mb158127

Doing a rebuild on my 2006 Fuji Touring and could use some of the community wisdom. I never knew how many moving parts there were to [selecting] a front derailleur.

bike spec sheet: https://archive.fujibikes.com/2006/Fuji/touring2

the above page says my seat tube angle is 73 degrees and I interpret this as meaning the seat tube line and a line parallel to ground.

I’m looking at front derailleurs such as Deore M591 which call for 66-69* chainstay angle. I interpret that as the angle between chainstay and seat tube. Fuji doesn’t give me that but my chain stays angle up from ground so of course my angle in the triangle will be less than the 73*, less by however many degrees up from parallel the stays are.

Am I on point so far?

Now can I correctly derive my chainstay angle from the information at that spec sheet?

or does anyone know off hand approx what that angle would be?

or, can anyone suggest a Shimano FD which meets these parameters:

• 3x9 (or 3x8, 3x10 if those are forgiving enough)
• bottom or dual pull
• At least 48 tooth for big ring; will prob go 48-36-26 if that all matters
• Some flavor of Deore is preferable, or else highest possible quality shimano which is suited to trekking (so probably the mtb stuff and not road? What is the difference in design anyway?)
• 28.6 clamp
• traditional or side swing
• and matches my unknown geometry of 73 minus X degrees

thank you

mb158127

PS where I am at right now is that I need maybe this T6000 which accommodates up to 48T, but is designed for 3x10 so may have a bit of chain rub? And I’m sort of assuming the angle is right based on it is “designed for trekking”.

https://www.modernbike.com/shimano-d...railleur-black

That would likely be paired w/ this Deore m591 RD which is long cage 9sp.

https://www.jensonusa.com/Shimano-De...ear-Derailleur


PPS I realize there is a XT level version, T8000, and T8000-H-3 appears to be high mount flavor which I think I prefer or at least I am familiar with.

mb158127

Ok - I answered my own question on the angles using an online protractor i found along with a stock pic of the bike




around 63*. So I think I’m picking up the T8000-H3 which would be suited for 63-69. Thanks for listening

mstateglfr 

The only possible issue you may have with that Deore FD is that its designed for a 50mm chainline which I would guess is more than your bike has. You bike is probably 5mm or so shorter in chainline. It could work fine right out of the box, it could work fine with some fiddling and adjusting, or it could work poorly.

A Shimano Sora 3503 or Sora R3030 front derailleur would work. Its a road triple so it is made for a road triple crank chainline.
A couple examples are below. A 31.8mm band can easily be shimmed with shimano shims.

https://www.ebay.com/itm/Shimano-Sor...Cclp%3A2334524

https://www.performancebike.com/shim...78443?v=508541

mb158127

damn I did not know to look for that and I think you’re right. I just did my best to measure without fully screwing in the BB (no tool here) nor tightening down the crank, so deducting what I could figure between the bb she’ll face and the face of the cup it seems to be about 45mm, maybe a mm less. I also see my original sora derailleur was for a 45mm per specs.

Is this easily resolved by just getting a slightly longer spindle when I order a new bb (which I was doing anyway)? Or shimming out 5mm somehow? Or will problems/noise arise from the rear?

mb158127

Ok I just checked with Sheldon and I have a few options. I’ll probably look for a Phil Wood adjustable Bb which gives me some couple mm if I need them. I was also looking for a new crank and may find I can make up another couple mm there with a higher profile. Maybe I’ll order the crank last so I can fill whatever gap I may need measured against the old one I have. Last resort there are chainring spacers in 1-3mm

mstateglfr 

Hey- like I said, it may work just fine. These things sometimes come together without an issue or work great once some adjusting has been done.
As for getting a longer spindle, if your crank is square taper, then sure you could get a bottom bracket with a longer spindle, if one is available that is 10mm longer than what you have(5mm each side).
Personally, I would just try the new FD and see if it works with some adjustments to the hi and lo screws before buying anything more. At worst, return the Deore and buy a Sora for $20-30.

cyccommute 

What shifter are you planning on using? The Deore won’t work with STI.

One other thing to know about Shimano front derailers is that the more expensive they are, the more finicky they are. The less expensive versions tend to be more forgiving on set up and will work with a wider range of cogs across then rear. Sora and Tiagra are great front derailers. Ultegra and DuraAce, not so much.

As to chainline, I’ve used STI with various derailers and mountain bike cranks for about 20 years without issue. I’ve used a RaceFace Turbine (late 90s) ISIS crank as well as Shimano external bearing cranks. If you need to adjust the chainline, you either get a short spindle on the bottom bracket in the case of ISIS and square taper or you move the spacers around on the external bearing cranks.

Finally, don’t make too much of the angle of the derailer. I’ve never measured it and just use the derailers. I haven’t really run across one that drags on the chainstay yet.

mb158127

dur - I knew to check for this and fully forgot. Thank you for the reminder. Guess the Deore is a no-go.

I had read about the finnikiness of top end and was not considering dura ace and ultegra. Maybe mistakenly I was thinking that the mtb lines would be more durable, and I guess that Deore XT would not be finicky by implication.

I have an older sora FD on there currently and tiagra brifters. I was thinking to upgrade to 105 brifters (st-5500) as I read that there are less plastic bits and frankly the aesthetics will match better. But also I am not settled because it is an expensive upgrade for little relative return.

looks like it will be a new Sora FD, thanks!

cyccommute 

Actually, the same holds for Shimano’s front derailers on mountain bikes. They get too clever with sculpting and Wingdings on their high end derailers and make them too complicated. XTR in the past have even had inner and outer plates move independently. I’d take an Deore or lower over an XT or above. Their absolute worst front came on a Specialized SWorks Epic I own. It was an XTR with the dual moving plates and was an E type (the one that mounts behind the bottom bracket). E type front derailers are bad enough but this one was mounted on a weight saving carbon plate which bent and flexed each time you shifted so it would never stay in place correctly. A marvelous and beautiful piece of engineering that would look good on any wall. Just don’t put it on a bike.

Doug64

I've used Tiagra 5403 FDs on 7 of our families' touring bikes. We also use 44/32/22 cranksets, 4 use mountain cranks designed for a 50 mm chainline. I used 103 mm square taper bottom brackets to pull the chainlines in to 45 mm. six of the bikes use Shimano Tiagra 4503 brifters, the other one still uses the stock bar-end shifters, IMO the Tiagra 4503 is one of the best touring FDs; it is durable works for a wide range of installations, but are hard to find. I have 4 spare 4503s in my spare parts bin just in case

My wife's 10-year old touring bike, which uses the Tiagra 4503 brifters, mountain cranks, and 4503 FD, turned over 25,000 miles this summer.

One of my touring bikes set up as described above.


The same setup as the LHT on a Bianchi Volpe

Germany_chris

I just went through this and bought a FD T-8000, 28.6 bottom pull is a PITA to find.

robow

Is there much difference between the older excellent Shimano Tiagra 4503 FD and the newer Sora 3503 FD ? Just curious.

cyccommute 

I can’t say. The 4503 had a problem with the casting for the spring stop. They tended to break. When my last one broke, I put on an IRD Alpina which I didn’t like much. I changed that for a Microshift which works great. I have some older Sora spares which I think will work. I also volunteer at a co-op so I have a nearly endless supply of older derailers available.

robow

Stuart, which particular Microshift FD model are you using successfully ? And are we talking brifters ? Also may I inquire as to what size chain rings you're running?
Thanks

cyccommute 

I just checked and I misremembered which front derailer was on which bike. My touring bike has a Shimano FD-R453 which is a Tiagra. I use a 46/34/20 RaceFace Turbine (ISIS from around 1995) crank on it. The derailer has a sticker on it that says “50 tooth” capacity. I have picked up a number of front derailers from my co-op that are Sora and Claris which I will use if this one breaks. The previous ones I’ve had problems with were from the early 2000s. I think this one is from around 2010.

The Microshift I have is a FD-R253-B/F being used on my commuting bike. I had a Ultegra on that bike with a 105 50/39/24 crank. I swapped out the crank for a 48/36/22 Shimano XT. I never liked the Ultegra that much and decided to give the R8 a try when it showed up at my co-op. It does rub a bit less than the Ultegra.

I did measurements long ago on the Ultegra and Tiagra (but don’t have them written down). The Ultegra has a significantly narrower distant between the cage plates than the Ultegra and a deeper sculpted part on the outer plate. That results in less range across the rear cassette without rubbing.

I use STI on both bikes.

robow

Thanks Stuart, and why didn't you care for the IRD Alpina ? I've used this on a 46/36/24 crank for years and it worked fine with 9 speed but maybe (could be in my head) not as well when I changed drive train to 10 speed and thinking of trying something new. Hence why I was interested in MicroShift FD-R732-B.

cyccommute 

The Alpina was a braze-on and I used a separate clamp. I didn’t find the connection to be precise enough nor the bolt holding the derailer to the clamp to be solid enough. The derailer tended to move a bit and made set up finicky. I find a solid clamp map just works better.