This has already been discussed but I cannot find answers to my particular situation.

I have a Giant Defy 2.5 (2009) with a triple crankset. The cranks are FSA Vero 30/39/50, the cassette is a Shimano HG50, the BB is a "FSA cartridge".

I want to switch to a double. I have the opportunity to purchase a Shimano 105 5800 Groupset (it comes with - I believe - a SM-BBR60 bottom bracket). The kit has everything needed (chain, shifters, BB, brakes etc.).

My question is, will it fit? (and if so what special tools do I need to replace the BB - which I find the most confusing part of the upgrade since I am not a mechanic expert).

Thanks! (Please don't ask why, I just want to do it... I know I can perfectly ride with a triple).

No clue , insecure about trying and screwing it up? bring it to a Bike Shop.

they will have removal and re installation tools you probably Lack.

Thanks, my main question was if it will fit, since I have to purchase it. re:installation, unfortunately I live in the middle of nowhere, there are no shops, that's why I am asking.

The bottom bracket is not your biggest problem. As long as you have the needed tools, swapping out the bottom bracket and cranks is about a 15 minute job. Rather, you will have a much bigger problem with your rear wheel.The 11 speed 105 cassette will not fit on your freehub. 11 speed cassettes require a freehub body that is just under 2mm wider than the one you currently have because the 11 speed cassette is thicker than your current cassette. So unless you can upgrade your rear wheel with an 11 speed cassette body, you cannot upgrade your bike to 11 speed

Forget the rear 'Speeds' change^^ stick with what you have . got 9 0r 10? stick with it , Repair- replace without "upgrading".

Cranksets just have chainrings 2 or 3 of similar target market IE road Triple to compact double also for Road bikes should be doable .

you have to buy all the tools for the job too. unless your local cyclists have formed a CoOperative.

>The 11 speed 105 cassette will not fit on your freehub
that's a bummer, thanks for the thought. What if I buy a new wheel that is 11-speed?

The rear hub I have now though, is a Formula RB32 (Axle Length:140mm QR:QR-11) I thought maybe QR-11 meant 11 speed compatible.

If your wheels were original equipment on your 2009 bike, they are not going to be 11 speed compatible. Shimano didn't start producing 11 speed components until 4 years ago. You could buy a new wheel to solve the problem.

The cheapest, simplest and easiest way to switch to a double is to unbolt the granny ring from your current crank and reset the low limit screw on your front derailleur to lock out that position.

Otherwise you are in for a major expense to what benefit? The 5800 group will require a bb tool to remove your square taper bottom bracket cartridge and a crank puller to remove the current crank, a different bb tool to install the Shimano external bearing bottom bracket, and a new 11-speed rear wheel.

The bike is a bit worn and an upgrade would be good. With an 11 speed 11-32 cassette I would get 34/32=1.06 (better than now - for climbing -). Even downhill it'd be better (50/11=4.55). Plus smoother shifting etc.
Only economically it wouldn't be smart but (because of wife etc.) I cannot get a new bike (parts though would go unnoticed.... ). I keep reading everywhere "I upgraded to 11 speed" etc. etc. so I thought it'd be easier.

Or, buy a new bike that is the same color as your current one. Most non-riding spouses, like my wife, wouldn't be able to tell it's a new bike.

there are 32t low gear cassettes in 9 speed too..

down hill I get to rest from the work getting up the other side.

She would see the courier coming, she's always around spying.

I will investigate 32T in 9 gears, that was only one of the reasons though. Here's so hilly sometimes I have to shift from granny gear to the big one directly, it's annoying. I ride for pleasure and yet keep thinking... I would do better with a double ... I would be better with 11 speed etc. etc..... It spoils the ride.

wide jump doubles have their own annoyances,just different ones.

if its 9 you are just replacing worn parts . there should be no domestic politics in tuning up the car , same thing.

maintenance.

At which point, you may as well be shopping for a whole new bike.

I don't know what kind of deal you're getting on the 5800 kit but that plus a wheel is easily into new bike territory in cost.

I know and you're right... but then again my cat is 14 and diabetic, I am not replacing him. This bike has... connotations. Thanks to you all for the advice, now at least I know what I need.

The 11 speed Shimano XT cassette fits on a standard 10 speed freehub, is this not the case also for the 11 speed 105 cassette?

No, road 11 speed cassettes require a different, longer freehub body.

Do you know why that is?

With 10 speeds, the road cassettes and mountain bike cassette would fit on the same freehub body.

Only Shimano/SRAM, campag does not. FWIW

Because MTB wheels have 135mm axle widths, whereas road is standard at 130mm. Shimano crammed 11 speeds onto the body by needing to redish the 10spd wheel and a longer freehub body.

Thanks.

Are there any moves underway to make the road axle width standard be 135?

BTW, that is a very sweet looking kitty in your avatar.

Have it delivered to your work address or to a friend who's in on the plan.

fietsbob is correct, there are 11x32 9-speed cassettes and a 9-speed era MTB rear derailleur will work with your current shifters and clear the larger cog.

Perhaps, but it can equally annoying jumping back and forth between the big and small rings, hunting in vain for just the right gear on flats. (50 tooth being too big, 34 tooth too small)

I made a quick spreadsheet, with all the ratios for an 50x34-11/32.
With the 50 tooth, ratios go from 4.55 to 1.79 in 10 shifts, then you move into the 34 and go from 1.70 to 1.06 in 5 shifts. In my opinion it's much smoother and nicer compared to a 9-speed triple.

Spread sheets are interesting but don't reflect how you really shift. First the 11x34 and 50x32 gears are crosschained and should be avoided. Second, when you make the change from the 50 to the 34T chainring are you really going to make 5 upshifts at the same time?