Topaz47

Hello, I'll go check a used hardtail MTB tomorrow. I will check the basics, that everything works and surely take a short spin before buying.

The bike is supposed to be like new. The seller told me he got about two years ago, then he got injured just right after and only rode it a couple of times around the neighborhood.

The bike is a 2020 Trek Roscoe 7.

Is there anything in particular to check? And any particular way to check it?

Thanks

katsup

You can meet the seller at a bike shop and have them look it over for a small fee. Although you do risk scaring the seller away if they have multiple interested parties.

DMC707

Its not that old - if it genuinely is "Like new" - would probably be pretty easy to print off the OEM spec sheet and take it with you

If its got a bunch of replacement parts and is scratched/dented - and the wheels are out of true, -- i'd question the "like new" claim

rumrunn6

probably same as any other bike

https://www.******.com/r/cycling/com..._learned_from/

https://www.bikeradar.com/features/h...d-bike-online/

https://totalwomenscycling.com/commu...yers-checklist

https://www.cyclingweekly.com/group-...nd-bike-340839

lots of youtube videos on the topic as well

rumrunn6

ride it
shift all gears
try the brakes
get off the bike, spin the wheels & look closely from the top for wobble, from the side for out-of-round
look at the gears & chain for signs of age
push down on the fork, see if anything weird happens or if you get any weird sounds
look at the fork stanchions closely for signs of damage
how was the guy injured? riding the bike? look for dents or cracks in the frame. while you ride it listen for creaks
what kind of tubes does it have? presta? are you OK with that?
I love buying bikes from ppl that had some reason for stopping, like they thought they would ride it to lose weight but that didn't work out for them so they gave up shortly after getting it. those are the best to buy

Eric F 

If it looks to be in the condition the seller claims, has all the original components (or upgrades), and everything operates as it should, it's probably fine. Ride it - Brake hard a few times, run through all the gears both ways, bounce on the suspension, and ride no-hands. Check that the steering, wheels, and cranks turn smoothly, easily, and without grinding noises.

Darth Lefty 

At only two years old it would have to be used pretty hard. In theory you should do some service on the oily parts like fork and brakes but it might not even need it.

Treks have a 3-year warranty for subsequent owners if you can get the original receipt from the guy.

Topaz47

Thanks for the comments, everyone. I already went and saw the bike.
The bike looked it had been used really little. Everything was stock and shiny.
The seller told me he got injured doing some other stuff, not riding, and that's why he's selling the bike after it sat in his garage for a year or two.
However, the gear shifting wasn't smooth.
The gears shift, but there were some points close to the highest gears (smallest sprocketes) in which the chain would come back and forth again.
I could hear some clunking noise and at some points, the transmission would get stuck if I tried to pedal backwards.
Looking from above, the derailleur plate looked off. Not sure if that's its name, but the double wall plate that holds the two little wheels that guide the chain. Well, in the lowest gears it looked straight and parallel to the chain, while in the highest gears it looked off to the side and it seemed to me that the chain was slightly touching the plate.
The seller said the bike was never dropped and that everything looked good to him in the gears,
My 10+ years old bike that I used around the neighborhood shifts better than that, and the chain doesn't block if I pedal it backwards.

So, I didn't know if it only needed a tune, or there was something broken. The seller was asking $1100 firm, Had the bike been 100%, I would have taken it, but not whit the gears like that.

DMC707

Sounds like the shifters just needed to be adjusted a bit

any bike needs this after the first few rides in most cases

rumrunn6

what if he fixes the shifting issues? he can take it to a shop & get it tuned up. I wouldn't sell a bike if it wasn't ride ready, also wouldn't buy one. yes it may be easy to correct, but if so, why not correct it, before selling it. plenty of other ride ready bikes out there. com'on ppl have some courtesy. "project bikes are completely different & that's not what you want. what kind of pedals?

Topaz47

I just saw that a new derailleur (SRAM Eagle SX) is about $90.

The seller didn't know about this, and he insisted the bike was right. He just bought the bike, got hurt doing something else and forgot about riding. One year or so later he decided to sell it.

Pedals are the original. He only added a bottle holder.

rumrunn6

if the rest off the bike is nice, maybe go take another look?

Topaz47

I looked at the whole bike as well as I could, and everything else was like new and working fine. I'm just not sure about the price if I have to replace the derailleur, as for a little more, I could get a brand-new Roscoe 6, which even though it has lower components, it should still be fine for a me,

Or maybe wait until something else used shows up in CL or Ebay. My initial idea was to get a decent used entry level hard tail for around $1000. Then, as I started reading reviews, I got excited about having air spring, 120mm fork, a dropper and 1x12, and hydraulic brakes. I'm still not sure between 27.5 or 29, but I guess any would work fine for me.

I got excited with a nice Santa Cruz Chameleon listed on CL, but it was a fake ad.
There is also a Kona Kahoona for $1100 I still have to check.

DMC707

95% chance the rear derailleur and shifter just need a little bit of adjustment

freeranger

Thought I saw a prev post about SRAM SX Eagle shifting not being so great--here ya go: SRAM SX Eagle shifting - fix or upgrade? - Bike Forums

Topaz47

Hello! OP here. Thanks again for all the comments and advices.

In the end, I passed on that Roscoe with the SRAM derailleur that looked bent to me. Days later a very nice Marlin 6 with an upgraded dropper post showed up on the listings, but the price was too good, and it didn't last long enough for me to go pick it up.

Finally, another Roscoe 7 showed up for $900 (2020, so 27.5+ tires). It had been used sometimes on the trails, but nothing serious. Almost everything looks like new. Only little scratches on the fork and pedals.
The gears shift well and the derailleur is always pretty much in line with the chain. Only when going from 1st to 2nd, sometimes it doesn't shift, and then it shifts twice when shifting from 2nd to 3rd. I will have to learn and try to tune that.
From the short ride I took around the neighborhood, it looks like I won't need those super light gears in the flat trails of South Florida. Will see.

The fork is supposed to be a Rockshox Judy Air. It doesn't say Judy anywhere in the fork. Probably the PO took out the sticker. I checked out a review on YT and everything seems to be the same, so it should be it. It has the lock, compression and rebound adjusters, and the air valve to set the preload.

It came with upgraded pedals and bottle holder. The seller also included a Harbor Freight hitch bike carrier, which is nothing fancy, but it gets the job done.
The seller told me he got the bike during covid but didn't get hook and then got a road bike that he used until he slipped in his driveway and broke his hip!!!! Now his wife forbids him to ride bikes so he's selling both bikes.
Happy with the bike. Hopefully will use it more than the previous owner.

Darth Lefty 

man you have some cursed bike customers out there!

prj71

Not sure why your mind went to new derailleur right away. Your post indicates that the bike just need shifter/derailleur adjustment. Cables stretch.

Topaz47

If I had been sure that that was the case, I'd have taken it, but I couldn't tell, so I passed and got the next one. The price wasn't good either. ($1100)

abnerspencer

Buying a used mountain bike has its downsides and difficulties, but if we know how to check it, we can still find a good bike that is right for us. The first thing I did was check the serial number to make sure it wasn't a stolen bike. Then I check essential parts like frame, brake,..... and seller's reliability.