Australian Cycling Forums - Bicycles Network Australia

I found it interesting that while some of the Shimano road cranksets have Al spindles, the M770 XT MTB cranks are steel. So I just replaced my 105 5650 compact road crankset with 5750 to find they are now using steel spindles in these too. Maybe they had a few more failures in Al than they thought they would and so went to steel. Good for me as I'm happier to keep these a bit longer and just replace the chainrings next time.

As suspected, the reason is long-term durability.

Shimano USA’s vice president, Wayne Stetina, has a different take on things: “The BB30 is an optimized design for an aluminum spindle, and 24mm diameter is the optimized size for a steel spindle. But, after five to 10 years, an aluminum spindle will eventually fail. Neither of the designs are the ultimate.”

http://www.roadbikeaction.com/Most-Popu ... kdown.html

Nobody wrote:

"Neither of the designs are the ultimate."

Which is why they should go back to the square taper. It is a design which proved itself for decades.

So many bottom bracket systems, till they settle down I'll stick with threaded external cups. I think FSA's suggestion that the 24mm spindle will go away from high end bikes will not come true, but time will tell.

rkelsen wrote:

Nobody wrote:

"Neither of the designs are the ultimate."

Which is why they should go back to the square taper. It is a design which proved itself for decades.

+1, i love square taper. Especially with a seperate axle BB, very easy to service.

Unfortunately it's not about the 'best'. New 'standards' are often created to increase profitability (e.g. Tapered steerers and 1.5 inch headset bearings) rather than building a better bike. If enough manufacturers move together they can act like a cartel anyway.

Having said that I doubt Shimano's claim that 'all aluminum 30 mm spindles will fail in five years'.

__PG__ wrote:Having said that I doubt Shimano's claim that 'all aluminum 30 mm spindles will fail in five years'.

He said, "But, after five to 10 years, an aluminum spindle will eventually fail."

Nobody wrote:

__PG__ wrote:Having said that I doubt Shimano's claim that 'all aluminum 30 mm spindles will fail in five years'.

He said, "But, after five to 10 years, an aluminum spindle will eventually fail."

and how many of us would use a spindle for that long anyway?

jasonc wrote:and how many of us would use a spindle for that long anyway?

I have. However, on average, the kind of person to buy a 30mm spindle is unlikely to keep their bike that long. The secondhand buyer just needs to be aware that Al crank spindles have a fatigue life.

jasonc wrote:and how many of us would use a spindle for that long anyway?

Never mind the spindle - the entire square-taper cartridge bearing set has been in my son's bike since 1995. Originally my bike, it's done plenty of kilometres too.

Nobody wrote:I found it interesting that while some of the Shimano road cranksets have Al spindles,

Have shimano (or anyone?) ever produced a production alloy 24mm BB spindle? I thought 24mm has always been steel?

ozdavo wrote:

Nobody wrote:I found it interesting that while some of the Shimano road cranksets have Al spindles,

Have shimano (or anyone?) ever produced a production alloy 24mm BB spindle? I thought 24mm has always been steel?

As per original post, my 5650 105 (2010?) cranks were alloy spindle. Also the Tiagra 4500 pictured below.

Has there been a reported flood of BB30 cranksets that have failed in the past few years?

I can't see how SRAM, FSA, Cannondale etc would send critical components off to market with a five year fatigue design life. In any case, it's the mileage that matters. Maybe a BB30 spindle will fail after 100,000 km or so.

But if BB30 spindles were as fragile as the Shimano rep suggested you'd have epidemics of amateur racers with broken cranksets.

I think the Shimano rep is just using a scare tactic to talk down the opposition.

There looks to be a fair thickness of metal on that tiagra crankset.

Seems unlikely to fail to me especially with the limited power I am able to generate

__PG__ wrote:I can't see how SRAM, FSA, Cannondale etc would send critical components off to market with a five year fatigue design life. In any case, it's the mileage that matters. Maybe a BB30 spindle will fail after 100,000 km or so.

Probably right about being about Kms and not time.

__PG__ wrote:But if BB30 spindles were as fragile as the Shimano rep suggested you'd have epidemics of amateur racers with broken cranksets.

Even steel can break if the bearing seizes.
http://www.bicycles.net.au/forums/viewt ... 34&t=40469

Have BB30 been popular for 10 years yet?

__PG__ wrote:I think the Shimano rep is just using a scare tactic to talk down the opposition.

The fact they changed from Al to steel for spindles says a lot in itself.

warthog1 wrote:There looks to be a fair thickness of metal on that tiagra crankset.

Nobody wrote:The fact they changed from Al to steel for spindles says a lot in itself.

But that was for 24 mm diameter spindles, not 30 mm.

__PG__ wrote:But that was for 24 mm diameter spindles, not 30 mm.

True. Like most things, the truth will come out eventually.

Bikes are like R/C cars. They change things and make them incompatible with old things to keep the market turning over.

If we're lucky, the change might even bring an improvement occasionally.

trailgumby wrote:Bikes are like R/C cars. They change things and make them incompatible with old things to keep the market turning over.

If we're lucky, the change might even bring an improvement occasionally.

I'll go with that too, b@stards

The amount of different bb designs is starting to get/has gotten a bit over the top now

Nobody wrote:

warthog1 wrote:There looks to be a fair thickness of metal on that tiagra crankset.

That would have to be pretty hard to break with the power the average punter puts out wouldn't it?

Wear on the surface where the bearings contact would be more likely to see it out IMHO.

warthog1 wrote:That would have to be pretty hard to break with the power the average punter puts out wouldn't it?

Since some on these forums have broken crank arms, nothing surprises me. Shimano must have had a reason to change. If I remember correctly doubles came with steel and compacts came with the alloy spindle. Maybe they thought compact users were soft and won't use their cranksets as much. Maybe they were proven wrong...

trailgumby wrote:Bikes are like R/C cars. They change things and make them incompatible with old things to keep the market turning over.

If we're lucky, the change might even bring an improvement occasionally.

Agree. Some of the changes I've appreciated over the last 20 years or so (in no particular order):
1 1/8" Aheadset (threadless).
Stems face-plates that unbolt so you can remove the handlebar easily.
Double walled rims.
Disc brakes.
Two bolt seatpost saddle rail clamps.
Seatpost clamps that are not part of the frame.
Dual clamp seatpost clamps (different size for frame and post).
STI/Ergo (although I still don't have them).
Wider range road cassettes and more gears (although I think 9 is plenty).

Product differentiation = consumer tie-in. People think that newer = better, get suckered in an then have to get all their parts from the original manufacturer.

Things that come instantly to mind...

Alloy freehubs. Just sooooo durable, but I guess "The Market" replaces the wheels before they need to get that cassette off.
"Unique" spokes. Because it's always fun to wait weeks to get a replacement for that spoke you broke, isn't it?
Every bottom bracket system since square drive. Although, I really do like the Shimano two-piece setup, it is engineering elegance.
Shimano's chain rings for the last few years. Cheaper to buy a new crankset than buy replacement chain rings - if you could even find them.
11 speed - because it has to be better than ten speed. Right? Or because it wears out quicker and you spend more on servicing.
Gary Fisher's wider front hubs. "Stiffer"? Riiight.
Carbon rims with alloy braking surfaces - awesome, a heavy rim that wears out just like ones you can buy for 25% of the price, and all you get is a .2kph speed advantage once over 40kph!
Everything claiming that a 15 gram saving in weight was worth the doubling in price.
Garmin - making you pay twice the price to get a feature that was implemented in the software and could have been made available to all of the older models.

Nobody wrote: Some of the changes I've appreciated over the last 20 years or so (in no particular order):
1 1/8" Aheadset (threadless).
Stems face-plates that unbolt so you can remove the handlebar easily.

YES!

Nobody wrote: Disc brakes.

MEH. other than for crazy muddy races (conditions where the race should probably be called off anyway) i reckon Vs or cantis are just fine. As for discs on road bikes .