Changing down to small cog ... sometimes yes, sometime no

[RichardWHardwick]

Hello folks
Doing the Wooler Wheel 100k in a few weeks (wary of the hills) and having problems with my bike - a Cannondale Synapse 150 Disc.

Basically, sometimes it changes down to the lower cog and sometimes it refuses, which obviously aint good when you've turned a corner and there's a hill right in front of you. There's no way I'll get up some of the Wooler Wheel hills in top cog. Psychologically, it's a problem when you don't know if it will work or not.

It's been in the local bike shop a couple of times and seemed fine but then a few rides later goes back to working sometimes and not others. The first time (January) it wouldn't go into bottom cog at all, probably from being left three months in top cog over winter I'm told.

I'm crap at maintenance, but I have a friend who's better - and has a book and a stand. He says it can't be that difficult to sort out. What do you reckon? What I'm hoping for from people on here are any tips ... what's the best thing to look at first? Time is running out and I'd really like it sorted. Bike is only a year old so shouldn't need new parts surely?

Any tips for me and my mate to look at first?

 

[busman]

The cable might have stretched slightly. There are 2 small screws on the front derailleur, a small adjustment to these may help.

 

[Bazzer]

Personally I have never had a problem on my bikes changing down to a front cog I haven't used for ages. Even where the bike itself hasn't been used for two or three months.
If I was in your shoes, I would check the whole of the gear changing system.
Disconnect the cable to the front mech and make sure the mech moves freely across the expected range. If it doesn't, this might be down to the adjustment screws or a poorly lubricated mech.
Then working your way up to the shifter, make sure the cable moves freely in the outer and there are not any breaks anywhere in the cable wire which might cause snagging.
Finally that the shifter itself doesn't have anything which might be causing it to snag or stick.
Then put it all back together. .
There are pleny of videos on youtube on setting up the front mech, if you and/or your mate are unsure.

 

[13 rider]

Gcn on youtube how to adjuster front derailleur. Just turn screws quarter turn then try you can always put it back .or cable tension.cover on video as well I believe

 

[annedonnelly]

If YouTube doesn't help Northumberland County Council have free sessions in learning to maintain your bike. Adjusting the gears was one of the things he showed us. As I had turned up on my bike I guy also offered to look at any problems I had.

I did a session in Blyth but I think they may have moved to Ashington. Give me a shout if you want me to dig out contact details.

 

[RichardWHardwick]

That's great - thanks folks. Will be looking at it sometime later this week. Hoped to have a few responses before looking at it.
Bazzer your reply seems a little in-depth scary. That's why I need to start working on my own bike for basic maintenance rather than taking it into a local bike shop whenever something reasonably basic goes wrong.
I think the suggestion of bike having a three month rest might have been that I hadn't cleaned it and live right by the windy salt air sea.
Anne regardless of youtube, I would be interested in the maintenance courses - as long as you always get to work on your own bike.
I live in Seaton Sluice, so Blyth would be great and Ashington fine.

 

[Bazzer]

Hope your maintenance course comes through before your big ride.
Have a look at the youtube videos, As @13 rider says GCN have a video, (there are others too), for adjusting the front mech.
If you are unsure, take pictures before you do something and/or make notes of what you have done, before you test it. E.g. right screw turned a quarter turn clockwise. That way, if something doesn't work after you have "fiddled", you know how to get it back to working. * Or at least working at bit better than before you "fiddled".

 

[Big Dave laaa]

Take it to another LBS if you aren't sure. Pay them for a decent service and put it behind you. The last thing you want on a big event is mechanical worries nagging at you. A good bike shop can offer advice ref. gear ratios etc. to make your day go smoother and more enjoyably. Good luck.

 

[DaveReading]

There is a spring in the front derailleur whose sole purpose in life is to put the chain on the smallest chainring (when the shifter cable tension is released).

If that isn't happening, it's likely to be one of two things stopping it: residual tension (or friction) in the shifter cable; or the limit screw on the derailleur not allowing the cage to move far enough inboard.

Once that makes sense, go and re-read Bazzer's post.

 

[RichardWHardwick]

Take it to another LBS if you aren't sure. Pay them for a decent service and put it behind you. The last thing you want on a big event is mechanical worries nagging at you. A good bike shop can offer advice ref. gear ratios etc. to make your day go smoother and more enjoyably. Good luck.

If I was sure it would work, I would take it to another bike shop - never been that delighted with the local one anyway to be honest.
The other one is 30 minutes drive away but it would be worth it if I knew it would work.
The problem is it works sometimes and doesn't other times, so the lbs said it was working, tested it and it was, then I go out and 10 miles later it decides not to, then it does a couple of times, then it doesn't again.
Infuriating.
I'd happily pay if I thought it would sort it for good. Getting a bit nervous it won't work on the day and I'll have to push up loads of hills on a tough course.

 

[RichardWHardwick]

There is a spring in the front derailleur whose sole purpose in life is to put the chain on the smallest chainring (when the shifter cable tension is released).

If that isn't happening, it's likely to be one of two things stopping it: residual tension (or friction) in the shifter cable; or the limit screw on the derailleur not allowing the cage to move far enough inboard.

Once that makes sense, go and re-read Bazzer's post.

Thanks Dave. Impressive use of colon and semi-colons too

 

[annedonnelly]

Richard - take a look at the SE Norhumberland prospectus at http://www.northumberland.gov.uk/default.aspx?page=5070#prospectus The contact details are on page 24.

The course I did was only a morning and we didn't do anything - we just watched. But there are more advanced courses and the guy was so helpful I think he'd probably find a way for you to turn up and work on your own bike. It's worth giving them a call.

If I could have done the more advanced course on a weekend I'd have signed up.

 

[puffinbilly]

I had the same problem over winter - think it was in January - tried all the tried and trusted methods (cables, springs, shifters etc) and nothing worked. I then took it to Edinburgh Bike Coop in Byker, was then assured it was only gunk in the front mech with riding it in foul weather. So the solution was I was to take it home and clean it thoroughly and give it a liberal spray of GT85.
I did this and it didn't work. I was convinced it needed a new mech and bought one.Then took it into Halfords in Newcastle to buy something and asked them to have a look at it and sure enough it was some gunk stopping the spring.

 

[deptfordmarmoset]

And I've got a compact that really doesn't want to change up when on some cassette rings, yet is well adjusted IMO and runs smoothly. It may be easier to get onto the smaller cog before you really need it. See whether it's easier to change before you're already close to cross chaining (or have completely run out of cogs on the cassette).

 

[Tojo]

Hello folks
Doing the Wooler Wheel 100k in a few weeks (wary of the hills) and having problems with my bike - a Cannondale Synapse 150 Disc.

Basically, sometimes it changes down to the lower cog and sometimes it refuses, which obviously aint good when you've turned a corner and there's a hill right in front of you. There's no way I'll get up some of the Wooler Wheel hills in top cog. Psychologically, it's a problem when you don't know if it will work or not.

It's been in the local bike shop a couple of times and seemed fine but then a few rides later goes back to working sometimes and not others. The first time (January) it wouldn't go into bottom cog at all, probably from being left three months in top cog over winter I'm told.

I'm crap at maintenance, but I have a friend who's better - and has a book and a stand. He says it can't be that difficult to sort out. What do you reckon? What I'm hoping for from people on here are any tips ... what's the best thing to look at first? Time is running out and I'd really like it sorted. Bike is only a year old so shouldn't need new parts surely?

Any tips for me and my mate to look at first?

I'm in Killingworth, I'll have a look at it if you want, I'm a l qualified bike mechanic, from what you're saying it just needs a bit adjustment, cleaning and tweaking, maybe a new cable or its just down to cable tension and adjustment, and basically if you want me to service it plus any parts i.e. cables it'll only be a few quid, and I'll not bullshit you......