Which triple front derailleur

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disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Which triple front derailleur

Post by disherwood »

I wonder if someone could advise...
I am riding an orbit tandem that has tiagra 3 x 9 sti shifters, a sora FD 3503 B bottom pull derailleur and a Alivio M3100 SGS rear derailleur with a truativ 52-42-30 chainset.......I’m having some chain suck issues on operating the front derailleur so have refreshed chainrings,chain and rear derailleur...I would like to replace the FD-3503 Sora front derailleur as the rivets on this item appear loose/worn
What front derailleur would the experienced recommend .?
Would you recommend continuing with the bottom pull or as the cable comes from above would a top pull make the changing more efficient.?
Although it has the right capacity the sora is specified as good for a chainstay angle of 63 to 66 degrees whereas my frame is nearer 69 degrees so one with a 69 degrees spec. would sit better in relationship to the chainset.
I am struggling to find a triple derailleur that on paper fits the required criteria.
Any observations would be appreciated
David
Valbrona
Posts: 2694
Joined: 7 Feb 2011, 4:49pm

Re: Which triple front derailleur

Post by Valbrona »

Does the inner cage of your current front derailleur contact the middle chainring when you shift from middle to outer?
I should coco.
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Which triple front derailleur

Post by iandusud »

I assume that you're using a bottom pull with a pulley. If so I don't see any reason not to continue so you have the option of top pull or bottom pull. Most (if not all) top pull FDs are designed for an MTB chainset and therefore for a wider chainline. This may or may not pose a problem with your current BB. With regard to the chainstay angle this shouldn't pose a problem with your current set up if you choose the right FD. I've been setting up a front mech on my tandem recently (you may have seen the thread). I fitted a Tiagra FD 4703 to match my levers and have got it working well. However the bottom of the cage is much shallower than on many (most) FDs which results in only being able to use the 4 largest sprockets with the small chainring before the chain rubs on the bottom of the FD. I have resolved this by fitting a Sora FD which has a much deeper cage. The pull ratio is identical.
Manc33
Posts: 2218
Joined: 25 Apr 2015, 9:37pm

Re: Which triple front derailleur

Post by Manc33 »

A used FD-6503 (Ultegra) on eBay. They usually go for peanuts at auction (under £20) and they always work properly.

I always go for the braze-on version, so then it can be clamped to any seat tube, as long as I've got the corresponding braze-on band clamp.

Image
disherwood wrote: 30 Jun 2022, 5:45pm...tandem that has tiagra 3 x 9 sti shifters, a sora FD 3503 B bottom pull derailleur...
...but also...
disherwood wrote: 30 Jun 2022, 5:45pm...the cable comes from above...
If you get one of those Ultegra FD-6603 then your bike frame needs to have bottom pull.
We'll always be together, together on electric bikes.
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

Hi Manc33

Funny you should suggest that.....I’m just hunting for the 6703 but will widen my search to the 6503....

Thanks for your input.......just sat down having played around with my 3503 B in the evening sun.....slowly understanding how all the ramps work.....whoever had the tandem before has not integrated a cable adjuster in the front derailleur equation.....as I’m impatient and can’t wait till my order arrives I’m working without one.....

Whilst i understand I can push the limits of the specified range I’m being pedantic and making sure I’m working within that range as i am anxious not to damage anything

They were using the sora 3503 with a 55-44-34 which is a bit above the largest recommended ring.....I’m looking at 52 or 50-39-32....
iandusud
Posts: 1577
Joined: 26 Mar 2018, 1:35pm

Re: Which triple front derailleur

Post by iandusud »

disherwood wrote: 2 Jul 2022, 7:28pm Hi Manc33

Funny you should suggest that.....I’m just hunting for the 6703 but will widen my search to the 6503....

Thanks for your input.......just sat down having played around with my 3503 B in the evening sun.....slowly understanding how all the ramps work.....whoever had the tandem before has not integrated a cable adjuster in the front derailleur equation.....as I’m impatient and can’t wait till my order arrives I’m working without one.....

Whilst i understand I can push the limits of the specified range I’m being pedantic and making sure I’m working within that range as i am anxious not to damage anything

They were using the sora 3503 with a 55-44-34 which is a bit above the largest recommended ring.....I’m looking at 52 or 50-39-32....
My experiments have led me to believe that all the Shimano road triple front mechs have the geometry and are therefore interchangeable with regard to the amount of cable pull. However trying to get it work properly without a cable adjuster I would have thought nigh on impossible. :)
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

Thanks... Agreed

Yesterday I had the gears working but feel the cable adjuster will improve the set up and enable me to tweak the settings

I've been forced to understanding how the ramps relate to the "minimum number of teeth between the biggest and middle chainrings" and the maximum difference between biggest and smallest.......as I'm a couple of teeth above the maximum largest suggested I have made sure the derailleur is sat as tight to the top ring as it should be

It's clear I'm not the first person to discover the potential of challenges with the triple setup.... When it works we forget how bad it can be
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

From experience... Are there notable do's and don'ts when it comes to what chain to use with what chainring... Eg. Truvativ, fsa, shimano with chains sram, shimano, kmc..?
NickJP
Posts: 797
Joined: 24 Sep 2018, 7:11pm
Location: Canberra, OZ

Re: Which triple front derailleur

Post by NickJP »

Our tandem is using a Campag Record 10-speed triple FD with 54-44-30 chainrings, and changes perfectly across that range of chainrings. We're using bar-end shifters, though, not integrated shifters, so we're not relying in any sort of indexing for the front shifting - I've always considered trying to use STI with triple chainrings as a total PITA. The FD is identical to this one: https://www.ebay.com/itm/394130670887.
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

Thanks
I use the campag old tech on a double set up and it's great
I've just had to do my apprenticeship on the potential challenges associated with triples...... Got a measure of success..... Not just refining things after suffering damage causing chainsuck even with new kit
Manc33
Posts: 2218
Joined: 25 Apr 2015, 9:37pm

Re: Which triple front derailleur

Post by Manc33 »

With no cable adjuster you need an inline adjuster and the cable housing needs cutting (to accommodate it) somewhere near the handlebars, so it's easily accessible. I try to avoid using inline adjusters but sometimes they are the only way to adjust the tension. Cheap ones can sometimes unwind themselves and they are a bit fiddly at the best of times.

If it's 9-speed then the FD-6503 might be a better match than a FD-6703 (10-Speed). I'm not sure if the 10-speed is any thinner but I'd get the FD-6503. They are old now but it's such good equipment, it doesn't matter.
We'll always be together, together on electric bikes.
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

That makes sense.... Thank you

I'm on the hunt for a FD-6503
TheBomber
Posts: 525
Joined: 16 Feb 2020, 8:18pm

Re: Which triple front derailleur

Post by TheBomber »

disherwood wrote: 3 Jul 2022, 7:56am From experience... Are there notable do's and don'ts when it comes to what chain to use with what chainring... Eg. Truvativ, fsa, shimano with chains sram, shimano, kmc..?
Not sure you’ll get definitive answers on what works best with what, but I’ve recently cured chainsuck on a 2x10 setup with Middleburn chainrings by abandoning the KMC X10 chains I’ve been using for years and fitting a Shimano one. The difference has been remarkable and very welcome. So it may be worth experimenting.
Valbrona
Posts: 2694
Joined: 7 Feb 2011, 4:49pm

Re: Which triple front derailleur

Post by Valbrona »

NickJP wrote: 3 Jul 2022, 10:38am Our tandem is using a Campag Record 10-speed triple FD with 54-44-30 chainrings, and changes perfectly across that range of chainrings. We're using bar-end shifters, though, not integrated shifters, so we're not relying in any sort of indexing for the front shifting - I've always considered trying to use STI with triple chainrings as a total PITA. The FD is identical to this one: https://www.ebay.com/itm/394130670887.
I liked using Record 10 because of the ability of the FD to cope with just a ten tooth jump from middle to outer, like with your 44/54.

Not sure quite how the OP manages to do his 42/52 combo without the inner cage of the FD striking the middle chainring.
I should coco.
disherwood
Posts: 324
Joined: 19 Jan 2008, 9:26pm
Location: Halifax

Re: Which triple front derailleur

Post by disherwood »

Thanks

Having researched the fd 3503 I’m coming to the conclusion that sora chainrings in this series come in 50-39-30.....the biggest recommended chainring size being 50t, minimum step down from top to middle being 11t and the largest recommended capacity being 20t..............the 50-39-30 set up with a 36 t max rear ( for the hills with luggage ) would be fine for me

I have set up the sora with 52-42-32......truvative rings - and its working............

Thanks for all comments....most helpful
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