Crank Arm constantly comes loose - need a solution to solve problem.
07-11-14, 04:11 PM
#1
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Crank Arm constantly comes loose - need a solution to solve problem.
My left crank arm constantly keep coming loose whenever I use my bike, how can I prevent this from happening??
What would be a cheap fix? (if any)
Please reply back.
What would be a cheap fix? (if any)
Please reply back.
07-11-14, 04:17 PM
#2
weapons-grade bolognium
Join Date: Dec 2008
Location: Across the street from Chicago
Posts: 6,344
Bikes: Battaglin Cromor, Ciocc Designer 84, Schwinn Superior 1981
Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 985 Post(s)
Liked 2,378 Times
in
891 Posts
New crank arm or crankset. Yours is toast.
07-11-14, 04:25 PM
#3
Bianchi Goddess
Join Date: Apr 2009
Location: Shady Pines Retirement Fort Wayne, In
Posts: 27,858
Bikes: Too many to list here check my signature.
Mentioned: 192 Post(s)
Tagged: 2 Thread(s)
Quoted: 2930 Post(s)
Liked 2,923 Times
in
1,491 Posts
I agree if the crank is coming lose from the spindle you need a new arm.
__________________
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
07-11-14, 04:51 PM
#4
Senior Member
Join Date: Dec 2005
Posts: 17,153
Mentioned: 481 Post(s)
Tagged: 0 Thread(s)
Quoted: 3807 Post(s)
Liked 6,676 Times
in
2,607 Posts
Take a look at the taper of that left-side crank arm. Does it look worn or widened? If so, it's a goner.
07-11-14, 06:19 PM
#6
curmudgineer
Join Date: Dec 2009
Location: Chicago SW burbs
Posts: 4,417
Bikes: 2 many 2 fit here
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 263 Post(s)
Liked 112 Times
in
70 Posts
Crankarm could be cracked at the hub and you're auguring for a rupture if it lets go completely while you're bearing down on the pedal.
07-11-14, 06:21 PM
#7
Senior Member
Join Date: Jul 2009
Posts: 11,128
Bikes: 1986 Alan Record Carbonio, 1985 Vitus Plus Carbone 7, 1984 Peugeot PSV, 1972 Line Seeker, 1986(est.) Medici Aerodynamic (Project), 1985(est.) Peugeot PY10FC
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Likes: 0
Liked 34 Times
in
27 Posts
+1 on the worn out crank arm..
It will take a gaggle of loose aluminumm crank arms before you can make the slightest "dents" on the tapers of a steel BB spindle......
But it still might be good to check that your crank arm bolts and spindle end threads are OK to make sure the are remaining tight when you ride.......
It will take a gaggle of loose aluminumm crank arms before you can make the slightest "dents" on the tapers of a steel BB spindle......
But it still might be good to check that your crank arm bolts and spindle end threads are OK to make sure the are remaining tight when you ride.......
Last edited by Chombi; 07-11-14 at 06:26 PM.
07-11-14, 07:17 PM
#8
Banned.
Join Date: May 2011
Location: on the beach
Posts: 4,816
Bikes: '73 falcon sr, '76 grand record, '84 davidson
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Likes: 0
Liked 22 Times
in
17 Posts
have you tried another bolt and washer? i would try a few little things (even blue locktite) before you buy a new arm. but if the arm is a generic one, they can be had for $10. it's the left too (non photo side), so it's not nearly as important.
07-12-14, 01:57 AM
#9
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes it's the left arm that comes loose, just replaced the nut for it & was wondering if adding a washer or lock washer would help?
The spindle is good, the arm is slightly worn in the back side on one of the flats but the rest is ok. Even my bike shop looked at it said it should hold up.
Rode the bike yesterday, had the same problem after 45 minutes of riding after I installed the new nut to the arm.
The spindle is good, the arm is slightly worn in the back side on one of the flats but the rest is ok. Even my bike shop looked at it said it should hold up.
Rode the bike yesterday, had the same problem after 45 minutes of riding after I installed the new nut to the arm.
07-12-14, 02:01 AM
#10
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes it's the left arm that comes loose, just replaced the nut for it & was wondering if adding a washer or lock washer would help?
The spindle is good, the arm is slightly worn in the back side on one of the flats but the rest is ok. Even my bike shop looked at it said it should hold up.
Rode the bike yesterday, had the same problem after 45 minutes of riding after I installed the new nut to the arm.
The spindle is good, the arm is slightly worn in the back side on one of the flats but the rest is ok. Even my bike shop looked at it said it should hold up.
Rode the bike yesterday, had the same problem after 45 minutes of riding after I installed the new nut to the arm.
07-12-14, 02:04 AM
#11
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Does Sugino even make crank parts for older models?? Would like to keep my bike original if possible??
07-12-14, 05:19 AM
#12
weapons-grade bolognium
Join Date: Dec 2008
Location: Across the street from Chicago
Posts: 6,344
Bikes: Battaglin Cromor, Ciocc Designer 84, Schwinn Superior 1981
Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 985 Post(s)
Liked 2,378 Times
in
891 Posts
Post a pic. I bet just about everyone on this forum has at least one Sugino crankset floating around in their parts bin.
07-12-14, 05:34 AM
#13
Still learning
If there is a bike coop or a craigslist bike flipper near you, they can probably dig a crank up for $5 and a whole crank set for about $15. It doesn't get a whole lot cheaper than that.
07-12-14, 05:55 AM
#14
multimodal commuter
Join Date: Nov 2006
Location: NJ, NYC, LI
Posts: 19,808
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Mentioned: 584 Post(s)
Tagged: 0 Thread(s)
Quoted: 1908 Post(s)
Liked 574 Times
in
339 Posts
07-12-14, 06:37 AM
#15
Senior Member
Join Date: Sep 2011
Location: The First State.
Posts: 1,168
Bikes: Schwinn Continental, Schwinn Paramount, Schwinn High Plains, Schwinn World Sport, Trek 420, Trek 930,Trek 660, Novara X-R, Giant Iguana. Fuji Sagres mixte.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 35 Post(s)
Liked 22 Times
in
10 Posts
You won't easily find an exact replacement but you will be able to find a 170 mm Sugino crank that looks somewhat like your old crank. The cranks are on opposite sides of the bike so it's not like you ever see them facing you at the same time.
07-12-14, 07:28 AM
#16
Banned.
Join Date: May 2011
Location: on the beach
Posts: 4,816
Bikes: '73 falcon sr, '76 grand record, '84 davidson
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Likes: 0
Liked 22 Times
in
17 Posts
you replaced the nut? not the bolt? do you have one of those spindles that takes nuts and not bolts? i hate those.
07-12-14, 12:47 PM
#17
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
07-12-14, 01:25 PM
#19
Wood
Join Date: Jun 2009
Location: Beaumont, Tx
Posts: 2,293
Bikes: Raleigh Sports: hers. Vianelli Professional & Bridgestone 300: mine
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 12 Times
in
10 Posts
Do you know anyone who can do heliarc? Quick fix...
07-12-14, 02:21 PM
#20
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
There ya go. Spend some quality time adding material with a welder, filing and checking the contact patch with Prussian blue, and you won't have to replace that $5 arm after all. 
07-12-14, 02:39 PM
#21
Bicycle Restoration
Thread Starter
Join Date: Jul 2012
Location: Saint Francis, Wisconsin
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Pictures coming, as soon as I can get some Wi-Fi to transfer them off of my phone. (No Cell Service)
07-12-14, 04:00 PM
#22
Senior Member
Join Date: Apr 2014
Location: The Witch City
Posts: 286
Bikes: 4 Raleinghs
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
07-12-14, 04:31 PM
#23
Banned.
Join Date: May 2011
Location: on the beach
Posts: 4,816
Bikes: '73 falcon sr, '76 grand record, '84 davidson
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Likes: 0
Liked 22 Times
in
17 Posts
aren't those nuts kinda special, in that they have ridges on the inside face? they're not perfectly flat, so they kinda have some grip. i only had one bb like that and vaguely remember them.
there are several left arms on ebay delivered at the buy-it-now price of $14ish.
there are several left arms on ebay delivered at the buy-it-now price of $14ish.
07-12-14, 07:44 PM
#24
curmudgineer
Join Date: Dec 2009
Location: Chicago SW burbs
Posts: 4,417
Bikes: 2 many 2 fit here
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 263 Post(s)
Liked 112 Times
in
70 Posts
I know a few nuts that are kinda special, but they aren't the kind that you can adjust with a wrench from your toolbox.
07-13-14, 12:00 AM
#25
Banned.
Join Date: May 2011
Location: on the beach
Posts: 4,816
Bikes: '73 falcon sr, '76 grand record, '84 davidson
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 59 Post(s)
Likes: 0
Liked 22 Times
in
17 Posts
^ these are different nuts that kinda grip. you don't grip these. they do that. self gripping nuts. very special, as far as nuts go. which isn't far. a few inches.