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poping noise when climbing hill(10 posts)

poping noise when climbing hillcrazyboy
Jan 10, 2002 2:10 PM
I need some help with the ol bike...... I recently purchased a trek 5200 and when I am riding and climbing hills my cranks seem to "let loose" and engage again when I stand up and really get on it. This making the loud poping noise. The cranks are tight, and a brand new chain. Help, is my cassette bad or is their something else to look at.

re: poping noise when climbing hillNRG Climber
Jan 10, 2002 2:15 PM
Sounds like exactly what happened to me when my cassette went bad. Put on a new cassette and all was well again.
Popping or skipping?Kerry Irons
Jan 10, 2002 4:57 PM
When you say "let loose" it sure sounds like the chain is skipping on the cogs. Standard rule is to replace the cogs when you replace the chain. While some avoid this by changing chains way before they're worn of replacing just a couple of the most worn cogs, it's not really worth it. How many miles on the cogs? Did the problem start when you changed the chain? You figure it out.
Standard Practice?grzy
Jan 10, 2002 5:09 PM
I'm pretty much taken aback by your mention of standard practice to always replace the cogs and chain at the same time. You start having problems with the chain well before any significant damage has occured to the cogs and shifting perfomrance suffers immediately. However, riding with a worn out chain is the best way to ruin a set of steel cogs (and alloy chainrings). I could see having to do both when maintenance is ignored (i.e. my wife's bike prior to me becoming her full-time mechanic), but I'd be buying a whole bunch of cogsets each year if I followed your "standard practice". Just where is the practice standard? Sounds like a ploy by a LBS to ripoff unsuspecting customers. I wear out chains frequently, but if I replace them right away the cogset is fine.

So where is this "standard practice" applied - I'd advise people to avoid this shop/mechanic.
Standard Practice?gtx
Jan 10, 2002 8:11 PM
I think you should determine what is most cost effective. If you're running Campy Chorus, the chain and the cassette both cost about $32--makes sense to replace them at the same time. If you're running Dura Ace, the cassette is $75 but the chain is $20--makes sense to replace the chain more frequently. I run 7 speed DA freewheels and replace my $10 SRAM chains about every 2-3000 miles to keep my ever-hard-to-find DA cogs happy.
You pays your money and you takes your choice.Kerry Irons
Jan 11, 2002 6:47 PM
Back in the day, you replaced chains when they had elongated 1% (1/8" per 12" of chain). At that point, you could almost guarantee that a new chain would skip under load on one or more of the old cogs. You just replaced both chain and cogs. With a modern shifting system, shifting starts to deteriorate right around the recommended chain replacement point - 0.5% elongation. If you want to get your cogs to last longer, you can replace your chain more freqently, but it's kind of false economy. I get around 10-12K miles out of a Record chain and steel (Chorus) cogs. It's $70 to replace them both. I would have to nearly double my cog mileage to justify changing chains more frequently - not likely to happen. This is not an LBS recommendation, it's my experience. And given the number of times you see this problem posted on this forum, I'm thinking it's lots of other people's experience too (whether they realize it or not).
Pay me now or pay me later.grzy
Jan 14, 2002 10:53 AM
Well if you buy lower end components then replacement cost is much cheaper. Once we start talking Record or DA cogsets and similar quality level chains and chainrings it starts to really add up into triple digits. Now factor in the worn chainrings resulting from a worn out chain. Consider how many chains you can buy for the cost of one cogset and a pair of chainrings. If you keep the drivetrain clean and lubricated you can avoid a lot of problems. If you replace the chain at first hint of shifting irregularities you will be money ahead, in my experience, having done it both ways. I always wind up with stretched and loosey-goosey chain and my cogs/CRs in fin shape. I'll typically see 1% to 0.5% of stretch and loose joints with insignificant wear on the teeth. I became a lot more aware of this when I started riding MTBs - quickest way to blow a race is to enter with a marginal chain. A fundamental problem is that most people don't believe in good lubrication or preventative maintenance. Grit and steel is a pretty effective grinding method for aluminum. The chain is a "fuse", that is it's the weakest link in the system and still the cheapest. Ultimately we all have decide what it's worth to each of us and I prefer to just buy chains.

I guess my whole objection was that given there's a bunch of choices how can one be called "standard practice?"
I'm with youDog
Jan 15, 2002 1:27 PM
I have 3 Record Ti cassettes. I may never replace them, as they get switched out fairly often and I replace chains before they wear out cogs. Even if cogs needed replacement, I'd likely try to replace only the worn out ones.

I've never seen a cassette wear out, at least as far as I knew about it.

Now, if I had to replace a cassette, I'd certainly replace the chain, too. As far as any "standard practice," I think that would be correct. I you don't, the chain might wear out the new cassette prematurely. Maybe that's what the shop suggested.

What wheels are you using?spookyload
Jan 10, 2002 5:42 PM
It sounds like the freehub is skipping. I know it was a problem with last years spinergy wheels. The pawls aren't fully engaging and high torque loads cause them to skip.
What wheels are you using?crazyboy
Jan 11, 2002 7:06 AM
Thank You to all that replied. I changed out my casette and replaced the bottom bracket which had a lot of play in it. Hills are a breeze now!