Knocking sounds when pedaling and gear troubles

[jv28@hotmail.com]

Hi all,

I'm new here and do not have much experience with bikes so I thought I'd ask the pros what they thought of these issues I am having. i watched some of the videos tutorials and they helped - I was able to tighten my brakes and now I to do that.

But the other two problems I have with my new bike, which I purchased from Walmart (yes, I know - bad move) because it was the only one I could afford (it was only $74, it's a men's 26" roadmaster mountain bike, 18speed) are this persistent "knocking" sound every time I pedal and weird chain noises when I use certain gear combination.

The knocking sound comes from the pedal area or the arms that connect to them - it happens on every revolution. Some have mentioned in another thread about the crankshaft? Not sure what that even is.

As for the chain sounds - at first my bike didn't like it when I use the 3 gear (right handlebar) with the 2nd gear (left handle bar). It skip and then fall into place almost causing me to fall. So it played with these two screws on the small gear, to adjust the tension as suggested on a tutorial on this site.

It seemed to fix the problem, but today I tried riding my bike and it is making all sorts of sound with the chain.

Did I buy a terrible bike that will continue to plague me with problems? I feel the bike is probably OK, but the kids who assembled it weren't too concerned with a flawless assembly. Will a tune-up help at the local bike shop? They want $60 (mind you I paid $74 for the bike).

[Joe_W]

Hm. I'd say you got what you paid for. Still, you can make those bikes work. The reason for the chain noise to return is (probably) that the cable has stretched (or that the barrel adjuster slips, unlikely but possible). On the other problem: Those noises are hard to diagnose... could be loose crank (the arm where the pedal is screwed in), loose or damaged pedal or just ungreased pedal threads. An ungreased seatpost also comes to my mind, though that makes more of a creaking noise.

[Bill]

Just wanted to add , does the noise happen after you go to a different gear in the back? Sounds like a rattle like the chain is touching something as you pedal? If so it is the chain touching the side of the front derailler. Not really much you can do because I think it is poor design. What I do on mine is barely move the front derailler (left side shifter) to adjust for the chain not touch the side of it. Try it out this should solve the problem. 60? Wow alot for a new bike.

[jv28@hotmail.com]

I don't think it's the seatpost because it makes the noise on every revolution while pedaling. It has to do with the pedals or the things interacting directly with them.

As for the chain, before it only did it when I shifted into that gear, all other gears worked fine. The only changes / adjustments I did afterwards was what I mentioned before and and I made the left handlebar gear more difficult and it worked fine.

I am going to try the suggestions later today and let you know - thanks for the tips. Lastly, I am out of a job for over a year and a half and bought the cheapo bike knowing it wouldn't be perfect but I do not want to get hurt on the thing!

[jv28@hotmail.com]

I found another bike shop, actually in manhattan with more flexible pricing. Here's what they charge for tuneups - do you think the $30 will be worth it for me?

Tune-Ups
General Tune-Up $30
-Inspect bike
-Adjust Brakes and Derailleurs
-Lubricate Chain and Gears
-Wipe Down Frame
Deluxe Tune-Up $60
-Everything in the General Tune-Up
-Adjust Hubs, Bottom Bracket, Headset
-Basic Wheel Truing
Overhaul $120
-Includes Everything in the General and Deluxe Tune-Up
-All Components Removed, Cleaned, Inspected, and Lubricated
-Bottom Bracket, Hub and Headset Overhaul
-Precision Wheel Truing

[Bill]

Sounds alot more reasonable then the other place.

[jv28@hotmail.com]

i think i found out what 'could' be the knock sound. my bike has a guard for the smaller crank wheel (sorry I do not yet know the names for these things) that spins the chain... well it's missing a bolt and causes it to move slightly... wasn't able to ride it or test but i have a feeling that could be it... do you recommend leaving this on? I guess it's good to have in case the bike tips over?

[Joe_W]

I'd go for the deluxe tune up, I am quite sure that hubs and head set are not set up correctly on this bike.
What is missing a bolt? The drop guard (your description sounds like one) or the chainwheel?

[jv28@hotmail.com]

(06-10-2010, 05:28 AM)Joe_W Wrote:  I'd go for the deluxe tune up, I am quite sure that hubs and head set are not set up correctly on this bike.
What is missing a bolt? The drop guard (your description sounds like one) or the chainwheel?

Yes, I think it is the drop guard, it is protecting the small sprocket (the one that is below the set of six larger sprockets) on the rear derailleur. The noise doesn't happen if I rest the bike on its handlebars upside down and peddle.

[jv28@hotmail.com]

I feel like I should have ordered the bike unassembled and either assembled it myself or pay the bike shop to do it. If I had the instructions to do it, I probably would have done it better myself.

[jv28@hotmail.com]

ok just toyed with the bike again and i am noticing these things... when i shift with any handlebar, the chains do not always move from one chain ring to another...

does this mean is adjustment is necessary or is there something messed up with the shifting system?

[Joe_W]

With the left shifter this (might) be correct, there are sometimes indexing steps to that you can fine tune the front dérailleur when changing gears in the rear. The right shifter is misadjusted.