Rob001

Hey guys, hope someone can help me. I live in the UK and have a Boardman Team road bike with Shimano 105 shifters. Unfortunately I bought the bike on eBay and thought it was okay until I was unable to sort out the up and downshift for the front compact chainset. It's too late to send it back as Ive put up with it for a while as I live in a hilly area and leaving it on the smallest ring is okay, but its starting to bug me now as Im going further afield. What happens is I get the front derailluer setup and it shifts up and down as it should, but each time I shift it gets harder to push the shifter lever across and the front derialluer moves a little less each time until it doesnt move at all. The front derialluer is brand new and moves easily so its not that. I installed a brand new cable so its not that and so I can only think its a dud shifter unless anyone has any other ideas? If it is the shifter, is this a known problem and can I fix it or shall I bite the proverbial and buy a new one?
Rob

Andrew R Stewart 

So during the ride the shifter action tightens up but then resets its self before the next ride? What happens if you did a ride with the cable not clamped at the ft der but still worked the shifter? Would it still start to tighten up? (I doubt it). Changing shifter function during a ride is often a cable friction issue. Or a rider getting tired and not using best technique as the miles add up. Andy.

Rob001

Hi Andy, thanks for the help. No it doesnt reset it just tightens up to a point where it no longer pushes across without a lot of effort and with no movement of the FD. Each time I shift up the FD extends out a little less each time while the shifter gets stiffer each time. And no it doesnt tighten up when there's no cable. This happens within about five or six shift ups, each time the FD moves a little less.

dsbrantjr

Check the cavble inside of the shifter to be sure that it has not begun to fray, which is causing it to get hung up. Catching it before it breaks is much to your advantage since getting the broken-off end out is a miserable chore.

With the bike in a stand or upside-down, pull on the exposed cable and see if you can shift that way, while pedaling of course. This will help to sort out whether it is the shifter or elsewhere.

Rob001

Hi DS, its not the cable fraying as its brand new. It will change by pulling the cable so it looks like its the shifter, I'll have to take it apart and see what I can do with it :s Thanks for your help.

wphamilton

More information: how does it get un-stuck after the five or six shifts gets it stuck?

Brand new cable as in you installed it, new with the bike, or replaced by a bike shop mechanic?

Indyguy

Rob,
Not sure if your issue is the same as I had or not but a least sounds similar.
I have 105 shifters as well
here is the thread I started a few days ago and solved yesterday
https://www.bikeforums.net/bicycle-me...ur-issues.html

The issue was the way the shifter cable was attached to the derailleur... how it was in the clinch bolt

I can post a pic if needed

Rob001

Hi WP, unfortunately it doesnt get unstuck that's the problem, it just stays on the smaller chainring and the shifter remains ineffective. The brand new cable was as I installed it, i'm pretty sure I did it okay, i'm normally quite adept at these things, i've built bikes from sctratch before so doing one cable was no biggy, although getting the shifter to work seems beyond me. Conversely though I have been known to miss the blindly obvious so it could just be me being a doofus.

Indyguy, thanks for the idea, but I've already tried switching the positions on how the cable attaches to the FD and no joy. Thanks for the idea though.

Rob001

Also the bloke I bought the bike from was a bike shop mechanic and he set the bike up before I bought it, and the front shifter didnt work then either, I just thought it needed adjusting but now Im not so sure, perhaps that's why he sold it. My fault for not asking him about it, doh! I have read up on 105 shifters and compact chainsets and it appears the earlier ones did have issues changing up and down on a 2 ring setup vs a 3 ring set up so I might contact Shimano and see what they have to say, it might be that Ive got one of these dud shifters and just need to change it, if the design's fubar then I wont be able to repair it anyway.

jimc101

What dud shifters & what design Fubar? 105 is a brand name from Shimano, you really need to be specific to the model number, guessing if it's a Boardman and from eBay, it's 5700. What does early mean, could relate to shifters from the 1990's or 1980's by just saying 105 is to vague, as the 105 name first came out in 1985.

the 5700 series has been around long enough for any issue to become know with it, and if there are any, they are so minor, that they are not 'known' and the design is not 'fubar'

Would suggest contacting a LBS as your first point of call, as they can see/resolve any issues you have.

migrantwing

Cable tension and limit screws? Also, blast the shifter internals with WD40 and in the channel where the inner cable runs in the shifter under the hoods.

gsa103

Ok, rather than blaming everything you need to start performing step by step diagnosis. Brand new cables does not mean that they're installed properly. My guess is that an end ferrule is loose and un-seating during riding, when you shift it gets jammed in a different position changing the cable pull.

First step is to isolate the FD from the cable + shifter.
Disconnect the cable at the FD. Manually pull straight up on the cable with light tension while working the shifter. If the cable moves properly the problem is the FD routing. If the cable doesn't move properly, you've got a kink in the housing or something.

Newer Shimano shifters rarely break. Usually the shifters stop clicking entirely because they're gummed up. Increasing cable tension is a sign of the cable or FD catching on something, meaning that the cause is likely not the shifter.

Rob001

Ah, excellent advice, thanks guys. Step by step logic and WD, I like it. Sadly ive let my frustration blind me as usual. I'll try tackling as suggested and rule out FD or shifter or cable. Might not get a chance to work on it for a bit but I'll post back when I'm further into diagnosis, or hopefully a cure
Thanks all for your help, its much appreciated.
Happy cycling
Rob