jessec

I know I know, don't mix standards. Looking to see what my best option is:

I have an 80's Norco Avanti SL bike - came with 2-speed front crankset
It has a JIS 68x126mm BB (likely 68x127 standard with tolerances a bit off - I'm using a digital caliper to measure)

I also have a Campagnolo Veloce crankset I'd like to use. It's a 3 speed set
It has an ISO 68x110mm BB

I don't have Campy tools (nor does my local co-op) to install the BB, but it's also a much different size even if they did.

Is it safe to grind down the inner part of the crankset to fit JIS square taper? (likely not, I know).
Is it better to source an ISO square taper of the right size to fit the crankset?
Is it best to just use a different crankset?

Thanks!

C9H13N 

Will this fit your Veloce BB? It’s only $10.

https://www.competitivecyclist.com/p...ge-and-centaur

jessec

That is the tool needed - however, it's a bit more costly in Canada. Doesn't seem to be available with the supplier my co-op uses, and online with shipping it seems to be $30+ CAD.
Finding a BB to fit is usually around $15 CAD at the co-op, assuming one is available to fit this crankset and my frame, and installed using more common BB tools.

Also, it doesn't solve the length issue, as the BB I have is just 110mm and that could potentially pose issues with the frame.
I suppose I could test that by hand fitting the BB to see the frame clearance with it, and if it fits then I can source out that tool.

conspiratemus1

Try it and see. If the crank doesn’t bottom on the spindle, the cranks and inner chainring don’t hit the chainstays, and the front derailer can cope with the suboptimal chainline, you’re golden. You won’t damage anything because the taper angle is the same.
Don’t grind out the crank hole. You will ruin it even if it “works”.

dddd

With triples (and even with some doubles) I'm always trying to have the right arm as far inward as allowable (in terms of chainstay/chainring clearance and in terms of the front derailer retracting fully enough to effect the shift down to the smallest ring).

I would do as stated above and test-fit everything, actually torquing the arm onto the spindle and testing the front derailer under loaded downshift conditions as well.

With steel frames it's slightly less of an issue as the front derailer pulls in further due to the thinner seat tube.

JIS generally works if the effective length ends up positioning the right crankarm ends up in the right position relative to issues I mentioned in the first paragraph.

But JIS tapers have longer and narrower flats generally, with the square corners much more rounded off. This definitely creates a class-B fit especially as the engagement length is also about 2-3mm shorter (which implies that the actual JIS overall spindle length needs to be about 5mm shorter than ISO/Campy.
For a heavier rider and/or harder and/or higher-mileage use I would avoid mixing tapers. I have done it myself but with limited mileage and with me being ~ 150lb.

Take note of whether the110mm spindle you have ends up positioned symmetrically in the frame, since this will affect your selection of any other bottom bracket length, whether it's JIS or ISO.

The Veloce bottom bracket can be installed to a somewhat reduced cup torque using big adjustable pliers with a toe strap wrapped around the cup flange to prevent jaw marks. This might allow you to test-fit everything first before making any final bb and tool purchases.

fietsbob

ISO crank will bottom out on a JIS square taper spindle. .... effectively making is narrower too
the opposite; JIS arms on ISO spindle will only go on half way..


I have several <C> 'race triples' they have used a 111 length BB or 115 for oversize seat tube frames
Probably same as your Veloce
they had a higher range version that uses the same spline as their cassette lock ring..







..

dddd

You have it backwards fietsbob, it's the JIS arms that will typically bottom out on an iso spindle (I've ground such ISO spindles shorter to make this work).

ISO arms suffer limited engagement (and also suffer greater "camming" forces from the narrower flats) on a JIS spindle.

I was thinking the same thing that the OP's ISO spindle is probably 111mm.

I actually like the chainline from running Mity Tour cranks on a modern 111mm ISO spindle (instead of the original 114mm with it's driveside offset).
The better Campag bb's feature adjustable chainline for fine-tuning the chainline, and like you mentioned use the Campag cassette lockring tool instead of the "big flange" tool.

fietsbob

Taper 2 degree all ... wider at start & finish for Campag version

I like the 'big flange' one better because I put an O ring on the spindle then put the crank arm on. it's another sealing barrier...

dddd

What do you mean by wider?

I measure across flats, 1/8" inch from the end of the spindle.
Typical readings are 12.9mm for JIS, and 12.7mm for ISO. Old Campy about 12.78mm

jessec

Correct, the JIS spindle is wider at the base of the taper, therefore not allowing the Campy ISO arm to fully engage. My JIS arms have the bolts right on them, and I can't even get the non-drive side arm on enough to start threading the nut on the end.
Also, I believe the actual standard is 68x110.5, so 110/111 I would consider the same, depending which way you round

I tossed the bike aside and worked on a couple others today instead, so I have no update right now.

Another thing to toss in the mix for fitment is that I cold-set the rear to 135mm and put on a set of 700c wheels (8spd rear), so that will also affect chain line when I test fit the Campy BB.

I am building this to be a long distance rider, so I expect to put a lot of km on it. I'm about 190lbs, so I'll be looking at getting the right fitment so it doesn't cause issues down the road.

fietsbob

Phil Wood co offers 3 different spindle types

jessec

I probably should have included these to start..

Campagnolo BB


Obviously it's not in the BB so I'd consider it 68mm

110.5mm?

12.7mm

14.3mm? Might have measured too low on it, but gives an idea

And original BB:


68mm BB

Almost 126mm BB? Consider 127mm standard?

12.7mm

13.7mm

dddd

Just curious if anyone knows what particular model of Japanese bottom bracket is supposed to be "JIS low profile"(?).

Visually, the early Sugino Mighty i.e. Suntour Superbe taper looks and measures just like Campag ISO, but I can't remember any Japanese manufacturer ever referring to their bottom bracket standard as JIS low profile.

Shimano never seemed to give their tapers a name. Suntour offered Superbe and VX tapers while Sugino offered Mighty and Maxi tapers which were exactly the same as Suntour's.
Shimano's was JIS according to my measurements including the 74xx spindle I showed above.
Sugino Mity and Suntour Superbe tapers measure identically to ISO.
Sugino Maxy and Suntour VX measure identically to JIS and thus to JIS.

EDIT: Jessec, just seeing your last post right now! Your measurements seem to accurately jibe with what I would expect to see there!

I wouldn't consider the 14.XXmm measurement relevent however, unless measured from a comparable distance from the end of the spindle as on the one you are comparing it to. It looks like the cheap JIS bottom bracket shown has considerable driveside offset to produce that larger number but it is also being measured much further from the end of the spindle.

One interesting thing I've noticed is that of the very many often-cheap JIS bb spindles I have measured, ALL were still of very accurate width/thickness as compared to every other JIS spindle, so good QC there even on the cheapies.

Charles Wahl

I think that the above info from Phil Wood is misleading: seems to me that what they mean by "Campy/ISO" is really "NEWER Campy, which is the same as ISO". In the early '90s, Campy changed their square taper designs to be manufactured to the ISO standard, the one with the slimmest end of the JIS / OLD Campy / ISO spectrum. OLD Campy was slightly slimmer than JIS, as dddd says above. When I have corresponded with Phil Wood about which BB to buy for an OLD Campy crank, they said to use JIS. OP has an ISO Campy crank, so the "mis-fit" will be more severe (cranks will ride the spindle further outward, and the crank won't seat as fully on a JIS spindle than it would on an ISO spindle).

SurferRosa

I don't understand what the problem is. You have the necessary parts, but not the tool? Can't you find the tool on ebay? What about a new Token (or similar) ISO cartridge bottom bracket? I don't think there's any good reason to use a JIS spindle for that crankset. The pics show a super cheap bottom bracket and spindle. Now if it were an earlier, pre-'88 Campy crank, then you might want to try a good quality JIS spindle in the appropriate length.

merziac

You absolutely CAN mix and match, especially this far down the line where most cranks have been taken on and off a few times and have likely been installed on the other at some point.

I think they stretch into compliance and are none the worse for it even in the long run being as they are really not that different.

If it fits, chainline is ok and it doesn't bottom out, you should be fine

dddd

Yes and the OP lives in the PNW so would have no use for anything but a sealed bottom bracket.

I have to admit though that I've spent much time and made various compromises (related to front shifting and taper fit) so as to achieve a certain minimal chainline dimension. Oversized aluminum frames with a triple tend to be a chainline disaster imo.

jessec

I totally understand the Campy BB is sealed and better for me - the concern I have is down the line with replacement when it wears out. That's why I was curious about what option is best. I suppose most current BB's use ISO standard, and the Campy set would fit on it just fine, so ditching the original BB would suit me just fine. I just didn't want to get a $30 tool for one job and not have it be the best option long-term.

I have hand tightened the BB and torques on the drive side crank. Plenty of frame clearance (though as seen by the chain line, and hearing the rear derailleur struggle I wish it actually fit closer). I have a Deore XT rear derailleur, but it struggles to hold the high front/low rear combination, but for the most part all other combinations seem to be okay on a quick inspection.

More photos:


High front, low rear

Skipping here a bit with this combo

Low front, low rear

Low front, high rear

Frame clearance - yes that's painters tape

Frame clearance - yes that's painters tape

Overview shot

Rear derailleur

SurferRosa

Maybe if you ride in the rain. I live in Seattle and prefer the original loose ball bbs with their cranksets.

New cartridge bbs simply don't wear out. I use Token bbs for two of my pre-'88 Campy cranksets. I'll never need to replace them.

Most new square taper cartridge bbs are JIS.

I hear ya there. That's why I installed new Token bbs that use the Shimano standard tool (Park Tool BBT-32).

Measure the chainline with a metric ruler per Sheldon's recommendation.

jessec

I won't plan to, but I'm sure it'll happen once in awhile. This original BB is definitely still in great condition, I already re-greased it and had it ready for a new crank.
Good to know - I haven't worn out of any BB in a bike yet from my own riding (which is good), I've just had to replace a bunch from old bikes generally left outside and other such abuse.
Was trying to build this bike up inexpensively (bike was $50 off Kijiji, wheels were free, rear derailleur was $15 I think from co-op? Campy crank from co-op, got 3x8 brifters from co-op)
CRAP! Haha. See I like having stuff that's easily replaceable. I could have sworn otherwise but haven't done a lot with BB's to measure and tell, and can't recall packaging ever saying what it is.
To keep costs down, I try to get parts through the co-op. Shimano or VP BB's are generally what they carry
That will be next up - just wanted to toss a few quick photos up for a visual.

jessec

Road triple recommended 45mm..
Based on measurements and calculations (Sheldon's chart for cassette's/freewheel's):

Front - 44.24mm
Rear (because it's a SRAM 8spd freewheel) - 45.4mm

Also - I haven't put a new chain on yet, which I plan to do, as I've been swapping parts in and out and didn't want to keep breaking a new chain. I usually try to tune up on an old chain as best I can, then replace it just once and do any final small adjustments with the new chain. Perhaps a new chain (KMC 8 speed) would be more flexible and have less trouble. If I recall, this chain is still from the original 2x6 setup.

dddd

That's good chainline.
As far as the shifting noise, I'm like you and so often try to make everything first work with what's there, must be curiosity.
The shifting and noise issues will greatly resolve with modern chain I can assure you!

The Sedisport chain was the best in it's day, but that was just over 30 years ago! They do last a very long time for better and for worse.
I recommend KMC X-series chain as the best bang for the buck in this case.

Now to get those cups tight! How big are your pliers?

jessec

Yeah 1mm difference shouldn't be a big deal with the variation there is, especially since the front is already closer inside than what it should be, and it's that line that's causing me the most issue anyway.
I already have a KMC chain from the co-op as I knew I was going to replace it anyway - can't recall what series, but it should be ok
I snugged up the non-drive side with tongue and groove pliers and a rag, but will need the tool to tighten up both sides. Have put out a call locally if anyone has one to borrow or sell me

Appreciate the guidance, everyone!
One step closer to getting this thing going... should be able to keep total cost under $200 CAD total for it, too