Bicycle Mechanics - Sugino 75 Crank Bolt Torque?? Grease or no?

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emailsfh
03-10-08, 10:48 PM
Hi folks, can't find this anywhere on the net. I have a Sugino 75 crankset that I'll be installing and don't know what the torque specification is on that. Also, not sure if I should grease or not (sorry to open that can of worms :rolleyes:).

Any thoughts?


carpediemracing
03-11-08, 04:58 AM
Don't grease the tapers.

Grease the threads and the washer under the bolt.

Tighten until it's snug then go about 1/8 turn more. Check daily for a week. For the paranoid, check weekly after that. Don't over tighten as you'll stretch the taper (best case) or crack the crank (worst case).

You should be fine with that. Before they were the schnizzle with the SS/FG group these were the cheap alternative to "real" cranks and what I described above is how pretty much everyone set them up, including the set I pulled off one of my bikes about 20 years ago.

I didn't search for torque values for Sugino 75s as I figured you already have.

cdr

emailsfh
03-11-08, 06:47 AM
Thanks carpediem. I guess I'm one of the "SS/FG" people. Pretty surprised that an item that has become so widespread seems so hard to find specs for . . . What does "snug" mean to you? Any estimates on torque? I have a torque wrench that only goes to ~200 in/lb. Should I torque with that, then give it an extra bit more? How much?


Retro Grouch
03-11-08, 09:37 AM
Thanks carpediem. I guess I'm one of the "SS/FG" people. Pretty surprised that an item that has become so widespread seems so hard to find specs for . . . What does "snug" mean to you? Any estimates on torque? I have a torque wrench that only goes to ~200 in/lb. Should I torque with that, then give it an extra bit more? How much?

200 in/lbs isn't nearly enough. Most cranks require around 30 lb/ft. That's 360 in/lbs. I grease the threads but not the tapers.

JSellers
03-11-08, 01:44 PM
Sorry I do beleive in 30 foot lbs torque but still think to grease tapers. Steel and AL normally don't get along over a period of time.

BCRider
03-11-08, 02:10 PM
Greasing the taper not only ensures that you won't get corrosion going on in there but it also avoid any risk of the aluminium galling on the stell and tearing up the crank's taper.

I've greased all my tapers and never had any issue with them in any way. They stay politely in place until I use my crank remover. And then they come off just as politely with no damage to be seen.

Grease it all with a light smear. The metal will love you for it.

emailsfh
03-13-08, 06:23 AM
Anyone else thinks this sounds ridiculously low, even if you ligthly grease the spindle?

Dear Mr. --

Thank you very much for your e-mail.

The torque is 12-16N.m.
However, this torque specification is appropriate
under the condition that the SG75 cranks are used with the NJS parts.

We recommend to grease the BB spindle slightly
to prevent seizing and rust on the spindle.

We also recommend to do maintenance periodically.

Best regads,
Yuki Iwai
SUGINO CYCLE INDUSTRIES, LTD.
iwai@suginoltd.co.jp
TEL. +81-(0)742-62-5311
FAX.+81-(0)742-62-5320
287-1 Tohkujo-cho, Nara, Japan 630-8144

operator
03-13-08, 06:28 AM
If you like rounding out your cranks - do it like post #2 described. If you don't want to worry about them do it the proper way and use a torque wrench. If you don't have one, get your LBS to do it for you.