Cycling UK Forum

Thanks for replies.
Re the tension, yes good point, so last night I re-assembled the gear and FD and tensioned the cable, but no luck, problem still there. I did not try more lubricant though, maybe that's worth a try.

Looking at the part more closely (the pawl that is not returning to position) I cannot see what mechanically it is interlinked with it to move it back. It seems to have full freedom of movement through about 180 deg. So it doesn't look like a lubrication problem.

But I did make a discovery this morning. I was thinking there must be something to move it back, so I had a much closer look under a bright light and made a discovery.

Just off to the right of the pawl, on the same spindle, is a tiny coiled spring, which is pinned at one end to the long lever, but at the other end is LOOSE !! So to your comment , Brucey, that could be the spring that i need to get working again. I've attached a pic, the arrow top right shows where it is attached (you can't actually see the connection but it is there, on the right, to the bottom of the large lever) and bottom left is the free end. Now why would there be a loose spring there? It could be there to return the pawl to position ready for the next move to the large ring.

But there appear to be two issues with that hypothesis. One there does not seem to be an obvious place to connect the loose end of that spring to, and secondly if it was to connect to the pawl direct , the way it is positioned the spring tension would be working the pawl away from were it needs to be, rather than pushing it into position.

So I'm thinking now that maybe there was another part ( that has gone missing, hence the sudden fail) , to which this spring attached, and in combination they moved the pawl. Anyone got any pics of the inside working of an ST-4700. LH that they could share? There is nothing like that level of detail on the Shimano documents I've seen.

Meanwhile I'm looking out on ebay for anyone selling a old ST-4700 for parts - if i had a working lever system I could see if mine was any different. In the meantime happy to hear any other suggestions, especially if anyone knows what that spring in the photo is suppose to do. I'm not ready to admit defeat yet - these levers are almost brand new and mostly been used on an indoor turbo trainer.

Thanks

Hello, I'm resurrecting this thread because I'm trying to fix a similar problem with a Tiagra ST-4700 LH shifter. Mine abruptly stopped working completely last week after having been intermittent over last few months. The inner lever works to change down to the small ring on the FD but the larger outer lever moves freely but does not engage or pull the gear cable when trying to shift to the outer ring. I have detached the cable from the FD and can see there is no movement in it when moving the outer lever - the problem is definitely in the lever mechanism.

What I would like a view on is whether this is fixable. I have tried all the youtube video advice about fixing shifter problems by removing old grease and then re-lubricating, but not having any joy with that.

The problem seems to be the "pawl" shown arrowed in blue in the photos attached. It does not engage with the ratchet wheel, unless manually pushed in. It, the pawl, is just rotating freely. If I push it in manually, it engages and shifts the gear, but as soon as we shift the other way it un-latches and then remains free. I can move it freely . In one of the posts above there is reference to it being sprung. It feels like it needs to be sprung as there is no other mechanism I can see to force it to latch. MIne is just moving freely . Should this pawl be sprung? Os it possible the spring is broken or lost?

What do you think ? Time for a new shifter or is this fixable?

Thanks
Liam