mcours2006

I'm planning to swap out a few components on my 1990's Bianchi Advantage, one which is the crankset. I was told my only option was a square taper one because of its age. Is this the case? Looking at some of the BB available, it seems to me that if I have the right BB shell width and thread I should be able to use an Octalink or Hollowtech?

Please help.

Thanks.

CliffordK

If you replace the bottom bracket, you can get any crank. Although, I think Shimano is moving away from Road Octalink (still supports MTBs).

Your Hybrid may take the MTB parts anywy. Do you have 135mm rear dropouts?

mcours2006

It's a 130mm OLD.

I am planning to replace the BB. What's on it right now is a square taper.

mcours2006

I should mention that I'm planning to put road components on the bike, converting it to a cross bike.

nfmisso

Pick the crankset, then a compatible BB.

HillRider

Given a threaded bottom bracket, most likely English by the 1990's even on a Bianchi, you have a huge choice of bottom brackets and cranks. Almost any square taper, Octalink or Hollowtech II can be used. Square tapers are limited and Octalink is no longer well supported so HTII is the logical choice. Pick a crank you like and then the bottom bracket to match.

mcours2006

Thanks for that. This is a relief for me because choices for square taper (as you pointed out) are very limited indeed.

D1andonlyDman

No, they're really not limited, unless you need 11 speed gearing - which is pretty unlikely for a 1990s bike such as the OPs. There are TONS of square taper triple and double cranks that are optimized for 9-speed gearing and which will work fine with 10 speed gearing. And most of them are available really inexpensively. You can easily find square taper Campy double or race triple cranks for under $120 new, and under $100 clean used, and there are any number of compact cranksets available for much less. The fact that they are older product does not mean they are not very easily found. One can go on ebay and find literally dozens of square taper cranksets, including numerous triples. Maybe they're limited at your LBS, but there are tons of them out there.

dabac

Unless I absolutely HAD TO, I wouldn't replace a functioning square-taper BB/crankset with Octalink or Hollowtech even if I was given the parts. There's just not enough of an improvement, and often durability will become worse.

bikemig 

Square taper is a fine design and there are good choices out there for an older bike. I'd certainly stay away from octalink.

mcours2006

I should have clarify my statement about availability of square taper cranks. I am only looking at the local used market, and here it is limited. There are a lot more HTII and Octalinks.

Currently the bike has a triple--48-38,..and I didn't bother to count the last. Triples are less abundant than doubles. My initial question was just to clarify whether or not I can expand my choices outside the square taper ones.

I already have 2/3x8 Sora shifters, so the only choice is whether I run a double or triple up front.

CafeVelo

As stated the used market (eBay for sure) is saturated with square taper cranks of all types. You can even get campy carbon in ST, and for a rather doable price. There's not much to be gained from a different BB type but weight savings, provided your cranks are good quality. I built my salsa with an older shimano crankset because I had it available and the silver color looks proper on a steel bike. It weighs more than the carbon crank on my go fast bike, but doesn't feel detrimentally softer. Do some looking, or hit up a well established LBS that's likely to have a bin of take off parts.

fietsbob

ROC China sourced Bianchis use British thread BB's.

mcours2006

You're right about eBay. I haven't had very good experience with eBay with the last couple of parts I purchased from there, so this time I'm just sticking with local stuff that I can pick up.

rmfnla

I practically built my Curtlo up off of ebay; can't beat the selection.

Look for NOS and remember that eBay guarantees everything; your biggest problem will be making up your mind...

Mr IGH

Lots of nice Hollowtech Tiagra for cheap on ebay, that's what I put on my 1978 frame. Square taper sucks to set up, Hollowtech is a breeze, never going back.

mcours2006

You're right about Tiagra cranks on eBay. I just did a quick search. I was looking for Sora cranks, just because I have a set of 8-sp Sora shifters.

Here's another questions: Can I use cranks labelled 9-speed (or even 10-sp) with an 8-speed cassette? Or would the chain be too wide for the crank, and thus premature chain wear?

edit:
Seems Sora cranks are more expensive than the Tiagras. Curious.

D1andonlyDman

Short answer - yes for a 9 speed crank. It's a little dicier with a 10 speed crank. In fact, i've actually found that 8 speed chains work very well in a 9 speed drivetrain overall, and I would recommend using an 8 speed chain with your 8 speed cassette if you choose to get a 9 speed crank, although 9 speed chains will also work fine.

HillRider

Actually, if you buy a 10-speed crank and want to use the "correct" chain, a 10-speed chain works just fine with an 8-speed cassette. My Surly Pacer beater/rain bike has a 10-speed HTII Tiagra triple crank and bottom bracket and a 10-speed Shimano CN-5600 chain with an 8-speed 13x26 Shimano cassette and an 8-speed indexed Shimano downtube shifter (on a Retroshift brake lever). It works very well and shifting is flawless.

Camilo

I wonder why the criticism of Octalink? I've only owned one, a 9 speed Ultegra triple, but it's worked perfectly for, I think 12 years. Easy to install, easy to remove. Durable. Looks good.

Frankly, I kind of dislike the HollowtechII cranks. I think the non-drive side is ugly and clunky looking, and fussier to install than Octalink. It's not that I actually dislike it, or that looks are the most important thing, but it's just not my favorite.

I recently bought a used Campy Ultra Torque crank and really like the ease of installation (and subsequent removal) and it looks much better - to me - than a HTII crank.

DMF 

I agree. If you don't screw up the spline fit, Octalink rocks. A little heavier, but very durable.

Camilo

My experience is similar. I've used 9 speed chains with 8,9 and 10 speed cranks and 8 and 9 speed cassettes. 8 speed crank-9 speed chain-9 speed cassette. 10 speed crank-9 speed chain-9 speed cassette. 10 speed crank-9 speed chain-8 speed cassette. And of course 9 speed crank-9 speed chain-9 speed cassette. On my 10 speed cassette, I only use 10 speed chain. But I'd also not hesitate to use a 10 speed chain on any of the above if I needed to (now that I think of it, I might be doing that right now.... I'll have to check.

They all shift fine. I think the rule of thumb is that any "higher" chain will work with any "lower" cassette, but not vice versa. The cassette spacing is set according to the width of the chain and a "lower" chain will be too thick and there won't be enough clearance between the sprockets. The inner spacing on all chains is the same, it's just the plate thickness - and therefore overall thickness - that gets thinner as you go up in "speeds". I don't think the cranks care at all about chains, or at least don't care within a generation (i.e. one up or down). The chainwheels don't care because all they feel is the inner width of the chain. Front shifting isn't as precise as rear shifting and therefore the overall width of the chain isn't as important.

Anyway, that's how I look at it.

D1andonlyDman

Except that 8-speed chains work fine on 9 speed cassettes and chainrings, plus, they are cheaper, and they last longer than narrower chains, and my experience is, they shift at least as well as 9 speed or 10 speed chains do on 9 speed drivetrains. And if your chain is TOO much narrower than the gears it is supporting, it brings up another set of problems. In particular, it becomes especially problematic to shift a narrow chain on a triple - as it can drop between the chainrings rather than on them. This isn't an issue with a 10 speed chain on a 9 speed crank, but it can be on an 8 speed crank, and is DEFINITELY an issue with older cranks having 6-7 speed spacing.

rmfnla

Best thing about square taper BBs is they usually have non-cartridge bearings that can be easily serviced.

Still, proper set-up is essential for any system...

Dfrost 

Huh? Shimano UN-55 BB's in a wide variety of lengths are available for less than $25.