Front derailleur reluctant to change up recently

For discussions about bikes and equipment.
Brucey
Posts: 44666
Joined: 4 Jan 2012, 6:25pm

Re: Front derailleur reluctant to change up recently

Post by Brucey »

LittleGreyCat wrote:Difficult to work out how..


sometimes they just bend; this is common with stronglight 99/100 chainsets.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
User avatar
Mick F
Spambuster
Posts: 56366
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Re: Front derailleur reluctant to change up recently

Post by Mick F »

LittleGreyCat wrote:New chain, 3rd time out, I think.
First lubrication after factory improved things briefly but then the problem returned part way through the ride.
That's the issue.

New chains in my experience, aren't very able to move sideways for a while.
They are stiff side-to-side and need breaking in to get more flexible.

Found this issue over the years on both bikes, but mainly my Moulton with a triple setup - 34/48/61 especially up to the 61t.
Mercian is 28/42/53 and still suffers with a new chain.
Mick F. Cornwall
bazzo
Posts: 221
Joined: 27 Jul 2012, 7:37am

Re: Front derailleur reluctant to change up recently

Post by bazzo »

Suggest you give everything a good clean and lube, then look online for how to set up front derailleur and follow it through. There is a Parktool one that is quite good.
Brucey
Posts: 44666
Joined: 4 Jan 2012, 6:25pm

Re: Front derailleur reluctant to change up recently

Post by Brucey »

LittleGreyCat wrote:On the last couple of rides the FD has been reluctant to change up into the biggest ring.
3 * 9 transmission.


LittleGreyCat wrote:New chain, 3rd time out, I think.
First lubrication after factory improved things briefly but then the problem returned part way through the ride.


Needless to say if you have recently been changing parts, it is a good idea to mention that early on; it is almost certainly not unrelated.

If you could say what parts you have been replacing and more to the point what the old parts were as well as the new parts, perhaps some further light can be cast...?

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
LittleGreyCat
Posts: 1185
Joined: 7 Aug 2013, 8:31pm

Re: Front derailleur reluctant to change up recently

Post by LittleGreyCat »

Brucey wrote:
LittleGreyCat wrote:On the last couple of rides the FD has been reluctant to change up into the biggest ring.
3 * 9 transmission.


LittleGreyCat wrote:New chain, 3rd time out, I think.
First lubrication after factory improved things briefly but then the problem returned part way through the ride.


Needless to say if you have recently been changing parts, it is a good idea to mention that early on; it is almost certainly not unrelated.

If you could say what parts you have been replacing and more to the point what the old parts were as well as the new parts, perhaps some further light can be cast...?

cheers


I am into the process of swapping between 3 chains (as recommended in various threads) to see if that can even out the wear instead of running one chain (and possibly some or all cogs) to destruction.

All that has been changed recently (apart from chains) is the smallest front ring.
28 changed for a 24.
This was discussed when I was trying to diagnose a strange clonk under load when climbing.
Potential conclusion was that it was a combination of pedalling style and a brand new chain adjusting to worn cog teeth.

As noted up thread, twiddling the stop screw has apparently cured the issue.
I did have to make a minor adjustment to slacken the cable slightly as it was grumbling about changing down to the smallest front ring.
However a couple of turns on the down tube adjuster and all is fine.

As soon as I get the chance I will give the drive train another check over as am still puzzled over the sudden manifestation of this problem some time after the last change made.
I can see that it might be a new chain with most of the initial stiffness still there but some of the factory lubrication worked out.
However I didn't see any sign with the other two new chains of the set of three.

It could be just a sign that the drive train is getting a bit worn and is less tolerant of new chains.

I am planing to take the bike into Spa for a service some time in the next month when in the Harrogate area so may well get a bit of the "Did you realise that....?". We shall see.
Brucey
Posts: 44666
Joined: 4 Jan 2012, 6:25pm

Re: Front derailleur reluctant to change up recently

Post by Brucey »

one thing that might explain both the clonk and the bad shift might be if the RH BB cup has started to back out of the frame.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
LittleGreyCat
Posts: 1185
Joined: 7 Aug 2013, 8:31pm

Re: Front derailleur reluctant to change up recently

Post by LittleGreyCat »

Brucey wrote:one thing that might explain both the clonk and the bad shift might be if the RH BB cup has started to back out of the frame.

cheers


Thanks.

I will give that a check over next time that it is on the stand (probably a few days now).
OldLimey
Posts: 142
Joined: 1 Aug 2020, 8:53pm

Re: Front derailleur reluctant to change up recently

Post by OldLimey »

About three-hundred yards from home, the left pedal began to feel a bit wobbly, and I thought I'd have to get a new set of pedals. Then two-hundred yards from home the whole crank arm fell off into the road. It's been a couple of years since I checked the bolts so it's my fault.

Twice in recent days the front derailleur was out of adjustment, which was unusual. I adjusted it, yesterday, and it was fine. But what was happening, that I didn't realize, was the whole bottom bracket was moving. The chain ring was out, thus creating the illusion that the derailleur was the problem. So, having put the bottom bracket and pedals where they belong, I had to adjust the derailleur, again.

There's something I never noticed, before. how 4mm of the crank arm splines are showing. I bought the bike, new, 4 years ago. There is a 19mm spacer on either side of the BB, and I'm wondering if they are the right ones. Both crank arms measure exactly 20mm from the chain stays, plenty of clearance, but it seems shorter spacers might be in order. I'm assuming the BB, spacers and crank arms are factory installed, but could have been bike shop installed. The bike shop has given me plenty of problems in the past so I no longer deal with them.

I'm thinking if I could put 17mm spacers on, if this would throw the FD out. Or if I put a 15mm spacer on the left side, only, if that is acceptable.
Just wondering what your thoughts are on this.
Attachments
splines.png
Last edited by OldLimey on 13 Sep 2020, 4:10pm, edited 2 times in total.
Jdsk
Posts: 24864
Joined: 5 Mar 2019, 5:42pm

Re: Front derailleur reluctant to change up recently

Post by Jdsk »

Thanks for the update.

Jonathan
Post Reply