FidelCastrovich

So i finally got my new wheels - Mavic A319/Deore hubs. Nothin fancy, but definitely inspires more confidence than the wheels that are now in the garbage.

The old wheels had a threaded cogset (freewheel?freehub?) and the Deore hubs take a regular cassette - so that had to be swapped. Along went the chain - replaced.
Now, whenever i apply above average pressure to the pedals, the chain jumps, skips a few teeth, makes a horrible grinding sound, i get a jolt in my groin, and then all is well again.
The bike-mech said that it's the crank - old and worn out. It actually has only 5K km on it, but it's a cheap Suntour, so maybe that's all you get out of them.

So now i'm facing a dilemma - look for a Sugino or Suntour square taper compatible crankset on EBAY or the like; or get a modern Deore/lx crankset and replace the BB to the Octalink standard, as well.

What do you guys think? I like the simplicity of the square taper and don't buy the manufacturers' marketing cr@p about ISIS/Octalink/whatever, but it's becoming more and more difficult to find Sq/T BBs.

Factors important to me - maintenance and prevalence, reliability, cost(don't wanna replace the almost new BB), 26-36-46/48 chainrings.

Thoughts and suggestions, as well as meaningless rambling are welcome.

truman

I replace splined cranks when they wear out with square taper.

cmarkey

https://aebike.com/page.cfm?PageID=30...ils&sku=CR1032
Sugino XD300 170mm 26-36-46 74/110 7/8spd - $45

This is a square tapered crankset, and the rings are steel, which is good if you want longer lasting chainrings, bad if you want to save a few oz. They also have the XD500 & XD600.

I haven't put mine on my bike yet, but they come highly recommended.

colin

EmmCeeBee

It's hard to imagine a crankset (i.e., the chainrings) wearing out in just 5km. Suntour used to make stuff that lasted forever (thereby driving themselves out of business). Sure, they probably made a few cheap parts, but then so did everybody else...

If the chainrings are worn, and are riveted onto the crankarms -- the sign of a cheap crankset -- then you have to replace the whole crankset. If they're bolt-on, the solution is to buy new chainrings; smart shoppers can find these less than $20 each.

Do you trust your shop? It sounds like worn chainrings (but I doubt the "5km" comment). But it might be misaligned derailleurs, a sticky link on the chain, or something else in the drivetrain.

Square taper is my preference. I'd stick with the BB.

-- Mark

FidelCastrovich

I meant 5K km, of course. Over the course of a year, day in, day out commuting.

Why do you prefer square taper?Reluctance to succumb to the marketing efforts of Shimano&Co, or because of an inherent virtue of the older system?

NoReg

I agree with the coment that you should look at other problems first. The simplest one is to check link by link your chain. YOu will quite likely find a few links that don't flex possibly. This could probably be fixed, but if your chain is also 5000 K old, then I would replace it. You can also check for crud that is making the pulley assembly unresponsive.

Tourists seem to prefer square taper because it is easier to find in bikeforsaken regions of the world. I have always used square taper sothat's all I know. And what has happened to me with every new unit is an anoying crunching sound with every circle of the pedals after about 500 miles. Remove, re-grease, replace with a serious wrench, and that's the end of that. But it is quite annoying with a new bike since the 500K may hit on your trip. If you are comuting this thing you should be able to work it in.

The other thing where square taper is questionable is for bikes that need the cranks removed to fit them in a case. Maybe if you have S&S couplings on a a large touring bike that needs to go into some samsonite, then you have the crank removal issue. I don't know what is better...

Another thing about square taper, is that nobody makes a touring groupo. So often you are getting either mountain cranks of maybe cross type cranks when you buy anythign new. These can all be made to work, but the XDs are perfact as is, and they run on square, and by the way there are some great square bbs like the Phil for those who want that kind of thing.

EmmCeeBee

"Yes", and "Yes". It's very likely that splined BBs in theory represent improved technology ("increased contact surface", etc.).... but in practice, I'm not sure. There are half a dozen designs, and the early ones failed. The marketing hype is confusing -- I see no reason to go with proprietary (Shimano) drives, and ISIS (open standard) drives have some documented shortcomings. For some reason, splined BBs and cranks cost at least twice as much as square taper, for comparable quality. In my opinion, the Sugino XD300/XD600 crankset is the perfect choice for touring, and it's a reasonable $45 (XD300).

See: https://en.wikipedia.org/wiki/Bottom_bracket
It's a long article, read the section on "Interface Types".

Square taper has to be assembled and tightened properly, but this is no big deal. If you're a big, heavy rider and mash the pedals, you might see eventual problems. But not in my experience.

Biggest factor for you is: if your BB is in good shape, why toss it? If you were buying a new BB/crank, possibly the biggest drawback with square taper is that it will be getting scarcer in the years to come. If this concerns you now, just buy new chainrings; next time you have to buy BB/crank, get ISIS. But not now, you've got a good BB.

Peterpan is right, with splined BBs, it's much much easier to remove the cranks. But with square taper, five minutes with the right tool never fails.

-- Mark

tacomee

Shimano still makes more square taper cranks than any other kind (Alivio and Nexave cranks are still square), so there is no worry about running out of square taper BBs. Alivio cranksets are pretty good quality, BTW. They look like the old Deore ones before the change over to Octalink.

vik 

My Sherpa came with a square taper BB so I went down to my LBS and bought a deore square taper crank for $50. Works great and as has been mentioned most of the world is using square taper BBs so parts will be around for a while. I don't know about Octalink, but ISIS BBs have smaller bearings to accommodate the larger diameter spindle and apparently they don't last as long as older style BBs.

GeoKrpan

I do remember at the advent of splined that creaking bottom brackets became much less common.
These days the problem with square taper cranks is that there's not much of a selection.
For example, Nashbar offers no square taper road cranks and only two square taper mountain cranks.
Square taper cranks now inhabit the low end so if you want a "nice" crank you'll have to go splined or integrated. Even the Nashbar Trekking and Compact Road cranks at $69.95 are splined.
At Nashbar the lowest priced Shimano BB's are the square taper UN53 at $19.95 and the splined ES71 at $33.25 so there's not much price difference.
Looking at cranks and BB's on Nashbar I noticed that replacement integrated cups cost less than BB's and that LX cranks are now integrated.