Bicycle Mechanics - Drivetrain skip...what is it?!?!

Several times per ride, usually from a stopped or slow speed, the drive train skips with a sort of clanking sound. Ultegra 10 speed cassette 3 years old, new Ultegra chain, DA rear derailleur. It is NOT jumping cogs I know that. It clanks and stays on the same cog. I can never see what it is in time or reproduce it on the stand. Drivetrain is clean and well adjusted (unlike me). Could it be a tight link? I can't find any. WTF?!?!?

cassette body needs replace or a really good cleaning--- but your better to replace it--- check the chain very closely--- could be a loose der or hanger always check wheel placement and axel play---- check your cables in mid range---

Thanks.

I know the cassette is old, but it is spotless right now and has absolutely no visible wear. With 5500 miles, do people still think it "needs" replacement?

The chain is new and clean. Do chains with master links do this?

Derailleur is tight. Hanger is on a titanium Serotta, never crashed. No way it's bent.

New Dura Ace wheelset is dead on.

So annoying!

Over time your chainrings, cogs and chain wear out together. If you put a new chain on an old cassette it will not mesh properly and will skip under load. The only solution is to replace your cassette (and possibly chainrings). This is often more obvious in the gears you use more often as they are more worn... especially if it is a small cog where there are fewer teeth to resist wear.

In the future, change your chain once or twice per season and you might be able to avoid this frustration.

Lar

I have a 2007 Fuji Roubaix Pro with the same set (Ultegra 10 sp) - and I have the same problem. I have 100 miles or less on the bike.

But - mine does this when under hard load (i.e. hillclimb).

I am a 6' 250# guy.

Ideas for mine? With less than 100 miles - could this stuff really be worn out? The chain has not stretched (I did check that).

bros---- dudes---- the cassette slides onto a body---- the body contains the little spring and teeth--- over time and even hard use can mess with this component--- I run a american classic a10 speed body-- aluminum-- its pretty sturdy- but the slots are indented from racing crit---- If the cogs are not tightly bound- the flex will take its toll on the body---- most bodys are replaceable--- not quickly--- but serviceable--- I see many low end cassette bodys fail---

You need to measure your chain often. A 24 pin interval of new chain measures exactly 12 inches. When any 24 pin interval elongates to 12 1/16th inches it's time for a new chain. You should not need to replace the cassette with each chain. A cassette should last at least as long as 3 chains.
When bikes with new cables skip it is usually because the cables and housings have "settled in" and the derailleurs need to be adjusted. With new bikes the dealer should do a first tune-up at no cost to the owner.
A tight chain link can cause a jerking action when it goes through the rear derailleur. This is a condition that needs to be corrected immediately. If the tight link fails to go through the rear derailleur it can cause serious damage to the bike.

Al

I have a 2007 Fuji Roubaix Pro with the same set (Ultegra 10 sp) - and I have the same problem. I have 100 miles or less on the bike.

But - mine does this when under hard load (i.e. hillclimb).

I am a 6' 250# guy.

Ideas for mine? With less than 100 miles - could this stuff really be worn out? The chain has not stretched (I did check that).


With a newer bike, esp. for a big rider, you might have a freehub that cannot handle the load - I had this problem when I got my first newer style bike - the aluminum freehub body was allowign the pawls to slip so it skipped like crazy under load from the first tije I rode it. The shop where I bought it (also where I worked) gave me a steel freehub body which somewhat alleviated the problem, but never eliminated it.

I am 6'4" and about 260lbs... I have good luck with Shimano hubs and their non-servicable freehub bodies -when they work, but they always die eventually (like 2 years or so). There are more expensive options like Chris King hubs, but I have no experience with them.

You should try posting a question about this in the Clydesdale forum. Those guys have seen it all. :)

A tight chain link can cause a jerking action when it goes through the rear derailleur---I THINK THIS IS MY PROBLEM. A METALLIC SOUNDING JERK IS EXACTLY WHAT HAPPENS. THERE IS NO WAY IT IS A WORN CASSETTE FREE HUB BODY ON A NEW DURA ACE WHEELSET. THE CASSETTE ITSELF HAS 5000 MILES BUT IT LITERALLY FLAWLESS IN APPEARANCE. I WILL REMOVE, CLEAN, AND INSPECT CHAIN ASAP. THANKS FOR THE HELP

Derailleur is tight. Hanger is on a titanium Serotta, never crashed. No way it's bent.

Might be true but I wouldn't bet the rent money without checking first.

Whenever I encounter a drivetrain issue that doesn't respond to basic tuneing, the first thing that I check is the derailleur hanger alignment and usually that fixes it.

You need to measure your chain often. A 24 pin interval of new chain measures exactly 12 inches. When any 24 pin interval elongates to 12 1/16th inches it's time for a new chain. You should not need to replace the cassette with each chain. A cassette should last at least as long as 3 chains.Al

IF the chain is measured often and replaced when found to be worn (as you describe above) then the cassette should not need changing. But if the chain is not measured often and the rider says one day "I've had my bike for five years now, and ridden six-thousand miles - I will replace the original chain!" then the cassette also needs to be replaced or it will skip under load.

i am a metallic sounding jerk............................... thank you......selah

Happened again several times this week. I have a compact crank on a 12-25 cassette. Maybe I need more chain wrap from my derailleur? Thoughts?

I have a 2007 Fuji Roubaix Pro with the same set (Ultegra 10 sp) - and I have the same problem. I have 100 miles or less on the bike.

But - mine does this when under hard load (i.e. hillclimb).

I am a 6' 250# guy.

Ideas for mine? With less than 100 miles - could this stuff really be worn out? The chain has not stretched (I did check that).

On a brand new bike I'd be more likely to suspect that you're dealing with some cable stretch or the bike wasn't perfectly setup. When you're really hammering any slight imperfections in the setup are magnified. In this case I'd suspect that your rear derailleur has either suffered a bit of cable stretch or if you're on the big cog on your hill climbs then maybe a limit screw tweak is in order. Either way, it's new so take it back to the shop and describe the problem to them.

Mike

try putting a different wheel on it-- same cassette size--- take a shot of makers, smoke a camel-- chill

On a brand new bike I'd be more likely to suspect that you're dealing with some cable stretch or the bike wasn't perfectly setup. When you're really hammering any slight imperfections in the setup are magnified. In this case I'd suspect that your rear derailleur has either suffered a bit of cable stretch or if you're on the big cog on your hill climbs then maybe a limit screw tweak is in order. Either way, it's new so take it back to the shop and describe the problem to them.

Mike

It seemed to be a limiter screw and the derailleur was slightly out of adjustment -- we worked on it last night at a "tune up" class at my LBS.

On a different note - should I not be in my big cog on climbs? I know I don't "spin" up the hills - but I am not really pumping up them either.

the less you shift --- the better--- the more resistance-- the more you build your body---- if you want to be a ratio head-- get a motorcycle ( not snarky at all) test your body! stay in the seat and go up and down the hills--biking is exertion and cardio--- build on a healthy foundation-- don't rely on your bike to do all the work....
I ride a single speed --- right now the ratio is 53-18 and I boogie up hills--- stress you body-- not your back and you will improve--- dont smoke or drink--- if you do smoke camel unfiltered and drink Makers....... good luck

It seemed to be a limiter screw and the derailleur was slightly out of adjustment -- we worked on it last night at a "tune up" class at my LBS.

On a different note - should I not be in my big cog on climbs? I know I don't "spin" up the hills - but I am not really pumping up them either.

Put it in whatever gear allows you to make the best headway on climbs. Keep climbing and you'll find yourself moving to higher gearing on climbs, going up climbs faster, and a shrinking waistline. It's a good thing.

Mike

I do drink Makers...but smoking isn't really my thing. :-)

I did just get a 29er single speed and have been loving in.

I have also recently been doing the spinning thing instead of just muscling up hills. I have seen a difference.

Bill

A tight chain link can cause a jerking action when it goes through the rear derailleur---I THINK THIS IS MY PROBLEM. A METALLIC SOUNDING JERK IS EXACTLY WHAT HAPPENS. THERE IS NO WAY IT IS A WORN CASSETTE FREE HUB BODY ON A NEW DURA ACE WHEELSET. THE CASSETTE ITSELF HAS 5000 MILES BUT IT LITERALLY FLAWLESS IN APPEARANCE. I WILL REMOVE, CLEAN, AND INSPECT CHAIN ASAP. THANKS FOR THE HELP


Clean isn't the issue. Wear is. Chains on smaller cogs will jump from wear that you literally cannot see with the eye. One way to check for this is run your fingernail past the edge of some of the teeth on the cog it's jumping on. If your fingernail catches or you can see a thin line of metal ridge along the edge of the teeth it's a sign that your cog is worn and likely that is why your chain is jumping. And yes this happens to even the best kept cassetes. It's especially bad when it happens to the smaller sizes since those teeth are shaped with a bit of a ramp to assist shifting easily and almost any wear will mess up their ability to hold the chain down in the gullets of the teeth.

Easing the B screw will encourage a little more wrap but it'll make your shifting a little slower. At 5000 to 5500 miles on the cassete and if you tend to ride in that one gear combo a lot I'd say it's worn and that's where your jumping is coming from. You'll never be able to duplicate this on the stand since it's related to the tension you're placing on the system.