Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the February Giveaway for Villy Custom Elvis beach cruiser valued at $590 💙


Bought a used bike, know nothing about bikes
#1
Hey everyone.

I just bought a used Giant ATX 770 at a garage sale. I know nothing about bike maintenance and couldn't find anything on the web for a general maintenance routine, though I did find a good cleaning tutorial on this site.

Here are my questions:

1. The gears start to shift after a few seconds even if you haven't pressed the button. Is this a question of maintenance or do I need a new shifter?

2. The back of my heel touches the ground when the pedal is at its lowest, is there anything I can do to fix this?

3. The bike is filthy, so I will clean it based on the cleaning tutorial from this site. Is there a good guide on the basic maintenance stuff I should do after that (in terms of tightening, lube, etc.)?
  Reply
#2
1. Likely it is maintenance-related... sort of. Dirt, gunk etc in shifters, cables / housing, dérailleurs or frayed cables can make it impossible to set up shifting in a correct way. Look at that and replace them as needed (also the brake cables). But then, the chain might also be worn. There is a tool to measure that, but a ruler will also work (12 full links should be 12 inch long, I think "stretch" should not be more than 1/16th for 12 links, look at tutorial on this site). Then, you might have to replace chain, cassette, maybe chain rings...
2. Don't really understand that... is your saddle too low? Basically a good starting point is this one: sit on the bike (balance against a wall, let somebody help you , whatever) and place heel on one pedal at the lowest part of the stroke. The leg should be almost fully stretched. Start from there and ride, then move saddle up or down and see if it is better. Proceed until satisfied.
3. Cleaning, lubing, checking cables (brake, shifters), replace brake pads, maybe overhaul bearings in head set and wheel hubs (should be done annually, depending on use / abuse / weather conditions). Dial in shifting, brakes, check frame for cracks, check stem / handlebars... also the tyres / inner tubes...
That's it off the top of my head. The list is most likely not exhaustive. I work with a check list that I don't have here, so I cannot check what I forgot.
  Reply
#3
1. The gears start to shift after a few seconds even if you haven't pressed the button. Is this a question of maintenance or do I need a new shifter?

In my case, I found a broken pawl (white plastic paperclip looking indexing part) inside the twist grip shifter. I didn't replace it, just ordered another shifter & greased it in the mean time. I followed the tutorial for adjusting the rear derail & found that even though it looked right, my lower limit (I mean the biggest cog) was wrong. Everything worked much better afterwards, even with the broken shifter part. It works so well I haven't put the new shifter on- sort of a cross between friction & index shifting!

Every used bike I get, the first thing I do is go thru the wheel bearings, clean, replace the balls (I have tons of spares) relube & re-adjust.
Then I check the bottom bracket for play & grinding. Then I go thru the headset- clean, replace bearings & relube.
Since I'm a huge heavy guy I inflate the tires to full pressure & inspect them for cracks etc...
Actually, Joe_W gave an excellent answer.
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Identify and Appraise Vintage Torelli Ro...
Yesterday 05:21 PM
Vintage bike stuff
Yesterday 11:26 AM
Hello from Oregon!
Yesterday 04:07 AM
Cracked shimano DI2 front derailleur
02-07-2023 10:51 AM
Bikepacking/gravel bikes
02-07-2023 03:45 AM
Help riding this tricycle
02-05-2023 01:00 PM
What was your first bicycle?
02-05-2023 10:02 AM
Riding in a foreign country?
02-04-2023 02:02 PM
Club Rides
02-04-2023 10:08 AM
ONLINE BIKE PURCHASING & SHIPPING
02-03-2023 07:48 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Sybian
15 posts
no avatar 2. enkei
14 posts
no avatar 3. Jason in Ecuador
11 posts
no avatar 4. Lss555
11 posts
no avatar 5. Talha
11 posts