Opinions on bottom brackets

[skerb]

So i just put in some Diabolus cranks with the diabolus x bb and it went out after about 65 miles. the bearings are shot. My question is should i buy a new Diablolus bb or should i keep my rf cranks and get a different bb for the cranks? It has to be xtype...but what should i do?

[sanjuro]

Get a new bb. Raceface was having big problems last year with the BB's and I wasn't satisfied with their fixes for this year.

I believe the Shimano bb's are compatible, and for the ultimate durability, I would switch the bearings to Phil Wood. That's what I did with my XT crank...

[OGDMFG]

you don't ride anymore.:twitch:

[stinkyboy]

www.philwood.com

[joelsman]

fsa also makes good inexpensive bearing/BB's. I have been using my gap x-type bearings for about a year in mud and wet and have had no problems.

[mattmatt86]

Brooks, you must have the worst luck in the world. Do you break this many things on your jeep?

[skerb]

no, hell i never had many problems out of my jeep...but dam if i dont go through some bottom brackets... Matt...you need to look at this thing...i cant believe how short a time it took to just crap out.

[psychobiker]

fsa also makes good inexpensive bearing/BB's. I have been using my gap x-type bearings for about a year in mud and wet and have had no problems.

i recently put these on the stinky feel better than the truvativ..

[skerb]

so are isis stronger than the xtype bbs? I was under the impression that external bearings should be stronger...so the RF Diabolus bb is $27 a pricepoint. Anyone know where i can find those FSA GAP xtype for a decent price. I also see the shimano but which one is the best out of the shimano line?

[joelsman]

any bike shop should be able to get an fsa BB, the gap cranks use a quad bearing version, you need the reg x-type BB. www.dropnzone.com has good prices and is the shop I use

my AM bike is almost 2yrs old with the same RF evolve xc x-type BB, I have had to adjust the bearing preload a couple times but they are still spinning good.

the x-type bearings are much larger than ISIS, so they should be stronger and last longer and the larger spindle makes them stiffer

[jvnixon]

The problem with outboard bearings is that they're more exposed to the elements. Getting a good set of bearings that are sealed properly in there will make them last a lot longer

[ElTORO]

What happened to your BB anyway??

I had one that froze after I let it sit for a week after a rain ride. Went to ck. it out and it would not move. I just slammed the cranks down and broke it free, took it off and soaked it in oil. It felt like crap for one ride then it all went away. I even went and bought a brand new one but never replaced it. I road that BB for over a year, mud, rain, snow whatever.

[skerb]

mine just has a few mms of play in it like the bearings are not tight anymore. the cranks are tight...but it can move up and down in the bearings.

[psychobiker]

so are isis stronger than the xtype bbs? I was under the impression that external bearings should be stronger...so the RF Diabolus bb is $27 a pricepoint. Anyone know where i can find those FSA GAP xtype for a decent price. I also see the shimano but which one is the best out of the shimano line?

www.bikeman.com , carver and the guys can help

[skerb]

www.bikeman.com , carver and the guys can help

called them up and they were very helpful...but they said they dont have the saint bb in stock and they dont know when it will be available again.

I think i will probably go with the shimano saint bb....but where can i find it to buy it....I need it as soon as possible.

[skerb]

found this just now...

"Crappy Aftermarket Bottom Brackets

I've been running the new style Shimano HollowTech II cranks since they were released in the Deore XT versions (FC-M760). Recently, this design has become the standard for performance bikes industry wide, with other firms manufacturing similar systems. The performance of this crank and bottom bracket configuration is truely stellar, the best that I have ever felt.

One serious shortcoming of this system is the bottom bracket internals, specifically the seals. Back in the days of the square tapered spindle, shimano set the gold standard by which every other bottom bracket must be measured, the BB-UN72. This was an XT level bottom bracket that came as a sealed unit, ran smooth, with little resistance, and lasted vertually forever. If by some chance you did destroy or wear out the unit, it only cost $25 to replace. Even when these units failed, the seals always worked to perfection.

The new HollowTech II bottom brackets are not on that level. After less than a year of riding, the left side of my original bottom bracket developed some play and rough feel. Since Race Face was introducing their replacement XC/AM bottom brackets at that time, I figured that I would give them a try. It always proves foolish to use less than a Shimano part. In less than 4 months, the Race Face bottom bracket had seized up entirely. Of course, I had to find this out just before a planned ride. Luckily, for some strange reason, my bro at Fairfax Cyclery, Bryan Harrell, had the replacement Shimano XT cups that I needed on hand. I was able to get the bike working and still enjoy a ride that day with my wife.

Bryan and I did a little research on my failed Shimano and Race Face bottom brackets, and this is what we learned. The Shimano bearing cartridges were labled HIC (Japan) 6805RD, (25 ID,37 OD,7 WD) with 15 x 1/8" bearings and a steel retainer. The seals were superior to the Race face unit in every way. The side that failed did so because it was contaminated solid with grit, but the bearing still worked and not too poorly either. The good side was clean and greased and rolled very smooth. The Race Face bearings on the other hand had branded seals (always a bad sign) labled RACEFACE X-TYPE 6805 LLU MAX. This is a full complement bearing, meaning that they forgo a retainer and put as many balls in the bearing that will fit. These bearings for example had 30 x 1/8" balls. Full compliment bearings are only meant for high radial loads. They are very prone to failure under axial loading due to the cutout required to assemble the bearings. These types of bearings have no place on any part of a bicycle (not even for suspension links). The reason that the Race Face BB froze was because the full complement bearing only left 0.050" of gap for all of the bearings to share. Besides the fact that these bearings were rubbing against each other almost contiually, once the seals failed and some dirt was allowed in, the unit resembled more a mortis and pestle than a bearing. No gap was left for the dirt to go, so it was just go ground in by the bearings until everything locked up.

Original part numbers for replacement bottom brackets are XT - SH14505 (Part No. Y1FU98110) and XTR - SH14500 (Part No. Y1E598240), The bearings used in all of these bottom brackets are single row, deep groove 6805 2RS1 (25 ID,37 OD,7 WD) with both sides having a neoprene labarinth seal.

Removal of the bearing is accomplished using a Motion Pro Blind Bearing & Bushing Remover Set, #080292 (K&L #35-1056), with the 25mm attachment. With the cups mounted in the frame, simply tighten the attachment into the bearing and slide hammer the bearing out. If you are like me and prefer a press over a hammer, just press the bearing out using the adapter to hold the bearing and press against the adapter. The new bearing is simply pressed in. Since the bearing is recessed into the cup, it helps to use the old bearing to push the new one into place.

Breaking news is that Phil Wood has a new tool to do all of the bb service work for about $65. If you plan on doing a lot of these, this is the tool to get.

When setting up a pro race bike, it would make sense to replace these bearings with a quality ceramic replacement or with some of Phil Wood's custom made 6805 bearings # PWX05 for $23 each. Whatever you do, avoid any MAX or full complement bearing. The quality of the seals is of primary importance."

http://www.peterverdonedesigns.com/bikebottombrackets.htm

[ElTORO]

wait arn't bb like $25.

[skerb]

ok....so ignoring that i have an xternal bearing bb...what is the strongest and longest lasting bb available? within reason...i just want somethign that will last me like 2 years...

[mattmatt86]

Brooks, I think that Bike and or you have a curse. At least you got the nixon the way you want it now. Im really not sure what bb you should get, the only company other than RF and shimano that Ive see with xternal bbs is FSA and I hate FSA with a passion and I really dont want to suggest something to you that I myself wouldnt ride. Whatever you deceide, I can put it on for you if you dont feel comfortable taking it to the LBS again.

[skerb]

ok, so i just took it apart and it looks like the bearings are fine, but the little plastic ends wore out...so im not sure whats wrong.

[skerb]

called up RF and they are sending me new cup seals for my bb...should be here in a week. no charge

[Sam B]

FSA also has a BB rebuild tool for pressing bearings in and out of cups. It works on the same principal but it is considerably cheaper. MSRP is only $29.99 - the part number is 230-2020 if you were to try and order one.

Regardless of brand, external BB's are closer to the elements, so spraying water at the cups is a bigger deal than ISIS, etc. People also forget that a seal on a cartridge bearing can be lifted off, old grease purged out, races cleaned and than regreased. Pulling the bearings out of the cups makes this much easier. Of course many of the small bits are kinda fragile, but that is a lot better than throwing out a whole cupset.