Kendeathwalker

I have some basic maintenance abilities, so I was going to attempt to fix the problem myself before running down to the bike shop. My problem is the chain slips under load, and I ended up dumping myself over the handle bars crossing a creek when the chain slipped off the front ring( got a pretty ncie cut on my shin). From things Ive read and heard Im going to check to see if there are any stiff links in the chain, if there are any broken or bent teeth,(bike is brand new so nothing should be worn yet). Im also going to dial in/tune the front a rear derailers. Is there anything else I should look for?

My other fear is just bad shifting on my part. For the most part I try to avoid cross chaining and shifting under load. It usually happens when Im on the middle ring between 12th-16th gear(im just guessing here, there arent any numbers on my shifters. Its usually when im on the higher end on the rear cassette middle ring in the front. When I granny gear it and spin through things It doesnt slip at all)



Thanks


If this is necessary to help me
My bike is a Specialized Rockhopper

Here are the Specs


FRAME
Specialized M4 Manipulated Alloy frame, fully butted, ORE DT, forged dropouts w/ replaceable 98954020 hanger, disc only
REAR SHOCK
FORK
RockShox Tora SLite, 100mm, alloy steerer, 32mm Cr-Mo stanchions, magnesium lower, coil spring preload and rebound adj. w/ LO, 13-15": standard spring, all others: "stiff" spring w/ preload adj., disc only
HEADSET
Specialized 1-1/8" threadless, loose ball
STEM
Specialized 3D forged, 4-bolt, 7 degree rise, 31.8mm clamp
HANDLEBARS
Specialized butted alloy, 31.8mm, 25mm rise, 640mm wide, 8 degree back sweep, 8 degree up, 2.6mm thick
GRIPS
Specialized Enduro, dual compound Kraton, no flange, 131mm
FRONT BRAKE
Tektro Auriga Comp, hydraulic disc, dual piston w/ 160mm rotor
REAR BRAKE
Tektro Auriga Comp, hydraulic disc, dual piston w/ 160mm rotor
BRAKE LEVERS
Tektro Auriga Comp
FRONT DERAILLEUR
Shimano Deore, 34.9mm clamp, bottom swing, dual pull
REAR DERAILLEUR
Shimano Deore
SHIFT LEVERS
Shimano Deore SL- M531, 9-speed
CASSETTE
Shimano HG-50, 9-speed, 11-34t
CHAIN
KMC X9 w/ reuseable Missing Link
CRANKSET
Shimano FCM442, forged alloy arms, Octalink Spline w/ replaceable rings
CHAINRINGS
44A x 32S x 22S
BOTTOM BRACKET
Shimano BB-ES25, Octalink spline, cartridge bearings, 68mm x 118mm
PEDALS
Alloy body and cage, 9/16"
RIMS
Specialized RHD 26", double wall disc, pinned w/ eyelets, 28/32h
FRONT HUB
Specialized Hi Lo, forged alloy, double sealed, ground race, 28h
REAR HUB
Specialized, forged alloy, double sealed, ground race, cassette, QR, 32h
SPOKES
1.8mm (15g) stainless
FRONT TIRE
Specialized Fast Trak Control, 26x2.0", 60TPI, aramid bead, 2Bliss ready
REAR TIRE
Specialized Fast Trak Control, 26x2.0", 60TPI, aramid bead, 2Bliss ready
INNER TUBES
Specialized schraeder valve
SADDLE
Specialized Indie XC, Body Geometry, 143mm width, front and rear bumpers
SEATPOST
Specialized alloy two bolt, micro adjust head, 30.9mm
SEAT BINDER
Specialized alloy w/ QR, brass washer
NOTES
Chain stay protector, reflectors, clear coat, owners manual

cuevélo

I think you've got it. Check for stiff links, and check the derailleurs. The derailleurs go out of alignment on a new/newly cabled bike as the housing settles into place. The only other things to check for are chain stretch and worn chainrings, but since you said the bike is new, I doubt that they are the problem.

trhouse

I had this happen recently with a used Peugeot with two front Biopace chain rings. These are Shimano rings that are oval shaped and not round. When I shifted from the large to small ring, the chain would skate over the tops of the teeth of the small ring. I checked the chain, adjusted the derailleur until I ran out of adjustment range to push the chain inboard more on a shift to the small ring but it still happened.

Then I noticed that as I rotated the rings on the bike stand, the large Biopace ring teeth never got closer than about a 1/4" from the front derailleur. I lowered the derailleur until the closest the derailleur got to the large ring was about the thickness of a dime. Problem solved, no slipping or skating chain.

nuovo_record

if it's a new bike, could you not take it to your LBS and ask them to explain your problem?

StanSeven

Most likely it's chain stretch. Use the adjustment mechanism and twist it some until you feel tension.