undesired auto shift.. i want it gone. CORTINA UPDATE PICS.

[FyrFytrRyn]

so i finally finished the cortina yesturday. took it out behind my home to some house pads to play around, any time i stand up and crank hard (or even normal) the SOB shifts, resulting in a knee into the tripple clamp and several words not acceptable in today's english language.i adjusted the the hi and lo limit screws, as well as played with the cable tension, no luck thus far. also, im unsure if its up shifting or down shifting, all i know is that it doesnt do it in granny, only when its below. any ideas appreciated, as this gets old after the second bruise. pics below, btw, aside from the phantom shift, the bike is like a cloud :bang:

 

[roadkillross]

WOW that thing is beautiful im loving the seat mast wut design is on there close-up por favor looks like skulls??

 

[FyrFytrRyn]

its actually a bunch of rockett and upheaval clothing stickers, all black and white though.. i decided NOT to PC that piece because i cortina is designing a new one for me in a larger size, so this is temporary. heres some close ups of the mast, as well as my ILL chain stay protector fashoned from ruberized PVC and zip ties, you might have seen this stuff @ your local machine shop (thick UV protecting junk), or even the "door" that seperates the freezer in some super markets (hanging flaps).. still got the ghost shift.

 

[spookydave]

does it have a full lenght cable housing on the rear?

 

[FyrFytrRyn]

no, the cable is exposed on the top tube and top of swing arm.

 

[ThinkFast]

Is your rear derailer hanging perfectly straight/vertical?

(Hi everyone)

 

[CalEpic]

If your limit screws are set, your cable tension is ok and the der hanger is aligned, it sounds like the suspension movement when you hammer is pulling on the cable housing causing it to shift. Try disconnecting the shock and cycle the suspension while pedaling in the stand to see if you can locate the culprit.

Nice looking sled by the way

C

 

[roadkillross]

damn thats a legit way to protect that new chain stay

 

[FyrFytrRyn]

so epic, if this is the problem how do i correct it? when i get back from my sunday ride ill check it out.. also, it skips only in the dirt, i can really pedal and bounce the bike and it doesnt skip, it seems like over chatter bumps (like when horses walk through mud and it dries) it goes nuts, especially under power.

oh yeah, the hanger is perfect. atleast if its supposed to be straight, if its supposed to be bent at all, then no. what?

and epic, whats the proper cable tension? i dont know i just keep playing with the adjusters but cant find a sweet spot, is there a guideline im unaware of?

 

[Abui]

so epic, if this is the problem how do i correct it? when i get back from my sunday ride ill check it out.. also, it skips only in the dirt, i can really pedal and bounce the bike and it doesnt skip, it seems like over chatter bumps (like when horses walk through mud and it dries) it goes nuts, especially under power.

oh yeah, the hanger is perfect. atleast if its supposed to be straight, if its supposed to be bent at all, then no. what?

and epic, whats the proper cable tension? i dont know i just keep playing with the adjusters but cant find a sweet spot, is there a guideline im unaware of?

I can't see the derailleur housing in the picture but it's probably running straight across the gap between the swing arm and the frame where it gets a lot of suspension-caused movement. You can reroute it close to the axis of the swing arm or replace the housing with a longer section that has a bend in it so that suspension movement works the bend instead of changing the tension.

 

[FyrFytrRyn]

ill look into that, i just saw that where the cable/ferrel runs onto the adj. on the derailer, its broken. basically the cable was unsupported because it broke off right before the ferrel/adjuster. im gonna cut the broken end off and re-farrel it, see what that does.

 

[CalEpic]

Take a look at this: http://parktool.com/repair/

Are you using a Shimano rapid rise derailleur?

On a normal derailleur tightening the cable tension will pull the chain to a lower gear (bigger cog) opposite with rapid rise.

At any rate, follow the Park directions for setting the high and low limits as well as the b tension. Assuming that the derailleur hanger is straight setting the cable tension as outlined should solve the problem unless the housing is being pulled when the suspension cycles. If that happens you'll never be able to adjust your problems away.

C

 

[FyrFytrRyn]

ill go over it tomarrow morning, thanks for all the replies!

 

[Flat Broke]

In looking at that pic of the drive side seat stay (though can ya really call it that on a bike like this ) it looks like you run an open rear deraileur cable down the seatstay. If this is the case, and you can't get it sorted out with the instructions from Park tools. You may want to swap to a full length cable housing that runs from the shifter to the deraileur. As someone else posted, try and route it so that the cable see's the least amount of movement from the suspension. Make sure to leave enough housing in the area between the front triangle and the swingarm so that as the suspension cycles, the change in geometry on the housing is minimal.

The bike looks great. Good luck getting her all sorted out.

Chris

 

[Evel Knievel]

Flex at the BB or stays ? Used parts ? Mix and match rings , cogs and chain ?

 

[soul rider]

chain slack? is the chain too long?
worn parts with new parts?

 

[dirttorpeedo]

cable too tite,too much tention,chain too short.the top pully wheel shood align with the gear it supposed to be in.good luck.

 

[FyrFytrRyn]

well i rode it on some dirt jumps in my back yard, it didnt skip. i just re ferreled it and lubed the cable, thanks for the info. i think i might still do the full length housing idea.

 

[Schecky]

:-k

 

[FyrFytrRyn]

hey schecky, where were you a month ago huh!?.. haha. its all sorted out now though.