[BasRice]

Hi,

So, I bought Shimano Deore XT front derailleur from Wiggle (https://www.wiggle.com/shimano-deore-xt-m8025-front-derailleur/?sku=5360710322) to upgrade my previous Shimano front derailleur.

I have it now installed, but it is not as planned. The height is now optimal with respect to the largest chainring. However, the problem (see the attachment pictures) is that the clamp is now over the lower screw hole for mounting the bottle cage; lowering the derailleur results in direct contact with the chainring and rising results in too much distance from the chainring (and also for additional problems with the bottle cage).

The installation, as shown in the pictures, works somewhat. The derailleur seems to stay in place, but given that the installation is done partly by using gorilla tape feels ... well not satisfying. Also, the clamp is not optimally tightened to the frame (even with the gorilla tape and all ), because of the factory pressed/molded washer (or whatever) in the frame around the mounting hole, making the installation surface uneven.

Summa summarum: Is there any solution to fitting the derailleur into a different spot on the frame (the previous derailleur was underneath the mounting hole)? Is there any, i.e., adjustable clamps available in this situation, for example, from problem solvers (https://problemsolversbike.com/products/shifters-derailleurs) etc.? Any other solutions come to mind? Or do I have to get a new derailleur that fits the frame?

Thanks to all!

 

[Harold]

First off, you need a low clamp design.

The wiggle page is no good anymore, fwiw.

Like this one.

https://bike.shimano.com/en-EU/product/component/deorext-m8000/FD-M8025-L.html

But, that particular derailleur requires bottom pull cable routing.

There's one other low clamp band 2x11 FD, the side swing model. It requires cable routing for "front pull" if you can work that out.

https://bike.shimano.com/en-EU/product/component/deorext-m8000/FD-M8020-L.html

I have to ask, what was your previous front derailleur? Your frame looks to be designed with a top pull derailleur in mind, and the only 2x derailleurs Shimano makes right now compatible with top pull are the various high clamp models.

The reason I ask is because for 10spd, you could get a dual pull low clamp derailleur like this one:

https://bike.shimano.com/en-EU/product/component/deorext-m780/FD-M785.html

 

[BasRice]

Harold,

Thanks for the quick reply!

So, I pretty much got a wrong model derailleur then

The previous front derailleur was Deore LX (FD-M571).

The frame (Nishiki Bigfoot X-29) is definitely a top pull design. It runs with a 3x9 drivetrain setup. I also have Shimano XTR (SL-M970) shifters that I got second-hand with a decent prize to upgrade the original Deore LX shifters.

(I would have posted attachment pictures of the previous Deore LX derailleur and of the bike itself, but the system refuses to upload any pictures.)

So, what would be your choice FD for a 3x9 setup with XTR shifters?

Thanks again!

 

[Harold]

So, what would be your choice FD for a 3x9 setup with XTR shifters?

That top pull cable routing definitely limits you.

To minimize changing things (like cable routing, which is possible, but extra work along with "it might not work well" caveats), you def need top pull.

You can find an old 9spd front derailleur, NOS or used, is one option.

Here's a low clamp, dual pull FD that might work:
https://bike.shimano.com/en-US/product/component/deorext-m780/FD-M780-A-B.html

Also this one:
https://bike.shimano.com/en-US/product/component/slx-m670/FD-M670-A-B.html

One thing to note is that the FD you bought that's installed incorrectly runs on a chainline of 48.8mm, and the two I posted are 50mm chainline. I had to dig to find the chainline for you old setup. According to this archive document from Shimano, 50mm should be correct.

 

[uzurpator]

First of all - your derailleur is a 2x specific for the 8000 series XT ( according to your link ) meant for 10T front difference and 36 or thereabouts big ring. What you are installing it to is a triple which requires a completely different front mech - unless you actually plan to replace the crankset.

Either way - FD-M8025 is not going to work with a triple crankset.

 

[sgltrak]

The previous front derailleur was Deore LX (FD-M571).

So, what would be your choice FD for a 3x9 setup with XTR shifters?

What was wrong with the LX front derailleur that came off the bike? If it still works fine, I'd put it back on and keep using it.

 

[Harold]

Either way - FD-M8025 is not going to work with a triple crankset.

Good catch on the triple. The angle of the pic was such that I didn't catch that at first.

OP, disregard all of my specific derailleur recommendations. You still need top pull and a low clamp, but need, no question, a 3x specific derailleur.

 

[sgltrak]

OP, if your area is anything like my area, the local bike shops and the local bike co-op and many private individuals have numerous used front derailleurs from all of the bikes that have been converted from 3x to 1x. Many will sell XT quality 3x front derailleurs for very low prices or give them away.

 

[BasRice]

Hi guys and thanks for the replies and the research done (i.e., the Shimano archive document)!

Ok, I will go and visit today one local Shimano Service Center and ask what they got to offer in terms of NOS or used FDs and advice.

Regarding the crankset, I actually installed a new Deore FC-M590 (44-32-22T). (Maybe should have gone with a two chainring setup, but got the 3x quite cheap.) So this is currently replacing the original Truvativ Firex (44-32-22) crankset. The rear drivetrain runs with the original Deore XT derailleur (cassette needed a reboot so it now runs with a Deore XT cassette). I am not absolutely sure (newbie) how do these changes affect the chainline(?)

Regarding the old FD, I guess it works ok. I just had in mind an upgrade to my old FD (with a completely wrong derailleur LOL )

P.S. I would have posted some pictures, but still can't upload any. Something wrong somewhere... hmmm.

 

[cobba]

Regarding the old FD, I guess it works ok. I just had in mind an upgrade to my old FD (with a completely wrong derailleur LOL )

Use the old one if there's nothing wrong with it.

If you have to get another one, look for FD-M770 or maybe a FD-M772, you can find them on ebay.

Specs: https://productinfo.shimano.com/#/spec/MTB/Front Derailleur

* there was a 9 speed FD-M770 and a 10 speed FD-M770-10

 

[BasRice]

I just got back from my local Shimano Service Center. I had my old FD with me and showed it. According to them, it is in totally fine condition (as in my own judgment as well). They were not 100% sure (?) of the compatibility between the old FD (Deore LX (FD-M571)) and my new crankset Deore FC-M590. They asked if I could come and show my bike to ascertain the compatibility (I traveled by car, currently unable to ride).

So, I guess, the easiest, most convenient, and cheapest option is to use the old FD.

Just as an option (as Cobba pointed out), would this work as an upgrade (https://www.aliexpress.com/item/SHI...ntain-bike-parts-3x9-speed/32830241710.html)? It is a double-pull design, not sure about the mounting (i.e., low clamp) though. Would this be worth the extra cost and fuss, in your expert opinion?

Thanks again, guys!

 

[cobba]

Link doesn't work.

 

[sgltrak]

I just got back from my local Shimano Service Center. I had my old FD with me and showed it. According to them, it is in totally fine condition (as in my own judgment as well). They were not 100% sure (?) of the compatibility between the old FD (Deore LX (FD-M571)) and my new crankset Deore FC-M590. They asked if I could come and show my bike to ascertain the compatibility (I traveled by car, currently unable to ride).

So, I guess, the easiest, most convenient, and cheapest option is to use the old FD.

Just as an option (as Cobba pointed out), would this work as an upgrade (https://www.aliexpress.com/item/SHI...ntain-bike-parts-3x9-speed/32830241710.html)? It is a double-pull design, not sure about the mounting (i.e., low clamp) though. Would this be worth the extra cost and fuss, in your expert opinion?

Thanks again, guys!

If the current front derailleur works, to me it wouldn't be worth the hassle or expense to replace it. I believe the differences in front derailleurs at the LX level or above is minimal and doesn't justify the expense and effort of replacing a functional unit.

 

[BasRice]

Thanks cobba and sgltrak for your replies!

The old FD it is then I guess - waiting for re-installation.

P.S. Quite odd that the links don’t work as they do work for me. There might be something off with the ”communication” between my computer and the Mtbr-forum because the attachment uploading does not work either. Don’t know nor understand.

P.P.S. Still, thanks again for all the assistance!

 

[cobba]

Worked out the link problem, you put )? at the end of the web address.

https://www.aliexpress.com/item/SHI...ountain-bike-parts-3x9-speed/32830241710.html

Use the old derailleur if it works and save some money.

Front derailleurs are basically a metal cage that push the chain onto and off the chainrings, the old LX will do the same thing as a newer XT.

 

[BasRice]

Cobba,

Yeah, sorry for the faulty link. My bad.

You are probably right with front derailleurs in general; with rear derailleurs the difference would be more meaningful.