Chainrings for Shimano Deore XT FC-M771 Hollowtech II 48x36x26 (9 speed)?

[raggydoll]

is it flat bar?

Yes. The front mech I was trying to sort was on a flat bar giant rapid triple 8 speed (trigger shifters). - (52/42/30)
Chain kept coming off the small ring so was trying to adjust.
Ended up destroying the cable cos I was clamping and unclamping so much.

New cable, start from scratch. Got there in the end. Best way to learn I guess.
Ended up leaving it so that chain rubs when on small ring and big cog (11-28 cassette).

No matter how much I set the limit screw it still randomly threw the chain off the small ring.

Not sure what could be causing that!

 

[Blue Hills]

Yes. The front mech I was trying to sort was on a flat bar giant rapid triple 8 speed (trigger shifters). - (52/42/30)
Chain kept coming off the small ring so was trying to adjust.
Ended up destroying the cable cos I was clamping and unclamping so much.

New cable, start from scratch. Got there in the end. Best way to learn I guess.
Ended up leaving it so that chain rubs when on small ring and big cog (11-28 cassette).

No matter how much I set the limit screw it still randomly threw the chain off the small ring.

Not sure what could be causing that!

No sorry I have no idea what kept throwing the chain off unless the mech was positioned wrong - the park tools book (maybe also on their web page) is very good on setting up front mechs - I have used it for all my triples.
Rubbing on small ring and big cog is a problem.
Reason I asked if a flat bar - no longer made I think (nor an equivelent for some reason) but you can get rapidfires for triples with an extra click or two to allow you to trim the front mech - maybe purists don't think much of them but I have used them on two 9 speed triple builds and one 8 speed triple. Often available in decent nick from ebay sellers - usually have 440 or 441 model numbers I think.
Perfect for bodgers like me.

 

[raggydoll]

No sorry I have no idea what kept throwing the chain off unless the mech was positioned wrong - the park tools book (maybe also on their web page) is very good on setting up front mechs - I have used it for all my triples.
Rubbing on small ring and big cog is a problem.
Reason I asked if a flat bar - no longer made I think (nor an equivelent for some reason) but you can get rapidfires for triples with an extra click or two to allow you to trim the front mech - maybe purists don't think much of them but I have used them on two 9 speed triple builds and one 8 speed triple. Often available in decent nick from ebay sellers - usually have 440 or 441 model numbers I think.
Perfect for bodgers like me.

I think they might be rapidfire shiters.
Weird thing is..left shifter has 1, 2 ad 3 as you would expect but the 1 has a line before and a line after which seems to let you trim it with a little half click.

This is good. Bizarely it doesn't let you trim on the way down (middle to small). When you click it goes straight down to the line BEFORE 1!

Ah bikes! Good when they behave!

 

[Blue Hills]

ah so you already have a trimmable one - i think some have one extra position and some two - yep I have found that the extra positions, or not all of them, are available on the way down but this doesn't seem to cause any problems - mr shimano probably a lot cleverer than me. They are very reliable shifters but if you ever are tempted to open them up, use JIS screwdrivers.

Rapidfire as I understand it just means flat bar indexed trigger shift shifters

 

[Ming the Merciless]

A chain ring with same BCD and four bolt should fit. Have a look on spa website. Doesn’t have to be Shimano. Note inner chain ring will have smaller bcd but inner ring rarely needs changing. It being middle then outer most times you do do it.

 

[raggydoll]

ah so you already have a trimmable one - i think some have one extra position and some two - yep I have found that the extra positions, or not all of them, are available on the way down but this doesn't seem to cause any problems - mr shimano probably a lot cleverer than me. They are very reliable shifters but if you ever are tempted to open them up, use JIS screwdrivers.

Rapidfire as I understand it just means flat bar indexed trigger shift shifters

I'll get a drop bar one day!

 

[raggydoll]

A chain ring with same BCD and four bolt should fit. Have a look on spa website. Doesn’t have to be Shimano. Note inner chain ring will have smaller bcd but inner ring rarely needs changing. It being middle then outer most times you do do it.

I think both outer and middle are 104BCD and inner is 74BCD.

Is a little frustrating that it gets a bit harder to find suitable stuff for 9 speed triples etc.

I understand though that as technology moves on they produce less and less stuff for the older technology.

They do still mke 9 speed triples though so worst case scenario I could maybe stick a new 9 speed crankset on it.
Just really like the deore xt. Feels really solid and smoothe!

 

[Ming the Merciless]

I run 9 speed and get my chain rings from spa

 

[Blue Hills]

but inner ring rarely needs changing.

why do you say this? you don't normally need as you power up hills, or because it's quite often steel?

 

[Blue Hills]

I run 9 speed and get my chain rings from spa

on shimano cranksets/spiders?
open question.

 

[fossyant]

I have to search high and low for my m570 LX chainset rings. Managed to obtain a lightly worn used one on ebay. New were in the States.

Same with my GXP double. Large rings £50 from Europe pre Brexit. £100 from UK.

 

[T4tomo]

Found the inner;
https://www.sjscycles.co.uk/chainrings/shimano-deore-xt-fcm771-64mm-bcd-4-arm-inner-chainring-26t/
Just a question of searching. Looks like buying a complete chainset is going to be almost the same price as the rings.
https://www.decathlon.co.uk/p/triple-chainset-with-30-39-50-teeth-170-mm-shimano-sora/_/R-p-197566

raggydoll
Don't do this. Deore is MTB range, the crank arms have a bend outwards which accomodates the shape of the chain stays on the frame. Sora is designed for road bikes and have much straighter cranks as road bikes have a narrower back end. You'll end up heel striking your chain stays.

Sometimes the inner ring has a bit of offset where it bolts onto the crank arm too. If you can only find a straight chainring with right number of hols ad BCD, then you can often replicate the offset with chainring bolt washers. you just need to measure the distance between the chainrings before you disassemble the existing one. also 1mm here or there won't hurt, but you don't want your chain to be able to slip down between chanrings

 

[raggydoll]

raggydoll
Don't do this. Deore is MTB range, the crank arms have a bend outwards which accomodates the shape of the chain stays on the frame. Sora is designed for road bikes and have much straighter cranks as road bikes have a narrower back end. You'll end up heel striking your chain stays.

Sometimes the inner ring has a bit of offset where it bolts onto the crank arm too. If you can only find a straight chainring with right number of hols ad BCD, then you can often replicate the offset with chainring bolt washers. you just need to measure the distance between the chainrings before you disassemble the existing one. also 1mm here or there won't hurt, but you don't want your chain to be able to slip down between chanrings

The plot thickens!

 

[Blue Hills]

Have you looked on the bay @raggydoll ?
I have a bike with a deore hollowtech crankset and also just a few weeks ago built another up with a deore square taper (call me mad!) and had the idea that the chainrings are pretty much interchangeable - I may well in the future take the hollowtech one out and put a spare square taper chainset in - the shimano packaging tells you which chainsets a ring is compatible with - it's usual for a chainring to be usable on several cranksets/spiders.
I'd also look at the possibility of using chainrings supposedly just for 9 speed Alivio.
Of course all this used to be far easier before brexit with access to all those sensible german companies serving their sensible riders.

 

[byegad]

SPA Cycles, Ring them, tell them what you have, tell them what you want, pay over the phone and await delivery. Always works for me!