30mm BB92 options?
- Thread starter Sandwich
- Start date
Undersized bearings is one reason sucks.
Not saying they don't suck, as I have one currently with dying bearings, but.... The bearing size will be more or less the same size on any BB92x30mm bottom bracket if I'm not mistaken. It's not like someone else has monstrous external cups with oversized bearings. Also, the bearing size shouldn't effect the sleeve situation. I think the issue is that there just isn't much room between the spindle and the frame. It's unclear why RF can fit a sleeve in there and no one else can.
Obviously I need to go to a 24 mm spindle down the line, looking at the 30mm spindle it's freaking huge and I'm pretty sure my legs would break off before I'd have any chance of bending that bad boy. But for now I'm trying to replace a shock before I spend money on a new crankset.
I must be doing something wrong as my 30mm RF cranks don't creak (in a BSA BB though).
Those have nice beefy bearings in external cups. The BB92 are internal in the frame so the larger spindle means the bearings have to get smaller to fit in the same shell. Overall not a great design.
@Jm_ I take back what I said about Enduro. They don't have a sleeve for their design though. I will be riding a lot of mud/rain for the next few months unless the storm gates close over here in Cali so I really prefer having a sleeve. Otherwise the Enduro looks great!
https://nsmb.com/articles/searching-30mm-bb92-solution/
Well, I rode with it all last year, we get lots of mud here, some of our "early" trails have all sorts of water flowing over them and the trail itself can be a river, one of the races I did was 100+ miles and it had rained a lot the few days before, so the race itself was non-stop puddles and splashing mud everywhere. This BB got plenty of mud days.
I took it apart at the end of the season and the grease was still packed in there, impressive given our conditions. That's good enough for me.
I took it apart at the end of the season and the grease was still packed in there, impressive given our conditions. That's good enough for me.
Well then... Non sleeve Enduro back on the table
Is the sleeve such a big deal? They get contaminated from the outside anyway, no?
I'm sure they get contaminated mostly from the outside but I'd rather not have them getting contaminated from both sides. There is a cable routing door in my frame just in front of the BB shell and I can only assume a certain amount of mud and water make it in there.
Sleeves are a double edged sword IME, they keep shit in too, as in water that enters through the BB.
I have 600 something miles on my pivot 5.5 with the wheels mfg kit using the enduro bearings. Havent opened them back up, but will once it dries up around here. They do still feel smooth. I have a bb drain hole, and nearby cable routing. I do ride my bike through alot of creek crossings, my most frequent spot has a dozen crossings. I try not to wash the bike too ofteb.
well,
im at 790 miles now, and they have vertical play on the NDS......
I did ride most days it rained and crossed like 300 to many creeks.....
impressive?
no I live in California
im at 790 miles now, and they have vertical play on the NDS......
I did ride most days it rained and crossed like 300 to many creeks.....
impressive?
no I live in California
Trek is the only company using BB95, right?
I think so. Sounds like most people/everybody else abandoned it or never went for it. Bearings on aluminum shell sounds like a pretty bad idea in general, IMO.
My frame is a superboost, also with a BB92 and I've been pondering crank options, of which there are sadly few.
I did have a random thought about trying to run 30mm DH cranks i.e. cranks that would fit in the old school 83mm BB shells. There's a 2 major obstacles I can see...
1. The BB itself
I'd need a BB that
i) has a 30mm ID to fit 30mm spindled cranks
ii) Interfaces with a 41mm diameter frame/BB shell
iii) Have around 9mm thick bearing housings?
2. The chainline would probably be over the 'ideal' of 56.5mm.
The second obstacle might be able to be remedied with one of those offset direct mount chainrings, my cranks are E13 with direct mount. Not sure about frame clearance...
The first obstacle though... Are there any BBs that fit the bill? An 83mm BB shell that measures out to 110mm (confirmed measurement on my DH bike) uses bearing housings that would appear to be 13.5mm thick. 9mm seems pretty narrow by comparison.
I've attached a drawing below to try and illustrate my point. Any thoughts?
I did have a random thought about trying to run 30mm DH cranks i.e. cranks that would fit in the old school 83mm BB shells. There's a 2 major obstacles I can see...
1. The BB itself
I'd need a BB that
i) has a 30mm ID to fit 30mm spindled cranks
ii) Interfaces with a 41mm diameter frame/BB shell
iii) Have around 9mm thick bearing housings?
2. The chainline would probably be over the 'ideal' of 56.5mm.
The second obstacle might be able to be remedied with one of those offset direct mount chainrings, my cranks are E13 with direct mount. Not sure about frame clearance...
The first obstacle though... Are there any BBs that fit the bill? An 83mm BB shell that measures out to 110mm (confirmed measurement on my DH bike) uses bearing housings that would appear to be 13.5mm thick. 9mm seems pretty narrow by comparison.
I've attached a drawing below to try and illustrate my point. Any thoughts?
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Hi, as I understan it, its a press fit, correct? If so, than the BB is pressed in the frame, the bearings are inside, and DH cranks should work, i have the same BB on My Supreme DH. I use the Hope BB: https://www.hopetech.com/products/drivetrain/bottom-bracket/press-fit-41-30mm-bottom-bracket/
Shimano has great options for Superboost - SLX, XT, and XTR cranks with lengths starting at 165mm for all of them. You also get a decent bearing in a BB92 frame with the 24mm spindle.
I've never seen an external bearing press-fit setup. Not sure it exists.
Not sure where I left this thread...I ended up reluctantly running shimano's bottom bracket with their cranks, and it's worked perfect for about the same amount of riding as I had my evil for. The evil setup was shit, 30mm raceface BB92 setup with 30mm RF cranks. I don't ride much and it still creaked. The shimano setup has been flawless even after I installed it in my basement with a ghetto press.
I do think that BB386 is the best setup going. You can run 30mm cranks with a plastic shell and full sized bearings without issue. It's like an oversized BB92.
So, my suggestion is to do it correctly and get a BB92 bottom bracket with 24mm spindle cranks. Or go for the 30mm BB and end up replacing your BB in short order.
I though an actual "advantage " of super boost rear spacing was running standard boost cranks in the BB for excellent chain line. This is what WeAreOne does with their frames.
I'd go for a Wheels Mfg thread together BB and run 24mm Shimano cranks, or 24/22 SRAM cranks. Ditch the e*13's....
The BB's are awesome, best application for that crappy pressfit system. I have had a few of them over the years, fully bombproof and smooth as silk.
How the F am I suppose to get my vice grips around that? Looks like it’ll break right off.
I got one bike with the dipshit92 standard and I do run 30mm, but it’s for XC only and I’m running the hope/enduro double row no-shell BB. I don’t really recommend this except for light riding or XC. It’s not worth it in the long run. When BB92 was being developed 30mm Next cranks showed up and the mfrs that knew better speced them on the BB92 frames that were designed for 24mm spindle cranks, shimano specifically. They just wanted to be able to have a lighter bike than their competitors, so they speced Next cranks instead of what they designed it for. The BB92 frames are better with a 24mm spindle. This is why sram moved to dub, they were in a rock and a hard place as more frame manufacturers jumped on BB92.
We aren’t using special tools anymore. Just multi-tools, like pipe wrenches.
Morning all. I think I've confused the message. So, a clarification...
I've already got some 24mm Race Face OEM Aeffect cranks in there. They're fine, but I'm thinking about future upgades. They actually weigh only 650g with 30t chainring. XTRs cost an arm and a leg (plus whatever else) and only shave off about 100g. F that.
That got me thinking about about other options that would fit. Ideally I'd keep the BB in there, as it's creak free and spins well. No need to fix what isn't broken. However, what we know is that there's basically not much going for 24mm crank upgrades. The only thing that comes close are some older XO/XO1 GXP 73mm cranks, direct mount, with a superboost chainring. I'd have to use a GXP adapter if I want to keep the BB in... anyone have experience with those? That's the least difficult option, but I'm wary of adaptors in BBs. Not sure....
That inevitably got me to thinking about swapping out the BB. Ideally I could run a 30mm spindled crank, but as @Jm_ has mentioned, the existing options require far too small ball bearings. Definitely a no go for me. Hence the whacky 83mm cranks in a BB92 idea I posted up there. Sounds like that's not going to be a possibility.
So, if we still consider swapping out the BB, then my only two options are either:
1. Dub BB. Anyone used these in a BB92 frame for an appreciable amount of time? The bearings will be slightly bigger than in the 30mm BB, maybe that's enough to allow for decent longevity? SRAM would have us believe so, but does anyone have any real world experience with them?
2. GXP BB. Certainly I'd have no qualms about those bearings. It is an older system though, so parts will be getting more limited.
TL;DR
Cranks are installed, I'm looking for upgrades for weight loss
DH cranks are out, the BB I'd need doesn't seem to exist
XTRs are out (unless someone sells them cheap), poor cost: saving ratio. 100g for approx $600 AUD. Ouch
GXP Sram cranks could be used with adaptor, not sure whether I'm asking for creaks though. GXP cranks could also be used with a proper GXP BB92. The first option is easier, but either option gives a decent cost: saving ratio
Dub BB is a consideration. Probably best cost: saving ratio, but I'm not sure about a DUB BB in a BB92 frame.
Hopefully that makes sense, although I realise it is a bit complicated! Any input is most welcome, direct experience with the above is best.
Cheers all!
I've already got some 24mm Race Face OEM Aeffect cranks in there. They're fine, but I'm thinking about future upgades. They actually weigh only 650g with 30t chainring. XTRs cost an arm and a leg (plus whatever else) and only shave off about 100g. F that.
That got me thinking about about other options that would fit. Ideally I'd keep the BB in there, as it's creak free and spins well. No need to fix what isn't broken. However, what we know is that there's basically not much going for 24mm crank upgrades. The only thing that comes close are some older XO/XO1 GXP 73mm cranks, direct mount, with a superboost chainring. I'd have to use a GXP adapter if I want to keep the BB in... anyone have experience with those? That's the least difficult option, but I'm wary of adaptors in BBs. Not sure....
That inevitably got me to thinking about swapping out the BB. Ideally I could run a 30mm spindled crank, but as @Jm_ has mentioned, the existing options require far too small ball bearings. Definitely a no go for me. Hence the whacky 83mm cranks in a BB92 idea I posted up there. Sounds like that's not going to be a possibility.
So, if we still consider swapping out the BB, then my only two options are either:
1. Dub BB. Anyone used these in a BB92 frame for an appreciable amount of time? The bearings will be slightly bigger than in the 30mm BB, maybe that's enough to allow for decent longevity? SRAM would have us believe so, but does anyone have any real world experience with them?
2. GXP BB. Certainly I'd have no qualms about those bearings. It is an older system though, so parts will be getting more limited.
TL;DR
Cranks are installed, I'm looking for upgrades for weight loss
DH cranks are out, the BB I'd need doesn't seem to exist
XTRs are out (unless someone sells them cheap), poor cost: saving ratio. 100g for approx $600 AUD. Ouch
GXP Sram cranks could be used with adaptor, not sure whether I'm asking for creaks though. GXP cranks could also be used with a proper GXP BB92. The first option is easier, but either option gives a decent cost: saving ratio
Dub BB is a consideration. Probably best cost: saving ratio, but I'm not sure about a DUB BB in a BB92 frame.
Hopefully that makes sense, although I realise it is a bit complicated! Any input is most welcome, direct experience with the above is best.
Cheers all!
So I've been on wheels bb92 30 for a while
I buy sram xxo and xx1 cranks with the old super narrow q factor for cheap like 200$, knock the spindle out and I've got a race face spindle (theg make a lot of lenengths) in there with a wave washer that gives the narrowest q I can fit.
I got around 1500 miles per bottom bracket.
Maybe 2500 miles on the crank arm.
Stated looking at dub and dub bbs when I had to replace the stuff looks like the wheels and enduro bbs are just the bb92/30 with a spacer....
Went back to what I was doing before.
I buy sram xxo and xx1 cranks with the old super narrow q factor for cheap like 200$, knock the spindle out and I've got a race face spindle (theg make a lot of lenengths) in there with a wave washer that gives the narrowest q I can fit.
I got around 1500 miles per bottom bracket.
Maybe 2500 miles on the crank arm.
Stated looking at dub and dub bbs when I had to replace the stuff looks like the wheels and enduro bbs are just the bb92/30 with a spacer....
Went back to what I was doing before.
huh, these guys seem to like the aeffects: https://nsmb.com/articles/race-face-aeffect-cranks-boxing-above-their-weight/
you're right about the xt/slx being heavier. Is it steel spindle vs. aluminum? You may gain some stiffness, but probably not much. I don't really agree with carbon cranks on a MTB, but you can if that's your thing.
you're right about the xt/slx being heavier. Is it steel spindle vs. aluminum? You may gain some stiffness, but probably not much. I don't really agree with carbon cranks on a MTB, but you can if that's your thing.
Is that shite because of shite weather infiltrating bearings and gumming things up?
Or shite because of inherent deign flaws?
I've got GXP on the roadie and it's done ok so far...
Not sure whether you're replying to me, but that's my experience. Race Face cranks in 24mm are surprisingly....adequate....in many ways. That said, I'm drawn to carbon becuase of weight savings, but not at the expense of replacing BBs.
Funnily enough, I found the same thing when I had RF Chesters on my first DH bike. I was expecting them to weigh a ton, but they were lighter than expected and pretty stiff.
I was, failed to quote. I think I have chesters on my DH bike. I do NOT like the way they go together (single bolt) but they are fine.
Do the GXP/X01 etc. setup have a BB92 setup? that could be OK even if you have to replace them regularly. I think my shimano BB cost me like $19. I'd gladly replace that once a year if it stays quiet until it gets crunchy (but it hasn't). Even if the GXP setup fails, if it's cheap then so be it.
is the RF steel or aluminum? I imagine you can save a bunch of weight with an aluminum spindle...if it's strong enough. My easton CF cranks are like 392 or 420 (blazeit) or something stupid. The shimanos sit at 600g pretty much regardless.
north of 600g with chainring.
xtrs are just under 500g without chainring.
no idea on race face, their cranks aren't something i'd consider.
I think you can't have alloy 24mm spindles, that diameter doesn't work with the material properties. Possibly might if the wall of the spindle was very thick, likely negating any weight advantages.
yea, if shimano could figure out how to reduce the spindle weight they'd have cranks with weights that would be comparable to carbon or eewings.
OK- I think I'd keep my eyes open for an older GXP X01 crankset and either run the adapter (they are cheap) or replace the BB with like a wheels MFG setup. I wouldn't go back to 30mm spindles in BB92 and I'm not convinced that DUB is any good. Maybe you can find a NOS setup or something that is barely used. Otherwise same deal with XTR...they don't seem to change much year to year so 3 YO XTR is still a nice setup.
TBF pretty much all modern BB standards are pretty poor at stopping that
this
what sort of weather and mileage are you heralding as "OK"?