On both of my cruisers the BB's begin to get play in them after about an hour of riding. Recently a new set of cranks, chain, chainring and bottom bracket was installed on an Isla Vista salvage rebuild. Same problem. Would adding a second left side locknut help the problem? Or are there other tips besides converting to 3-piece cranks? I'm careful about tightening the adjusting cone and locknut just to the point of pressure resistance in the crank movement.

My wife's Bildabike is the step thru frame version of my Bildabike and her's does not loosen. Same mechanic services all three bikes, lol.

Thanks in advance for any replies.

One piece cranks will feel either slightly over tight (lumpy) or slightly loose during adjustment. The tolerances are just not precise enough to achieve a perfect adjustment. I always adjust them to microscopically too tight. My experience is the same as yours, in short order they become slightly too loose. If I readjust them, they will again become slightly too loose in a short time. If I just leave them alone, they will remain microscopically too loose forever. They don't continue to get more and more loose.

Thanks, SquidP. I'll try the micro overtight approach.

Hand pack the bearings with automotive bearing grease,
Next super clean all the crank and cup threads, then fill the threads on the crank with blue loctite.
Let It setup for a couple of hours before you Install It all.

Several layers of loctite drying out between each application can make a nice thick rubbery thread filler
that can really hold.
Followed by that microscopically too tight thing.

No Idea If that would work but Its what I'd try.

Thanks, Sindy, good advice. I used marine grease during the BB and crank replacement. I even wondered if the BB loosened because I packed so much in, lol. There's some Medium Strength Lochtite downstairs so I'll try that and mark the locknut position to the crankarm to see if it's backing out.

I may be overconfident at the moment, though, I finally found the "Change Avatar" function.

It's not the lock nut coming loose. At least not on my bikes.

I don't use loctite at all. Just some grease on the threads. The assembly itself never works it's way loose. Once I tighten everything down, it remains tight forever. It's only the feel of the adjustment that changes. Nobody is 100% sure why, but one piece cranks are notorious for this.

Even Sheldon Brown and Jobst Brandt acknowledge this phenomenon. And offer no remedy.

Come on, SquidP, you know that there are no unexplained phenoms in mechanical engineering. You've been spot on with all the previous instructions so this is shocking. I'll debunk this mystery with a micrometer, photos, and large blocks of time.

You are correct Sir.

The true scientific explanation as reported by a team of NASA engineers;

Abstract: Cheap ass primitive parts that only kinda fit together, sorta well enough, until you start jumping off curbs, which knocks their previously precisely mating surfaces into a state of mildly caddy wompus.

Our final verdict: Can't be fixed, no way, no how.

Lol, copy that, sir. I'm still going to put a second locknut on the left
side crank arm.

To each his own.

If you want to make your bike unnecessarily heavy, who am I to stop you. Those nuts are extreme tonnage.



Plus, you are adding all that dead weight to only one side of the bike, which is going to cause the bike to handle horribly. No more hands free riding because the bike will now violently swerve to the left, right into oncoming traffic. Additionally, you'll need to spin the extra massive load since it is added rotating mass, so getting the bike started and going up hill will be a nightmare from now on.


Buy hey, at least that microscopic play will be gone.

Interesting all this,
What about an upgrade to a modern crank assembly ?

Sacrilege!

The fun is in making a poor design work a treat.

Yup, that's it. I've been lucky to have spent time in shops and on roads/trails with a few folks of exceptional mechanical skills and knowledge. No doubt SquidP and others on this forum have those levels of expertise. I'm just a hack with a wrench but with cruisers the parts are cheap, the risks low, and the rewards high. 😄

Sindy - Eventually I plan to try 3-piece cranks on one of my cruisers. Which type of rim and spokes were used on the rear wheel you replaced? Thanks for noting how smooth the replacement hub turned out to be.

The fender hangar you had me grind-off will compensate for the extra lock-ring weight, no? If I veer off dramatically to the left it will either be into the Atlantic Ocean or over unsuspecting beach dwellers catching some rays. Haha, thanks for your tips. Ride report forthcoming as it's Labor Day, the beach is packed, and I'm headed down there now.

I have converted old American OPC bikes (Varsity, Speedster) to a three piece crank set up. They look the biz on those bikes and work extremely well. They spin smoothly and have developed no odd noises.

Improved function, weight savings, and increased sex appeal. I highly recommend it to those who are considering it.

But on a cruiser? For me personally, it's one step too far. Too big of and aesthetic move towards modern. I know, I know, I know. I'm already riding around on aluminum rims, seat post and stem, so what's the big deal? Eh, For me it's the old school look of the chain rings. I like it.

Plus what Aubergine writes below.


+1. It's the challenge.

I'm envious. Man I miss the sounds and salty smells of the ocean. Originally from So Cal myself.

I had planned for a full day ride today. Down to the lake (9 miles) and then along the beach and the parks and then hit the coffee/frozen yogurt shops. But Canada, Montana and Washington are experiencing wild fires and we are surrounded and our area is being filled with smoke and ash. Yesterday was doable for a short 15 miler, but today it's a little too dense to spend all day out there.

I told Sheldon back in the mid 80s how I did my ashtabula cranks... I guess it fell on dead ears. The most important thing is torquing down the drive cone that holds the chainring in place, especially these days with really poor fitting drive pins. This involves putting the crank in a vice and using a bottom bracket lockring wrench or similar tool with a long handle... 12" should suffice. As I've mentioned before in other threads it's not such a big deal on cruisers without coaster brakes but bikes with coaster brakes will put alternating forces on the drive cone causing it to loosen and tighten, if it wasn't torqued adequately, which causes variances in bottom bracket bearing play. From my experience this wasn't such a big deal with older bikes that seemed to have tighter drive pin and chainring drive hole tolerances but the newer ones just seem so sloppy and those are the ones I usually have problems with and the ones on which I have to modify/shim the pins or weldup the drive pin hole on the chainring and redrill it to an appropriate size. Ashtabula cranks and bearings aren't of the greatest precision however I can get mine to spin freely with no play or notchiness whatsoever.

Aubergine, SquidPuppet, You boys are old school,
Take a bow

^^^What he said and add BassNotBass. Many thanks.

After beach riding yesterday I detected a slight wiggle in the Warden's front wheel so a hub rebuild ensued. Rebuilding my BB and torquing down the drive cone with a breaker bar extension will have to wait. That's something I will enjoy, though.

SquidP, I've grown to love the seaside living after moving here from the red clay of North Georgia. All the local hysteria about the Irma Hurricane is a taxing, though. Little chance it hits here but I hope those in Florida can dodge this big one. Last year we stuck around for Hurricane Matthew (only a Cat 1 here) and it was a fascinating experience. We'll skidaddle if a cat 3 or above is ever imminent.

Be safe Florida folks!

Thanks for that. I've never found one loose, as in LOOSE, but I've never considered that there could be back and forth movement. And if it did exist, it would for sure cause the issue.

I know I am late to the party, but one thing to check for that is easily overlooked is the possibility of a cup being loose and moving occasionally in the frame.

The years I lived in N Georgia were memorable to varying degrees but one thing I do not miss at all is the Georgia red clay. The SC coast was a good move... beautiful coastline which always makes the heat and humidity of The South so much more bearable.

I hope you go unscathed.

Thanks, hopefully Irma will lose some bite or meander out into the Atlantic. Be safe Florida cruiser lovers.

That's a fine shirt in your link! It is very nice here but my remains are to be returned, preferrably not any time soon, to the red clay terra firma of Georgia.