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Discussion Starter · #1 ·
Im currently riding a GT Palomar AL that I bought 3 years ago which has been great to me! My frint derailleur has become a little bent out of shape and is a hassle to dial in to get proper shifting. I want to convert it to a 1x drive train for simplicity sake but I think I want to uograde the bottom bracket as well. Currently has a threaded square taper, cartridge sealed bracket and was wondering if I could fit any other bottom bracket as long as its the right size? Can someone explain to me what I would need to know before I go a buy a new bracket and crankset?
Thank you all in advance!
 

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Bottom brackets go between the frame and the crank. As such, they have to fit both. A BSA threaded bottom bracket will fit your frame and they come in different flavors to fit different crank spindles. You need to chose a crank that will work with your frame and a threaded bottom bracket that will fit that crank's spindle. The crank needs to have the appropriate spindle length and chain line for your frame.
 

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You could be better off just buying a complete new crankset with Bottom bracket, that’s what I’d do.

There may be some information about your bottom bracket either stamped or engraved on the bottom of the frame. Flip the bike over upside down and look at the bottom bracket part of the frame. It may tell you the width of a BB that your frame will accept.

I am not familiar with that frame so i don’t know whether it used a threaded or press fit bottom bracket.


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More than likely is a BSA threaded. Italian thread very uncommon, so I'm sure a BSA should fit it.

Key would be to measure the BB she'll so that you know if it's a 68/73 or an 83. That will make a big difference.

If it's 68 or 73, it's simple as getting a basic BB of your choice that fits your new crank you choose and put appropriate spacers to ensure correct chainline.

If it's 83, need a BB and crank specific to that. I'll say I highly doubt it's an 83.

Have any ideas of which crankset you're wanting to use or budget for it? Reason I ask is with multiple spindle sizes (hollowtech, GXP, DUB, and 30mm), there is a huge range of brackets ranging from **** to very good. I've run nearly all of them, so I can give feedback on what I've liked there.

Hope that helps

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I recently took everything apart to clean. The cartridge says 73mm and I was thinking of hollowtech. I havent done much research on cranks yet.
What budget you got for it?
Hollowtech is good with lots of inexpensive options for both.
GXP is the old SRAM interface. Works well, but might be tough to find brackets once SRAM fully goes DUB.
DUB is new SRAM BB. Gives stronger crank feel with slightly better bearings than 30mm. Being newest, can be pricey, but Truvativ has some good DUB cranks reasonably
30mm is what I run now. Lot of **** BB out there that get crunchy quick. I bought a wheels manufacturing one and it's awesome (they also make Hollowtech as well). They're expensive BB, but are extremely well made, spin like nothing else, and you can replace the bearing cartridge without replacing the cup from frame.

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Discussion Starter · #8 ·
I would like to go a cheaper but still reliable route. It is an entry level MTB that I use for a lot of road and trail riding and Im planning on buying a new bike in the next couple months so I dont need any "crazy" upgrades. Ive looked at some Hollowtech bottom brackets and theyre not all that expensive so I will probably go that route. Can you reccomend some mid-upper range models, if thats how they break down? Also, as far as cranks go, can I just get any hollowtech compatible crank sets? Ive been hearing a bit about chainline and spacers. I understand the concept of chainline but wondering how my crank choice will give me the best setup
 

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You have a $400 bike.
What do you think you'll gain from "upgrading" the b/b?Aside from making your wallet $200ish lighter....
Unless there's something wrong with the b/b....ride the bike.
Save that money for the new bike
 

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Discussion Starter · #10 ·
Current bb is rough, chainrings have wobble throwing iff my front derailleur which is bent out of shape. I wana convert to a 1x not using the stock chainrings. Square taper from what I hear is just old and outdated and leads to chainring wobble. So why wouldnt I want to replace it
 

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Current bb is rough, chainrings have wobble throwing iff my front derailleur which is bent out of shape. I wana convert to a 1x not using the stock chainrings. Square taper from what I hear is just old and outdated and leads to chainring wobble. So why wouldnt I want to replace it
Square taper b/b does not lead to chainring wobble.
But hey....good luck.
 

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Chainline determined by BB shell and rear hub spacing.
Do you have a QR skewer or an axle? Need to know spacing for rear hub, as that will determine crank chainrings.
https://www.chainreactioncycles.com/mobile/us/en/race-face-aeffect-single-chainset/rp-prod146212
I run Race face Next cranks (love them). This is alum "little brother" that works quite well. Works with hollowtech BB.

https://www.jensonusa.com/Shimano-M640-Zee-6873mm-Crankset-W36T
Good Shimano Zee. Single ring, bomb-proof. I have used this in the past and liked it. Also uses hollowtech BB.

https://www.jensonusa.com/Truvativ-Descendant-6Kal-Eagle-Dub-Crank
Uses DUB BB. Larger crank spindle, so slightly stronger. These are inexpensive and work well.

https://www.jensonusa.com/Ethirteen-TRS-170mm-Crank-Arms
These are great. Unique chainring interface. Uses direct mount rings. 30mm bottom bracket. If you go this, don't go cheap on the BB. Cheap 30mm BSA just wear out fast

I buy my parts with the intention that they will go from frame to frame on my bikes. I build my own bikes and wheelsets.

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I still have a square taper BB on my 1995 Boulder Defiant. Your BB is not causing any wobble. There's no real performance gain by "upgrading" your BB. What does "Current bb is rough" mean? Maybe you need to clean it. It makes no sense to spend 50-75% of what your bike is worth on a bb/crankset, but hey, I've done nonsensical crap before.
 

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Agree. Square taper is a perfectly solid BB design that has been around forever. You can get a new Shimano square taper cartridge for something like $25 and it will be nigh bulletproof. You can get a 110/74 bcd square taper crankset for around $60. Then you'll need to figure out what ring you want to put on that. A good LBS can help you out with all that.
 
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