Bottom bracket trouble Options

[Chris_L]

Hi All,

I'm a newbie on this forum although I have been a bit of a hidden reader for a while (clicked the I am under 13 button when trying to register and then never got round to sorting the issue until now).
:oops:

Anyway to the point!
I have a Trek Liquid that seems to have aquired a taste for bottom brackets. I don't cover many miles on the trusty steed but the bottom bracket seems to surrender at the first sign of mud.
Its an ISIS BB with the last two sacrifices being Truvativ giga pipe. I was just wandering if anyone has any views on Race Face ISIS BB's or do I believe the hype and get one of the new SKF units.

Thanks in advance,

Chris

[Rockymtnway]

Two things. First, when you say your bike's acquired a taste for eating bottom brackets, how many are you talking about/how long are they lasting? The reason I ask is that if your bottom bracket shell isn't properly faces, this can lead to extra friction and, yes, shorter BB life. Just something to check before proceding with a high end BB and eating that one alive, too.

Next, most Isis BBs are not very well sealed, so I can't say I'm surprised you're having problems. There are some sealed better than others, or I think it was MattCyp around here who was experimenting with a Race Face unit with replacable bearings. Otherwise, the best sealed BB is unfortunately not a Isis, but rather the XT Octalink, but that would mean a change in cranks. Hopefully there's some others to point more light in the tunnel. :wink:

[Chris_L]

Yeah,

Forgot to mention I had the frame back to the dealer/LBS to check the faces were true. I think you hit the nail on the head suspecting the seals, the cranks feel a little gritty and become stiff if left unturned for a while.
I managed about 6 months light use from the last one although the BB previous could possibly be explained by a rather dramatic failed bunny hop of a felled tree. Probably not the best time to try and learn to bunnyhop.
:oops:

[Mattcyp]

Yep, I forked out £70 for one of these.

First impressions were what a great, well built and superbly sealed unit. I then had it fitted and realised the price for all the seals, it stiff to turn at first. Due to this the bed in process is a long time, perhaps 100km before it settles down. In the time before it would occasionaly make a clicking sound, or feel a little sticky.

Thankfully, it's now settled down and seems to be working superbly in all kinds of weather. I'll write more as it gets older on the thread i started about it a while back.

So far, i'd recomend it but it's too early to say with a solid opinion. It looks like it'll do the job, and new bearings are only £17, but time will tell on these things!

Imagine how much Chris King could make with a sealed Bottom bracket!

[Rockymtnway]

Imagine how much Chris King could make with a sealed Bottom bracket!

I have serious bones that they don't! They were part of the design team for the new ISIS bottom bracket and then they don't even produce one? What's up with that?

I love ya' King, but share the love and build a proper BB! :swearing:

[brf]

6 months from an ISIS BB is about the norm. The FSA Platinum Pro has a 1 year warranty so I send mine back after 6 months and get a free replacement (from Wiggle).

[Chris_L]

Thanks people,

I will have to make my mind up soon as I am bracketless, whatever I decide I will keep you posted!!!

[Jonny69]

Hi, from what I can understand then ISIS is crap because the bearings are too small (therefore octalink must suffer the same problem) and the new shimano/raceface/truvativ outboard bearing style BB's are also useless?? So that leaves the 6 splined BB from tune which costs about £400 with the cranks and the old school square taper.

So what are people running and what is breaking. I have been questioning whether to buy some XTR cranks nearer the end of this year, when they are cheap but the rings are butter and the bearing are as bad.

Are there any viable alternatives to modern standards?

Jonathan

[DK]

 

So what are people running and what is breaking.  
Jonathan

I am still using an LX square taper and an LX splined that have both done just over 4000 miles. In my experience ISIS and HT 2 have a life that can only be measured in a few months.

Same with chainrings, I use my bikes six days a week and Deore steel are the only thing I have tried that lasts. Might consider changing to Middleburn chainset with Shimano LX/XT square taper B/B.

[Rockymtnway]

Hi, from what I can understand then ISIS is crap because the bearings are too small (therefore octalink must suffer the same problem) and the new shimano/raceface/truvativ outboard bearing style BB's are also useless?? So that leaves the 6 splined BB from tune which costs about £400 with the cranks and the old school square taper.  

So what are people running and what is breaking. I have been questioning whether to buy some XTR cranks nearer the end of this year, when they are cheap but the rings are butter and the bearing are as bad.  

Are there any viable alternatives to modern standards?

Jonathan

Isis has poor sealing, thus muck gets in the bearings and they die in wet climates. In the states, I can get 2-3 years out of one, but over there, mine didn't last a week.

Octalink is probably the best out there for sealing and longevity, but you're limited on crank options since Shimano is no longer making them. There are some other manufacturers who've stayed with Octalink and if you find a crank that you like that fits them and use the Shimano XT Octalink BB, you get a pretty solid set up.

I have two sets of XTRs and yes, the rings wear quickly, but for about $40 more than a replacement set of rings you can get some Boone Ti rings that will probably live beyond your years if well cared for. The only problem I've had with the Boone rings is in mud and muck, they're not highly polished and tend to have a lot of mud stick to them, which in turn causes chain suck. They are brand new and still breaking in, so this could be part of the problem, but I'm just giving an honest review of my experience. As for the bearings on the XTRs, the sealing is an absolute joke. However, there is hope on the horizon. FSA is now making a ceramic outboard bottom bracket that's compatable with the XTRs. They're spendy (about $170), but ceramic has lower friction, doesn't rust, and is more durable than steel, so I see a lot of potential. I plan on buying a set this summer, but with our local weather, it may not be a good test for your crud.

As for square taper, the only people who see going back in time as a salvation are folks who didn't grow up with them. If you think the modern BBs are bad, take a trip in a time machine and use one of these. They would constantly get stuck, come loose, round out your crank holes, they had a lot of the same sealing issues as ISIS, and they weighed a ton. An ISIS on a bad day beats a square taper.

In summary, ISIS good, but lousy sealing, Octalink better but few crank options, external bottom bracket really good bearings, but no sealing, but possible salvation if you can afford it.

[DK]

I have never had a problem with square tapers coming loose or wrecking cranks and I have been cycling off-road since before they came on the market :shock:

[Jonny69]

"FSA is now making a ceramic outboard bottom bracket that's compatable with the XTRs. They're spendy (about $170), but ceramic has lower friction, doesn't rust, and is more durable than steel, so I see a lot of potential."

So when they are out in the UK they will be about £100-130 I expect, alot of money for bearings that should really be coming standard on the top of the range shimano chainset.

I ran square taper until anout a year ago. I think they are not that bad.

So the only thing to do then is to get an FSA platinum and send it back every 6 months. I think I will buy two and then I will not have any time off the bike., and I will have a spare if they break.

Anyone have any experience with these? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...AMEWA%3AIT&rd=1

They are light and pretty cheap, and they look pretty cool.

Jonathan

[Chris_L]

The race face signature FR that I fitted has given up the chase. It managed about 150 miles, this is very poor in my opinion. I have ordered replacement bearings for the unit although they are difficult remove as it is impossible to get a bearing puller behind the bearing. I will see how this set of bearings go and then try ANOTHER bracket next time. :banghead:

[Toxophilus]

Several things -

I never had an issue with square taper BBs - I started riding MTBs about 18 years ago and after all, that was all that was available at the time (except oddities like Bullseye or Tioga Revolvers). I had a Royce Racing BB in my Bontrager Race Lite OR which lasted 3 years and over 4000 miles before the bearings had to be replaced. FAG also produced a near bullet-proof cartridge BB. Rounding out and axle breakage is most likely down to poor materials and ham-fisted installation than anything else.

ISIS internal bearings are without doubt crap. Yes, the large-diameter hollow axle stiffens things up and reduces the likelihood of twisting and breakages but whoever designed them committed a major cock-up by not leaving enough room for decent bearings. Octalink and Truvativ's Howitzer BB are more promising.

To my mind, external bearings are the way forward but both Shimano and Race Face seem to still be having major problems with reliability here. That said, my Hollowtech 2 unit (Hone chainset) seems to be holding up well touch wood.

[Chris_L]

I think I'm going to bite the bullet and swap the cranks and fit the hollowtech 2 system. Throwing good money after bad is not my favourite passtime, maybe the Shimano LX fits the pocket at this time.

[Gareth]

I had little problem with square taper except when they became difficult to remove. One key self releasing crank bolts helped enormously with this but I still prefer Octalink. Sure the bearings are smaller than external ones but the sealing is way better and I love them (the XT can be had for £17). Hollowtech cranks from Shimano are also excellent even if you do need steel or Ti rings for the granny and middle after a year or so.

Phil Wood are doing some replacement sealed bearings for Shimano which look very promising however and they don't cost the earth: Sideways Cycles

:idea:

[Doug]

I never had an issue with square taper BBs

I had nightmares with deforming the crank interface due to the amount of power I can put through the cranks. (I snapped an ISIS BB in the Alps powering out of a corner trying to race someone.) This included Cook Bros, Shimano, Campag, you name it I bent it causing the rings to wobble laterally and the chain to catch the sides of the front mech no matter how much I set it up. In the end I got some steel cranks and it never happened again but they were about 700g the pair compared to the Cook Bros 420g

[Toxophilus]

I think I'm going to bite the bullet and swap the cranks and fit the hollowtech 2 system.  Throwing good money after bad is not my favourite passtime, maybe the Shimano LX fits the pocket at this time.

The LX crankset is exactly the same as the Hone item, and so far I have no complaints about it, except the middle chainring wore out completely within 200 miles... :shock:

[Doug]

Like Toxo says, be prepared to change your rings pretty quickly on a Shimano chainset. I reckon if you left them out in the sun theyd melt :shock: