JIS taper crankset on campagnolo square BB

[thinpin]

What would the consequences of fitting a compact requiring JIS 103mm BB on a campagnolo chorus 102mm BB be? I understand campagnolo square taper is different but by how much?

[PacNW2Ford]

Google "Sheldon Brown ISO JIS"

[ultraman6970]

Hmm it will work, well you can do that, the issue I believe is that the crankset wont set so deep as it should... or is backwards? can't remember.

The only way to know how deep will go is to try what u want to do.

Uppercase for the ones that like the things done right ok?? WHAT YOU WANT TO DO IS NOT THE RIGHT THING BECAUSE U CAN DAMAGE THE CRANK OK?. sudden death of the crank? doubt it, shimano squared tapper last forever (IMO). Never seen a shimano crank to crack in the tapper area ever. If you dont have the dough then go ahead and try, is your call. The worse case scenario the crankset wont clear the chain stay (pretty much that will happen IMO).

Maybe somebody here has a BB to give away???

[Kontact]

The crank will bottom out on the untapered base, which will fail to support the crank and break it.

Don't do it. Buy a cheap Miche BB or something.

[Louis]

Try slathering the BB taper with JB weld first and see what happens. Then let us know. :p

Just kidding. Use the right stuff, even it costs more time or money.

[thinpin]

Its not the cash. Just jack of changing out the BB every time I want to pop the compact on. :beer:

[oliver1850]

I have checked some different spindles at times, and they vary on the cross sectional dimension at the very end. The length of the taper can vary as well. The Token 102 I checked has a longer taper than the Chorus I checked. Cranks will vary as well. A Topline looked as if it would rub on the cups when tight, a tricolor 600 looked like it would clear. If you try it, it would be a good idea to put layout fluid or Sharpie ink on the spindle and install the arms. Then remove them and make sure that the arm has not run out of tapered section of the spindle (this is what kontact was talking about). Before removing check that the spindle has not come past the seat for the arm bolt.

[Louis]

Its not the cash. Just jack of changing out the BB every time I want to pop the compact on. :beer:

Would it be easier to change the cassette? Or the wheel + cassette, if you want to go that route and have an extra rear wheel.

[oliver1850]

The easy way is to have another bike with a compact.

[Louis]

The easy way is to have another bike with a compact.

And the most difficult way of all would be to get in shape and not need the compact to begin with.

(I go the triple route.)

[thinpin]

And the most difficult way of all would be to get in shape and not need the compact to begin with.

(I go the triple route.)
The particular climb is 20km of sustained 10% with a 500m pitch of 16-18% depending on who you believe. Its for my wife's bike and she's normally happy with the 53/39. She doesn't like to have the compact on her shiny Tommasini all the time cause it spoils the look!

[oliver1850]

Here's the tricolor arm on the Chorus spindle. There was still clearance under the bolt, the spindle did not protrude past the bolt seating surface. As you can see, this combination is very close to running out of taper. After I removed the arm, the scrape marks appeared to have stopped before the arm ran out of taper. The longer taper of the Token spindle would be safer. Of course there's no guarantee that all Tokens will in fact have a longer taper. Some could be shorter. I think Sheldon mentions this in his discussion. You really have to check this on a case by case basis and know what to look for.

[Louis]

The particular climb is 20km of sustained 10% with a 500m pitch of 16-18% depending on who you believe.

That does look like a real challenge. I think she needs a climbing bike. Either a Parlee or a Crumpton with sub 1350g wheels. :)

[thinpin]

Thanks guys. I think I'll just run with it properly. I just need pay attention and not wreck the threads one day!

[pavel]

It seems like the easiest solution would be to buy a campy square taper compact version of the same crank you already have, no? Then you only have to change the drive side arm when you want to go compact.


....Ah.

i backed up and read your post again. from your bb, I am guessing you have a record or chorus crankset, in which case finding a square taper compact version is not particularly easy, especially if you require a length other than 170. Still, save your requirements to your ebay searches or wait to see if something pops up here.

[mistermo]

Your issue is nearly identical to the one I face. I've decided to do as another suggested and merely swap the drive side crank between compact and 'regular'. It's not Record or Chorus, but I wouldn't hesitate, in fact I'd prefer, to use this Centaur crankset on a Tomassini. If you need a 172.5, I've got one.

http://www.ebay.com/itm/CAMPAGNOLO-CENTAUR-CT-10-Speed-Crank-34-X-50-t-170mm-Alloy-ULTRA-DRIVE-EPS-NEW-/330679440013?pt=Cycling_Parts_Accessories&hash=item4cfe07d28d

I was in Provence a few months ago and saw two beautiful shiny steel Tomassini's with these, near Mt Ventoux. Your climb resembles the Ventoux.

[oldpotatoe]

What would the consequences of fitting a compact requiring JIS 103mm BB on a campagnolo chorus 102mm BB be? I understand campagnolo square taper is different but by how much?

Both 2 degrees but the JIS is physically bigger than ISO in millimeters. So a JIS crank will go on farther, maybe too far, bottoming and getting loose when ya ride, potentially ruining the crank, breaking the crank or with the 1mm less, small ring hitting the chainstay.

I have 103 JIS BBs, BTW-IRD and TA, both BSC and the far superior Italian threading.

[Kontact]

Both 2 degrees but the JIS is physically bigger than ISO in millimeters. So a JIS crank will go on farther, maybe too far, bottoming and getting loose when ya ride, potentially ruining the crank, breaking the crank or with the 1mm less, small ring hitting the chainstay.

I have 103 JIS BBs, BTW-IRD and TA, both BSC and the far superior Italian threading.
Why is Italian superior?

[thinpin]

The crankset on there is a record with 102mm BB. To use a centaur I would still need to change the BB to a 111mm (or is it 115mm, I cant remember).The crank I use is a stronglight and JIS 107mm BB.

[Kontact]

The crankset on there is a record with 102mm BB. To use a centaur I would still need to change the BB to a 111mm (or is it 115mm, I cant remember).The crank I use is a stronglight and JIS 107mm BB.
Why switch them at all? Compacts are fine for normal road use.

Alternately, why not just buy a JIS traditional crank and stop using the Chorus on this bike?

It just seems like you've created a lot of work just to be able to use a Chorus crank part time.

[thinpin]

You have a point, not sure swmba would agree.

[sg8357]

Why is Italian superior?

It means full employment for bike mechanics and Loctite Corp.

[oldpotatoe]

Why is Italian superior?

Cuz, why, because it's 'Italian', of course.......shhhheeezzzz



http://www.youtube.com/fiatusa

[Kontact]

Cuz, why, because it's 'Italian', of course.......shhhheeezzzz



http://www.youtube.com/fiatusa
Okay, I couldn't tell you were kidding.

[oldpotatoe]

Okay, I couldn't tell you were kidding.


Ya need to lighten up francis..this is about toys, afterall.

[fiamme red]

Ya need to lighten up francis..this is about toys, afterall.It was hard for me to "lighten up" when the Campagnolo Italian b.b. on my Merckx (not installed tightly enough by my LBS) started unscrewing in the middle of a ride 100 miles from home, nearly leaving me stranded. :rolleyes:

[Kontact]

Ya need to lighten up francis..this is about toys, afterall.
I honestly thought you were implying some sort of advantage to the metric thread or something that I hadn't heard before. How is that "not light"?

[oldpotatoe]

I honestly thought you were implying some sort of advantage to the metric thread or something that I hadn't heard before. How is that "not light"?

Every time I respond to a thread, on ANY forum, about Italian BB threading, I say the 'far superior Italian threading', have been for as long as I've been on these forums...

There is an advantage...it's Italiano-

Owner-

Vecchio's

[oldpotatoe]

It was hard for me to "lighten up" when the Campagnolo Italian b.b. on my Merckx (not installed tightly enough by my LBS) started unscrewing in the middle of a ride 100 miles from home, nearly leaving me stranded. :rolleyes:


Seen more than a couple, happened on my Ciocc, before I started wrenching.

Takes a certain diligence when installing Italian threaded BBs, of course, but it's, it's still......


Italian, tho.

[ronlau]

Peter,

I have a few bikes with Italina threaded BB, can you explain what do you mean by installing with diligence? The usual steps done by good LBS to owns and use Campy tools?

BTW, Roland Della Santa explained to me why he uses Italian BB.

1. It is lighter than English BB shell.
2. It is easier to chase in his shop, no need to change the tool.
3. Della Santa is his last name.

Thanks,
Ron

Seen more than a couple, happened on my Ciocc, before I started wrenching.

Takes a certain diligence when installing Italian threaded BBs, of course, but it's, it's still......


Italian, tho.

[Kontact]

Peter,

I have a few bikes with Italina threaded BB, can you explain what do you mean by installing with diligence? The usual steps done by good LBS to owns and use Campy tools?

BTW, Roland Della Santa explained to me why he uses Italian BB.

1. It is lighter than English BB shell.
2. It is easier to chase in his shop, no need to change the tool.
3. Della Santa is his last name.

Thanks,
Ron
My Campy English chasing tool has both sides - nothing to change there, either.

[ronlau]

Oh, sorry not being clear. What I mean is during manufacturing , you don't need to set up the left and right side for English BB thread. You need only one for Italian thread BB.

My Campy English chasing tool has both sides - nothing to change there, either.