[CabezaShok]

I got a Truvative Howitzer Blaze crankset/GXP BB for cheap, i havent installed yet, as i dont own the special tool to do it. I was planning on using these on my commuter MTB but the GXP 140mm wide external bearing BB seems better suited for AM/DH instead of commuting....but im not sure.

Q: is the GXP Howitzer bottom bracket overkill for commuter?
Q: For reliability, should i stick with ISIS V.S GXP?

Id be greatfull if someone could chime in on this.

 

[AndrwSwitch]

Isn't the Howitzer line specifically marketed for downhillers? It looks huge... Did you just buy it because it was cheap? A deal's only a deal when it's on something you were going to buy anyway...

ISIS wasn't renowned for reliability, due to the size of the little balls in its bearing relative to those in a square taper bottom bracket. I'd guess that Truvativ came up with the Howitzer to buy themselves a little more space for bearings, before the external bottom brackets came out.

My general attitude with my commuters is that it's a bike I'm going to expose to rain, snow, road sludge, thieves and vandals, and never compete on. So any expenditure beyond the minimum is overkill. That means that if your current crank is actually broken and this DH crank is the cheapest that'll keep it rolling, it's the right one. Otherwise, don't bother. If I had to replace the crankset on a MTB-based commute bike, I'd probably get this one.

http://www.bikesonline.com/deore-m590-170mm-2-pcs-crank-bb-26-36-48-black.htm

or maybe an Acera or Tourney crank with the same gearing. 44t is often not enough for a 26"-wheeled MTB with slick tires.

 

[CabezaShok]

Why did i buy these? Well my LBS gets brand new OEM crankset+BB combos for cheap, and the LBS mechanic said external bearings are WAYYY better. Like you said i should have bought something like the 26/36/48T Deore crankset you posted, but my Truvative Howitzer+crankset and BB cost me only$69...but i should have considered id need to spend $30 on a GXP BB tool (wasted money if GXP is better for DH/AM use) Durability is paramount for me... and im reading that external bearings in GXP wear out fast

So ISIS isnt that reliable....and i guess square taper is the only way to go then?

 

[AndrwSwitch]

I'm rather fond of my external bearing crankset.

But if all you want is service life and you're good at installing crank arms correctly, square taper actually does have a really good record. I think it fell out of favor because some riders can feel flex using that style of bottom bracket and incorrectly installed crank arms get badly damaged if they develop play. (Correctly installed ones would too, but it shouldn't come up.)

I don't think my BB tool cost $30...

 

[Jvan_wert]

For a commuter? The old square tapers that you can press apart and re-lube, treat em right they will longer than you. You want to go external bearing BB check out real world cycling web site. Their external BB don't have that plastic spacer like shimano or race face does and they come with double seals to keep the water out.

 

[Thor29]

I disagree with the other guys. If you have it, use it. I am running a RaceFace Atlas AM crank on my main commuter bike. So it's a little heavier, so what? I'm not racing. Also, the tool you need is less than $20 - Universal has the Park BBT-9 for $17. You don't need a Truvativ specific tool - all the external bearings use the same tool so you can use it for other bikes too.