3 piece cranks
07-21-05, 05:38 PM
#2
"Uh-uh. Respek Knuckles."
Join Date: Jun 2005
Location: CA
Posts: 1,094
Bikes: '06 LeMond Versailles, '04 S&M Beringer, '03 Quamen Bowls, '68 Raleigh Grand Prix (converted to fixed gear)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Nope, it means your sprocket is not aligned on the spindle. If it wasn't out of round before you installed the cranks it could mean a couple things. First, visually check to see if your sprocket wobbles side to side or up and down when you turn the cranks.
Side to side wobble means there is either a spacer or a space of some kind between the sprocket and crank arm. If this isn't the case it means either your sprocket is bent or your crank arm needs to be properly faced with expensive tools.
Up and down wobble either means the sprocket is not centered on the spindle or the sprocket itself is out of round. Did you ensure good sprocket fit on the spindle? If your cranks use a 19mm spindle (Profile standard), you'll probably need a little spacer that pops into the spindle hole on your sprocket. Did you use that or put the sprocket on loose? Is the spacer thicker than your sprocket, resulting in a space between the sprocket and crank arm (see above)? If that checks out and the sprocket fits cleanly on the spindle you've probably just got a cheap sprocket that's not perfectly round.
Side to side wobble means there is either a spacer or a space of some kind between the sprocket and crank arm. If this isn't the case it means either your sprocket is bent or your crank arm needs to be properly faced with expensive tools.
Up and down wobble either means the sprocket is not centered on the spindle or the sprocket itself is out of round. Did you ensure good sprocket fit on the spindle? If your cranks use a 19mm spindle (Profile standard), you'll probably need a little spacer that pops into the spindle hole on your sprocket. Did you use that or put the sprocket on loose? Is the spacer thicker than your sprocket, resulting in a space between the sprocket and crank arm (see above)? If that checks out and the sprocket fits cleanly on the spindle you've probably just got a cheap sprocket that's not perfectly round.
07-21-05, 06:34 PM
#3
Senior Member
Join Date: Apr 2005
Location: Louisville, KY
Posts: 424
Bikes: Metal Dagger, Bianchi Veloce (Stolen), Bianchi Pista, S&M Challenger
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
cranks faced w/ expensive machinery ??? what like a bench grinder...
we're talking BMX here, not F1 racing!
if you used your existing chainring, did you get a space for the hole that fits on the spindle. The ones sized for 1 pc cranks are larger i think. if there is no spacer, it has probly shifted to give you what appears to be an off-round sprocket....
we're talking BMX here, not F1 racing!
if you used your existing chainring, did you get a space for the hole that fits on the spindle. The ones sized for 1 pc cranks are larger i think. if there is no spacer, it has probly shifted to give you what appears to be an off-round sprocket....
07-21-05, 08:05 PM
#4
"Uh-uh. Respek Knuckles."
Join Date: Jun 2005
Location: CA
Posts: 1,094
Bikes: '06 LeMond Versailles, '04 S&M Beringer, '03 Quamen Bowls, '68 Raleigh Grand Prix (converted to fixed gear)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by kwhord
cranks faced w/ expensive machinery ??? what like a bench grinder...
we're talking BMX here, not F1 racing!
we're talking BMX here, not F1 racing!
As a mechanic I get to see all sorts of janky backyard solutions people come up with to avoid paying a bike shop 10 bucks, and it's pretty ridiculous. BMXers are so notorious for this, a shop I worked for had 'BMX TOOL' written on the biggest hammer and crescent wrench in the shop. Most BMX bikes ride like crap and most BMXers think that's all right, long as their parts are stamped with the most popular logo.
07-22-05, 01:47 AM
#5
Senior Member
Join Date: Nov 2004
Location: Between the mountains and the lake.
Posts: 16,681
Bikes: 8 bikes - one for each day of the week!
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
Mmmm, shop tools.
Anyway, he's put the sprocket on with the spacer all jacked up. I did that the first time I worked on a BMX with a Euro BB. It slipped while I was racing, and I count myself lucky that I only broke the chain on one side plate.
Anyway, he's put the sprocket on with the spacer all jacked up. I did that the first time I worked on a BMX with a Euro BB. It slipped while I was racing, and I count myself lucky that I only broke the chain on one side plate.
07-22-05, 10:26 AM
#6
Senior Member
Join Date: Jul 2004
Posts: 1,102
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Well, a facing tool is definitely expensive, but many shops have facing tools in house and may be able to do something. I wouldn't expect this to be the case as decent cranks should come properly faced.
Most often the sprocket is slightly out of round, or it is off angle slightly.
Most often the sprocket is slightly out of round, or it is off angle slightly.
07-22-05, 11:43 AM
#7
Senior Member
Join Date: Jun 2005
Location: Ashland, VA
Posts: 1,344
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Sheldon Brown has some info on his site about realigning a bent chainring. I saw it about a month ago. I'm too lazy to search for it again.
07-22-05, 01:40 PM
#8
"Uh-uh. Respek Knuckles."
Join Date: Jun 2005
Location: CA
Posts: 1,094
Bikes: '06 LeMond Versailles, '04 S&M Beringer, '03 Quamen Bowls, '68 Raleigh Grand Prix (converted to fixed gear)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by BMXTRIX
Well, a facing tool is definitely expensive, but many shops have facing tools in house and may be able to do something. I wouldn't expect this to be the case as decent cranks should come properly faced.
Most often the sprocket is slightly out of round, or it is off angle slightly.
Most often the sprocket is slightly out of round, or it is off angle slightly.
07-22-05, 04:06 PM
#9
Senior Member
Join Date: Apr 2005
Location: Louisville, KY
Posts: 424
Bikes: Metal Dagger, Bianchi Veloce (Stolen), Bianchi Pista, S&M Challenger
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
part of the fun of bmx is inventing ways to hood-rig your bike.
07-22-05, 04:08 PM
#10
Senior Member
Join Date: Nov 2004
Location: Between the mountains and the lake.
Posts: 16,681
Bikes: 8 bikes - one for each day of the week!
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
It's just installed incorrectly. That's my bet.
07-24-05, 01:40 PM
#11
Dig.
Join Date: Mar 2005
Location: VA
Posts: 6,168
Bikes: FTW, Gunnar Roadie, Open U.P, Gunnar Rock Hound, S&M CCR
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by hypersnazz
Nope, it means your sprocket is not aligned on the spindle. If it wasn't out of round before you installed the cranks it could mean a couple things. First, visually check to see if your sprocket wobbles side to side or up and down when you turn the cranks.
Side to side wobble means there is either a spacer or a space of some kind between the sprocket and crank arm. If this isn't the case it means either your sprocket is bent or your crank arm needs to be properly faced with expensive tools.
Up and down wobble either means the sprocket is not centered on the spindle or the sprocket itself is out of round. Did you ensure good sprocket fit on the spindle? If your cranks use a 19mm spindle (Profile standard), you'll probably need a little spacer that pops into the spindle hole on your sprocket. Did you use that or put the sprocket on loose? Is the spacer thicker than your sprocket, resulting in a space between the sprocket and crank arm (see above)? If that checks out and the sprocket fits cleanly on the spindle you've probably just got a cheap sprocket that's not perfectly round.
Side to side wobble means there is either a spacer or a space of some kind between the sprocket and crank arm. If this isn't the case it means either your sprocket is bent or your crank arm needs to be properly faced with expensive tools.
Up and down wobble either means the sprocket is not centered on the spindle or the sprocket itself is out of round. Did you ensure good sprocket fit on the spindle? If your cranks use a 19mm spindle (Profile standard), you'll probably need a little spacer that pops into the spindle hole on your sprocket. Did you use that or put the sprocket on loose? Is the spacer thicker than your sprocket, resulting in a space between the sprocket and crank arm (see above)? If that checks out and the sprocket fits cleanly on the spindle you've probably just got a cheap sprocket that's not perfectly round.
couldnt have said it better myself..
!
07-24-05, 01:56 PM
#13
Dig.
Join Date: Mar 2005
Location: VA
Posts: 6,168
Bikes: FTW, Gunnar Roadie, Open U.P, Gunnar Rock Hound, S&M CCR
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Originally Posted by iweargirlspants
yea what he said.
