FE11244

Hi,

Wondering if you can help me out with this problem.

I have a mid '80s steel frame Bianchi, Italian made. I took it to my LBS to have a compact chainset fitted because I need the lower gearing. The mechanic said this was fine and sent off for the parts, a Shimano Claris 8 speed chainset and the appropriate bottom bracket (I don't know which one).

Several days later I received a call from the shop telling me that they were unable to fit the chainset because the bottom bracket was incompatible with the frame (and that others had been tried). More precisely, I was told that the external type bottom bracket required for the chainset would not fit the frame and, further, that the only kind of bottom bracket which would fit is an apparently no longer produced Italian threaded internal type square taper bottom bracket (And by implication that the current bottom bracket is incompatible with new cranks). So, the upshot of all this is - no new chainset, and I was told there is effectively no way to change the current chainset to a modern one of any kind.

Now, I should say that the mechanic is great in my experience, one of the most helpful people I've come across and always does a through job.

But... Is this correct? I thought it was common practice to upgrade parts in this fashion. It seems odd to me that there is no option to upgrade. Unfortunately I don't know enough to figure this out on my own. Is therea reason why I shouldn't be able to get a new chainset on an '80s Italian bike?

Thanks for your help

andr0id

A frame of that vintage should have a very standard Italian threaded BB shell. If you measure it, it should be 70mm wide.

You should get more details about what he thinks won't work.

Perhaps the Claris BB is only available in English, but you should be able to use the BB shown below with any hollowtech II crank.

OK, I see Claris is not HTII. Get a HTII crank so you can use the Italian BB. 105 should work.

Shimano Ultegra 6800 SM-BBR60 Bottom Bracket | Competitive Cyclist

FBinNY 

I haven't checked (and won't) but expect that there should be some 36x24 (Italian) external BB available from someone, but maybe not.

However all isn't lost, worst case scenario, you can buy 110BCD mtn cranks, and set them up as doubles with the rings of your choice. Use of mtn cranks is very common on road bikes, especially bikes set up as touring bikes. There are still Sq. taper cranks and BBs available if you can't find an external with Italian thread.

veggie

Doesn't Claris use standard road octalink? if so, a used 105/ultegra bb can be found and used.

skimaxpower

It should be easy enough to find a square-taper bottom bracket. Velo-Orange makes a high quality one for a fair price.

You might have to broaden your horizon with regard to the crankset (chainset) you select, and get one that is square-tapered (rather than hollowtech, for example.)

FE11244

Thanks for the suggestions. The mechanic mentioned something about the octalink system needed for the Claris, his point seemed to be that it is just incompatible with the frame and will not fit, though I have seen that Italian threaded octalink bbs are available. What confuses me the most about this is the fact that he had seen the bike then sent off for the parts, I would've thought that he could have said without trying to fit the parts that there would be an issue.

FE11244

This is what I thought - about choosing another crankset- And why I was surprised when he said that there was no option whatsoever. I'm still confused however (since I'm a total novice with this) what difference the square taper makes as to whether the bb fits inside the bb shell. Also there is already a square taper bb on my bike, but, as I say the mechanic made no mention of a compatible and modern crankset.

FastJake

The main thing you need to realize is that the mechanic screwed up. And he's blaming it on the frame/parts. You can still get Italian thread square taper bottom brackets and run a compact crank that way. You can still get Italian thread Octalink bottom brackets and run your Claris crank. You can even go all the way to the newest HollowTech II design and get Italian thread bottom brackets for that. You can use literally any bottom bracket design you want.

Find a new mechanic, hopefully one that is at least somewhat competent. When replacing a bottom bracket on a bike the FIRST thing to do is determine the threading. Not after the parts are ordered and when trying to install them, "uhh.... this doesn't fit."

I hope they aren't making you pay for the wrong parts they ordered...

HillRider

The Sora FC-3550 is a compact Hollowtech II crank and is the least expensive of it's type. It works with any of the Hollowtech II external bearing bottom brackets and some models are available in Italian threading. The Sora is a "9-speed" crank so it should work ok with the rest your current drivetrain even if it's 7 or 8-speed. The Tiagra 4650 is also a compact HTII crank but is "10-speed" and my require a 10-speed chain to work properly.

Edit: OK a little more searching discovered that the Claris cranks use a V-2 Octalink and, since these were intended for MTB use, I don't think they were ever made in Italian threading so that may be what your mechanic missed. The V-1 (road) Octalinks did indeed come in an Italian threaded version but that won't do you any good. Square taper, V-1 Octalink and HTII bottom brackets are indeed, as FastJake noted, all around in Italian threaded versions.

FBinNY 

I suspect that the mechanic was either inexperienced, unfamiliar with stuff older than 5 years or so, or wasn't wearing his thinking cap.

There are Iralian BBs out there, and there are compact (or mtn) cranks that fit them. It's just a matter of finding one of each that matches.

andr0id

The only reason I can think that it wouldn't fit would be that the down tube or seat tube extend into the BB shell and interfere with a cartridge style BB. Frame builders could be a bit sloppier with clean up when the only spindle type was a square taper.

If that's the case, an external bearing style BB should work since they use about the same amount of threads as a cup.

FE11244

This is what I was afraid of, not least because he's the only mechanic for miles but also because he's always seemed to be really good.

No, I didn't have to pay for the parts thankfully.

I'm sure he knew the threading on the bike is Italian. It's mystified me.

FE11244

I did wonder if the problem might be something particular to that frame. If so and the mechanic knew, he didn't explain it very well.

HillRider

As I reported above, I believe the problem was with the Claris crank requiring a V2 Octalink and these were never made in Italian threading.

FE11244

Thanks, I think this is the information I need to specifically bring up with the mechanic. So the options (if I've got this straight) are: Get a new square taper crank to work with existing bb. Get a new square taper bb and crank. Get a v-1 Octalink bb and compatible crank (NOT claris). Get a HTII bb and compatible crank like the Sora FC-3550.

Thanks for the help, this is the kind of info I was looking for. The only option it seemed I had before now was getting rid of the bike.

himespau 

That's surprising to me that it was never made for italian threading.

fietsbob

Need a different source of a JIS square taper BB if at Claris' Price Point Its only made in British/ Asian Standard

Above is Hollow tech external BB, not square taper ..

An Italian crank , ISO square taper would have more likelihood to be offered in Italian thread Older Campag race triple in my Pinarello.

I have an extra Italian thread 115 <C> ISO taper BB (bought because seller guessed wrong, then I got the 111 instead..)

FastJake

A quick ebay search reveals this Octalink V2 Italian thread BB for sale: Shimano BB ES25 Octalink V 2 Bike Bottom Bracket 70mm Italian Threaded | eBay

So assuming the OP could find the spindle length he wants, I think it's possible to use his V2 Claris crank with the bike. But I should note that I've never used Octalink so I'm not too familiar with it. Skipped right from square taper to HollowTech II...

headloss 

Octalink v1 is no longer made, so scratch that off your list. You can still buy a crank/bb but they are getting more difficult to find.

Beyond that, ask around, maybe a friend has some spare parts. I know lots of guys that pull off a Claris level crank as soon as they buy a new bike...

What type of riding do you do? If you are running a triple, stick with square taper (there are more available parts). If you are running a double, you might as well just go HT2... FSA is compatible, fwiw.

FE11244

I have one more question: The cheapest option would seem to be to stick with the square taper bb that is on the bike and get a square taper crankset. Is it as simple as that? Or are there compatibility issues with square taper cranks and square taper bbs? The cranks that are coming off the bike are Ofmega.

Thanks

Edit

It seems there are compatibility issues, between ISO and JIS. So likely the best option is new bb and chainset.

FBinNY 

Not overly surprising if it came out after the Italian OEMs adopted ISO BB threads. Without an OEM request, they wouldn't tool up to make it in Italian.

Just about every main street component is driven by OEM sales. Years ago companies would list selections or variants of many items on their commercial spec sheets. I'd place orders for small numbers to broaden the offerings or fill niche needs, and the response would be that they don't actually have it, but could make it if asked. "Could make it if asked" means if an OEM asked for 10,000 or something on that order.

CliffordK

Campagnolo bottom brackets were different from most of the Asian bottom brackets. It should still work with most Campy square taper cranks.

This appears to be a SRAM 24mm Italian BB.
SRAM GXP Team Bottom Bracket | Backcountry.com
SRAM GXP Team Bottom Bracket | Competitive Cyclist

Although I think SRAM cranks may be slightly different than other brands.

It sounds to me like your mechanic/LBS is not wanting to help you get the right parts.... or you are too cheap to buy through the LBS.

shelbyfv

Stronglight Impact JIS Compact Chainset Road, Chainsets, CHAINSETS ROAD This seems like a nice option.

himespau 

I've often thought those Stronglight Impacts are attractive (if you believe the rumors, they're made by Sugino), but that would require also buying a new BB. Probably. I mean JIS cranks can go on ISO BB spindles, but the mating is in't consistent through the crank due to differences in taper and can lead to widening of the crank hole.

HillRider

OK, the V2 Octalink was used for early 8-speed Sora and Tiagra road cranks so I suppose that's why there were a few made in Italian threading. They were not common.