm sticking out the end of the crank? Will
there be enough material between the holes for a secure fit? I'm
guessing the 175mm position would no longer be safe, so maybe I should
cut them off and file right at the threads?

The cranks are budget 1991 Sugino GPs that originally came on my
Bridgestone RB-1. They're not hollow or anything 😉

Thanks for the reply posts so far everyone!

-Mike

Mike Reed said:

...
Does anyone have an opinion on getting an LBS to drill & tap some 175mm
road cranks I have at 155mm? Then I could just use those and he'd still
have his lil' critter crankarms.

Any problems with an extra 20mm sticking out the end of the crank? Will
there be enough material between the holes for a secure fit? I'm
guessing the 175mm position would no longer be safe, so maybe I should
cut them off and file right at the threads?

The cranks are budget 1991 Sugino GPs that originally came on my
Bridgestone RB-1. They're not hollow or anything 😉....

Shortening cranks is not routine for several reasons - here is a link
to a webpage of someone who specializes in shortening cranks:
<http://bikesmithdesign.com/Short_Cranks/shorten.html>.

--
Tom Sherman

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

There are 11-28 and 11-34 freewheels out there (Shimano Mega 7).
Probably doesn't help your cause since I think the piccolo is a 6sp.

Quoted message said:

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

That's not a crank spider, those five arms are part of the chanring. It
attaches somehow at the BB spindle (I haven't extracted the arm yet to
see how it works).

Anyone have any ideas on this one?

I'd look into getting different cranks, but they are probably 155s or
something, so likely to be rare and expensive. Besides, all I need is a
chainring if I can ID this one.

-Mike

http://www.burley.com/images/PDF/PiccoloSpec.pdf suggests you've got a
140mm 44t, and yes, that looks like a one-piece crank and chainring.
The whole shebang ought to come off with a standard extractor, but the
chainring isn't replaceable.

140mm is actually fairly standard for kid's bikes, but 52t chainrings
certainly aren't. Your best bet is to follow some links and find
someone who specialises in short cranks. If you can find a LBS willing
to do it then go for it.

Marvin said:

140mm is actually fairly standard for kid's bikes, but 52t chainrings
certainly aren't. Your best bet is to follow some links and find
someone who specialises in short cranks. If you can find a LBS willing
to do it then go for it.

140mm cranks are pretty standard mini-BMX items. Here's some:
http://www.bikepartsusa.com/product_info.phtml?p=01-98434

The Bulletproof crankarms are available in increments of 5mm from 140mm
to 170mm.

Jeff

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

So, what the heck kind of chainring is this:
http://img109.imageshack.us/img109/8803/piccolo0vr.jpg

As others have pointed out, that crank and chainring are staked
together and can't be separated. To change ring sizes, you'll need a
different crank.

Quoted message said:

I'd look into getting different cranks, but they are probably 155s or
something, so likely to be rare and expensive.

These are relatively cheap ($30) and available in sizes from 140mm up:

http://www.danscomp.com/cgi-bin/hazel.cgi?action=DETAIL&item=452006

Chalo Colina

Ok, so what do you guys think of this idea? drill some 130mm BCD holes
on this swaged ring. Then bolt a 52T or 53T chainring onto the smaller
one. I could just go 65mm from the center, and use the center of the
"spider" as a guide. I have a reasonable shop set up and should be able
to manage this on my drill press.

Thoughts?

Marvin said:

Mike Reed said:

I've got a Burley Piccolo trailer-bike that my son rides, and I'm sick
of him being out of contact everywhere except climbing hills. He just
can't keep up in the 42-13 with that 20" wheel. I want to replace the
chainring.

Or get a 5 or 7 speed internal gearhub. Much easier for kids, and they
have a nice overdrive

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

Mike Reed said:

Ok, so what do you guys think of this idea? drill some 130mm BCD holes
on this swaged ring. Then bolt a 52T or 53T chainring onto the smaller
one. I could just go 65mm from the center, and use the center of the
"spider" as a guide. I have a reasonable shop set up and should be able
to manage this on my drill press.

Thoughts?

Based on the photo, I'd guess that the 130mm holes will interfere with
the existing holes that hold the chain guard on the crank. Your idea
might be a non-starter.

If you replace the crank with a 3-piece unit, you'll also need a bottom
bracket. Don't forget that when you figure the price of the project.

--
Dave
dvt at psu dot edu

Mike Reed said:

Ok, so what do you guys think of this idea? drill some 130mm BCD holes
on this swaged ring. Then bolt a 52T or 53T chainring onto the smaller
one. I could just go 65mm from the center, and use the center of the
"spider" as a guide. I have a reasonable shop set up and should be able
to manage this on my drill press.

Thoughts?

If the holes don't coincide with some other "feature" of the existing
rings, as another poster pointed out, it should be workable. This will
affect the chain line just a tad, but if you bolt the rings directly
together (no spacers), it shouldn't matter much.

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

NOTE: If 130mm bcd holes run into trouble, try 110 - lots of cheap
rings available in that design.

Good luck,

Mark

Mark Janeba said:

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

I don't need to worry about using chainring bolts since there's no
inner ring. I can have a 1/4" of bolt with a nut from Home Depot
hanging out there if I want. I could also potentially grind some
chainring nuts down to size.

Quoted message said:

NOTE: If 130mm bcd holes run into trouble, try 110 - lots of cheap
rings available in that design.

Yeah, but there's already a 42 on the bike, and a standard 44 or 46
ring wouldn't be enough. I need a 52 or 53, and those are $25 in 110mm
BCD from what I've seen.

Quoted message said:

Good luck,

Thanks

Mike Reed said:

Mark Janeba said:

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

I don't need to worry about using chainring bolts since there's no
inner ring. I can have a 1/4" of bolt with a nut from Home Depot
hanging out there if I want. I could also potentially grind some
chainring nuts down to size.

Granted, no inner ring - but the bolt holes in the new ring you bolt on
are still standard size holes - you'll want a big bolt so that the
chainring doesn't wiggle around on its mounting bolts.

Quoted message said:

Quoted message said:

NOTE: If 130mm bcd holes run into trouble, try 110 - lots of cheap
rings available in that design.

Yeah, but there's already a 42 on the bike, and a standard 44 or 46
ring wouldn't be enough. I need a 52 or 53, and those are $25 in 110mm
BCD from what I've seen.

Oops, sorry - I was thinking of $25 as cheap - at least compared to a
new crank. I *do* understand the urge to do bodge jobs for pocket
change, I do it myself often.

Mark

Mark Janeba said:

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

I'd just put the spacers under the bolt head, not between the chainrings.

--
Dave
dvt at psu dot edu

In article <[email hidden]>,

Mike Reed said:

Mark Janeba said:

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

I don't need to worry about using chainring bolts since there's no
inner ring. I can have a 1/4" of bolt with a nut from Home Depot
hanging out there if I want. I could also potentially grind some
chainring nuts down to size.

Short chainring bolts are not that hard to find. BMX and track bikes use
them, so just go to the appropriate kind of bike shop (or web store).

Quoted message said:

Quoted message said:

NOTE: If 130mm bcd holes run into trouble, try 110 - lots of cheap
rings available in that design.

Yeah, but there's already a 42 on the bike, and a standard 44 or 46
ring wouldn't be enough. I need a 52 or 53, and those are $25 in 110mm
BCD from what I've seen.

Quoted message said:

Good luck,

Thanks

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

dvt said:

Mark Janeba said:

On second thought, you'll need bolts the same diameter as the holes in
the new rings - may be hard to find regular chainring bolts that short
(if you use no spacers).

I'd just put the spacers under the bolt head, not between the chainrings.

Of course. I should have seen that; a tidy solution.

Mark