Front Derailleur Problem - how to fix it.

ROK ON

Hi. Since my new frame has been built up, my front deraileur has effetively stopped working. It used to work beautifully (so much so, that I never heard it shifting).

It now sounds like a chainsaw when shifting.
I have an Ultegra SL Triple.

The problem appears to be that shifting from 50 into 39 causes slipping t0 the small ring, and shifting from this 30 ring back to 39, causes a chainsaw type noise that feels like my chain is going to break.

Two bike mechanics have "fixed" this issue for me, to the extent that it has gotten worse. As a result I had very big gearing problems on y'days cycle.

Does ayone on this site know how to fix a derailleur (i would pay), or can anyone recommend someone who can do it.

I have been told by the two bike shops, that I do not need a new front derailleur or chain. Given that bike shops like to sell stuff, I can only assume that they are telling the truth, in that they could have sold me one, but said that I dont need it.

Thanks

Lumen

Try this first.

Lots of similar on interweb.

kona

Well assuming its not a issue with your chainset,

There are only 3 adjustments on the front mech:

Height and direction.
Cable tension.
Limits

If 2 mechanics have tried and failed to fix the issue then id Imagine its not as straight forwad as it would seem.

Who adjusted it?

Also, Is it the correct derailleur for the chainset?, Topswing? Bottom swing? Is it capable of shifting onto larger chainrings?

ROK ON

kona wrote: »

If 2 mechanics have tried and failed to fix the issue then id Imagine its not as straight forwad as it would seem.

Who adjusted it?

I'll not say online. Two mechanics at two different stores in Dublin.
First one set up the bike (but it was poor IMO). So I brought bike to a different shop, told him the problem. He aid he fixed it. I think he made it worse (I may ask for my money back tbh).
As for match of derailleur and chain - all are same make Ultegra SL. Have had for 6 months without issue.

kona

ROK ON wrote: »

I'll not say online. Two mechanics at two different stores in Dublin.
First one set up the bike (but it was poor IMO). So I brought bike to a different shop, told him the problem. He aid he fixed it. I think he made it worse (I may ask for my money back tbh).

If they cant adjust a front mech they shouldn be mechanics.

What is the derailleur you are running?Ultegra too? also what chain?

Is It just struggling when in a particular gear at the back or is it in all of them?, Is your chain the correct length?

bcmf

Is your Front Mech DEFFO a triple?
Initialy when I read the post I though of chain wear. If your chain is worn it will not help your shifting.
But I would also make sure that your mech hasnt slipped slightly downwards on the frame itself.The front mech is a relativley simple piece of kit.
I would be concerned that a "mechanic" couldnt fix a pretty simple prob* like that.


*I mean pretty simple in relation to all the other mechanical goings on on a bike

doozerie

What gear are you in (i.e. which sprocket/cog at the back) when you are changing on the front, as that may be your issue? You should always avoid the extremes (big ring at front plus big ring at back, small ring at front plus small ring at back), but with a triple chainset you have a larger number of combinations that you should avoid. If you are in one of the "extreme" gears and then try to change on the front, you are more likely to encounter problems. This may not be the sole cause of your problems, but would certainly contribute.

Other possibilities are a loose chain (may need to be shortened), a loose/slack gear cable (it may have slipped at the point where it is clamped to the front mech, or it may have stretched with use), worn chain rings, etc.

ROK ON

Folks, thanks for all the suggestions.
However, I actually only want the name of a good bike mechanic that I can bring the bike to and he/she will tell me (1) whats wrong (2) how to fix it and (3) how much.
That is all.

I wont fix this myself due to (1) lack of ability and (2) more importantly lack of time when I get home.
Finally I am a true believer in the Law of Comparative Advantage. I am happy to pay an expert for their time, if they are indeed an expert.

TinyExplosions

I'd say drop it into Joe Dalys, they've sorted me out before (provided that's not one of the ones you've already tried)

ROK ON

TinyExplosions wrote: »

I'd say drop it into Joe Dalys, they've sorted me out before (provided that's not one of the ones you've already tried)

It's not. I will try that. Thank you.

kona

ROK ON wrote: »

Folks, thanks for all the suggestions.
However, I actually only want the name of a good bike mechanic that I can bring the bike to and he/she will tell me (1) whats wrong (2) how to fix it and (3) how much.
That is all.

I wont fix this myself due to (1) lack of ability and (2) more importantly lack of time when I get home.
Finally I am a true believer in the Law of Comparative Advantage. I am happy to pay an expert for their time, if they are indeed an expert.

make 100% sure all the parts are compatible, no point spending more cash if it isnt. As for a decent mechanic? hit and miss IMO. Id drop it into cyclogical, but just dont ask for a pump:pac:

biker_joe

What are ya doing with a triple ya baby !! Get a double .... less problems !

Chips Lovell

Off topic I know, but what new frame did you go for?

abcdggs

you might try square wheel or something along those lines in temple bar beside the head shop. it's great in my limited opinion,

ROK ON

el tonto wrote: »

Off topic I know, but what new frame did you go for?

I managed to get the exact same frame as the one that was cracked. Dolan Hercules SE. I was happy with the frame, so with the insurance money, I wanted to get the same one if I could, and I did.

I am also in the process of getting a new bike, Orbea Aqua. I actually met the guy who sold it to me y'day on the Wicklow 200, how informed me that it has already arrived.

Chips Lovell

ROK ON wrote: »

I managed to get the exact same frame as the one that was cracked. Dolan Hercules SE. I was happy with the frame, so with the insurance money, I wanted to get the same one if I could, and I did.

Ah right. I'd forgotten the Dolan was damaged. Thought you'd already gotten the second frame.

ROK ON wrote: »

I am also in the process of getting a new bike, Orbea Aqua. I actually met the guy who sold it to me y'day on the Wicklow 200, how informed me that it has already arrived.

Jimmy Stagg?

ROK ON

el tonto wrote: »

Ah right. I'd forgotten the Dolan was damaged. Thought you'd already gotten the second frame.



Jimmy Stagg?

Not him, but the tall youngish (ie 30's, not an auld fella like Jummy Stagg) bloke that works there. But yes, the Orbea was bough in Staggs. Good price too IMO.
Have not been on it yet, but looking thru the Orbea brochure (anyone can have it if they want), the great thing about them is that you choose your frame first and then your groupset. While you cant get every bike/with every group, you do have a hell of a lot of choices to go for. I wish more companies would take that approach.

doozerie

ROK ON wrote: »

Folks, thanks for all the suggestions.
However, I actually only want the name of a good bike mechanic that I can bring the bike to and he/she will tell me (1) whats wrong (2) how to fix it and (3) how much.
That is all.

I wont fix this myself due to (1) lack of ability and (2) more importantly lack of time when I get home.
Finally I am a true believer in the Law of Comparative Advantage. I am happy to pay an expert for their time, if they are indeed an expert.

One thing to bear in mind is that, if the issue is even partly related to your choice of gear combinations, a mechanic won't necessarily be able to diagnose that in the workshop. Also, a mechanic can fine tune a bike to perfection in the shop but it is only when the bike is being ridden, and pressure applied to the drivetrain, that some problems tend to show up. Gear issues, in particular can be very tricky to resolve when the bike is hanging on a workstand.

That doesn't mean you shouldn't have a mechanic look at it, of course, but it does mean that you should also take the time to look at things (like your choice of gear combincations) yourself while riding the bike.

kona

doozerie wrote: »

One thing to bear in mind is that, if the issue is even partly related to your choice of gear combinations, a mechanic won't necessarily be able to diagnose that in the workshop. Also, a mechanic can fine tune a bike to perfection in the shop but it is only when the bike is being ridden, and pressure applied to the drivetrain, that some problems tend to show up. Gear issues, in particular can be very tricky to resolve when the bike is hanging on a workstand.

That doesn't mean you shouldn't have a mechanic look at it, of course, but it does mean that you should also take the time to look at things (like your choice of gear combincations) yourself while riding the bike.

Good point , however A good mechanic will test his work before he lets the bike go, so a small test run in all gears usually is enough. Takes 2mins.

The lazy mechanic or the one who just doesnt care, will just kick the bike out the door.