Compatible Front mech for M8000 XT Chainset

[smuggers]

Morning...

Just wondered if anybody can point me in the right direction for a front triple mech that will work with my new M8000 XT triple chainset.. Have just taken my old Deore triple off my Vagabond & it soon became clear the current XT mech would not be compatible with the new XT chainset.. The main problem being I cant get the outer plate close enough to the outer chainring teeth.. In the photo I posted thats about as low I can get the mech without the bottom on the mech catching the chainstay.. The mech cage appears way to long.. Had a quick look and it mentions High & low mount band on triple mechs, but want to be 100% sure which I need before I order.. Any help appreciated, thanks.. The XT chainset is a 40.30.22 btw..


Smuggers..

[smuggers]

Also whilst I'm at it, I have 2 spacers on the drive side hollowtech 2 bottom bracket & noticed I might be able to remove one & still have enough room for the small ring to not catch the chainstay..Or should I keep 2 spacers on ??


Regards..

Smuggers

[Brucey]

if you look in the specs it will say which

a) chainring sizes and

b) chainstay angles

the FD is meant for. As you have found if you try and use a trekking mech (meant for 48T say) with a 40T outer it is liable to hit the chainstay on some frames.

You can adjust the chainline if that suits you but not all FDs will permit the narrower chainline without fouling the frame.

cheers

[smuggers]

Thank you, Brucey... Going to get a LX or SLX mech. The XT chainset will be going on a new build soon.. Going to visit a few bike shops over the coming week & see whats available.. Thanks again Brucey..

[thelawnet]

the front mech will have a full code name. you need to have sharp eyes, but it's there.

I'm guessing you have FD-M773. (Other models may have an additional suffix, such as FD-M771-D)

This was for a 63-66 degree chain stay angle, and either 44-32-22t or 48-36-26t chainset.

It's a clamp band type, high clamp/down swing. The cable route is dual pull (either way), though yours is routed from the top.

At the time, 40t top rings don't seem to have been a thing.

The current XT front derailleurs for a 40-30-22 triple with 66-69 degree chain stay angl are:

FD-M8000-D (direct mount)
FD-M8000-E (e-type mount)
FD-M8000-H (high clamp band mount - this one you want)
FD-M8000-L (low clamp band mount)

There's also FD-M7000-10-H and FD-M6000-H which should be much the same.

You could also consider a FD-M611-B, which is a top-pull, down swing FD whereas the M6000/M7000/M8000 use the newer side swing design.

There are also a few options for a 63-66 degree chainstay angle, such as:

FD-M4000-DS3/FD-M2000-DS3/FD-M371-3, which are for 40/30/22, and are down swing dual pull

[smuggers]

Hello thelawnet!!

Many thanks for the information provided. Very helpful indeed & I'm going to have a browse online for a FD-M8000-H. Am I right in thinking this mech will be OK for my cable routing type ? Gear cable runs under the down tube & through a plastic mount under the bb shell.. I have frictionless dura ace 9 speed for the required FM & hope to run a 10 speed sram chain on this new set up? Do you think that would be OK?

Really cant thank you enough for the info you have given..

Many thanks..


smuggers..

[thelawnet]

Well I didnt mean to necessarily get the fd-m8000-h, rather that it was the right mount type.

You might be better off with fd-m4000-ds3 - it depends on your chainstay angle. Obviously if it is exactly 66 degrees it doesn't matter.

You could check the existing derailleur and buy one with the same range, but it would probably be as well to just measure the chainstay angle of your frame.

[reohn2]

My Genesis Longitude has a 40/30/22 Deore M615 chainset with an M615 Deore Shadow front mech,I can't see the dimensions of your XT chainset being any different to my Deore,and the Logitude frame has very similar geometry angles both having a 72.5 degree seatube angle.The Longitude has a 77mm BB drop,4mm more than the Vagabond so the tail end of the M615 mech should clear the chainstay with more clearance on Vagabond.

[smuggers]

Thanks for the helpful comments.. I have ordered this FM - https://www.tredz.co.uk/.Shimano-Deore- ... _92596.htm

Hopefully I will be back on the Vagabond soon.. smiles.

Regards

Smuggers

[reohn2]

The one you've order is a front pull whereas the photo of tqhe XT in the OP is bottom pull,that's OK if you're aware of it as the Vagabond will cope with either but you'll need a straight through outer cable for the front mech you've ordered.

[smuggers]

Thanks for that reohn... So I will have to run the gear cable with outer another route from the current one along the downtube & under the bottom bracket.. Nothing ever straight forward when your mechanical skills are at best basic!!

Regards..

smuggers

[smuggers]

The one you've order is a front pull whereas the photo of tqhe XT in the OP is bottom pull,that's OK if you're aware of it as the Vagabond will cope with either but you'll need a straight through outer cable for the front mech you've ordered.

Just noticed reohn, the main title on link says front pull & when you click on description it says side pull !! Sigh...So going to see what arrives.. 50/50 chance it could be a side pull.. Not keen on having a front pull, even though it would work..

[reohn2]

Just noticed reohn, the main title on link says front pull & when you click on description it says side pull !!

I'm 99.9% sure that mech is a front pull

On the Vagabond there's brazeons for two outer cables on top of the downtube run side by side,outers held in place by cable ties,one for the rear brake outer and one for the front mech outer if a front pull mech is being used,the front pull front mech outer terminates at a stop on the front mech itself.
If a bottom pull front mech is used the outer terminates at the adjustable barrel stop on the left side of the headtube and the inner goes conventionally under the BB.

[thelawnet]

The one you've order is a front pull whereas the photo of tqhe XT in the OP is bottom pull,that's OK if you're aware of it as the Vagabond will cope with either but you'll need a straight through outer cable for the front mech you've ordered.

Just noticed reohn, the main title on link says front pull & when you click on description it says side pull !! Sigh...So going to see what arrives.. 50/50 chance it could be a side pull.. Not keen on having a front pull, even though it would work..

There isn't side pull.

Traditionally you had 'high clamp, bottom (or down) swing' vs. 'low clamp, top swing'. This referred to the position of the clamp (high or low), and whether the swing of the derailleur is from the top or from underneath the clamp.

The cable routing is what 'side pull' refers to, again you had 'top pull' (from the top tube down), or 'bottom pull' (from the bottom bracket up).

Shimano like to come up with new designs for everything every couple of generations, and what they came out with subsequent to your current FD was 'side swing'. This routes the cable similar to 'bottom pull', but then cuts out the bottom bracket. This is called 'front pull'.

https://handsonbike.blogspot.com/2016/0 ... lleur.html

Hence if you want to route the cable the exact same way you need an older design, i.e. one that is NOT side swing, but down/bottom swing, since the point of side swing is to use a more direct cable route than either top swing or down swing.

Likely there's not too much difference in Shimano's FD performance, beyond the basic design, so an Altus down swing one may not be any worse than your current XT, for example.