1955

Hey all.

I bought a MTB so I would be able to ride with my 10 year old daughter, so I really didn't need much. But of course I've now been on a couple of rides with my buddies (Carbon Canyon) that I usually road ride with and I need your expertise. I have an 8 speed with an Alivio derailleur on the back that kind of sucks. Just wondering if I'm stuck with it, because it's an 8 speed, or if I can upgrade to something that will work better using the existing shifting levers?

TIA

ed 

Is it new?

A new Alivio should shift fine for a while w/o the parallelogram or main pivot bolt getting loose. It may just need adjustment.

Yes though...you can install a 2:1 RD and be just fine.

sirtigersalot

derailleurs are reverse compatable, by which I mean a 9spd derail works with anything with 9 or less speeds, and 8spd works with 8 or less spds, so yeah you can get a new derail as long as its shimano (sram makes a few that are compatable but I wouldn't bother)

as chelbord said u may just need an adjustment,

also what shifters are you running, that may be your weak link, crappy shifter + good derail = crappy shifting

jjbod1

For a cheaper derailleur, the Alivio is really pretty decent. Had one on my 07 Gary Fisher Wahoo, beat the crap out of that thing,maby had to have it ajusted a couple times over a year. And now I have one on my hybred/path bike,shifts great. Also if you reseach them on line they get good reviews. Just like the others said, most likly need ajusted. Or could just be crappy shifters. Try ajustment first. Most shops will charge 6-10 bucks.

1955

Thanks all. I come from a road bike background and know how to adjust theses things, but I've had problems keeping it on the second cog. When I'm in second gear, it wants to climb onto first gear when I hit a bump, or peddle hard. I bought the bike less than 2 years ago (I think) and don't have many hours on it at all and all except the last two rides have been with my daughter on flat, bumpy ground. The bike mostly sits in the garage. I did break the chain a while back just climbing a 4 inch curb.

Could the rear hanger just be out of alignment? Every other gear works fine, it's just staying in second that gives me fits.

-_RebelRidin'_-

maybe the cog is worn?

1955

The bike has no more than 15 hours of VERY easy riding on it. Even though I've had it for almost 2 years, it's hardly been ridden at all. It's been doing this almost from the start.

roccobike

Uhh, very easy riding but the chain broke? My computer is still working on that one.
If you're concerned about the derailer, put it on your rack and watch it from the rear, make sure the alignment with each cog is correct and that the cage is not leaning to one side. Shift to the small cogs, grab the derailer and see if there is play in the mounting bushing or the cage bushing. Personally, I doubt an Alivio rear derailer needs replacement this soon. Actually, it sound to me like your derailer barrel adjustment is just a quarter turn too tight, but you know how to adjust it so I'm sure you tried turning the barrel. Also check your low gear limit screw. If it's set too tight, then you may have to have the barrel adjusted tighter just too reach the low gear. Again, this should show up when you check the cage alignment with the low gear.
I know it's a long shot, but when the broken chain was replaced, did they install an 8-speed chain? The only other thought that comes to mind is lube the cable at all entrances to housing with chain lube. I know it's a long shot, but maybe your cable is binding at the high stress point which is the low gear.

CCrew

Other thought that comes to mind is that someone threw a new chain on it right out of the box without fitting it.

-R

1955

When I broke the chain, I was rolling up to my apartment...there is maybe a 10 degree incline for about 5 feet and then the small curb. I was in either first or second gear and was going to pop the front wheel over the curb, when I pushed on the pedals, the chain snapped. Now I'm sure there was a lot of torque on the chain at the time as I was almost stopped, but I've never broken a chain in my life and just assumed that the chain that came with the bike was junk.

On the last ride I did, I hosed the chain and RD down with White Lightning Chain Lube and didn't have any problems, BUT I only used second gear very gingerly and mostly stayed away from it. I'll get out there today and give it a thorough looking over and run it through the gears.

Thanks for the info, I'll check that stuff out.

Yes it's an 8 speed chain and I did completely clean the grease off of it, lube the crap out of it and fit it, thanks.

Thanks,
Ralph

1955

Thanks for all the help. I found the problem.

Coming from a road bike background, I never thought to look at the gears in the back. After cleaning and tweaking the RD, I was re-oiling it and noticed that it wasn't spinning true. The problem wasn't 2nd gear at all, but instead it was 1st gear that was bent in towards 2nd, so every time I was in 2nd, it was trying to jump onto 1st whenever that spot came around. I must have gotten the chain stuck between the dork disk and 1st gear, bending it at some point. After trying to fix it while still on the bike without any luck, I broke down and tore it apart. I laid the big gear on a big flat metal plate I have, and straightened it out.

Everything works like it's supposed to now. I just have to get used to the fact that different things go wrong on a MTB than a road bike.

ed 

That sounds to me like 1 of 2 things may have gone down:

1. You got a twig stuck in the drivetrain while riding and it bent the gear inward. (unlikely)
2. You were in that gear and started going up a hill and realized you didn't have the juice to come through, so you shifted to an easier gear under power and it put a cross-load on that gear as it made its way up to the next. (likely) If this happened, always remember that when you're going up a hill and need to shift to an easier gear...

-dig deep
-find a small burst of energy
-give your pedals a good power surge
-let up on the power (soft pedal) as you shift
-don't get back on it until your chain has seated on the next easier gear.

1955

Thanks for the advice. I have a feeling that that's just what I did. I was probably with my daughter and was busy watching out for her and not paying attention to my own riding.