Have you asked them?

Only reason to swap the bottom bracket is;

a) it is faulty or worn (but they just did that for you)
b) the crankset they are fitting requires a different BB standard. In which case, why?

New cassette and chain is normal when they are worn. But why a new crankset 🤨

Seriously there is no way for us even remotely guess if this is called for without any information at all. You will have to ask them what their reasons are. You can also mention that the BB has been recently changed by them. Come back here with whatever explanation they give you after that and we will be able tell you if it sounds plausible at least.

I think it's worth learning to do all these repairs yourself. Not to actually do so all the time, but so you have a better understanding of the bike and the time involved in fixing it. Then, if you decide to return to using shops for service you'll be a more informed consumer.

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http://www.jt10000.com/

The lifespans of the parts you listed are all different so its pretty unusually to need to change everything at once.

If the cassette is shot its good practice to replace the chain as well but this will be the cheap part of the fix. You need to find out what the shop thinks the problem with the cranks are as this is the expensive part in terms of replacement cost. It will also be helpful to know what type of bottom bracket you are working with.

If you have an old square taper style bottom bracket that was on the bike for many years I suspect the shop are correct. The crank arms will be damaged where they attach to the BB and will have in turn already damaged the 'new' BB. The best remedy is a new BB and crank. If you have a newer pressfit or threaded BB the cranks should last as long as the bike frame so it very unusual that they need replacing. If something has gone wrong with modern cranks the new style BBs are cheap so I can see an argument to replace them whenever you change the cranks. Overall the question you need to ask is what is wrong with my cranks.

I have had a similar experience and was quoted £150+ to replace the parts and 'service' the bike. In reality all the bike needed was a new 7-spd cassette and a chain and I only took it to the shop because the bike uses a old cassette+freehub one piece systems and I didn't have the special tool required to change it. I spent about £40 on the required tool plus the new parts and 4 years later its still running fine.

Yes. Definitely :). Or maybe not ...

If your drive train is worn, you don't need a whole new crankset, just new chain rings. And those are dead simple to replace yourself.

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Taco cat spelled backwards is....taco cat.

Maybe the original poster misunderstood and it was chainrings. That would make a whole new drivetrain which is common if the chain is old and stretched and wasn't replaced soon enough.

but if it is a loud squeaking / cracking sound, it could be that the crankarms themselves are damaged. Depending on the crankset being replaced vs what the LBS has available to replace it with, that could mean a new BB even if the BB is fine. The old square taper BB's came in about a bazillion different widths, that needed to be matched to the frame / crank combo.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

I don't think it's worth it to learn all this stuff - and I did it myself about 2 years ago.

It's too time consuming to learn and you do it so infrequently (like replace a BB) that you will forget most of how to do it by the next go around.

Learn it if you think it will be fun for you, but it's a mixed bag in terms of a time investment even if you're a long-term committed cyclist. At least in my case, I made so many mistakes en route to getting to 'right' that from a cost-benefit perspective, it was likely better to be overcharged once by the LBS than to spend 3 weeks troubleshooting each suboptimal part. And yes, you will make every mistake in the book and a lot that the book won't even come up with if you teach yourself.

I recall spending 4 weeks and hours on end troubleshooting my shifting that would work fine for like 3-4 rides, then suddenly and abruptly crap out to the point I could barely shift. Looked online, forums, etc., no easy answer, so I had to figure it out myself. The problems:

- Had passed the RD wire the wrong way on the bolt. REALLY easy to do, but it's hard to troubleshoot if you don't specifically look for it, and the wire will slip at a key moment
- Didn't put a metal ferrule on my shifter housing in the brifter. Turns out the wires from the cable housing started popping out and pushing through the brifter rubber - I only noticed it a few weeks later when a housing wire poked me in the hand since it went thru and thru
- Bent rear hanger. Took me a week before I justified spending the money on a hanger adjuster, which finally fixed it
- Cable housing bend too tight - slowed shifting

Not big errors, but combined, were enough to tank my riding for a month. And that was just one of many DIY errors that compounded over time. I think I've got most of it figured out now, but I def wouldn't say it was worth my time in retrospect, esp since once I got it right, I didn't have to mess with it again, ever.

Depends on the person. Some people are quite mechanically inclined and have no problems tinkering, figuring things out and getting them to work. Both of my grandfathers were like that, they could fix virtually anything. (one was a machinist, the other a carpenter / general contractor) Show them how to do something once, and they would be able to do it again even years later.

Some people try to drill holes in the wall with the drill in reverse (my dad). He's better off paying a mechanic. He became an accountant.

I'm more like my grandfathers than my dad, but not quite at their standard.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

Yeah, I guess.

This is going to sound harsh, but your list of errors is a lot. If you follow instructions that kind of stuff shouldn't happen so much.

Also, keep in mind that it's not "once" your possibly being overcharged if you don't know, but for your whole life of riding.

But yeah, your and everyone's MMV. Perhaps my advice is only for people who are pretty good mechanically in general as Jason points out.

I will add that I mainly learned by figuring things out, but that was a long time ago.

Nowadays with stuff like the Park Tool website, torque wrenches etc, it seems pretty straightforward to get things right. An installation might take time to read the details and do it slowly - and for sure that's a cost some people don't have. But go step-by-step and it's not that hard for must stuff.

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http://www.jt10000.com/

That's what YouTube was invented for!

Jason,
I finished lowering your saddle for you.
Oh, and the weird noise you were complaining about, it was just an empty gel pack jammed in your cassette.
That'll be $125. :)

When you say they "fixed it" the first time you took it in, did they actually replace the BB then or did they pull it out, clean it up, regrets and put it back in? You don't necessarily need to replace it to stop creaking. Maybe it had life left in and they didn't replace it the first time but now it's worn out.

It's still too high.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

This.

At least if you're decent mechanically in general.

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http://www.jt10000.com/

I honestly don't think most bike maintenance requires one to be that mechanically inclined. I've been teaching myself as I don't want to spend money to have my indexing done or derailleurs adjust or brakes or size a new chain.. It takes a lot of patience at first. I've changed my bottom bracket and crankset which was stupid easy. It's also why I don't ever want a pressfit bottom bracket as I don't have the equipment to do that myself. In the long run it saves me a lot of money. Occassionally I will run into some frustration where I can't get something just right and I take it into my LBS. I think with youtube there are a million videos showing how to maintain your own bike.

You don't have to be mechanically inclined, I agree. But you WILL need to be ready to invest more time than you expected, depending on what the job is.

I actually found it unusual that everything would work out just as it did in the videos (which are a great resource - I wouldn't have even attempted my full bike overhaul without them!)

If there's even one small difference, it can make a huge difference, as I mentioned with my examples of the missing ferrule in the brifter, etc., in my examples above. The difference here is that a good bike tech will fix this instantly AND have the part on hand right away, whereas you as a DIYer, will have to deal with a bit of time and frustration, as well as wait for parts. (I felt like an idiot ordering tiny ferrules, but turns out they are important!)

I will say though that if you don't count the time lost to DIY learning, the dollar cost is substantially lower when you DIY your bikes, even if you're buying a good deal of extra parts and tools. My LBS charges $20 to change a front brake out, and that does NOT include the cost of the brake. If they have to redo cabling, that's another $15, or $25 if internal cable routing is required. That's something I can do super fast and easily now, although I will also admit I bought an entire extra front brake the first time as I didn't have the right long mounting bolt (yet another small piece that foiled me) to mount it. Still ended up a lot cheaper than the LBS.

The videos help to dumb things down, but I learned all this stuff back in the pre-internet dark ages, by taking apart my bike and then trying to put it back together. Those were the days when mechanical knowledge was more important (cable housings were unlined and cables weren't stainless, loose ball BB's in the hubs, BB, and headset, cup and cone adjusters. Most components could be rebuilt rather than thrown out. Learning the importance of Loctite on Italian threaded BB's. Trying to center the old style single pivot brakes was a challenge, since they couldn't be so tight that the calipers didn't move, but they had to be tight enough that they didn't shift off centre.

Now it's a lot simpler, but I don't think I've ever actually used a youtube video to figure out how to fix something on the bike. even bleeding my disc brakes, which is probably the trickiest thing to do on modern bikes, was a matter of pulling them apart and seeing how they work.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

This all is true.

So unless you're an expert, don't let their be differences. Even seemingly small differences.

For sure this makes the work time-consuming, and for sure it can result in the bike being unusable when you find you need another part. But it's not that complicated if you have new, fairly standard parts and follow instructions exactly (unless you are sure that doing it differently will work - which only comes with experience).

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http://www.jt10000.com/

I agree with pretty much everything you said. It always depends. I think for my tri bike I'm a little more wary about messing with cabling as it's a little more complex so it would take longer. but for things like adjusting derailleurs and indexing gears the more I do it the faster and better I get it. some of it I enjoy doing until it gets super frustrating. I'm upgrading my groupset on my road bike buying used components off of ebay and doing the work myself will save me a ton. But I'm planning on that taking awhile.

I learned stuff like that too.

But more recently I've learned by video or at least good instructions.

I remember maybe 10 or 15 years ago installing a threadless headset for the first time. There were parts of the process that frankly did not make sense to me and I was super-worried doing them. But I got the right tools and just followed instructions - came out perfect. With new, non-exotic equipment that's it - follow the instructions and it's done. It's like baking a cake from cake mix.

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http://www.jt10000.com/

I wouldn't say it's THAT easy. Ok, if you have all the perfect parts ready to go, that totally match the video, it might be.

But tiny variations make a big difference, and for a rookie that hasn't seen it before, that can add up to a lot of frustration and time lost. It all looks easy peasy as pie on the video, but the moment you have one part that doesn't quite fit, or you route something slightly the wrong way, major headache can ensue.

In all my cases of frustration, it was NEVER a situation where I was doing something so obviously wrong that the video pointed it out. It was always some tiny-seemingly little thing that no video mentioned, but busted your entire plan.

Again, I'm saying this as an ex total rookie bike noob who has zero mechanical background, no bike tools, nothing. So I certainly would do 10x worse than anyone who may have used tools around the house at least a little. But I learned a LOT!

I guess my take home message is that 90% of my time was spent troubleshooting tiny-seeming things. It only took 10% of the time to get nearly the entire job done as the videos suggest. But that last 10% was never explained properly on a video, and can be really annoying and take a shockingly long time as a rookie noob.