ISIS vs square taper, pro and con.

[dominicosavio]

I am going to order a MiddleBurn crankset but i don't know which system I should get. Isis or square taper. And what are the best bb for each system?

[drevil]

Isis or square taper. And what are the best bb for each system?No. Yes. Phil.

[Dirt]

No. Yes. Phil.
yup4567890

[Vecsus]

Ditto the above. My ideal build is going to have to wait til I get back from my year in Turkey (may 2009) but the middleburn with a phil wood BB is what I'll build my steel 29er out with. I'm stealing the shimano XT for the RIP9 I'm in the process of building (the bike I will be taking to turkey).

The Middleburn is simply beuatiful and the Phil Wood BB is a classic. The two are, IMO, a perfect combo.

[mjbrox]

Ditto the above. My ideal build is going to have to wait til I get back from my year in Turkey (may 2009) but the middleburn with a phil wood BB is what I'll build my steel 29er out with. I'm stealing the shimano XT for the RIP9 I'm in the process of building (the bike I will be taking to turkey).

The Middleburn is simply beuatiful and the Phil Wood BB is a classic. The two are, IMO, a perfect combo.


Your building a RIP9?

Very cool, what size? I am going to build my RIp on Thurs

[BikerMiker]

I've had better luck with Shimano UN-series square taper BBs than the Phil Wood BBs. That was just me.

mike

[allencb]

I've had better luck with Shimano UN-series square taper BBs than the Phil Wood BBs. That was just me.

mike

I've never used a Phil BB, but I've had no trouble at all with the Shimano UN series either. You can't beat a $25 BB that lasts longer than the bike.

Chris

[DaveG]

I've never used a Phil BB, but I've had no trouble at all with the Shimano UN series either. You can't beat a $25 BB that lasts longer than the bike.

Chris


But for the price, it was pretty hard to argue with. Had one last 6 months, and another last almost a year and a half.

Personally I'd get the new XT crank; it looks sweet.

Dave

[dominicosavio]

why everyone picks square taper over isis?

[g_barr]

Both ISIS and SqT have been around a while and are still around. The pros/cons are probably based more on personal opinion/preference than objective standards. That said, I'm disappointed no one has mentioned the pinacle of BB/crankset technology. I highly recommend Ashtabula. I have some that are >25 years old and they work like they did when brand spanking new. You cannot go wrong with these and they'd make you look like a superstar on a Ti ride.

[dominicosavio]

I highly recommend Ashtabula. I have some that are >25 years old and they work like they did when brand spanking new. You cannot go wrong with these and they'd make you look like a superstar on a Ti ride.

I thought they only use that in BMX

[jabberwocky]

Honestly, I've had a few square taper cranks and haven't been that impressed. Every one I've had has creaked and flexed, even the Phil. I had to take my Phil/ENO apart every few months to clean the interface or it would pop and creak. And the combination flexed enough that I occasionally hit the crankarm on the chainstay when cranking out of the saddle.

I've had two ISIS cranks and haven't cared for them either. The interface is better but the bottom brackets didn't last very long.

I've had the best luck with regular Shimano outboard bearing cranks. They aren't as blingy as some of the singlespeed specific ones but they are way stiffer and more reliable.

YMMV.

[philvw]

I highly recommend Ashtabula.

Certainly no creaking with the crankset interface there! Ha! Good one.

[Dirt]

why everyone picks square taper over isis?

ISIS bottom bracket spindles are larger in diameter. Since bottom bracket shells are a standard diameter, the bearings had to get smaller. Manufacturers went to using multple bearings on each side to compensate for this, but they couldn't overcome problems with smaller bearings being more succeptable to failure due to contamination. The closer the bearing is to the size of the crud that gets past the seal, the more likely it is to fail.

External bearing bottom brackets were created to solve this problem. Other issues result from using them. They're better than ISIS, but still have durability problems for many people.

Pete

[RetroG]

Honestly, I've had a few square taper cranks and haven't been that impressed. Every one I've had has creaked and flexed, even the Phil. .

Teflon tape on the bb threads works great.

[dominicosavio]

I've had two ISIS cranks and haven't cared for them either. The interface is better but the bottom brackets didn't last very long.

Have you tried Crank Bros cobalt BB? They have 5y warranty

[jabberwocky]

Teflon tape on the bb threads works great.Tried it. The creaking came from the interface itself (where the crank presses onto the spindle).

It was always solvable by pulling the cranks off the spindle, cleaning the spindle and inside of the crank real good an putting it back together. It would be good for a few months, then start back up.

The noise didn't bother me that much (although it was amusing that my singlespeed was noisier than my geared bikes), but the flex definitely was a dealbreaker for me. I'm too used to outboard bearing cranks, which are comparably very rigid.

EDIT:
Have you tried Crank Bros cobalt BB? They have 5y warrantyNo. I've replaced all my ISIS cranks.

[punga]

I'm also a fan of the ISIS (actually, the original, Shimano Octalink on my XT cranks). The BBs are pretty bomb proof for me, considering I'm not the most gentle with my equipment. I replace mine about once a year, and last time it may have been premature as I was trying to route out other creaks.

I've had limited experience with the external BBs and in at least one instance, the left crank arm kept loosening after repeated tightening. And cranking down on the bolt actually caused the BB to seize up. Not sure what was wrong since I had little experience with them, but there wasn't much we could do trailside except retighten it frequently.

p!

[DaveG]

I've had limited experience with the external BBs and in at least one instance, the left crank arm kept loosening after repeated tightening. And cranking down on the bolt actually caused the BB to seize up. Not sure what was wrong since I had little experience with them, but there wasn't much we could do trailside except retighten it frequently.

p!

That was the race-face one right? I like the Shimano ones where you tighten pre-load and then clamp the crank arm on. It's basically like a headset/stem interface. I'm not a huge fan of Shimano stuff in general, but they've nailed their cranks. I always had issues w/ the Octalink stuff creaking. No issues w/ the newer outboard bearing cranks.

Dave

[drevil]

I'm also a fan of the ISIS (actually, the original, Shimano Octalink on my XT cranks). The BBs are pretty bomb proof for me, considering I'm not the most gentle with my equipment. I replace mine about once a year, and last time it may have been premature as I was trying to route out other creaks.

I've had limited experience with the external BBs and in at least one instance, the left crank arm kept loosening after repeated tightening. And cranking down on the bolt actually caused the BB to seize up. Not sure what was wrong since I had little experience with them, but there wasn't much we could do trailside except retighten it frequently.

p!
IME, Octalink is way better than ISIS.

[punga]

That was the race-face one right? I like the Shimano ones where you tighten pre-load and then clamp the crank arm on. It's basically like a headset/stem interface. I'm not a huge fan of Shimano stuff in general, but they've nailed their cranks. I always had issues w/ the Octalink stuff creaking. No issues w/ the newer outboard bearing cranks.

Dave
Yeah, that was that day. Luckily your boy had a 8mm wrench. My CB's multitool doesn't give much leverage.

The Shimano design looks smart.

p!

[punga]

IME, Octalink is way better than ISIS.
I had ISIS(Truvativ Firex) previously and I didn't have too many problems when they were on my bike. Just went back to the XTs because they were lighter.

p!

[Dirt]

Have you tried Crank Bros cobalt BB? They have 5y warranty

Plan on using that warranty 1-2 times per year.

I've seen very few ISIS BBs that really last. I own one that has lasted very well. It is a Race Face signature model... I've had no trouble with it. I've had 3 just like it fail regularly.

[jabberwocky]

That was the race-face one right? I like the Shimano ones where you tighten pre-load and then clamp the crank arm on. It's basically like a headset/stem interface. I'm not a huge fan of Shimano stuff in general, but they've nailed their cranks. I always had issues w/ the Octalink stuff creaking. No issues w/ the newer outboard bearing cranks.

DaveWhat Punga mentioned is a problem with the Raceface outboard bearing design. They have a press fit interface (similar to ISIS) on the drive side with a self extracting bolt. The press fit NEEDS to be bottomed out to work. But if the BB cup spacers or the shell itself isn't perfect, the crank can start pressing on the bearings before the interface bottoms out, leading to either the cranks being loose or the bearings binding. I've had this problem, and I solved it by sanding about 0.5mm off one of the BB cup spacers.

The Shimano design is much better in this regard. The crank has the ability float a few mm in each direction and is preloaded with a their tool and then tightened with a pinch bolt. Plus, Shimano has the interface on the non-drive side, which is a smarter place to put it from an engineering standpoint.

The funny part is that both Raceface and Shimano went through the effort of coming up with a far superior design for the bb/cranks and then saddled them with crappy quality bearings.

[paulson]

The funny part is that both Raceface and Shimano went through the effort of coming up with a far superior design for the bb/cranks and then saddled them with crappy quality bearings.

check this out:

http://www.speedgoat.com/product.asp?part=128695&cat=25&brand=189

[DaveG]

What Punga mentioned is a problem with the Raceface outboard bearing design. They have a press fit interface (similar to ISIS) on the drive side with a self extracting bolt. The press fit NEEDS to be bottomed out to work. But if the BB cup spacers or the shell itself isn't perfect, the crank can start pressing on the bearings before the interface bottoms out, leading to either the cranks being loose or the bearings binding. I've had this problem, and I solved it by sanding about 0.5mm off one of the BB cup spacers.


Yeah, I have both. The Shimano is simply a much better design. I can only guess that they've patented it somehow to keep other companies from using it.

[jabberwocky]

check this out:

http://www.speedgoat.com/product.asp?part=128695&cat=25&brand=189Yeah, I've seen the Phil bearings. That particular setup seems expensive, because the cups are about 30 bucks and the bearings from Phil are 24 each. So Speedgoat is charging like 60 bucks just to swap the bearings, which is pretty easy to do. :confused: But I know of other shops that sell the cups pre-upgraded with Phil bearings too.

I run a set of Enduro bearings on my main trail bike and they have been way more durable than the Raceface ones.

There are definitely options out there. The problem with the crappy stock bearings is they got the outboard design a bad reputation with a lot of people (which is understandable when they burn through bottom brackets every few months). Its pretty dumb to spend the energy and money to come up with a great design, and then cripple it (in the eyes of users) with bottom brackets that are inferior to what people are used to. Raceface/Shimano could at least offer a higher quality bottom bracket themselves.

[yueq]

Outboard bearing cranks need to be installed and torqued to the spec (well, all cranks do). Also, the bottom bracket shell threads need to be chased first. If you force the bearing cups in, you will ruin the bearings.

Just my 2c.

[yueq]

I run a set of Enduro bearings on my main trail bike and they have been way more durable than the Raceface ones.

There are definitely options out there. The problem with the crappy stock bearings is they got the outboard design a bad reputation with a lot of people (which is understandable when they burn through bottom brackets every few months). Its pretty dumb to spend the energy and money to come up with a great design, and then cripple it (in the eyes of users) with bottom brackets that are inferior to what people are used to. Raceface/Shimano could at least offer a higher quality bottom bracket themselves.

Agreed, agreed.

BTW, the new RF bearings now come with Phil Wood grease.

[Dirt]

Yeah, I've seen the Phil bearings.

I run a set of Enduro bearings on my main trail bike and they have been way more durable than the Raceface ones.

It is cool that there are more options now. I just wish it were possible to run a 5-bolt crank with external bearings. I like the 20t granny gear with 29er wheels with big tires.

Pete

[jabberwocky]

I just wish it were possible to run a 5-bolt crank with external bearings. I like the 20t granny gear with 29er wheels with big tires.I love hearing about the obscure problems you 29er folks have. ;)

[DaveG]

I love hearing about the obscure problems you 29er folks have. ;)

Actually, don't you really mean "I love hearing about the obscure problems you weak legged folks have. ;)"

[jabberwocky]

Actually, don't you really mean "I love hearing about the obscure problems you weak legged folks have. ;)"That would be redundant. Since, you know, all 29er riders have puny, weak legs. ;)

[Dirt]

I love hearing about the obscure problems you 29er folks have. ;)

I seem to have more obscure problems than most. I'm not sure that they have anything to do with wheel size though.

Pete

[jon_baler]

Yeah, I have both. The Shimano is simply a much better design. I can only guess that they've patented it somehow to keep other companies from using it.

The Shimano design does have it's benefits, but I hate the special tool that you need. It would be much better if they just used a regular allen wrench, but I guess they wanted to keep people from over tightening.

[jed]

For square vs ISIS, go square. And go with the Shimano UN series BB's. I have a Phil Wood, and it is nice, but the Shimanos work just as well and are way cheaper.

External bearing cranks are better as far as stiffness-to-weight, though. I prefer Shimano or FSA, as I have had great luck with them. The FSA afterburner has a pinch bolt design similar to Shimano XT. I have a set of Afterburners and I like them, they are comparable with XT's. But I think the XT's are the go-to crank, it's hard to beat them for performance vs value vs weight vs durability. But if you have the bling, the XTR M970 is the ultimate. Race Face is OK, I run the Deus XC crank on my SS, but I gave up on their bearings and run XTR bearings instead. No issues since I switched to those. I probably would not buy another Race Face crank.

[mscard]

I guess I'm the odd ball out but I'm used to it!

Between square taper and ISIS I'd go with ISIS. It's noticeably stiffer than square taper, just make sure you use a lot of the right color loctite on the crank arm bolts - I did have one come loose at the 12hrs of Cranky Monkey on my last lap. I have not had the rumored bearing problems others have had and I run one on my daily commuter which is exposed to rain, snow, mud and just about every weather condition without the level of maintance it deserves.

The outboard bearing design is nice but also a bit of a PITA. Tensioning the system properly is a hastle and the bearings seem to take much longer to break in - at least on the FSA and Race Face systems I'm using.

[dominicosavio]

Which ISIS BB do you use?

[mscard]

- American Classics on my cross bikes
- Stronglight on my MTB race bike
- A basic Race Face on my spare MTB (this one has the least use on it).