I don't mean the obvious "well, the bike" answer, more the piece of kit that's been a constant on your riding adventures for some time; the piece of kit you reach for because it just works.
For example: mine is probably my Wingnut MPS pack. It made me smart a little when I bought it back in 2008, but has been used in various guises at least once a week since, and modded to add little functional features I wanted. It's been used all over Europe and been up and down more peaks than I care to count. It's tough, incredibly comfortable and intuitive; I'll be genuinely upset when it finally falls apart.
Is there a piece of kit you're genuinely attached to? Something that 'just works' for you?
Leatherman Wave, bought in ooooo 2004, got me out of more jams (bike and not bike related) than I care to think of.
Tld xc gloves.
My Rudy Rydon Photo Rx glasses with optical insert. I wear them for track, road, off-road, night and day. They just work, never slip, and always seem to have just the right amount of tint. My prescription is too big for conventional Rx sunglasses.
Highly recommended.
That will be my 4 years old Camelbak Podium 660ml bottle. It has never fell out of the cage (it's not slippery in texture) and despite being used almost everyday in every conditions and carrying anything from water to freshly squeezed juice it hasn't developed any "unpleasant scent" (well, it receives a gentle bleach-therapy occasionally).
Outside it looks like it has just survived a nuclear war...
A pair of MAdison M:Tech 40 shorts. I have probably worn them every day since I bought them 3 years ago. Some of the stitching is starting to go but they've been brilliant.
Or my Lefty Supermax fork.
Would be AyUp lights and Garmin 800...
Plus the award for kit I never have to think about for years... Time Atak pedals and Sidi Dominator shoes
Garmin 800. Easy plotting of routes and navigation has made it so much easier to explore a new area. Used to do it old school with a map and compass but this is quicker and easier to record rides.
Combined with various websites like bikehike and Strava it has really openend up a lot of new trails, some right on my doorstep.
Im not saying, in case the unmentioned item decides to defecate on my chips and fail.
MP66s & Dakine backpack
Topeak mountain morph.
Probably my track pump 😆 never fails, and works perfectly.
Berghaus convertible jacket/gillet. First bit of bike specific clothing I bought years ago and still going [s]strong[/s] Berghaus don't make bike kit any more so won't be able to replace it when it dies. 🙁
Camelback mule rip off i bought from Aldi for £9 about 8 years ago. Use it for MTB and Commuting and is still going strong. Best thing I've ever bought I think.
Camelbak Podium 610ml and BBB side entry bottle cage. Perfectly sized for a very tight fit in the middle of my Superlight frame.
Enables backpack free riding in the summer.
Conti tubes 😈
Not had any problems seating the tyre bead, or sealing problems, and no need for ghetto inflator / compressor etc. 😉
That, and SRAM 991 chains. They just work. Why do anything different from what you know works?
Very much liking my Reverse RCC-810 carbon bars at the moment (and the Stan's fluid in my tyres).
Not exactly bike kit but its got to be my chillington hoe - not with me all the time when riding but has made trail building and maintenance so much easier - great bit of kit
DMR zip grips.I got worried they were going to stop making them and found somewhere doing them for £4....so I bought 10 sets.
Fender Bender thing, whatever its called.
Clothing - Merino arm warmers. A perfect solution to those changing spring conditions, the fact that my pair were £4 from PX makes them even sweeter.
Workshop - A bike stand, mine isn't an expensive one but it makes working on the bike so much easier. A track pump pushes it bloody close too.
Bike - Di2 on my road bike. Flawless shifts, simple setup and the battery lasts for a long time. Simply awesome.
DMR zip grips.I got worried they were going to stop making them and found somewhere doing them for £4....so I bought 10 sets.
Damn you! once I found out they were stopping making them I ordered 5 sets through my lbs but they only had 2 left! Ace grips.
Original Flite Ti saddle. Nothing else fits my bum like they do. Been on them for 20 years now.
Also got a Mk 1 Topeak Alien that refuses to fail. Missing a Torx head for rotor bolts & brake lever clamps but does everything else I need it to, including cutting cheese & opening beer.
My Specialized crop top. Had it for ever and its still going strong. Cant find another that is as comfy and supportive
Another one for Ay-Up lights. Ground Effect clothing and Dakine 8 track shorts
lights.
far and away, the best thing to happen to off road cycling in my time
Leatherman Wave, bought in ooooo 2004, got me out of more jams (bike and not bike related) than I care to think of.
I loved my Leatherman Sideclip. Genuinely gutted when it went missing somewhere between Tring and Kitzbühel. To add insult to injury Leatherman stopped making them and they've since become a bit of a cult item, so the few that appear 2nd hand are selling for quite a premium.
Concor light saddle..
the old version.. have to keep trawling ebay to find new ones..
and onza ules grips..
cant wait for the lock on version to come out!
Currently loving a Topeak Ratchet Rocket for pretty much any bike fettling and diy job.
ISM Saddles - I have 5 of them, one on each bike 🙂
Hope vision 2 light. still going strong after 4 years of commuting and night rides.
Other than that, my xt chainset has outlasted 3 bikes!
My Blackburn mammoth pump - fairly big but utterly reliable, pumps up tyres fast and about 20 years old now. I kind of miss it now I run tubeless and just take a micro pump out riding just in case. Still if I ever get a bike with fat wheels, it'll be great for them.
[img] 
[/img]
Alpkit koala seat pack, I hate riding with a backpack, but like doing longer rides where food, clothes and a few spares are required, I originally bought if for bikepacking only, but almost always find myself reaching for the koala rather than an old bar bag I have or a backpack.
When it's properly attached I often forget I have it there, which is often the best thing you can say about a bit of kit!
Deuter bum bag. Kind of like Batman's utility belt. Kind of......
Nike knee warmers ... Bought in alpine bike sale(Glasgow) £5 around 2001 and been worn to death and still get regular use despite few holes 😆
my wing nut enduro.
even when it weights a ton, its doesn't seem to register on my back at all. super well designed to access stuff on the move as well.
looks weird so it goes with me and my bike!
Camelbak Charge - water / tool carrying duties as good as it could get.
Only pain is pulling it apart to clean properly
Lyriks
Stiff, loads of travel, reasonably light(ish) functional adjustment, easy to maintain.
My 10 year old Gore Windstopper jacket. The original N2S one whos name escapes me? Bit holey after a couple of offs but still best for anything for about 6 months of the year.
XTR cranks - noticeably lighter and easier to spin. Probably others out there but these have been my first and the difference to XT was staggering.
Another vote for the Topeak rocket ratchet for quality, do it all tool with a chain splitter too.
My Gore windstopper gillet
Just been discussing this earlier. Without doubt the best thing i have added to my bike is my dropper post (mine is a Stealth Reverb).
For gadgetry its got to be my Garmin 800 with HR and Cadence Monitors... I know i'm a geek!
The only bit of kit I've genuinely felt a bit emotional about was my old marz 55rc3 ti fork.
Soooo smooth and stiff.
Also owned the 44, 66 and 888 versions but they were never quite so impressive.
De-feet arm warmers and gloves.
Gore jacket and gillet.
Garmin edge 800.
Bike:Suspension
Kit: Lake Winter Boots
Evoc fr trail backpack
Thomson dropper post
And my leatherman that has got me out of a few jams.
Shimano AM41 shoes
Bontrager XR4 Team tyres
Buffalo windshirt...
1992 ish
[url= https://farm8.staticflickr.com/7467/16296535745_8ccdd36a87.jp g" target="_blank">https://farm8.staticflickr.com/7467/16296535745_8ccdd36a87.jp g"/> [/img][/url][url= https://flic.kr/p/qQ51je ]001 (2)[/url] by [url= https://www.flickr.com/people/7904024@N08/ ]jimmyg352[/url], on Flickr
2011 ish
same one but It's a bit 'snug' now.
[url= https://farm7.staticflickr.com/6096/6298567962_b0dbba54f5.jp g" target="_blank">https://farm7.staticflickr.com/6096/6298567962_b0dbba54f5.jp g"/> [/img][/url][url= https://flic.kr/p/aAzNPm ]Evans sportive[/url] by [url= https://www.flickr.com/people/7904024@N08/ ]jimmyg352[/url], on Flickr