tajimirich

Hey all

First up, I apologize if this post contains too many incorrect terms and such. I swear I love cycling hugely, I just do it very much on my own as a result of my location and skills in the local lingo so I'm not very close to the community or the terminology.

Anyway, I've got a weird issue going on in the righthand pedal of my Giant Contend 2 bike (2021 model, I think)

I took this bike out on it's longest ever ride last week - a 70km round trip (I get where i need to get with 15-25km bike rides, i rarely find cause to go further, this indeed was a purely elective ride to a picturesque gorge in eastern Aichi prefecture), by the end of that trip this problem started evidencing itself.

The bike:
As I said, it's a Giant Contend 2, I'd say it's about 18 months old. It's a budget aluminum frame road bike, I can't afford anything more (my dream is a butted and lugged steel frame bike, I want neither more nor less, such frames just don't seem to exist in Japan). It was fitted entirely with 'Claris' level Shimano components when I first got it, but my weight and power bent or broke or straight up detached (ouch!) many of those components, and they've entirely been upgraded to Tiagra, 105s or ultagra components by now. ALL OF THIS WORK was done by my utterly competent 'bike shop guy', not by me! It's not ideal, you can see it written on his face, and he's always ready to tell me that a lot of the issues with the bike are because it's a cheap model, but he gives me his blessing to ride out into the world so that's good enough for me.

The issue:
- There's a defect in my right pedal - or it's attached components - which is generating a somewhat randomly occurring misfunction in the plane of that pedal.
- It's random, it doesn't happen at specific points on the pedal stroke, it doesn't happen in time with my pedaling, increase in frequency when i pedal faster, or anything like that.
- it seems to happen more when I am putting greater power in to the pedal - accelerating or climbing a slope.
- It seems to usually happen at the top of my pedal stroke, or at the bottom.
- It seems to be louder if my foot is to the outside of my flat pedal (i use flat pedals with gripping screws protruding, mountain bike style, because i can't justify buying/lugging cleats for myself, and my commuting style doesn't really suit it)
- It is sometimes a single 'click', some times a few 'click' sounds.
- It isn't just a click, there is also a small physical 'drop', or 'jump' in the pedal - the jump doesn't stay in the linear plane of the pedal stroke, it's more or a feeling of the pedal dropping a millimeter or the like.

Things my bike shop guy and I did to fix it:
- At the start of this noise my chain/pedal setup fore of my front derailleur was Tiagra, after this only the crank is still tiagra..
- First thing's first, my chain ring was bent out of shape. This wasn't so astonishing, I put a lot of power into the pedals and this particular chainring lasted me a good year. It was replaced.
- The replacement chainring and it's thick 'shield' (the part that goes between the chain ring and the crank/pedal assembly) is ultegra, now.
- The crank (the only thing that hasn't been replaced) is Tiagra, it doesn't totally fit into the new ultegra but it functions fine. the noise was happening before any of these replacements were made. My rear hub was 11-speed, the front chainring is now also 11-speed, apparently, so the whole system is in better balance now... apparently..
- the pedal has been replaced - it was, and remains in new form, a shimano "PD-GR500-L". I thought it might have been a bent-down pedal or somesuch, my bike shop guy was skeptical and, yes, after paying for a replacement set of pedals nothing is fixed. Always listen to bike shop guy!
- He spent a goodly while readjusting my whole gear setup, and breaks, he took apart my pedal and chainring setup, re-greased everything, no dice.

My speculation:
- I think it must be something to do with the 'crank', the arm attaching the pedal to the chainring. I only think so because it's the only thing that hasn't been replaced yet. Maybe when I put enough pressure on it, some lose part pops out of place for a moment? Just my guess. i don't know if my symptoms match this diagnosis, though. And I don't know how to fix it?
- I do deform the bike quite a bit when i'm putting a lot of power into it, bike shop guy and i have long since determined this, but I've been doing that for the entire time I've had the bike so I don't think it would be the cause of this.
- I would say i'm more of a sprinter than a climber, if we're going by physiology tropes from Le Tour, though I try to soldier over whatever terrain gets put in front of me, I am actively considerate with my gears but when I'm going through unfamiliar terrain, unfamiliar traffic light changes and the like, I don't always make sufficiently early gear changes with total accomplishment.

Anyway, I'm sorry for yakking on so long. I love this bike and i'm looking forward to my next long ride - even longer than the ride last week hopefully - I just don't want to have my right pedal freaking out throughout whatever ride I choose to do next.

Peace! Huge thanks for any and all help Happy to correct any giant glaring holes in my information on what's going ion. Also happy to try and make a video to capture the noise if that's requested.

-Rich

Jack Tone 

If it happens with every pedal stroke, and you have already replaced the pedals (and they are tight), with no change, then I think it can only be the bottom bracket, crank attachment, or chainring bolts.

tajimirich

hey mate thanks for your reply

actually it doesn't happen 'every pedal stroke' as such, it's a pretty random sound - doesn't happen at a certain point in my pedal rotation, or whathaveyou... the 'clicks', or whatever i might describe them as, tend to happen when i'm either first putting pressure on the pedal at the top of my rotation, or when most of my body weight is on the pedal at the bottom of that stroke, though it sometimes happens at other moments.

yes, pedals have been changed, the whole setup has been regreased and tightened up in the last day or two, the only thing that hasn't been changed is the crank itself, connecting the pedal to the chainring.

Rich

qwaalodge

If this is more of a jolt than just clicking then it might be "chain skipping" caused by either stretched chain or worn cassette.

If the crank is literally moving off the axis, then it's likely loose Bottom Bracket bearing and the problem can be fixed simply by tightening. Worst case scenario, frame is cracked.

Could be a rogue ball bearing or rogue screw that fell on one of the frame tube, especially the downtube.

eduskator

Well, it looks like you need to troubleshoot further. If your LBS has already inspected the pedals and crank arms, I will take for granted that they lubed the threads & torqued them to the right specs. The next step is to inspect the crank IMO. Any LBS would be able to perform this type of maintenance if you don't have the knowledge and/or required tools. I believe the Content has a threaded bottom bracket FYI, its a little easier to maintain.

I had a creaking noise last year coming from the groupset somewhere. Took 6 months to get rid of it. 3-4 trips to my LBS later, they lost patience and ended up removing every moving parts on the bike and reinstalling them. As of this day, I still don't know what part was to blame.

tajimirich

Hey mate
You're right about that, he pretty much pulled the whole assembly apart and re-greased/tightened it.

From memory, this is what he did:
- remove chain
- remove cranks, that whole assembly
- clean out the bracket
- clean the crank threads, the whole crank set-up
- re-grease everything
- replaced the chain ring and the 'shield' it was attached to
- put it all back together, marrying a 'tiagra' crank to a 'ultegra' 'chain ring shield' (dunno the name)
- replaced the chain with a new one, a more expensive Shimano which is apparently dure-ace quality or something
- spent an age recalibrating my now 11-speed bike
(he had to make the front derailleur have three settings to fit in all the gears, one for the big ring, two for the small ring, as an aside I'm interested in knowing if there's anything i can do to make my gears work without needing such a bodgy workaround)
- warned me that the heaviest gear is faster and the lightest gear is heavier now. I said okay.

... the bike rides as smoothly as it ever has now, it's a joy.. except for the iffy gear changes and this clunk

I wonder if the crank might have stripped threads, or if its connection to the chainring is somehow loose... if it's a bearing i think i'll just have to speculate about it to my bike shop guy and ask him to check :/

I sometimes think the creak is tied to humidity, like break screeches, but this one is definitely a mechanical thing in a way that didn't evidence before. Even my bike shop guy, who is far smaller than me, could get the pedals to clunk pretty easily when he did a test ride... usually he struggles to reproduce the same defects that i hear.

It might be pertinent for me to say that the effect seems to happen more if my foot is placed on the outer rim of the pedal, if i'm pushing off and my foot hasn't quite dropped onto the right place, which suggests that there's some kind of lateral force at play...?

Rich

Mojo31

Check to see if your saddle shell has cracked.

tajimirich

Hey guys,

Sorry I haven't been able to post for a bit. Birthday a few days ago and spent a lot of the time since riding

The problem was solved! More or less... My Bike Shop Guy replaced the Tiagra crank and the Claris bracket with a 105 crank and a dureaa-ace bracket.

Well it must have been one of those two components, because the issue is gone. The 11-speed 105 crank balances (in his words) better with 11-speed hub and, well everything else that is 11 speed, and yeah even i know claris components don't stand up long to my attentions. My money's on the bracket. Anyway, yep, the bike's running smooth and silent which is how I llike it.

Thanks for all your suggestions!

Rich