Point

Well, a 7 year old crankset now has the value of a case of crushed PBR cans. The press fit steel spindle and aluminum spider interface started giving way, and now I can't trust it anymore for fear of total failure on the road. I'm peeved, since compared to all other cranks and bottom brackets I have (all square taper), none have ever let me down, and are still going strong. Who came up with this design "improvement"? Sure the BB can be installed quicker by some machine or unskilled person, but aside from that, where's any advantage?

So much for complaining - any opinions on keeping the triple or going compact double for the replacement?

justkeepedaling

Which crankset?

stilltooslow

When well designed and manufactured, it's both lighter and stiffer, the elusive formula all cycling component developers seek. Some are certainly built better than others though.

jolly_ross

Quick installation means cheaper build cost, means cheaper price, means more sales. The manufacturers don't necessarily share your passion for long lived equipment. Turnover means profit.

---

Re road triple or compact, there is a cheaper way. I do this because I go on one or two euro-mountain-pass cycling weekends per year - but spend most of the time in flatter regions near home.

Get a mountain bike cassette (I use a 32t lower), a longer chain to go with it and long cage derailleur. I keep the 3 of them together - switching the set over for climbing holidays. It's not as low geared perhaps but it sees me up big hills often with a gear or two to spare.

waters60

The opposite of your BB is my 20 year old sealed bearing Campy BB that came with my Merckx. Many thousands of miles and it has been flawless. I talk to friends about newer ceramic Campy BB's that cannot tolerate dirt?! Utter failure of utility. All of my '92 Chorus parts have been worthy heirs to the Nuovo Record groups I rode before. Makes me afraid to buy newer stuff.

merlinextraligh

Like there were never any problems with Square taper cranks. Aluminum crank arms will fail over time where the arm attaches to the steel spindle, with the hole in the crank arm enlarging, particularly if the crank is ridden with the fixing bolt just a bit loose.

Old square taper internal BB's had an advantage with friction, over modern external sealed bearing bb's, but I don't think many people would maintain that square taper is a superior interface for attaching a crank arm to a bb spindle.

Point

I'm in total agreement. I've got a 30 year old Tange cup and cone BB that still runs fine - just maintain it. 25 year old square taper (don't know the brand) on an old Trek - still no problems. To have a crank break, and the shops just say I should be happy to have gotten 7 years? As for any improvement, the only advantage is to the maker, not the customer

JohnDThompson 

Point taken, but it does seem that modern equipment is not designed for longevity.

(still using my 30+ year old equipment here)

Point

Lighter? A Shimano 600 crank from 20 years ago weighs about 600 grams - add in 300 grams for a square taper BB and the weight isn't that far off a modern crank - a new Ultegra double and BB combo weighs 960 grams. As for stiffer, the small amount of torsional bending in the spindle isn't worth mentioning, and the external cups don't do a thing for lateral deflection anyway.

Point

Any modern crank will fail on the non-drive side if the fixing bolt or clamp bolt is loose - really no difference from riding a square taper loose. Proper maintenance.

rpenmanparker 

OP, the failure of your embodiment of the BB model after seven years does not discredit the part in any way. It is the same as saying you drank a quart of whiskey twice a day and lived to be 110 or you never ate a gram of fat and died of a heart attack at 25 years old. So what. Is that the mean result expected? I don't think so. Unless you know the average usable lifetime of the particular part and its comparable competition (earlier, later, contemporary) and their standard deviations, you cannot derive any conclusion about its design integrity or manufacturing quality. Blow off steam if you must, but know it is just anecdote, among the least reliable of all data types.

In a broader sense the preoccupation of many on this forum with eternal longevity of their bicycles is ludicrous as is taking the failure of a bike part or wheel or frame as a personal affront. Everything wears out, some things sooner, some later. Some newer bicycle and bike parts designs emphasize other attributes like weight, aerodynamics, stiffness, etc. at the expense of longevity. That may or may not be what you want, but it is certainly neither evil nor a conspiracy against you and all other right thinking consumers. If you really think you will be happier with an obsolete square taper BB and compatible crank that you haven't already owned for 25 years or so, just go for it. I'm sure you will be able to find one somewhere. Personally I'm happy to have the modern developments. If some designs don't work out as I expect they should, well...(shrug)...that's life. As a good friend of mine says, "Hey, it ain't a kidney."

rpenmanparker 

Your facts are wrong. The 6800 Ultegra double crank weighs 668g without BB cups and bearings. They weigh 76 g. Total 744g or 1/3 lb less than the old crank you reference. If you switch to SRAM Red with oversize spindle, the total has been shaved at least another 100g or more. Advances have been made, albeit with some compromises. Way of the world.

justkeepedaling

New Ultegra double and bb 960 grams? Um no. Try a couple hundred less than that

qqy

The larger spindle DOES make a substantial difference in stiffness, and makes installation much easier. As does the wider bearing stance. Then again I have snapped a couple cartridge BB spindles, so maybe I'm a freak. I would suspect that the larger external cup BB bearings would last longer, but haven't seen data to back that up. I will say that it's silly you can't service external BBs more easily, and that OEMs advocate that you toss them if there's a problem.

waters60

It is not that I obsess over the longevity of my bike. I just marvel over it and love the idea that in today's world of expendable consumer goods I own something that has lasted so long and performed so well. Sooner or later I will need to buy a new bike. It will be interesting to see if I get 20+ years out of it.

merlinextraligh

Difference is that square taper BB's are much more prone to coming loose. The reason octalink was developed, and now 2 piece cranksets was that the square taper interface isn't as good at holding a crankset together.

Campag4life

+1
Back on track. Agree with Merlin again.
Square taper in my opinion is pretty flawed. But BB30 which I believe you will see evolve toward PF30 with collet BB in the next five years...former is flawed as well. I believe sweet spot still is threaded BB with external bearing crank aka DuraAce or Campy Record UT. Pick one.

Campag4life

Exactly. Octalink which was a stepping stone to 2 piece outboard bearing cranks offered greater surface area interface for more robust crank arm/spider attachment compared to square taper. It can still be argued what is better today...Shimano's dual pinch bolt crank arm attachment which is excellent versus more common industry splined hard shoulder end bolt attachment which is solid as well. Thankfully square taper is gone. A hard shoulder is much more secure than a tapered square or spline which even changes chainline and Q-factor due to mating spline tolerance stack up.

pallen

Its pretty simple - we've traded some longevity for lighter weight. If you prefer the old school, really long lasting stuff, its still out there.
https://store.velo-orange.com/index.p...cranksets.html

stilltooslow

And that product is actually out there, manufactured by Praxis. Beautifully made, it provided for a superb, bombproof fit of my DA crank into my PF30 frame. I generally have disdain for press fit anything.

waters60

Interesting. They need to work on the finishing a little. Self extractors are a pet peeve of mine. Great concept for a problem that did not exist. Crank arm extractors are a great tool and one of the more satisfying ones to use, especially when you feel the crank arm release from the spindle. With self extracting bolts, it asks too much of the hex wrench to loosen a tight bolt. Most of the time they work, but if they don't it can get ugly.

Campag4life

Well then you have disdain for most machine assemblies out there because most use press aka interference fits throughout. They do have their place and without them, we would have many gas engines on the planet.

But you are quite right and Praxis is what I was referring to implicitly in my post. I believe their BB is the future. BB30 is needless and costly to manufacture due to insert molding and/or finishing machining of cup bores. PF30 is a single molded in 46.0mm hole. Shift the complexity to the BB...which isn't much complexity by comparison. The Praxis BB is simple, effective and elegant and more importantly unlike BB30...non invasive. What I meant by the next 5 years is...a collet BB will be much more the norm and likely adopted by OE bike companies and not just the aftermarket...provided they can work around the patent infringement.

stilltooslow

Yeah, I know that, but I was really referring to their use on bikes. Even there, they do work pretty well in some places such as sealed bearing hubs. But for an old 'ball and cone' guy like myself, there's nothing like threads to give one confidence in a stable, creak-free fit.