Front mech for 48,38,28 chainrings on tourer

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Bice
Posts: 293
Joined: 18 May 2020, 7:33pm

Front mech for 48,38,28 chainrings on tourer

Post by Bice »

I am shifting my steel frame Diamant women's tourer triple 48,38,28 with a Shimano Ultegra 6703 front derailer.

I described the build here: viewtopic.php?t=151691

It actually does shift OK with this, although it is supposed to be used with a minimum 13T difference between the chainrings. Not the 10T difference that I have. As a result, it is set very high above the chain.

As I say, it does work remarkably well even though set about 1cm higher than the chain, and I have toured some distance with this arrangement. But I am now preparing for a long tour, and I am thinking a better front mech arrangement would be wise.

I have been looking for a Shimano 105 FD-5703, which has only an 11T minimum, but all those that I have found are band-on not braze-on. This steel frame has a braze-on.

Spa says it has a black braze-on FD-5703 but the picture shows a band-on arrangement, and I have not come across a braze-on version to date, so wonder whether it's a mistake. I could ask, of course: https://www.spacycles.co.uk/m8b0s106p26 ... Front-Mech

(I have now asked via email)

It seems to me that a Shimano Sora FD-3030 would also be an improvement. It is a 9 speed, in theory. It too has an 11T 'top-mid tooth difference'. So I would be able to lower the mech quite considerably.

https://bike.shimano.com/en-EU/product/ ... 030-F.html

I am using the bike as an 8-speed, and shifting with downtube Suntour ratchet friction shifters.
Last edited by Bice on 8 Feb 2023, 12:08pm, edited 3 times in total.
Daily: Carlton Courette 1982 mixte 42, 32, 22 x7
Van Nicholas Yukon titanium 50/34 10sp
Lazzaretti steel 1996 10sp 48/34
Trek 1.7 10sp 3x 2010;
Ciocc steel 1984 50/34x7
Marin Bolinas Ridge MTB c1995, 7x42, 34, 24
Scott Scale carbon MTB 27.5 inch
roubaixtuesday
Posts: 5815
Joined: 18 Aug 2015, 7:05pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by roubaixtuesday »

I'm no expert in such matters, but can report that we have a 3030 FD on a 46/36/24 setup, and previously on 46/36/26.

Works impeccably with both, using STI shifters.
Valbrona
Posts: 2696
Joined: 7 Feb 2011, 4:49pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by Valbrona »

I have always wondered whether the IRD triple front derailleur would do the 38/48 jump as you require. Older triple Campagnolo FDs would, like 36/46 or 38/48 combos.
I should coco.
peetee
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Joined: 4 May 2010, 10:20pm
Location: Upon a lumpy, scarred granite massif.

Re: Front mech for 48,38,28 chainrings on tourer

Post by peetee »

In line with Valbronas comments I can add that a Campagnolo 9speed triple front will happily combine with Shimano shifters to cope with 30/39/48 combo. I have used another chainring combination too but can’t recall which suffice to say IME they are not at all finicky.
The older I get the more I’m inclined to act my shoe size, not my age.
Glen
Posts: 45
Joined: 5 Aug 2019, 8:13pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by Glen »

Whilst hoping to appear helpful rather than just opportunistic (!) I have a NOS 5703 braze on front derailleur which I have been meaning to put on Ebay. Yours for £28 posted. And it's silver! Send me a PM if you are interested.... Cheers
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105 triple.JPG
Bice
Posts: 293
Joined: 18 May 2020, 7:33pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by Bice »

peetee wrote: 8 Feb 2023, 1:39pm In line with Valbronas comments I can add that a Campagnolo 9speed triple front will happily combine with Shimano shifters to cope with 30/39/48 combo. I have used another chainring combination too but can’t recall which suffice to say IME they are not at all finicky.
An absolutely free solution, perhaps, is to swap my Campagnolo Centaur triple (quite modern, bike in attic so can't easily check ID) serving as a double on my Italian steel road bike and use it on this bike instead. It is a smaller lump of metal than the Shimano. That would mean using the Shimano Ultegra 6703 shifter on 48,34 chainrings with Campagnolo ErgoPower shifters. Can't see why it would not work.

Not sure I could actually bear the bother of doing this, however, or the aesthetics: I like my Campag stuff where it is.

You always said these Ultegra 6703 triple shifters shift absolutely fine even when set high and I am just back from a 25 miler around Richmond Park. The gears on the Diamant shifted perfectly, and I was front shifting a lot on 8-speed and getting a good tune going.

It is always satisfying to overtake people on an insistently retro, odd-looking bike like this (below), put together with spare parts hanging around, when they are on something worth more than my car (note: on the other hand, my car is a 1997 Volvo 940).

Back to the shifters ... the massive gap above the chain obviously does not matter with a shifter that is such a wide lump of metal like these Ultegra triples. The only problem I have had is when riding with the club, getting tired and then I have forgotten to shift off the big chainring, cross-chaining badly. That means stopping and loosening the wheel to get it unjammed.

Glen's sales offer is too good to resist, and another triple is not going to go to waste.

Image

When I was assembling the bike I found that the front mech Ultegra FD-6703 had to go much higher (about 1cm higher) than shown here below, where the low set mech was blocked by the middle chainring and would not shift. As the mech is on this bike a braze-on, not a band-on fitting, it only works when set at the highest possible setting. The pic above just about shows how high the mech has to be to work.

Image
Daily: Carlton Courette 1982 mixte 42, 32, 22 x7
Van Nicholas Yukon titanium 50/34 10sp
Lazzaretti steel 1996 10sp 48/34
Trek 1.7 10sp 3x 2010;
Ciocc steel 1984 50/34x7
Marin Bolinas Ridge MTB c1995, 7x42, 34, 24
Scott Scale carbon MTB 27.5 inch
peetee
Posts: 4292
Joined: 4 May 2010, 10:20pm
Location: Upon a lumpy, scarred granite massif.

Re: Front mech for 48,38,28 chainrings on tourer

Post by peetee »

You will have to remind me, did I assure you about the high mech position in another thread? I have done this with my Dura-Ace 10x3 you see; it now shifts with a 48t ring instead of the standard 53t.
The older I get the more I’m inclined to act my shoe size, not my age.
Bice
Posts: 293
Joined: 18 May 2020, 7:33pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by Bice »

You have mentioned it a couple of times and said it works well, and it does.
Daily: Carlton Courette 1982 mixte 42, 32, 22 x7
Van Nicholas Yukon titanium 50/34 10sp
Lazzaretti steel 1996 10sp 48/34
Trek 1.7 10sp 3x 2010;
Ciocc steel 1984 50/34x7
Marin Bolinas Ridge MTB c1995, 7x42, 34, 24
Scott Scale carbon MTB 27.5 inch
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geomannie
Posts: 1093
Joined: 13 May 2009, 6:07pm

Re: Front mech for 48,38,28 chainrings on tourer

Post by geomannie »

roubaixtuesday wrote: 8 Feb 2023, 11:55am I'm no expert in such matters, but can report that we have a 3030 FD on a 46/36/24 setup, and previously on 46/36/26.

Works impeccably with both, using STI shifters.
+1
geomannie
jimlews
Posts: 1476
Joined: 11 Jun 2015, 8:36pm
Location: Not the end of the world.

Re: Front mech for 48,38,28 chainrings on tourer

Post by jimlews »

This old style FD should work with 28/38/48

https://www.ebay.co.uk/itm/275553318402 ... Sw5g5jf-36

I've no knowledge of or connection with the seller.

EDIT: The item description says that it is for a double C/S but it looks like a triple to me with that deep inner plate.

If buying make sure that you are buying the actual FD in the photo

https://manualzz.com/doc/53869442/shima ... loded-view
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