hybridbkrdr

I've watched a few videos on installing Hollowtech II, Octalink and square taper cranks. Do you find Hollowtech II tricky to work with? I mean, you can't put too much torque on the crank bolts but they can't be too loose either?

By the way, the BB30 standard looks like a pain to work with. But, there are several manufacturers for square taper bottom brackets. Seems like the easiest standard to me.

HillRider

Hollowtech II is very easy to work with. The pinch bolts that hold the nds arm are just alternately tightened to about 100 inch-pounds with a 5 mm hex key. That's pretty tight and about as tight as you are likely to get them with a standard L-wrench.

fietsbob

a plastic cap does the side preload.. do buy the tool ... the 2 bolts in the crank arm hold the adjustment,

So in that... somewhat like your threadless headset..

you read the service manual ?

Marcus_Ti

Follow directions WRT to locktite and WRT torque and you'll be fine.

It is when you don't follow directions that hilarity starts happening in addition to breaking things.

dedhed

I just get it on enough to make sure the locking plate goes in. then crank down the bolts

https://www.performancebike.com/shim...QaAqxQEALw_wcB

davidad

Handy site: https://www.bikeride.com/torque-specifications/

Proper torque and sequence are important. I know of at least two instances of the left arm coming off,

Andrew R Stewart 

Agreed that tapered square is the most versatile, and good enough for my generation's cycling gods (Merckz, LeMond). Andy

carlos danger

eeh no not really. there is small disc to adjust them. maybe 2 inches 5cm across. and you basically tighten this as fairly snug.

and if you are working with a half inch bit you have to tighten it as hard as you can by hand.
done. thats it.

hybridbkrdr

Maybe I should have been a bit more specific. One of the things I saw in the youtube videos was someone saying if you have the cranks too tight, it will ruin the bearings. If you have it too loose, that's not good either. So, would you find it easier if Shimano designed a system where the cranks click once they're in the proper place?

TimothyH

There is no adjustment. All you have to do is snug up the disk to 1.5 Nm which is not tight at all.

Installation instructions are at https://si.shimano.com/pdfs/dm/DM-RAFC001-03-ENG.pdf. See page 17. The TL-FC16 tool comes with the cranks.




The newer thread-together bottom brackets from Praxis, Enduro or Wheels Manufacturing are going to be much easier to install and will never creak or cause problems.

Praxis Conversion for BB30/Shimano

Wheels Mfg Thread Together for BB30/Shimano

Enduro Torqtite for BB30/Shimano

Shop around for price.


-Tim-

alcjphil

The tool used to preload the bottom bracket bearings is very difficult to overtighten. The pinch bolts holding the cranks in place should be tightened using a torque wrench. The proper way is to tighten the first bolt, then the other, then go back to the first and back to the other twice more to make sure that both pinch bolts are at the same torque. If you do that you will almost never have problems with an HTII crank

Le Mechanic

I've worked with all of them for many years in my day job. Hollowtech II cranks are probably the easiest to work with and the shift quality is hard to beat with the larger spindle diameter and ridged chainrings. Not sure if my video was one you may have watched, but it's a splined preload cap to snug the crank together, and 2 bolts tightened with a 5mm hex key to 12-14Nm. The Sram GXP system is similar, probably simpler in that all you need is an 8mm hex wrench to remove or install the cranks. BB30 is great functionally, but requires way too much maintenance for my liking. Square taper cranks look pretty, but compared to modern technology, performance wise, they're not great. The spindle flexes under load and puts excessive stress on the bearings, you need a crank puller to get them off, if the spindle bolts and not torqued correctly, the crank arm works loose and unless you're using a modern cartridge BB, you gotta deal with keeping the BB adjusted and maintained, which to me is the worst crank standard overall to deal with.

AnkleWork

As noted above, Shimano now specifies a torque range for the preload because too much torque opened the BB seals of some models. Be circumspect.

Metaluna

“Ruin the bearings” is way too strong of a description IMHO. If you have the preload too tight, it will subject the bearings to elevated wear, meaning your bottom bracket won’t last quite as long (because radial cartridge bearings don’t do well with side loads), but that’s a long way from ruin. You’d probably still get thousands of miles out of the BB. Sure, if you crank down on the preload cap with a tool attached to a socket wrench you can probably break something, but if you use that little plastic wheel and just snug it down with finger pressure, I think it would be pretty hard to mess it up.

hybridbkrdr

Do any of you think T47 bottom bracket will be the way to go?

FML123

I have a Shimano RS-500 crankset. The website for the bike says it has a PF30 bottom bracket. Frequently, especially if I'm pedalling hard, I start to hear a clicking sound in rhythm with every revolution of the crank. If I get off the bike and try to spin the cranks backward, it's slightly too tight, doesn't spin freely. If I loosen pinch bolts and back off the preload cap a little, then tighten the pinch bolts back down, the crank will spin freely, and the noise will disappear. But after 2-3 short rides the BB bearing is too tight again. What am I doing wrong?

WizardOfBoz

I would point out that some of the torque values above are different than what is in the Shimano Dealer's manual:
https://si.shimano.com/pdfs/dm/DM-FC0002-12-ENG.pdf

Use instructions to properly install your BB.

To preload the bearings, Timothy had it right: Snug up the NDS arm using the tool and your fingers. Then push down the (useless, IMHO) little plastic thingie, and then tighten the crank arm crank bolts to 12-14 Nm. As suggested above, you do this by alternately tightening each of the two opposing crank arm bolts in turn, working up to 12-14 Nm. I believe that this is 106 to 124 inch pounds.

WizardOfBoz

When you say "bolt", singular, I wonder are there two pinch bolts on the crank arm? Do you gradually tighten them both by alternating? Do you use a torque wrench?

Doing all these things SHOULD keep your crank arm from loosening, but you may wish to try threadlocker (use medium, or blue, and definitely not permanent, or red) on the crank arm bolts.

If you've gone through a lot of cycles of your bolts loosening, you may have significant wear on the arm. Have a look, or have your LBS take a look.

FML123

Sorry, singular “bolt” was a typo; I just fixed it to read “bolts.” Yes, there are 2 pinch bolts on the crank arm, and I do gradually tighten them by alternating. I haven’t been using a torque wrench since it happens on the road, but can start checking that at home. My crank arm isn’t loosening at all, as far as I can tell. Rather, the preload on the bearing seems to be tightening during each ride. The bike is only 6 months old and I haven’t ridden it much at all, maybe only 200km total. Would LocTite on the preload cap threads stop the problem? I’m reticent to apply it to plastic parts.

hybridbkrdr

I know this sounds slightly off-topic but does anyone know if the problem described by FML123 would be solved by using the T47 bottom bracket? Would it be better to use internal or external bearings? (I think T47 is available for both.)

AeroGut

Is it at all possible that your bottom bracket was not pressed in properly and is working its way out? Look closely where it meets the frame and make sure it’s still pressed completely in.

WizardOfBoz

My suspicion was that the crank arm was coming loose and somehow your pedaling would tighten it up. Aeroguts idea is intriguing, as I suppose the theory is that the bearings themselves were working outward and tightening things up.

The only other possiblity I can think of offhand is if the BB30 housing in the frame is somehow bent or misaligned. The FSA video below is a bit over the top but does show how you could test the BB part of the frame before installing bearings.

veganbikes

Hollowtech II is just fine by me not really had any issues so far. They are pretty easy to work with and you don't need a crank puller which is nice though you probably will want a cap tool which aren't expensive and certainly a torque wrench which you would want anyway for normal bicycle maintenance.

As far as T47 I do like the idea and hope it sticks around a while! I probably won't buy anything T47 for some time but I currently don't feel the need for it but maybe if I was a stronger rider I might see the need. Standard BSA threading has not been a problem.

FML123

Interesting. I don't know if that would fix the problem but I do like a threaded BB. I just bought this bike in Jan 2019. Last bike before that was bought in 1999. Pressfit didn't exist and all spindles were square taper.

FML123

Thanks AeroGut, I'll check it out.