Now worn out two LX hollowtech II chainsets. The first I think may have been my fault for not tightening the bolts evenly on the left crank arm but with the second one I have been very careful when tightening but its knackered as well now after about 18 months. ISIS bottom brackets didn't last very well when I had them so now considering square taper. Is the alloy in the LX HII softer than SLX or XT? What do folks think?

What was wrong with square taper anyway ?

Try getting a decent BB in square taper, other than a royce . . .

Like LCD TV's, progress . . . but not as good . . .

Fd

You said ISIS (Race Face, FSA) didn't last, but Shimano used Octalink, and the last XT one I had ran for over two years, before I sold it on the bike.
This one may be roadie, but you get the idea
Looking on CRC you may struggle to find cranks though

Can't you still get the Shimano BB's? They were all right for what they cost.

2nder for Octalink .Bearings INSIDE out of the way works !

yep – Ive gone back to SqT.

Now use middleburn on a Phil Woods.
Also have an old XT739 SQT crankset on UN72 BB.
I have a few spare UN72s too to keep me going till I retire. 🙂

I'd be very interested to discover exactly what caused your splines to die, Steven.

HT2 is certainly the future. It's a far stiffer than any square taper system and the many pairs of cranks I've had on various bikes have suffered nothing worse than worn our bearings.

Having said that, I bought a pair of Middleburn cranks a couple of years ago and they are lovely…

And you can indeed still get Shimano square taper BBs for not a lot of money and they still go the distance.

Sorry about that, I used to have a race face chainset before the hollowtech II and went thru a few bottom brackets with that. If I could afford one I'd get a Middleburn but that will have to wait.

As I said, I think I may have killed the first one when I hastily transferred it to a new frame and maybe didn't tighten the bolts on the arm evenly. But I'm only guessing, I thought I'd heard it was possible to ruin the splines this way. The last one has been fine for about 18 months but is goosed now. Been very careful when tightening the bolts on it.

That second one is a weird one.

Did you take it off/put it back on often?

Did you grease/anti-sieze or not the spline before putting the left crank arm on?

Did you use a torque wrench to do up the bolts "equally and evenly"? (Yeah, cos I do. Everytime. Honest…)

Didn't use a torque wrench, did grease them and would only have taken it off to change a chainring which was ages ago.

I ve never left square taper. Too many stories of isis and the like not lasting long….especially when you live 6 miles from the wettest place in England….

I run a Royce sq taper/Middleburn in both bikes. With the chain off the cranks will spin a dozen times with a firm tap on the crank arm.

the cranks will spin a dozen times

Oh cr@p I can't resist…. must resist… but… can't…. nooo……

I don't want to write this but I am compelled: why do people continue to think that the length of time that cranks/pedals/wheels/headsets/children's roundabouts spin for is somehow a measure of their quality?

For those that can't get away from the idea, here's a tip: if you thoroughly degrease your bearings and reinstall them, grease-free, they go round for MUCH longer when you spin them.

4 sets of Middleburns on square tapers here and not so much as a creak out of them. If you buy decent cranks, square tapers are unbeatable. Been on every bike ive had in the last 10 years including the frames i have snapped with no problems at all, downhilling and jumping included. Have a set for sale, 5 bolt though as they are prettier, if anyone wants a life free of crap bearings and constant BB changing.

Can't you still get the Shimano BB's? They were all right for what they cost.

Yeah, £12 on CRC for a decent one.

I never swapped over. I have Middleburn on my Superlight. FSA square taper on my SS commute and My Pinarello has square taper as well….

"If it's not broken, don't fix it"

mccett pics and aprice please to email in profile cheers

far stiffer than any square taper system

bearing in mind the flex in the frame would anybody really notice the added stiffness in the BB/cranks?

I'm a luddite. I'm still on Sq. taper and octalink.

"would anybody really notice the added stiffness in the BB/cranks"

it really was quite noticeable switching from Deore Sq taper to XT HT2 on the same frame.

When my external BB went lbefore last winter I put my old Octalink crankds back on, still going strong now; for the average rider external BBs offer no benefit IMO.

Yea I gave up a couple of years back, use Middleburn / square taper and its been fit and forget. Would like to get hold of a UN72.

Still using a pre-cartridge Shimano sq taper BB on my SS. the bearings had gone eventually after 17 years, so I bought some more ball bearings for a couple of quid, and serviced the lot. Runs like a dream now.

Square taper on my track bike, too.

And on my road fixed (if I ever get the seized DS crank off…!)

I'd never go back to square taper on a mountain bike. Forever rounding off crank arms etc.
Probably the high end royce or middleburn stuff is all great but at the lower end, ht2 is much nicer. Noticeably stiffer and easier to fit/remove Imho 🙂

But can you still get UN72's ?

Middleburn on the posh bike and Shimano M442 (£55 RRP inc rings) on the winter filth bike, both square taper.

Square taper BBs seem to last longer for me, and I'm running meagre LX cranks. Problem is sourcing chainrings when they wear out. Just transpanted the whole drivetrain to a new frame and it's still running smooth. I've had to replace 2 or 3 square taper BBs since 1994 I think
Since 2006 I had an ISIS that lasted 2 years (but was really really **** when replaced- huge play in the bearings) , a HT2 (shimano) that lasted 6 months (seized after one winter) and have now got a hope ceramic HT2 that is still very smooth but hasn't done a winter yet.
Like so many things in life "progress" isn't necessarily better for joe public, it's just a way of flogging more stuff.

would anybody really notice the added stiffness in the BB/cranks?

I did when i swaped my square taper road chainset to a GPX one. You could see the chain rings flex when pedaling and more often than not here it as well.
I have a Hone chainset that is 5 years old has been on and off a fair few times (even swaping frames) and the splines on that are as good as new.

+1 for HT2.
No issues on 2 sets apart from 1 set of bearings. Cranks are a doddle to remove & new bearings are cheaper than BB's.
I suspect a lot of issues are caused by ham fisted home mechanics & I'm one of those (rounded off cranks & stripped extractor threads). I've found HT2 to be a bit more idiot proof.

My theory is that when you bend a 'flexy' crank at the start of the power stroke, you get that power back when it springs back at the end of the power stroke. 🙂

For this reason I don't think the flex issue is a problem as it is different to flex in a noodley frame which really is just wasting power twisting tubes.

It makes perfect sense in my head, but that doesn't mean it isn't total bollocks.

Middleburn/Race Face Ti here. Just about to order a Royce though as I need a longer axle for a new frame.

I've had External BB cranks, they were pretty rubbish. Splines were too soft and developed play, the BB was a joke.

My theory is that when you bend a 'flexy' crank at the start of the power stroke, you get that power back when it springs back at the end of the power stroke

I could see this if you were twisting the shaft as it would pull the chian but side ways flex doesn't help drive the chain and just absorbes energy.

What do people think of that new BB30 system? Big bearings but on the inside seems like the best of both worlds maybe??

It makes perfect sense in my head, but that doesn't mean it isn't total bollocks

it is total bollocks 🙂 ignoring the fact the flex won't be in perfect line with the rotational axis (side to side flex), if that theory worked you'd have cracked the conservation of energy conundrum and solved our energy woes with your 100% efficient machine. In reality, you may get some of the transferred energy back via the "spring" return action but much of your output will be lost as heat.

ISIS bottom brackets didn't last very well when I had them

I know they aren't generally flavour of the month but the Superstar ones are pretty good , 2 years without a hitch so far on my P7

I killed the splines on a HT2 – I think its due to overtightening the bolts which then deformed the grippy bit meaning I could get it to grip tigh enough, who knows. Also had another one fail when the granny ring bolt threads on the spider threaded.

Now using a Raceface external bottom bracket which seems to suit my mechanical ineptitude much better.

+1 stiffness increase going to HTII,

very noticeable, i guess if you area very light rider it may not be so obvious

and i dunno about flex in cranks themselves but i notice it on the bb of my octalink commuter especialy when im trackstanding

As a current HT2 user I’m impressed with the cranks; stiff, light-ish and they last if fitted properly, but the stock BB’s are shite, I’m quite impressed with the Hope steel BB I bought for my Hone cranks it’s done 6 months without issues (so far), we’ll see how winter progresses…

What annoys about HT2 me is that it’s cost me an extra £50 to make the bloody BB work, I’m glad I’d not plumped for a set of XT’s as for the difference in cost I reckon Middleburn Square tapers and a decent Shimano BB are probably worth the money for bearing durability, yes the cranks cost marginally more and if a small amount of flex bothers you then maybe they aren’t for you but you should have 2 years bare minimum out of a UN72…

As for BB30, just what the world needs, yet another standard, the principle is fine but it’s not a million miles away from ‘Mid’ BB’s… Obviously my luddite rants will wither and die in a few years when I find myself sat onboard a far superior bike with BB30 cranks, and an E2 taper, semi integrated head tube, 12mm rear end maxle and QR15 forks… but until I buy into every Fad going they’re all shite and a total waste of money…

middleburn and square taper on mtb/cross bikes fancy new fangled thing on road bike. Tried isis bb mtb and it lasted 450k. posh bike have royce bb with middleburn, marvelous combination.

mt – Member
middleburn and square taper on mtb/cross bikes fancy new fangled thing on road bike. Tried isis bb mtb and it lasted 450k

wow! 450k! I can't even imagine doing that sort of mileage… 😀

Never used anything else…!

So really ht2 was created for the small minority of riders who regularly mash their cranks being gnarly or for those riders with a poor pedalling action.
If old technology can compete with the new technology there's something not quite right.