Snakeplisskien

Hi All, I've got a new (5 months old) Orro Terra C Ekar that seems to be falling apart. My front brake completely gave up, and now the bike developed this two-tone knock every cassette rotation (not chainring). I'd put a link to video, but I'm not allowed as a new user... It gets worse when I put load on pedals, but there is no noise if I don't pedal (when I push the bike). I am trying to figure out if it's just a matter of putting some grease or should I return it under the warranty? Thanks for your advice!

Edit: I've put the link to the video of the knock in my user profile if anyone is interested.

Mr. 66

Under warranty, bring it back for service, don’t mess around with a failed brake.

Thank you for saving the president…

Andrew R Stewart 

I agree, take the bike back to the shop that sold it to you. Most shops have an after purchase follow up servicing as part of their sales policies. Oh wait! You did buy from a shop where you can look the seller in their eyes? If not I wonder what the non shop seller's return/refund policy is. 5 months is a very long time after purchase to ask for a return.

Did you repair the "Gave up" front brake yet? This should be your first concern as a primary safety issue. This might be as simple a fix as tightening a cable, or indicate a bigger problem waiting to become a danger to your steering and general control.

The two clicks per wheel rotation when pedaling might be the ratchet mechanism acting as a pivot point. If the freewheel/freehub has sloppy bearings and the cog set can slightly rock when pushed laterally the ratchet pawls can act as hinge points where the rocking will go back and forth. When the chain is on a cog that is laterally offset from the pawls the chain will want to pull the cogs to one side (of the cog set's rock/slop) and as the freewheel/freehub rotates a half revolution the chain still wants to pull/rock the cogs to that same side but the cogs now being pulled were from the other half of the FW/FH. Thus the chain pulls that half of the FW/FH and it rocks a bit. A knock/knock or click/click with each wheel turn results as the cogs rock back and forth under the chain's pull.

What cog the chain is on (how much leverage the chain's position has on the FW/FH relative to where inside the FW/FH the pawls are located, how much slop the FW/FH has in it's bearings, how much pedal pressure, cadence can all effect how much rocking there is and if it's enough to be heard.

Is this what is going on? I don't know, but an experienced mechanic could likely tell pretty quickly if given a chance to test ride. No mater what's going on I strongly suggest this bike sees a qualified person to access and possibly correct the problems. Some possible problems might be first order safety ones (like that front brake), might be function limiting ones (like gear shifting, or corroded/frozen suspension) or just be annoying (like the sloppy FW/FH clicking I just described). Most shops will give a verbal assessment pretty much on the spot and offer repair cost estimates for free. There could well be more issues not yet recognized. Andy

Snakeplisskien

Thank you very much for your replies. The reason I decided to post this here instead of immediate warranty return is that I use this bike daily to commute... I bought this bike online, so by the time the seller returns the bike for repair to manufacturer it might be 2 months that I am without a way to get to job and back (I know I should have thought about that when buying the bike online, but here we are - it was a cycle2work scheme). So naturally I'm hesitant to go through warranty if I don't absolutely have to.

I think you might be onto something Andrew with the ratcheting mechanism. Upon closer inspection the knocking noise is on gears 1-8, but 9-13 the chain kind of oscillates or jumps up and down every rotation. I also rotated the crank without chain, and pushed the bike without pedaling, it's quiet in both instances. Irrespective, it doesn't seem like anything I can repair myself...

Do you think this could lead to accelerated chain wear? I had to change the chain after 800km... It was already stretched out...

Thanks again for the replies/advice.

rm -rf

A new chain needed after 800 miles seems unlikely. Chains wear out faster from getting really dirty and wet, or from very strong big riders with huge pedal forces (but then the rear tires wear out very fast too.)

"Front brake gave up". New chain. "two tone knocking--should I grease something?" I think you need to either learn how to adjust or repair these items, or take it to a local shop that can fix it correctly.

Something to check for the two tone knock: Have someone hold the seat to lift the rear wheel off the ground. In one of the knocking gears, turn the pedal by hand very slowly. Watch the chain where it connects with the cassette. Look for a "jump" where the chain plate is slightly caught by the next cog, is lifted a bit, then drops into the correct gear tooth. To fix this, the derailleur needs a slight adjustment -- but look at the Park Tool link below, before you try turning random bolts or cable adjusters.


I've learned how to do my own maintenance by using the Park Tool repair guides. They are step by step, easy to follow, very little previous experience needed.

grumpus

The way you wave the camera around makes it hard to get an idea of what's actually happening.

KerryIrons

If you can't realistically send the bike back, a trip to your local bike shop, bike co-op, or even bike club where a knowledgeable member would likely be willing to diagnose your problem(s).

veganbikes

I would take it to a shop figure out the approximate cost to fix and reach out the the OEM and see if they are willing to cover the costs or pay you back.

In the end if you are biking to work get a second bike for this very situation so you can have one in the shop and one rideable bike. Or find a different way to get to work which is super easy these days and there are so many options out there it is staggering (even if you may not love all the options they can work for a few days or a week)

In terms of bike I would look at something common and easy to fix. Campagnolo is cool and Ekar is a nice step forward for the big C but it is not as common in shops where Shimano or SRAM might be or get a single speed/fixed gear (you can build something nice that performs well). In the end it will help out greatly and most people have space for an extra bike despite pleas of not having space (with all the various racks and mounting options you are hard pressed to not be able to have two bikes)

delbiker1 

I have to agree with taking to a local shop, or other knowledgeable source to figure out what the problem actually is. It's going to cost a minimum of one hour labor, if it is something minor, could be a quick return. However, check with seller you bought it from first, quite likely could void the warranty if worked on by an unauthorized shop/mechanic.

Bill Kapaun

You didn't post your location, but some communities have "Bike Kitchens" or "Bike Co ops" (Cooperatives) where you can get repair help used but serviceable parts etc.
They'll help diagnose and show you how to do it, rather then do it for you is the general theme. I'd expect if it was getting close to closing time, the degree of help would increase.

bblair

If you don't the expertise, then you need to hire someone who does.

Not to throw gas on the fire, but this is the risk you take when you buy online. If you know what you're doing, then fine. If not...well...the money saved must now be spent.

A buddy told me a story last week: his BMW needed a new cabin air filter. Not wanting to pay dealer prices, he bought one on Ebay for $25 and attempted it himself. One ruined airbag and $1100 later the dealer finished the job.