Bottom bracket life?

[daihard]

old'uns said:

Shimano Saint on 2 of mine, seem to be bulletproof.

I've swapped spacers around on one of them to get chainline right when going fro 2x to 1x, no problem as such just cranks slightly offset from centre.

Cheers will have a look at Saints too

[daihard]

LankyFreak said:

daihard said:

Managed to get the frame from CRC last year when they were half price, plus another 10% off. Wasn't fussed on red at the time but that was all they had left in my size but it's grown on me since

Picked up most of the rest second hand bar the forks which are probably overkill for what I use it for

Nice! Always liked a Ragley.

Cheers! Was this or the Hello Dave, which I preferred, but when the frame came up half price I couldn't leave it there!

[Mars]

daihard said:

Mars said:

daihard said:

frisbee said:

daihard said:

Thanks for the replies all.

I've been looking at Sram GXP, the look similar to the Shimano ones I've been using but can anyone confirm they're compatible before I go ahead and order?

Cheers

GXP aren’t compatible, the non-driveside end of the shaft is 22mm, shimano are 24mm.

Thanks for the info, better remove them from my basket!

... also, the GXP is not "located" at both sides. It only has a step in the shaft on one side. Technically an inferior design to the Shimano BB but I think they made it like this to avoid patent infringement with Shimano. Regardless, my GXPs seem to last about 4000 miles through all sorts of abuse including riding through deep fords and flood regularly and I'm absolutely not shy about blasting them with the jetwash.

In lockdown, SRAM GXPs were hard to get. I managed to find one but when it died, I bought a cheaper replacement which, in fairness, has lasted for 3K miles to date and still seems OK.

I also have a couple of bikes with Shimano BBs and you'd have to be really trying hard to overtighten them but as you're having problems with both bikes, I don't think it's an alignment issue. Are you fitting the spacers correctly?

I have 2 spacers on the drive side on both bikes, maybe I need to double check this too if this isn't right? Both bikes change gear fine, I thought the spacers were only to get the chain line right? Happy to be corrected if this sorts my issue

They are but I was wondering if the BB tube was too short or long, whether that might impact how much of the crank spindle sticks out on the non-drive side. The more I thought of it, the more that doesn't matter - the ND crank arm clamps onto the splines regardless of how much the spindle sticks out.

[Note: It's different to the GXP (which I was mixing it up with in my head) where the splines are tapered, so the amount of spline presentation is important, however that's automatically handled by the drive-side not have a dead stop so that side can stick out to compensate for irregular length BB tubes. Theoretically you only need adjust the alignment (with spacers) on the nd-side on GXP although you can add spacers to the drive side to increase your overall BB width up to the backside of the drive side crank arm. I doubt that has much impact anyway]

Anyway... we're back to the problem in hand. I can't help think that if you're having trouble with two separate bikes, it might be how you've installed them but I'm struggling to think what exactly.

[Barchettaman]

7 years on my kid’s Octalink BB, I thought it was on the way out the other week as the crank was clicking/clunking but it (and the BB shell) just needed a clean and regrease of the threads.

The bike has lived outside since I built it in 2017. 3x8 Claris group set.

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

[daihard]

Mars said:

daihard said:

Mars said:

daihard said:

frisbee said:

daihard said:

Thanks for the replies all.

I've been looking at Sram GXP, the look similar to the Shimano ones I've been using but can anyone confirm they're compatible before I go ahead and order?

Cheers

GXP aren’t compatible, the non-driveside end of the shaft is 22mm, shimano are 24mm.

Thanks for the info, better remove them from my basket!

... also, the GXP is not "located" at both sides. It only has a step in the shaft on one side. Technically an inferior design to the Shimano BB but I think they made it like this to avoid patent infringement with Shimano. Regardless, my GXPs seem to last about 4000 miles through all sorts of abuse including riding through deep fords and flood regularly and I'm absolutely not shy about blasting them with the jetwash.

In lockdown, SRAM GXPs were hard to get. I managed to find one but when it died, I bought a cheaper replacement which, in fairness, has lasted for 3K miles to date and still seems OK.

I also have a couple of bikes with Shimano BBs and you'd have to be really trying hard to overtighten them but as you're having problems with both bikes, I don't think it's an alignment issue. Are you fitting the spacers correctly?

I have 2 spacers on the drive side on both bikes, maybe I need to double check this too if this isn't right? Both bikes change gear fine, I thought the spacers were only to get the chain line right? Happy to be corrected if this sorts my issue

They are but I was wondering if the BB tube was too short or long, whether that might impact how much of the crank spindle sticks out on the non-drive side. The more I thought of it, the more that doesn't matter - the ND crank arm clamps onto the splines regardless of how much the spindle sticks out.

[Note: It's different to the GXP (which I was mixing it up with in my head) where the splines are tapered, so the amount of spline presentation is important, however that's automatically handled by the drive-side not have a dead stop so that side can stick out to compensate for irregular length BB tubes. Theoretically you only need adjust the alignment (with spacers) on the nd-side on GXP although you can add spacers to the drive side to increase your overall BB width up to the backside of the drive side crank arm. I doubt that has much impact anyway]

Anyway... we're back to the problem in hand. I can't help think that if you're having trouble with two separate bikes, it might be how you've installed them but I'm struggling to think what exactly.

It's looking likely I'm doing something wrong, agreed. I've ordered another Deore BB for the Ragley firstly as that's the noisiest at the moment. Rode it today and it sounds awful! The cheapskate in me has won but I'm thinking if I install paying attention to how tight I do the preload and also double check my spacers as have both been suggested earlier in the thread, hopefully they're my issue and even the Deore BB will last longer than I'm seeing at the moment.

Cheers again for the replies all

[daihard]

Barchettaman said:

7 years on my kid’s Octalink BB, I thought it was on the way out the other week as the crank was clicking/clunking but it (and the BB shell) just needed a clean and regrease of the threads.

The bike has lived outside since I built it in 2017. 3x8 Claris group set.

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

Wow! 100,000km! I Do about 1500 miles a year so they'd last me a good while!

[TGCOTF-dewey]

daihard said:

Barchettaman said:

7 years on my kid’s Octalink BB, I thought it was on the way out the other week as the crank was clicking/clunking but it (and the BB shell) just needed a clean and regrease of the threads.

The bike has lived outside since I built it in 2017. 3x8 Claris group set.

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

Wow! 100,000km! I Do about 1500 miles a year so they'd last me a good while!

My old xc bike had a sqr taper bb. It did many thousand miles through north Yorkshire rubbing compound all year round and never once needed changing. As BBs go, by far the best for reliability. Cheap as chips too.

[bobbo89]

I used to round square taper cranks for fun back in the day, ok for light duties but for owt else they're ste!

[WPA]

Barchettaman said:

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

I doubt that is correct, most bottom brackets are only 3 / 6 months warranty due to the abuse they suffer.

[daihard]

TGCOTF-dewey said:

daihard said:

Barchettaman said:

7 years on my kid’s Octalink BB, I thought it was on the way out the other week as the crank was clicking/clunking but it (and the BB shell) just needed a clean and regrease of the threads.

The bike has lived outside since I built it in 2017. 3x8 Claris group set.

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

Wow! 100,000km! I Do about 1500 miles a year so they'd last me a good while! [/quote

My old xc bike had a sqr taper bb. It did many thousand miles through north Yorkshire rubbing compound all year round and never once needed changing. As BBs go, by far the best for reliability. Cheap as chips too.

I'd have to replace my cranks if I went over to a square taper BB. Don't really want to spend any more money if I can help it!

[gazza285]

bobbo89 said:

I used to round square taper cranks for fun back in the day, ok for light duties but for owt else they're ste!

The only ones we ever saw with problems when I worked in the shop, were ones that hadn’t been sufficiently tightened, or mismatched standards. Never seen one that had been fitted correctly fail.

[bobbo89]

gazza285 said:

The only ones we ever saw with problems when I worked in the shop, were ones that hadn’t been sufficiently tightened, or mismatched standards. Never seen one that had been fitted correctly fail.

Long time ago now, almost 20 years but back then all the work on my bikes was done by a LBS as I had neither the tools or knowledge to work on them myself.

I think it's more likely I was running cranks that weren't suited for the type of riding I was doing TBH but I still think sq taper is a weak design, never had a problem after switching to ISIS.

[WPA]

bobbo89 said:

I think it's more likely I was running cranks that weren't suited for the type of riding I was doing TBH but I still think sq taper is a weak design, never had a problem after switching to ISIS.

Square taper is fine, loads still use it as it allows better chainline adjustment, my last bike was square taper and got 5000 miles of a Stronglight bottom bracket no issues.

[bobbo89]

WPA said:

Square taper is fine, loads still use it as it allows better chainline adjustment, my last bike was square taper and got 5000 miles of a Stronglight bottom bracket no issues.

For what use though? Road, yeah fine, I'm coming at this purely from a MTB POV

[TGCOTF-dewey]

bobbo89 said:

WPA said:

Square taper is fine, loads still use it as it allows better chainline adjustment, my last bike was square taper and got 5000 miles of a Stronglight bottom bracket no issues.

For what use though? Road, yeah fine, I'm coming at this purely from a MTB POV

Folks used to race DH on them in the 80s and 90s without major issues. Middle burn ST cranks were bomb proof.

[bobbo89]

TGCOTF-dewey said:

Folks used to race DH on them in the 80s and 90s without major issues. Middle burn ST cranks were bomb proof.

I'm talking Truvativ somethings circa 2003/04....

[gazza285]

bobbo89 said:

….Truvativ...

There’s your problem.

[Barchettaman]

WPA said:

Barchettaman said:

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

I doubt that is correct, most bottom brackets are only 3 / 6 months warranty due to the abuse they suffer.

10 year warranty, apparently.

“SKF wanted to design a bottom bracket with a maintenance-free life expectancy of 10 years or 100,000 km (65,000 miles) under harsh conditions, so they had to address these concerns. They also made all parts from stainless steel or aluminum, so corrosion is not an issue.”

[gazza285]

Barchettaman said:

WPA said:

Barchettaman said:

The SKF square-taper and Isis BBs are guaranteed to 100,000km I think.

I doubt that is correct, most bottom brackets are only 3 / 6 months warranty due to the abuse they suffer.

10 year warranty, apparently.

“SKF wanted to design a bottom bracket with a maintenance-free life expectancy of 10 years or 100,000 km (65,000 miles) under harsh conditions, so they had to address these concerns. They also made all parts from stainless steel or aluminum, so corrosion is not an issue.”

We used to fit FAG bottom brackets, the cups were plastic, so corrosion was never an issue. I cannot recall ever exchanging one that had worn or broken.

[Lotobear]

I've rarely had to replace BB's but on cleaning my 5 month old Nukeproof Scout yesterday I discovered the bottom bracket was utterly shagged out, massive lateral play.

I stripped it and discovered knackered Chinese bearings leaking rusty water. I would have claimed were it not for the fact that CRC have no gone tits up.

Happily I found a brand new pair of Hope cartridge bearings in my stash that I must have bought years ago from my old Commencal - fortunately exactly the right size so all is now well.

...but I would have expected much better of a bike with a RRP of £2,500 than stty Chinese bearings in the BB. It has seen a lot of wet riding this winter but even so.