Out of Sync Crank?

I'd switch to hollow Tech cranks Sounds like you've rounded the bottom bracket or its a single spine out of alignment Sent from my GT-P1000 using Tapatalk

Quoted post said:

Originally Posted by CBNutrition [IMG]/img/forum/go_quote.gif[/IMG]

I'd switch to hollow Tech cranks
Sounds like you've rounded the bottom bracket or its a single spine out of alignment
Sent from my GT-P1000 using Tapatalk

Excellent, I was hoping for an excuse to upgrade to hollow tech cranks. This appears to be a square taper bottom bracket, so I think it may just be rounded like you said. I was thinking of upgrading anyway just because the fact that my left crank kept coming loose all the time, what a pain!

Any particular MTB crankset you guys would recommend for someone not looking to blow a ton of cash? I was thinking maybe this Shimano SLX 9?
nashbar.comProduct 10053 10052 195962 1 202630 10000 202429Open ↗

Quoted post said:

Originally Posted by slmaurice [IMG]/img/forum/go_quote.gif[/IMG]

Excellent, I was hoping for an excuse to upgrade to hollow tech cranks. This appears to be a square taper bottom bracket, so I think it may just be rounded like you said. I was thinking of upgrading anyway just because the fact that my left crank kept coming loose all the time, what a pain!

Any particular MTB crankset you guys would recommend for someone not looking to blow a ton of cash? I was thinking maybe this Shimano SLX 9?
nashbar.comProduct 10053 10052 195962 1 202630 10000 202429Open ↗

How did you manage to round a square tape BB axle? They're typically not very fragile. The rounding, I'll bet, is in the crank arm. What brand and model of cranks do you have?

The Shimano cranks for which you provided the link at Nashbar will be solid (i.e. good performance, not solid as in "no voids"😉 cranks. One thing you will need to either do yourself or more likely have a shop do is to have your BB shell faced. That's a process that ensures that the two faces of the BB shell (uhm on the left side of the bike and on the rights side of the bike) are parallel. With the new cranks (i.e., cranks developed with external BB bearing cups), facing the BB shell is an essential step. It reduces the chances of experiencing irritating noises from the BB, but more importantly it ensures that the BB bearings are loaded correctly, thus maximizing their useful lifespan. If you install your cranks on your own, be sure to follow the manufacturer's directions. Your BB and associated bits (including the crank) should be inspected every year.

Quoted post said:

Originally Posted by alienator [IMG]/img/forum/go_quote.gif[/IMG]

How did you manage to round a square tape BB axle? They're typically not very fragile. The rounding, I'll bet, is in the crank arm. What brand and model of cranks do you have?

The Shimano cranks for which you provided the link at Nashbar will be solid (i.e. good performance, not solid as in "no voids"😉 cranks. One thing you will need to either do yourself or more likely have a shop do is to have your BB shell faced. That's a process that ensures that the two faces of the BB shell (uhm on the left side of the bike and on the rights side of the bike) are parallel. With the new cranks (i.e., cranks developed with external BB bearing cups), facing the BB shell is an essential step. It reduces the chances of experiencing irritating noises from the BB, but more importantly it ensures that the BB bearings are loaded correctly, thus maximizing their useful lifespan. If you install your cranks on your own, be sure to follow the manufacturer's directions. Your BB and associated bits (including the crank) should be inspected every year.

Heh, it may be a problem with the actual crank arm then. It must have happened during one of the rides it came loose. The crank arm was wobbling badly and it must have rounded something off. I do not know which model the crank arm is, but the BB and crank arms are just a basic shimano set that came stock on my Gary Fisher bike. Hopefully when I can get some tools to remove the crank arm and BB, I will have a better explanation. A couple of rides ago there was an awful creaking noise coming from the BB, so I think it's ready to come out.

Thanks for the tip, I'll be sure to bring the bike over to my LBS once I get everything apart and get the frame prepped for the new external BB, it looks pretty rusty in there too.

Quoted post said:

Originally Posted by slmaurice [IMG]/img/forum/go_quote.gif[/IMG]

Heh, it may be a problem with the actual crank arm then. It must have happened during one of the rides it came loose. The crank arm was wobbling badly and it must have rounded something off.

That'll surely produce the evidence you found. While you will have to shell out some pesos to get a new crank, consider it a valuable learning experience.

Quoted post said:

Originally Posted by slmaurice [IMG]/img/forum/go_quote.gif[/IMG]

Heh, it may be a problem with the actual crank arm then. It must have happened during one of the rides it came loose. The crank arm was wobbling badly and it must have rounded something off. I do not know which model the crank arm is, but the BB and crank arms are just a basic shimano set that came stock on my Gary Fisher bike. Hopefully when I can get some tools to remove the crank arm and BB, I will have a better explanation. A couple of rides ago there was an awful creaking noise coming from the BB, so I think it's ready to come out.

FWIW. I'm not sure that the Hollowtech II (or, MegaExo, or Ultra Torque) external BBs are the best option ... but, if you must ...

However, while you are debating which crankset/BB option might make the best replacement with regard to cost and/or aesthetics, you may want to consider "fixing" the damaged taper ...

• BTW, shame on the bike shop for sending you out the door with a poorly prepped bike -- riding with the insufficiently secured square taper crankarm has indeed resulted in deformation of the aluminum taper of the crankarm. An FSA crank & BB for under $100 (check eBay) will be almost as good as the SLX crankset which costs $250+ at Nashbar.
  
  

Alternatively (it's not that you shouldn't spend the money [did that Gary Fisher cost more than $600 when it was new? Is spending almost 50% the original cost for just a crank a good idea?], but if you can spend it on something else for your bike (how about a better suspension fork which you can always move to another frame in the future if something happens to your GF frame?) or yourself, then why spend the money, unnecessarily?) , if you have sufficient tools on hand & a couple of dollars, or less (i.e., "free"), you can remedy the problem by SHIMMING the crankarm's damaged taper ...

Suggested tools include:

• Snips or metal cutting scissors
  
• File
  
• Pliers
  
• Brass stock/foil OR Tin Can OR Tin Can lid
  
• You can use either use Epoxy OR Tub-and-Tile Caulk to secure the shim in the arm's taper OR let contact pressure hold it in place.
  

1. clean the receiving taper of the damaged crankarm of any grease -- a paper towel w/ dishwashing solution & hot water will work ...
   
2. cut a small square of cardboard about 3/4" x 3/4" which you can fold over the BB's taper (wipe the grease off, first) ... this is a template which you will use to determine the piece of metal that you are going to cut & bend
   
3. transfer the cardboard template to whatever piece of metal you choose to use
   • use the file (or, emery cloth) to round the edges of the shim that you fabricate
     
   
   
4. bend the metal, accordingly
   
5. loosely "test fit" the damaged crankarm on the BB's taper with the shim in place
   
6. assess -- if the arm fits well (i.e., snugly) & the offset from the stay is almost right then remove & (optionally) put a dab of tub-and-tile caulk on the face of the shim that will nest in the receiving hole of the crankarm ... or, if you are confident that you know what you are doing, use a dab of epoxy
   
7. put the arm on the BB
   
8. secure with the crank bolt [LIST] if you don't have a washer for the bolt then you may want to cut a washer from the top of a milk jug's cap
   
   

Good luck.

Very helpful post, but I am a day late reading it. I did consider the price of the bike new, which was around $600, but the bike was given to me from my parents as a birthday gift 2 - 3 years ago, so I lucked out there a bit. I'm totally new to MTB upgrades, so I'm having a hard time gauging what is worthwhile upgrade and what is not. Unfortunately, when I first received the bike, I did not ride it as often, as hard, and as fast as I do now, so the crankarm seldom came loose. I should have just brought it straight back to the LBS after the first time it happened, but I just tightened it back up and thought nothing of it, live and learn I guess.

The SLX crankset was actually on sale a couple of days ago when I originally posted the link, I just purchased it yesterday for $140 shipped to my doorstep, just waiting for it to arrive (should be here Wednesday).

I took the old crankset apart yesterday and both the crank arm and BB are damaged, the crank arm seeing the worst of it. I'll post some pictures up soon when I get the chance.

I took the bike over to the LBS and the mechanic said there was absolutely no reason to get the shell faced. He said that unless the paint is chipped / uneven or there is physical damage to the frame, there is no need to get the shell faced. He admitted he wouldn't even face the shell if it was his bike. I'm not really sure who to believe at this point.

slmaurice said:

I took the bike over to the LBS and the mechanic said there was absolutely no reason to get the shell faced. He said that unless the paint is chipped / uneven or there is physical damage to the frame, there is no need to get the shell faced. He admitted he wouldn't even face the shell if it was his bike. I'm not really sure who to believe at this point.

You might want to look for a new mechanic. First, paint has nothing do with proper facing. Paint should always be removed from the faces of a bottom bracket shell, especially if you're bottom bracket has external bearings. Second, the paint on the faces of a bottom bracket shell says nothing about whether the BB shell faces are parallel or not. Some frame makers do face their bottom brackets. By no means do all. Checking to see if a BB shell is properly faced is standard procedure for a proper bike build.

Quoted post said:

Originally Posted by slmaurice [IMG]/img/forum/go_quote.gif[/IMG]

I took the bike over to the LBS and the mechanic said there was absolutely no reason to get the shell faced. He said that unless the paint is chipped / uneven or there is physical damage to the frame, there is no need to get the shell faced. He admitted he wouldn't even face the shell if it was his bike. I'm not really sure who to believe at this point.

FWIW. I agree with the mechanic at your LBS ...

And, I do not think that every frame needs to have the BB shell faced (of course, the lastest BB30 & BB386 + any similar BB shells do not need any preparation) ...

But, some people in the Forum think that I am amongst the unwashed infidels who just can't-or-won't follow the various mandates of the various manufacturers ....

Regardless, none of the more plebian, mass-produced frames that I have needed to have the BB shell faced ... it's a sample of only about a dozen ... maybe, I have just been lucky (!?!) and the next frame will need to have its BB faced!

• YOU can check to see if your frame's BB shell needs to be Faced by removing the BB
  
• INSERT a sheet of typing-or-copy paper in the BB shell
  
• With one edge flush to the edge of the BB shell which is being checked, square up the other edge of the paper tube that you have 'created' ... if the edge of the BB is not square, then you will see a deviation from the flush edge of the paper
  

[*] REPEAT on the other side of the BB shell

• for example, if the frame uses an auxiliary under-BB cable guide & the end of bolt can be seen inside the BB shell, then the guide needs to be removed to perform the test
  

BTW. I think the 'myth' that facing was required prior to installing External BB cups (e.g., Hollowtech II, MegaExo, UltraTorque, etc.) may be a consequence of a lot of older custom frames having been retrofitted with Hollowtech II BBs a dozen years ago ...

OR, someone encountered a disproportionate number of bad "samples" way-back-when.

The local bike shop I used years ago would routinely face the BB shells on racing frames as he'd rarely find that they were 68mm exactly and rarely were the edges completely parrallel - even on Cinelli's finest cast BB shells. His reasoning was that if you're going to go to the trouble of spending extra money on a Campag record BB (back when they "super lapped" the BB shells) then getting the BB to sit perfectly square and butt up against a perfectly flat surface was something that needed to be done - plus it's a pretty quick procedure in the grand scheme of things.

But... if you're not looking to set your personal world on fire with endless amounts of really hard training over the next few years then such prep may be overkill. YMMV.

Personally, on a steel frame I'd face the BB shell and headtube.

Quoted post said:

Originally Posted by swampy1970 [IMG]/img/forum/go_quote.gif[/IMG]

The local bike shop I used years ago would routinely face the BB shells on racing frames as he'd rarely find that they were 68mm exactly and rarely were the edges completely parrallel - even on Cinelli's finest cast BB shells. His reasoning was that if you're going to go to the trouble of spending extra money on a Campag record BB (back when they "super lapped" the BB shells) then getting the BB to sit perfectly square and butt up against a perfectly flat surface was something that needed to be done - plus it's a pretty quick procedure in the grand scheme of things.

But... if you're not looking to set your personal world on fire with endless amounts of really hard training over the next few years then such prep may be overkill. YMMV.

Personally, on a steel frame I'd face the BB shell and headtube.

Okay. I must not be communicating clearly ...

I thought that I alluded to to the need for "custom" bikes to have their BB shells faced as the probable reason for the universal recommendation to have the BB shell faced prior to installing a Hollowtech II, MegaExo, or UltraTorque BB cup ...

• when I briefly considered building my own frame about 30 years ago, I was well aware that the Cinelli castings were very raw AND the BB & Headtube would need to be faced AND I was therefore mystified as to why the custom framebuilders of-the-time-and-shortly-thereafter didn't do so before having their frames painted.
  

I don't think the recent crop of aluminum frames which have English or Italian (e.g., PINARELLO ... presuming the Pinarello no longer uses the ill-timed M.O.st alternative to an Italian threaded BB and has reverted to an Italian threaded shell .... certainly, if COLNAGO still makes an aluminum frame then it probably has an Italian threaded BB shell) BB shells need to be faced ...

And, as I mentioned, none of the plebian frames that I have needed to be faced ... I would say that it was due to the superior craftsmanship of Japanese frames, but it's even true of the two, lowly, 70s vintage French frames that I have (yes, I modified a set of MegaExo cups to fit in a vintage French frame; and, I subsequently tested the cups in both French frames). Undoubtedly, the shells on the mass produced frames were faced to facilitate the subsequent mass-production assembly.

So, inexpensive frame ... facing is probably not required ...

Expensive frame ... facing may be required!

But "back in the day" includes a time when 531c frames were about $250 off the shelf - not custom. Then again, I don't know what it was like here in the US 20 years ago.. Unless you got something along the lines of Peugeot's Carbolite 103 tubing he faced the BB shells.

That is all I'm gonna say on this. I'm not letting this one degrade to the point to where you tell him to use Campag ergo shifters and drag it on for another war and peace non-epic.

Quoted post said:

Originally Posted by swampy1970 [IMG]/img/forum/go_quote.gif[/IMG]

But "back in the day" includes a time when 531c frames were about $250 off the shelf - not custom. Then again, I don't know what it was like here in the US 20 years ago.. Unless you got something along the lines of Peugeot's Carbolite 103 tubing he faced the BB shells.

An off-the-peg Reynolds 531c frame may not be custom, per se, but it is hardly as plebeian as a Carlton produced frameset whose BB shell is undoubtedly subjected to the equivalent of an electric-knife-sharpener whereby the face of the BB is prepped to facilitate the mass-production assembly.

Quoted post said:

Originally Posted by swampy1970 [IMG]/img/forum/go_quote.gif[/IMG]

That is all I'm gonna say on this. I'm not letting this one degrade to the point to where you tell him to use Campag ergo shifters and drag it on for another war and peace non-epic.

HMmmm. One of the nicest looking bikes that I've seen was a CANNONDALE with CAMPAGNOLO shifters!