UK Yank

To start with, I'm no bike mechanic, but am not a total techno-idiot. Yesterday, while slogging up a mud hill I developed some mechanical problems that lead me to ask the following questions.

Chain slippage. No issues at all in any gear on the first part of the ride. Get to a long muddy uphill stretch and two things happen. First, most of the bottom foot and a half of bike turned into a mudcicle. Just about then my chain started skipping. I assume this was because it is a) too loose and b) packed with mud and rock. On the center ring up front, it skipped a lot even after I half-assed washed the mud off in a puddle. A skip or two for a few minutes on the large ring, then no skipping on that ring. Switched back to the middle ring - skipping returned, but not as bad as when I was doing my best imitating the Wehrmacht's drive to Moscow in autumn '41. Any advice/ideas?

The chain is not new, but the front ring does not look worn. I took a hard look at it, and the teeth are all uniform and don't appear to me to be worn (pointy, shark-fin shaped etc - was told on another forum to look for that.) The casset in back looks fine as well - uniform teeth on all and no obvious wear.

Thanks,

Paul

UK Yank

Found this on another site:

Measure a length of chain containing 12 outer side plates. From the first pin of plate #1 to the first pin of plate #12 should measure exactly 12 inches. (Or, hold a new chain alongside the old chain to check for stretch.) Put lateral stress on the chain (gently bend it sideways, or hold it so gravity makes it sag sideways). The chain should not have more than 2 inches of lateral sag over 12 inches of chain. If the chain fails either of these tests, it should be replaced.

Did that, and the chain is right at 12 inches. Am trying to figure out how to execute the "sag test."

Paul

UK Yank

Read the seat post thread, particularly the part about "use the search - it's all been covered before..." Did so and came up with this.

You do understand how to use your gears propertly dont you. When in the big ring on the front you should only use say the smallest 3 rings on the back. In the middle the next 3 rings on the back and when in the small ring on the front only the largest 3/4 rings on the back. If you go say from the smallest ring on the front to say the 7th ring on the back, it could be that your chain will jump around as you are crossing your chain.

I'm about to head out. Will try this out and see if it fixes the skipping.

Paul

Dr.Deltron

Sounds like you may just have a stiff link or two. Turn the pedals backwards and watch as the chain goes through the pulleys on the rear deraileur. If you do have a stiff link, it will skip as it goes around the pulleys. Locate the errant link(s) and stress the chain sideways, both directions. Also look for little burrs that occur when shifted under load. If your chain has a burr, you will probably have to use a chain tool to remedy the problem. Break the chain at the bad link, file off the burr, reinstall chain. Check for other faulty links & fix them. Lube & go! I also carry a "wash" bottle when riding in mud to clean the chain with. I usually use one of my old bottles that has previously developed mold & yuk from not cleaning after the ride. I wouldn't drink out of it anymore, but it's great for mud removal, especially if you have to use puddle water.

MajikMan

I doubt it's a chain-length issue. If you've been riding the same chain for a while and the skipping just developed, I don't think that's the cause. If the chain was that stretched, I don't think the cassette and chainrings would not also be worn. Stiff link sounds like a good place to start looking.

UK Yank

Thanks - I'll check that out tomorrow. By the way, went for a ride today in a howling wind. Actually had to lean to the right on the bike to stay straight. Was dang fun!

Paul

Avalanche325

That is absolutely the perfectly WRONG description of how to use your gears.

Do a search on the road forum on "gears speed ranges".

UK Yank

Av,

Thanks for that. Did the search and found the following.

[quote] No you can't really run all 27 gears even though they call it a 27 speed bike. In reality you will use at most the 4-5 lowest gears (largest cogs) when in the small ring, maybe the whole cassette when in the middle ring and only the top 5-6 (smallest cogs) when in the big ring. At most you might use 20 gears +/- and in reality I found I was using like 16 at most on mine so I switched to a compact double. [quote/]

Sounds more in line with what is correct - middle ring should be able to access all the rear cogs with lmits only on the big and small rings. Make more sense to you?

Paul