New Tiagra 4700 shifter
Bought a new bike last week from an internet retailer and the front shifter is doing something weird.
Sometimes in the small ring when going to shift up, the shifter doesn't engage. You swing the shifter to change gear and it's like there are no internals - doesn't make any noise, doesn't feel restricted in any way like it would when shifting - ie. it's very easy to swing the shifter with minimum effort. It last's a minute or so and then goes back to normal and shift's fine.
It isn't making any horrible noises, don't and haven't had to force anything - everything feels perfectly normal when it works.
Any ideas as it's bloody annoying?
Sometimes in the small ring when going to shift up, the shifter doesn't engage. You swing the shifter to change gear and it's like there are no internals - doesn't make any noise, doesn't feel restricted in any way like it would when shifting - ie. it's very easy to swing the shifter with minimum effort. It last's a minute or so and then goes back to normal and shift's fine.
It isn't making any horrible noises, don't and haven't had to force anything - everything feels perfectly normal when it works.
Any ideas as it's bloody annoying?
0
Comments
-
I know exactly why this is, it sometimes happens to me (I have 105 11 speed so should appear identical)
There are 2 reasons:
1) you have accidently, slightly nudged the downshift at the same time. This can happen if you are wearing thick gloves. This is easy to re-enact - just push both levers at once (just a tiny amount) then release the downshift and keep pressing the upshift. It will move in the way you describe above.
2) This is harder to describe - but - if you look when engaging the downshifter, it pushes a small metal bar up and in (basically it moves with the downshifter, but is a shorter bar). It's on a spring and normally falls back when you release the downshift. Sometimes, this metal bar doesn't fall back to its resting position, next to the downshift. This means that when you then try to press the upshift, it doesn't change. It's easy enough to reach with your fingers when in tops or drops position but you basically push it very softly back into position and then it shifts fine. It is basically the same problem as 1 but triggered a different way.
On 2) I found this out when I had my bike in the stand with the hoods folded back as I was changing a cable. When I was adjusting my gears and was trying to downshift, it would only go once, as this little bar was getting caught where I had peeled the rubber back. I had to push it back down manually each time then change gear.
Hope that helps - it's very hard to describe in words without pictures but all hosting sites are blocked at work.0 -
That's brilliant, cheers.
I've just come from 5800 105 but never had that problem.
I assumed I had been doing as you described in 1) but after it happening a few times last night I was making a conscious effort to avoid the downshift which still made no difference.
On 2) - is there any way of solving or do you have to tweak the bar yourself every time it happens? If not I'm hoping it's just something that will bed in and in time work as it should?0 -
I just tweak the bar. I'm not really sure why it happens, but it is a nuisance, especially when you're riding fast in chaingangs and you can't shift!!
Annoyingly shimano shifters aren't good at being disassembled and serviced0 -
Hmm, just had a play with the bike and I see the bar your talking about, however this doesn't seem to be sticking. When it won't shift the bar is back in place and moves back and forth with the downshifter.
I wonder if something is fouling inside the shifter?0 -
Could be a shard of cable getting the mechanism stuck. had this on older rear STIs as the cable frayed. Soon after it snapped leaving me in the 11 gear for the club hill climb. A justifiable DNF I think.0
-
I think it should always move inwards with the downshifter, but sometimes doesn't return to its original position.0
-
But when it doesn't work it's not engaging the cable at all. It's not like it's trying to pull the cable then giving up, it's totally free.
Tbh, I need to have a good look tonight but the bike is only days old and I'm waiting for a response from the shop re. damaged fork so will let them know about the shifter when they get back to me.0 -
So, had a good inspection of this last night.
I don't think it's the same problem as you describe coriordan. When the shifter wont work, if I jiggle the front mech with my fingers it solves the problem. Until I shift to the small ring again and then I have no shifter.
The little bar you mention is always in place.
I think the cabling, which is internal, is getting fouled inside the down tube.
I'm (still) waiting to hear back from the bike shop re. damage to the fork. I also have this shifter problem and the left crank arm started making a horrific noise on the way home last night. Whoever's put it together hasn't done a very good job.0 -
I also had a think about this issue last night when riding home - with me it is the downshift which becomes fouled when the smaller bar isn't in place or if I brush the upshifter. The upshift is always fine, so not quite the same issue.
Good work finding out what was causing it. Good luck resolving0
