# Want to upgrade my B/B, but need advice!



## cam256 (Dec 23, 2018)

Looking to get new bottom bracket for my Kona Honzo. Came with SRAM Powerspline 73mm, which is already crapping out after 3 months of heavy use and I'd like something more reliable, durable and serviceable. Looked at Hope and Chris King, but honestly like what I hear more about Hope overall. I could definitely use some advice! Will I need to purchase an adapter to make the switch? Will I need a new crankset as well, or will I be good with my current set? Any other parts i may need to purchase? Etc
Very grateful for any advice from experienced riders.


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## Battery (May 7, 2016)

What crank are you using? I just swapped my BB out for a SRAM DUB and installed my SRAM GX DUB crank too. The DUB crank lineup uses 29.8 diameter spindles (or 29.9mm, can't remember my caliper measurement lol) and was designed to fit any frame bottom bracket width. If you upgrade, you can pretty much transfer the BB and crank to any frame and adjust the width with the special locking collar. Just a side note, the DUB crank doesn't work with any non-DUB BBs and vice versa. This could explain the difference in spindle diameters versus 24mm or 30mm. 

If you go the DUB route, make sure you get an installation tool that is 46mm in diameter. Standard BBs are 44mm. I got mine from Amazon for about $20. 

I've heard good things about Hope BB's as well. They are very spendy but it seems the quality is very good.


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## Lone Rager (Dec 13, 2013)

If the BB is powerspline, the crank arms are too. When you say it's crapping out, what's going bad. Are the bearings bad or the crank arms loose on the spindle. The the former, you can get another powerspline BB. For the latter, you might get new arms.

Otherwise, you need a new BB and crank. The BB needs to fit two things; the frame and the crank spindle. 73mm threaded BSA is what your frame is and is very common, and desirable over press fit BBs. You can get threaded BBs to fit 24mm cranks (e.g. Shimano, Race Face, etc.), GXP cranks, or DUB cranks with the appropriate threaded BB. I'm with Battery above in suggesting a DUB crank and BB.


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## cam256 (Dec 23, 2018)

My crank is sram nx, its starting to sound like a new bb would require new crank arms as well.


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## cam256 (Dec 23, 2018)

Within even a month of use, the left side crank would keep coming loose after only about a 4 mile ride. I got it tightened down real nice so it doesnt do that anymore, but I could also already notice some play between the crank arms. Now it's rather squeaky, which could be solved with a little maintenance or another power spline, but I ride nearly every day so I figured investing in a premium powerhouse may be a good idea.


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## Lone Rager (Dec 13, 2013)

When a crank arm is ridden while loose, the splines in the crank get distorted and it will keep coming loose no matter what. That's true for just about any crank arm, square taper, microspline, ISIS, etc... The fix is to replace the crank arm. In some cases the spindle may even get distorted, in which a new BB is needed as well. It's always a good idea to tighten crank arms to the designated torque spec with a torque wrench. This helps ensure they won't come loose and get damaged. 

NX is level or grade indication, not a model, so there are many different types of cranks labeled NX.


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## cam256 (Dec 23, 2018)

Sorry about that! I'm not too versed yet, but you're right. The bike shop I purchased my honzo from must have neglected to tighten it to the right specs, or the parts were just bad from the beginning. Not to call them out or anything, I trust in sram's parts as well as the guys at my local bike shop. Either way, based on yours and Battery's recommendation as well as some research, I think going the DUB route will be the best option for me.

Thanks so much for your help and advice!


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## Harold (Dec 23, 2003)

It's also worth pointing out that for most cranks, unless you torque that crank bolt to spec, the arms will repeatedly loosen up. Lots of crank bolts have torque settings somewhere in the 50Nm area (check the crank for verification on torque spec). 50Nm is no f*cking joke for a part that rotates on you when you try to tighten the bolt, so there's a REALLY good chance that the crank bolt has never been properly tightened.

Most shops check crank bolts during the initial build, but it's something that can be easily overlooked. I also question if OP ever took the bike back to the shop who sold it, at least for its initial checkup. This seems like the sort of thing that a shop would take care of ASAP at no charge. Or was this bike purchased from an online dealer?


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## cam256 (Dec 23, 2018)

It was purchased from my local bike shop, and as soon as I noticed the issue, I took it in to them and they had it tightened down to spec free of charge. I go to them with any issues or questions I have usually and they're always very helpful and get me back on the trails. Great guys, great shop, I just think it was overlooked initially.


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## Harold (Dec 23, 2003)

cam256 said:


> Great guys, great shop, I just think it was overlooked initially.


Probably right. And if it keeps loosening, I guess the damage was done and it's not completely fixable anymore.

I know when I was a new guy at the shop, I missed some crank bolts. That shop also didn't have a double-check system in place, either. I've worked for shops since that used such a system for builds. One guy pre-builds the bike, and then afterwards, one of the experienced mechanics goes through the bike to check bolts and fine tune adjustments.


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