celerystalksme

first off, i NEVER work on my own bikes...so this is going to be a new adventure and i may have followup qustions...

my cx bike...a blue cx6.5...the front derailleur isn't shiftinging! he cable is very taut, and stiff. and the shimano 105 shifter won't budge if i press the lever to go into the small chainring.

what do i do?!?!?!

thanks!!!!!!!!!

rs1101

so im assuming you have sti shifters. does it feel like the shifter isnt catching? or is the lever itself stuck?

Panthers007

Put the chain, manually if need be, onto the small chainring in front, and the smallest cog on the cassette*. Now check the cable-tension. Is it really taut? If so this likely is the problem. It should be somewhat tight in the most relaxed position. But very tight? Nope. So you'd need to undo the cable anchor bolt and adjust the tension so it's somewhat tight.

*You can also use the combination of small front chainring and largest cog of the cassette. Proceed the same way.

celerystalksme

yeah, i have shimano 105 sti shifters. the small paddles goes in (but doesn't do anything at this point). but if you try to push in the whole shifter to shift into the small chainring, it won't budge. and the shifter cable is SOOOO taut.

everything was fine yesterday...and then all of a sudden, while i was on my trainer, it all froze up!

rhenning

It is the reason I don't own these. Ae this point you get to a buy new one. These were never designed to be either worked on or repaired. Roger

celerystalksme

Nevermind...new problem!

Ok...after rhenning said it's probably busted and i have to buy a new sti, i figured, "what the hell...i'm just gonna yank on the shifter real hard."

so...i pressed REALLY hard on the shifter to upshift and downshift. *KLUNK* it shifted down! and now it shifts up and down just fine! but not really...

it shifts into the big chainring just fine. nice and smooth. but...shifting into the small chainring is rough...i have to press a bit harder...and it makes a thunk-thunk sound. it's a rough shift.

any advice?

[edit]ok...sometimes it's a thunk-thunk sound. sometimes it's just one thunk. and the cable is now the loosest cable. i think it might have stretched out a bit from being stretched so tautly for so long.

Panthers007

I'd suggest overhauling the system, replacing the cable, and oiling everything that moves. Put it back together and have another go. If you ascertained the FD was in proper working order during the overhaul, then I'd look at the shifter as the cause. If you found the FD was stuck or similar during the overhaul, then you found the cause.

waldowales

Are you sure the front derailer clamp didn't slip?

nitropowered

I had this happen to a customer's bike. The STI lever is shot. If your bike is less than 2years old, take it to your shop and get it warrantied.

What probably happened is you were in your big ring, then you tried to shift up thinking you were still in the small. What that does is it puts unnecessary strain on the shifter. Shimano sends out this info card with 105 shifters that say Triple A -> B -> C, Double A -> B XX C. You tried to go from B to C and busted something internally.

I think Shimano understands this issue and the shifter I sent back was warrantied no questions asked.

davidad

If you have it moving spray WD 40 into it and work it. A lot of black gunk will come out. Do this a few more times. Every 6 months or so repeat.

Panthers007

WD-40 is best used as a cleaner. If you remove old oil or grease, then it should be lubricated with something close to what was there - either grease or good oil. WD-40 will disappear very quickly if you try to use it for lubrication purposes.

What is said on this video I'm linking holds true for using WD-40 for using it on anything bicycle. Except to clean parts.

https://bicycletutor.com/no-wd40-bike-chain/