tanocupado

I'm a newbie (bike commuter, not racer), just trying to get help to keep my bike working & doing the work myself if possible. I'll start with a post as I start the research to learn what I need to. The crank arm broke, plus prior to that I had trouble with the square taper not tightening enough & slipping. So I've decided I don't like the square taper much, but if my only choice is to replace with another one of the same type I will. I'd like to replace the whole crankset, keeping the bottom bracket if possible, changing the spindle too if I can get a different type that I won't have trouble getting tight (otherwise, keeping the same spindle). I'll probably do my searching on ebay. I just want something that fits & is strong & won't break, willing to pay for decent quality but don't want to pay premium for the most light-weight thing out there. I'm concerned about getting a used vintage crank, as this is the second old crank arm I've broken in recent years, presumably just because the metal fatigues as it ages (I don't generally get in wrecks). Any recommendations? Also, if you can give me pointers about what to measure & what to look for to make sure that what I end up with is compatible, that would be appreciated. Let me know if there's more info I need to add here in order to get an answer.

thumpism 

What usually happens when crankarms keep coming loose on the square tapered spindle is that it loosens for first time, probably due to not having been retorqued, rounds out a little bit, and then continues to loosen thereafter and can't be made to stay on.

I'd look for another Royale crank, or else a Sugino Maxy or Mighty crank for the bike. The Mighty is forged and better, the Maxy looks similar but is swaged and cheaper but entirely serviceable. Both have chainrings that use the same 110mm BCD as your Royale (probably made by Sugino) crank and either should fit on your existing spindle. I use a Fuji-branded Maxy on a mountain bike.

bmthom.gis

If you don't mind mixing new with the old, I am a big fan of throwing an external bottom bracket and corresponding crankset. My commuter (old Peugeot) has a Truvative GXP (or whatever the order the letters are in) and my gravel grinder has a FSA Mega Exo.

bmthom.gis

Oh, and it's a pretty sure bet you have a 68 mm English threaded bottom bracket. You shouldn't have trouble replacing it at all. They are cheap!
I coat the threads with anti-seize before putting a new one on...makes for a much easier time when it comes time to replace or remove for whatever reason

bmthom.gis

If you go with the external route, make sure the cranks come with a fixing bolt. If not, it's like a 2 dollar part. Mine were scavenged from a friends parts bin and he did not have the bolt.

Lascauxcaveman 

Almost any road double crank set designed to work with a square taper should work, although some require longer spindles to position them correctly in respect to the bottom bracket (getting the chainline correct). Best bet would be maybe just shop online for one the same as your old one, provided that one lined up properly. Your local bike shop or bike co-op could certainly score a compatible crank for you.

McBTC

When putting on a 'new' replacement crank arm are you remembering to lay the bike over with the opposite crank on a piece of wood and with a piece of wood on the 'new' arm, give it a good couple of hard raps with a hammer to seat it before running in the bolt to hold it in place?

tanocupado

Thanks for the replies. Yes, the old one lined up perfectly as it was the original, & it was Sugino. I guess my concerns are: a) getting the chainline correct & not having to screw with anything else to make it work, & b) getting a vintage matching set that's already old & ready to break even though it looks fine. The first concern can be resolved by replacing with exactly the same Sugino if I can find it, but it will be vintage, & probably used, right? Or can I get it new? I don't mind at all mixing new with old IF everything lines up - might even prefer new - especially if I can get rid of the square taper which, as I said, does not impress me. (As thumpism said, mine got loose the first time - even though I tightened it well with a wrench - & from then on it couldn't be made tight no matter what. I don't want the same scenario again. I'm tired of crank problems.) So, if I get something newer, how do I know the chain will line up? How do you measure the old crank arm &/or spindle to ensure the new crank will work with the existing derailleur? Also, what type of spindle/crank arm joint is the most trouble-free to install (better than square taper)? By the way, I'd prefer just buying on ebay to going to a shop, as I can probably get a better price & also get it ordered much sooner than I will have the free time to make the trip to a shop. I like cheap but also need to get my bike working ASAP. Specific recommendations I can look for, that are likely to be in a moderate price range, would be appreciated. Thanks again for the help.

bmthom.gis

External bottom brackets come with spacers to use if you need them. Each brand has is own special connection to match with cranks. The BB themselves are cheap and very simple. The spindle is attached to the drive side crank arm.
FSA cranks aren't that expensive on ebay and many apear to come with the bottom bracket. Just search mega exo cranks.

bmthom.gis

If you manage to wear the BB out, you just replace the two cups. I found a new set for $14 a few weeks ago. You won't wear out the spindle or the connecting areas

rhm

The old one failed because of damage, probably caused by faulty installation or maintenance. Age wasn't a factor; the same thing would happen to a new one if installed the same way. There is no reason to expect a similar crank to fail the same way, provided it is installed correctly (tight enough).

oddjob2

If your going for a new spindle, just get a cartridge, Shimano UN26, in the appropriate length for your crankset. If you want a crankset, pm me. I have many that should work fine.

rhm

I don't think he can send private messages yet; hasn't made enough posts.

John E

Concur.

At least in the early-to-mid 1970s Maxy and other lower-end cotterless cranks used a narrower spindle and a fixing nut, making them incompatible with the Mighty Compe (Campag. clone) series, which used a more conventional fatter spindle and fixing bolt.

Given my utter disdain for Maxy, I would use the latter system, even if it means replacing the spindle. As others have mentioned, a sealed cartridge unit is also a great way to go, but that also requires Mighty Compe or a good Shimano or European crank. If you go that route, read up about Shimano vs. JIS vs. ISO spindle thicknesses on SheldonBrown.com. They all use a 2-degree taper, but some cut off the taper earlier than others, making a fatter spindle and placing the cranks farther outboard. If the end of the spindle is too thin, you won't be able to torque your fixing bolt down properly, and you'll be back to your wobbly crank syndrome.

JohnDThompson 

Not to mention, Sugino used the "Maxy" moniker for a variety of low-end cranks: There was a 3-arm version with the large ring permanently swaged to the arm, a 3-arm version with both rings removable, a 5-arm version with the large ring swaged to the arm, and a 110mm BCD inner ring, a 5-arm, 110mm BCD version with both rings removable, and a 5-arm, 144mm BCD version with both rings removable. Perhaps even more.

tanocupado

So, ANY Megaexo "double" crank with BB would fit? (Or a Truvativ GXP? They seem to be less expensive?) I suppose mine must be 68mm English, although when I measured the shell looked to be 70mm. (Why is that?) Some Megaexos on ebay specify "Road Bike", some specify "English" and some say "Compact". What is "Compact"? Does it need to specify "Road" and "English"? I was looking up info on the external bearing systems, & it talked about the potential problem of machining the shell face. HELP! Is there any of the external designs that is less susceptible to this problem? I don't want to have to machine my frame!

FYI, the old crank failed (broke) near the pedal, so it had nothing to do with the installation at the spindle. Either it was metal fatigue, or I'm stronger than the average rider (I lean toward metal fatigue as the reason!). And no, I don't think I can do a PM.

tanocupado

Another question: I've got another frame that I believe has a 73mm BB shell and uses a longer spindle, and I might eventually want to move everything from the Fuji frame to that frame. (It's larger, fits me better, & I think lighter.) Any chance there's a type of newer BB/crank design that fits old threaded shells and is adjustable between 68mm & 73mm? (I noticed the newest FSA design on their website is supposed to be usable with any size shell, but I assume it's expensive & don't know if that works with the threaded shell.) The other frame is a Falcon with Reynolds 531 tubing.

tanocupado

Can you speak to the issue of having to get the BB shell "faced"? Do you have experience putting new external bearings on vintage bikes, without having them machined or anything, and having success? I'd like to go with something new if it would not be problematic, & I'd rather not have to take in the frame to a bike shop for machining, wait extra time, pay extra, etc. Ideally, just want to get a new BB/crankset and put them on.

bmthom.gis

Sorry, I stepped away from this thread. yes, as long as you have English threading, and you absolutely should on an 80s Japanese bike, you can use any English threaded bottom bracket. I have yet to have to get a shell "faced." Yours failed near the pedal, but you also had problems with a square taper. With an external BB, there is no more square taper - it uses a completely different design.

I have put two external bb's on vintage bikes. One is a 70-something Belgian made Superia, the other an 87 Peugeot. Have experienced zero problems installing or riding them since installed.

tanocupado

Just to correct this comment: I got a chance to go measure the Falcon frame, and it's English 68mm. It was just the crank spindle that was extra long on that bike for some reason. So I can interchange the BB between frames.

tanocupado

I started a new thread, since this changed to more of a discussion of options in new cranksets & BBs. It's at https://www.bikeforums.net/classic-vi...age-frame.html