Failed BB......Help!

[hophead]

The bottom bracket on my not quite 3 month old Bianchi DISS is on it's way south. The cranks rock back and forth causing the chain to eat into the bash guard. The stock BB is a 113mm TruVative ISIS.

What do you all recommend as a replacement? I want something that will last. If that means replacing the cranks & chainring too, so be it. The chainring does have some uneven wear due to the chain running off center on part of my pedal stroke. At least half of the teeth are mushroomed on the outside edge.

This may be covered under warranty since the bike is less than three months old, but I may not go that route. I am not interested in putting junk that will fail in another three months back on my bike.

[markie]

I am not interested in putting junk that will fail in another three months back on my bike.

A bottom bracket should last longer than that. It may have just come loose in the frame. In which case riding like that might have done frame damage.....

Either way, go back to where you bought the bike.

Oh and mushroomed rings are normally the result of riding into log piles.

[Dirt]

I know this isn't going to be good news for you, but there are issues with the ISIS bottom brackets... issues that have most of the manufacturers of them changing their designs. Lots of them are going to outboard bearing designs in order to deal with this problem.

The basic idea behind the isis BBs was to make a larger axle and very durable splines. This was achieved very well. The problem, however, was that the spindle was large enough that it made very little room for bearings. For that reason, the bearings are not holding up well.

There are other things that could be contributing factors. If your BB cups are too tight, they could be putting too much side-loaded pressure on the bearings, causing the BB to feel like crapola.

If your chain is too tight, it could also put too much side load on the bearings and cause them to bind (something I found on a friend's single speed last night).

Some bottom brackets work better than others. I've generally had better luck with the FSA BBs that have double bearings on each side (I believe they are the platinum series). They're more expensive, but they've lasted me longer on every bike that I've used them.

I've also had pretty good luck with the Race Face Signature BB's. They are similarly designed with double bearings on each side. The Race Face BB's are a little more difficult to get the tension correct on. If you overtighten the cups, they feel like they're binding.

With either bottom bracket, I use a combination of grease on the inside threads of the BB and blue locktight on the outer threads of the bb cups to make sure that everything stays snug.

I'll be installing a raceface Signature BB on my new bike tomorrow and I'll take photos of what I described above and post them up if that will help.

Peter

[cloughja]

I agree with Peter on the FSA platinum pro model, and I'd also add the newer Truvativ "gigapipe" models to your list of decent ISIS BB's.... those also use 3 or 4 sets of bearings as opposed to 2 on the original models.

[TrailVictim]

I dropped $105 on a Gigapipe Max Ti (4 bearing) and it was terrible. The extra bearing put way to much resistance on the crank not to mention it creaked like an old rocking chair. Yes, I installed it correctly(proper torque) as did the 2 different shops I took it to thinking I was doing something wrong. Nobody could get it to shut up. I went back to using a FSA Platinum which has been working fine.



Just my 1/2 cent

[Dirt]

I dropped $105 on a Gigapipe Max Ti (4 bearing) and it was terrible. The extra bearing put way to much resistance on the crank not to mention it creaked like an old rocking chair. Yes, I installed it correctly(proper torque) as did the 2 different shops I took it to thinking I was doing something wrong. Nobody could get it to shut up. I went back to using a FSA Platinum which has been working fine.



Just my 1/2 cent

I've found that most of my ti BB's creek. I'm too huge to ride them anyways.

Thanks for posting up.

Pete

[cloughja]

...The extra bearing put way to much resistance on the crank...

That's interesting... I just installed a steel gigapipe on my commuter bike and did notice the increased resistance. I just assumed it would go away after a break-in period, like most sealed cartridge bearings. It's not something I notice at all while riding anyway, but I'll keep an eye on it.

[markie]

But have you all been destroying bottom brackets in just 3 months? Remind me to avoid them in the future if you have.

[Nick]

Truvative, FSA and RF are wiggling pretty hard out of the ISIS fiasco - look at all the external bearing BB cranksets out this year - there's hardly an ISIS to be found...

[riderx]

But have you all been destroying bottom brackets in just 3 months? Remind me to avoid them in the future if you have.We just had this conversation Tues. night. Did you forget?

[Dirt]

That's interesting... I just installed a steel gigapipe on my commuter bike and did notice the increased resistance. I just assumed it would go away after a break-in period, like most sealed cartridge bearings. It's not something I notice at all while riding anyway, but I'll keep an eye on it.

I might also check the cup tightness. If you've got the cups too tight, you might be side-loading the bearings. Loosen them 1/8 turn and see if the BB feels better. It is sometimes a hard balance to find between tight enough to hold stuff together and loose enough to let the bearings spin freely. That is where locktite can come in handy.

Pete

[cloughja]

But have you all been destroying bottom brackets in just 3 months? Remind me to avoid them in the future if you have.

My original ISIS was a Truvativ sealex SL... I think I killed it in about 6-9 months, but I wasn't riding very hard at that time. I replaced it with the same model from the parts bin and it died within about 6 months too, I think. The FSA Platinum Pro ran fine for over a year, and was still doing so when I sold it a couple months ago. I just installed the Gigapipe so I can't judge the durability on that one.

Truvative, FSA and RF are wiggling pretty hard out of the ISIS fiasco - look at all the external bearing BB cranksets out this year - there's hardly an ISIS to be found...

Not quite... FSA is releasing an external bearing bottom bracket that still uses the ISIS interface and would work with older ISIS cranks.

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=60&pid=120

[Nick]

Yup, my point exactly - external bottom bracket.
At least there is some sort of option out there for folks with ISIS cranks that have had thier bb's shat out on them - BUT at minimum 100 bucks retail is it really worth it?

[markie]

We just had this conversation Tues. night. Did you forget?

I know you can break anything in no time at all, Uri.


I thought for normal people 3 months was far too short a lifespan. I mean I got nearly a year out of my second hand shimano BB. It saw plenty of miles and let go gently.

If it was me I would be right back to the bike shop to piss and moan. They dont like me at bike shops.

[Dirt]

Not quite... FSA is releasing an external bearing bottom bracket that still uses the ISIS interface and would work with older ISIS cranks.

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=60&pid=120

I saw those. The only problem is if you want to run a 108mm bb spindle on a 68mm shell or 113 on a 73mm shell.

If you like a wide BB, those will work.

Pete

[cloughja]

I might also check the cup tightness. If you've got the cups too tight, you might be side-loading the bearings. Loosen them 1/8 turn and see if the BB feels better. It is sometimes a hard balance to find between tight enough to hold stuff together and loose enough to let the bearings spin freely. That is where locktite can come in handy.

Pete

Thanks for the pointer, but I did check that already. The non-drive side spacer is actually a big rubber o-ring, so that helps prevent side-loading. I did play around with the torque on that cup and got it so that is was just tight enough to not bind at all. I guess I also should have pointed this out before, but I noticed alot of drag in the bottom bracket before I even installed it, so I'm sure it is the seals right now.

As far as the locktite, the cups came with some thick, red thread-locker already stuck on them so I'm trusting that for at least the initial install.

[cloughja]

Yup, my point exactly - external bottom bracket.
At least there is some sort of option out there for folks with ISIS cranks that have had thier bb's shat out on them.

Right, but "external" doesn't mean "non-ISIS." That was the problem with ISIS in the first place... it is just a standard for the crank/BB interface, not accounting for the rest of the BB. So, that new external BB from FSA is still just as much ISIS as the others, although causing some new problems as Peter pointed out.

Also, just for the record, I'm not a huge fan of ISIS or anything... I just think it's gotten a really bad rap becuase the early BBs sucked. Personally, I doubt I'll buy another ISIS product again... I'm running a square-taper crank on my singlespeed and when the budget allows, will pick up a compact road crank in either square-taper or Octalink for my commuter.

[hophead]

Ok, let me get this straight--ISIS is junk, but it seems that the consensus is that Raceface & FSA make the best of the worst.

I will probably replace my BB this weekend if I can find a suitable replacement. Who around here carries FSA or Raceface BB's? Also, I don't seem to have the tool to remove the cups. It's a 40mm external spline. The only external spline tool that I have is 46.5mm. I suppose any bike shop would have this tool, but I would like to buy one. Anyone know the Park tool number for it?

If I were not limited to ISIS, what's best? I have no problem replacing the cranks too if there is a more durable setup available.

[cloughja]

Ok, let me get this straight--ISIS is junk, but it seems that the consensus is that Raceface & FSA make the best of the worst.

I will probably replace my BB this weekend if I can find a suitable replacement. Who around here carries FSA or Raceface BB's?
Pretty much. It's not just any FSA or RF though. The RF "Signature" models are supposed to be the good ones. I have heard mixed reviews on those, though, so I would recommend FSA. For FSA, make sure you get the "Platinum Pro" or above. I don't think their regular "platinum" model has the extra bearings... confusing, eh? I don't know about local shops, but I got my last platinum pro for about $40-$50 online.

Also, I don't seem to have the tool to remove the cups. It's a 40mm external spline. The only external spline tool that I have is 46.5mm. I suppose any bike shop would have this tool, but I would like to buy one. Anyone know the Park tool number for it?
My Truvativ's required the Park BBT-8 (http://www.parktool.com/tools/BBT_8.shtml)

If I were not limited to ISIS, what's best? I have no problem replacing the cranks too if there is a more durable setup available.
I don't think there's a definite "best"... it really depends. Here's my personal take on the other systems... If you don't mind buying Shimano parts, and can find a corresponding crank to your liking, the (now older) Octalink systems are just fine. They tend to creak if you don't install the crank arm with the proper torque, but that's the only complaint I know of. Square-tapers are also great, unless you're big and burly afraid of flex. Bonus: Phil Wood BBs are all square-taper. I don't know much about the external-bearing cranks and they seem too expensive and complicated to me. Does anyone else know of any specific benefits of the integrated systems over square-taper or octalink?

[hophead]

My Truvativ's required the Park BBT-8 (http://www.parktool.com/tools/BBT_8.shtml)
That looks like it would work except for the fact that it's too big. Nominal diameter is 37mm not 44mm. Overall diameter is only 40mm.

Do you have a BBT-8? If so, can you tell me what the diameter is? Maybe it's a misprint on Park's website.

[cloughja]

That looks like it would work except for the fact that it's too big. Nominal diameter is 37mm not 44mm. Overall diameter is only 40mm.

Do you have a BBT-8? If so, can you tell me what the diameter is? Maybe it's a misprint on Park's website.

Yeah, I have one.... 44mm outer diameter on the splines, 37mm inner. The splines on the tool generally stick out past the notches on the BB, so being 44 outer in stead of 40 shouldn't be a problem.

[hophead]

Nevermind. The BBT-8 is correct. The size is a misprint on Park's website.

Thanks.

[themonkeyman]

I happen to have a BBT-8, and the inner diameter (I.E> from the inside surface of two aligned splines) is 37mm. The oustide diameter of the tool, and probably the widest part of the BB flange, measures 44mm, like you said.

Hope that helps--Graham