Front Der. Prob..

[Skeeter]

Hey just had a quick question for all of you guys.
I cannot get the front middle ring gear to stay engaged. As soon as any torque is applied it slips off into the small ring. My LBS said I probably need a new middle gear. Does that sound right. If i have the rear der. shifted into a small rear gear it stays engaged, but as i shift towards the bigger rear gears it slips off.
Im obviously a newbie and have no idea. I looked at the gear but don't know what the heck i was looking for.
Has anyone else had any problems like this and what did you do about it.

Thanks in advance

[mtnbikerdude87]

How old are the chainrings? Now you said when you apply torque, it slips, so it sounds like you have a worn chainring. I remember when I had my middle chainring worn on my raceface crank, it would slip everytime I stood up in a climb and that just ruined my climbs. I replaced it and it skips no more.

[LBmtb]

Can you take a picture and post it? Chainrings do wear out eventually. Check the teeth on it and see if they're deformed or anything.

[dirttorpeedo]

if you've got worn chain rings it will slip and mash a knee into your stem, it happened to me this morn. ouch.old chain,cogs,and chainrings all go together. if you change any one of those and it's been awhile (years ) they've all worn together,for instance, a new chain will not sit into the cogs or chainrings, it will ride a little on top. you've got to get new stuff, professionally speaking of course. my bill is in the mail.hehe, hope that helps its hard to tell without seeing it tho.good luck!

[Skeeter]

I'll take off the chainring tonight and post some pics of it. Im sure thats it, the bike was a hand-me-down given to me by a friend. If i replace the middle chainring, should i replace all the gears; ie., smaller and larger gear up front also. And should i replace the chain too?

Regarding dirttorpeedo's "my bill is in the mail.hehe," dont worry the check is already in the mail.

[LBmtb]

You can check the chain by doing this . . .

Ruler. Tension the chain by pressing lightly on the right pedal. Hold a 12-inch ruler against the chain. On a fresh chain, 12 full links (from pin to pin) measure exactly 12 inches long. If 12 links measure 121/8 inches or more, replace the chain.

[Skeeter]

OK i do believe the ring gear is the problem, see the pics.

Regarding the ruler and chain, I believe i did this right but my measurement listed 11 3/4", or maybe 12 1/8, depending what mark you measure to.

[pshloss]

I'm dealing with the same problem on two bikes right now! I'm starting with cassette and chain. I'll let you know what happens, but it won't be until this weekend. In my experience, chainrings rarely cause problems unless they are super worn or damaged by hitting rocks or something. If you do change a chainring, I definitely recommend changing the cassette and chain at the same time.

[Epic_Mtn_Biker]

i'm doing the chain/cassette change this week, they sell he little chain gauge thingy for cheap

[dirttorpeedo]

Originally Posted by Epic_Mtn_Biker

i'm doing the chain/cassette change this week, they sell he little chain gauge thingy for cheap

or change the chain about every six mos. it gets expesive changing a whole drive train so often, chains are cheap. so you myay not need the chain gauge thingy.(yes that is the technical term at the bike shop)

[EndoMaster]

Originally Posted by dirttorpeedo

or change the chain about every six mos. it gets expesive changing a whole drive train so often, chains are cheap. so you myay not need the chain gauge thingy.(yes that is the technical term at the bike shop)

I would stick with the chain gauge thingy. I managed to stretch out my last chain to .75 (according to my park tool) in less than 4 months. If I left it on there for 6 months I think i would have stretched further than 1.0 or more.

The tool is cheap insurance and IMO can extend the life of your other drivetrain components. I must add that am on the big boned so I wear down stuff faster, especially now that I'm riding more often. Using a time period like 6 months wouldn't work for me, that's why I say use the tool.

Agustin

[Krunk]

Dude, visually looking at it, it's shot ! i used to be a bike mechanic/builder.Also I'd certainly take a look at the wear on the chain and cassette.Don't wast your money on a drive train tool! you can see it visually it's not that technical ! spend your money on a new chain . Try and get a connecting link such a srams power connector chain ... you can install or remove your chain by hand... with no tools.

[Skeeter]

Thanks for all the advice. I went ahead and got a new chainring along with a new chain, and am having my LBS check the adjustment of the front der. just to make sure there is no more problems. Thanks for all the help.