New Bottom Bracket / Crankset **HELP**

[Steven W.]

I'm riding a 2008 redline monocog29er and I want to replace the bottom bracket and crankset. I've been looking at the external bearing integrated set ups, but don't know anything about them. The current bb is 110.5 x 68 square taper. What size should I be looking for? What brand do you guys recommend? Know of any shops in the metro that might carry something in stock for quick turn around? Thanks for any help.

[Tomg]

Integrated and external bearing are two separate things. Shimano has a new integrated BB and then there is the BB30 standard supported by Cannondale, FSA, and a few others. For integrated you must have the correct BB shell because the bearings are a press fit into the shell so you can rule that out right away unless you want a frame maker to do some serious welding on your frame.

In the realm of external bearing BB's any of the Shimano Holotech's are good, as are the RaceFace. I'm partial to the Shimano XT, as it is pretty much bomb proof, but know lots of happy RaceFace users. I'm staying away from Truvative. Too many horror stories out on MTBR.

My $0.02

[Steven W.]

Integrated and external bearing are two separate things. My $0.02

Thanks for the info...didn't do enough research to learn that on my own. Thanks Tom!

[manual63]

I have actually had great luck with the Truvativ Stylo cranksets. I was riding one on the XXIX for awhile and did a lot of beating on them.......and I had zero problems. Now I have a set on my Redline and so far everything is sound.

I think the problems people have with many cranksets is that they are not installed properly. That is the most important part, make sure they get installed correctly or you will ruin a set faster than you can say....."tweaked splines".

[Steven W.]

What's the BEST way to determine what size BB i'll need to purchase assuming i've got the the 110.5mm now?

[bigpeddler]

I have not had very good luck with Truvativ. The crank arm presses it's way on to the inner BB shell.

I have had great luck with my Shimano XT.

Any external BB should work...you have a 68mm shell width and they come with spacers. The 110.5 is your square taper spindle length...not sure if I know how to convert that into a modern crank

[Yeti-Mclovin']

Just stay away from any crankset that has the driveshaft pressed on the non-drive side crank-arm i.e. Raceface and maybe the Truvativ Blaze - for which I have no experience. On this type of crankset the Circumlongitudinal forces that act on the drive side cause the cranks to wear out the splines really really really fast ( I took care of one within 300 miles - under normal riding conditions, kept it clean, removed, cleaned, lubed, reset to torque, etc. and still had prob's).

I swapped out the Raceface ( after changing 3 bb's and a crank-arm) for a Shimano XT - which has proven - bombproof and with a very good warranty exchange program.

Raceface cranks suck ., . . period. DO NOT GET ONE. I know of several people whom have had this problem. And if you have a Race Face Deus or Evolve and you haven't had this problem . . . then you aren't riding hard or frequently enough! :cool:

[El Chupacabra]

I have actually had great luck with the Truvativ Stylo cranksets. I was riding one on the XXIX for awhile and did a lot of beating on them.......and I had zero problems. Now I have a set on my Redline and so far everything is sound.

I think the problems people have with many cranksets is that they are not installed properly. That is the most important part, make sure they get installed correctly or you will ruin a set faster than you can say....."tweaked splines".

I agree. I have both Truvativ Stylos and Shimano XTs and they were both properly torqued by me during installation and checked weekly to make sure they aren't loosening up. So far, things have been looking good. The Stylos seem to flex a little bit more than the XTs, but I know better than to take 5 foot drops with them.

[El Chupacabra]

What's the BEST way to determine what size BB i'll need to purchase assuming i've got the the 110.5mm now?

Both cranksets come with the appropriate spacers to cover 68mm & 73mm.

[Tomg]

My comments on Truvative were not based on any personal experience. It's just that they seem to get a lot of criticism on MTBR including a lot of reports of Stylo breakage. Maybe a design defect early in the run????

Regarding sizing. Not sure about the others, but all Shimano HollowTech cranks are designed around the chainline for a 135mm rear hub spacing and a 9 speed cassette. There are no options with regard to spindle length. As long as your bike was designed for a nine speed drive system you should be good to go. (There are a few custom builders out there making offset rear triangles but you won't have to worry about that.)

What you will need to consider is how long a crank to purchase. 165mm to 180mm is pretty commonly available in 5mm increments. Longer cranks = more torque & slower cadence and visa-versa. Zinn recommends 0.21 to 0.216 times your inseam as an optimum crank length. http://www.zinncycles.com/cranks.aspx

[At the Gates 2121]

Raceface cranks suck ., . . period. DO NOT GET ONE. I know of several people whom have had this problem. And if you have a Race Face Deus or Evolve and you haven't had this problem . . . then you aren't riding hard or frequently enough! :cool:


what does not riding frequently or hard enough have to do with this I have the evolves on my bike and have never had a problem with them period. i ride over 1000 miles a year dirt and about 500 paved commuting. I am not really hard on my parts but apparently i dont ride often enough or hard enough maybe you got a bad set of raceface cranks but I have been riding rf for 8 years now and love them .....i had the same thought about mavic for years about there rims being trash I just had a bad set of rims by them I found that out with my next set which was a stock set i know there is more then jsut me that likes race face on the forums. granted it isn't Hope or some other glam brand they do the job for me and do it well

[Yeti-Mclovin']

My point - and sorry if I sounded arrogant - didn't intend to - was actually being stupid while making a point.

I think that riding in MN versus a lot of the riding I was doing in CO, UT, WY is a lot more technical twisty flowy X-C oriented packed dirt/mud which is awesome and may be a bit easier on parts so maybe a R-F cranks would last longer here?

This is comparing to the infamous boulder strewn western X-C trails like Porcupine Rim (The whole Thing), Hall Ranch, Sourdough, Dakota Ridge around Denver) Etc. These trails would literally thrash my and my close friends Race Face cranks due to the design of the product (I've literally seen 4 BB replaced and cranksets) - and I hung in there with'em cause I actually liked'em but I didn't like the life span or the creaking that would eminate from them because the splines would get loose even with a properly torqued retainer bolt due to wear. I even kept the RF cranks and went to an XTR bottom bracket that lasted for about 40 miles between Fruita and Moab near the western rim/westwater mesa area before I got play in the BB again - and yes the whole trip I maintained it and torqued it. So after that trip I was sick of paying out the dough to fix the R-F cranks, got home, and immediately replaced the crankset with an XT due to the pressed on Drive Side crank.

So sorry I should've put a smiley face like this :) instead of the :cool: douche' baggins emoticon.

Didn't mean to offend just more or less I felt like Douche' Baggins when I said that!

[Mike P]

Just an FYI.....If or when you go to external bearings, make sure you have your Bottom bracket(bike frame itself) "Faced and Chased"! This will make sure the bearings are square to your frame and they won't bind or drag on you when tightened up.

[manual63]

A debate about which crankset is best can go on forever. I tend to shy away from Shimano for many reasons, none of them being that they are bad products.

RaceFace, Truvativ, FSA, Shimano and a ton of other brands do make good cranks. But if you are trying to save money and you get a cheaper crankset, then go abuse it......you are asking for trouble. The key is to make sure a good crankset is installed correctly, I can't stress this enough.

Make sure you get the crankset that is built for your riding style. If you get an XC crankset and then do drops and such, you will most likely have issues. I think the reason most people have issues with products is because of poor install or not having the proper product to fit their needs. There are some exceptions, but not many.

In my opinion, MTBR is the last place to go to get a good honest opinion. Too many people jump to conclusions without really knowing what the issues truly are.