issue: Truvativ Firex 3.3 GXP moving outer ring to middle...

nickfox

Hi all

I have a shiny new boardman team FS http://www.boardmanbikes.com/mtbfs/fs_team.html

with a shiny new Truvativ Firex 3.3 GXP crankset (it came with it)
http://www.chainreactioncycles.com/Models.aspx?ModelID=23241

I don't use the 22t front inner ring or the middle 32t and the 44t outer ring is perfect but not comfortable on the rear 32t highest cog but would be prefect if it was more centrally aligned.

so... i tried to swap the outer ring with the middle ring but it does not fit! the middle chain ring will move to the outer position but not vice versa.

this could be just a unique feature of this crankset but if not...

this poses more questions; if i get a chain guide with rotating bash guard (http://www.chainreactioncycles.com/Models.aspx?ModelID=11437 for example)
and i want to use a 42t chain ring, how can i be sure that i am buying the right ring to fit the middle position on my crank? assuming that im going to have to buy a new, larger middle ring.

CRC seems to have "middle" and "outer" chain rings but some do not state any positional preference.

how can i be sure?

help!

thanks - nick fox

nicklouse

it is normal and happens on many cranksets.

the bash ring will fit.

why would you want such a big ring? you will find it pain in the butt.

Oh, try using your gears a bit better.

and before spending on a bash that is not really needed on an XC bike get to know the bike and your riding.

supersonic

Why not just remove the inner ring, and keep the 32t middle and outer as they are?

42/32 is the same gear (ish) as 32/24 - you will spread the laod more effectively, and things will last longer. Plus more lower gears should you need them.

Must be quite flat where you live!

nickfox

thanks nicklouse im quite sure the bash guard will fit the outer position on my crank from the internet trawling i have done

however my question was about middle chain ring fitting and whether a 42t ring will fit the middle position if i go out and buy one. or do i need a "middle" specific ring? im just not sure if my current 44t outer ring is unusually large or the middle mounts on the crank are unusually small?

if we pretend for a moment that i have a DH rig, and want to fit a single 44t+ chain ring with an MRP style chain guide then i must fit the guard plate to the outer ring position on the crank and fit the 44t+ chain ring to the middle position on the crank, so... where shops like CRC refer to "middle" and "outer" rings (http://www.chainreactioncycles.com/Models.aspx?ModelID=4322 and http://www.chainreactioncycles.com/Models.aspx?ModelID=4008) do they just say this as a guide or are there differences in the fitting such that a 38t "middle" is not the same fitting size as a 38t "outer"?

cheers
thanks for the fast responses by the way

slcoldstone

Middle and Outer are different fit as standard, you do not have a "freak" crankset, why this is i do not know but a way to be sure is to check item descriptions for, things like; DH chainring, single speed Chainring, Middle chainring (as you mentioned) etc. Not only will these fit the middle position on your cranks but also come without ramps or shifting pins and generaly look nicer http://www.chainreactioncycles.com/Models.aspx?ModelID=4322 is not really for single ring set up, you want something like http://www.chainreactioncycles.com/Models.aspx?ModelID=28192

Sorry for the late reply! you probably worked it all out by now!?

nicklouse

slcoldstone wrote:

Middle and Outer are different fit as standard, you do not have a "freak" crankset, why this is i do not know but a way to be sure is to check item descriptions for, things like; DH chainring, single speed Chainring, Middle chainring (as you mentioned) etc. Not only will these fit the middle position on your cranks but also come without ramps or shifting pins and generaly look nicer http://www.chainreactioncycles.com/Models.aspx?ModelID=4322 is not really for single ring set up, you want something like http://www.chainreactioncycles.com/Models.aspx?ModelID=28192

Sorry for the late reply! you probably worked it all out by now!?

it depends on the make of cranks. not all of them have different shoulder heights. and ahimano for one year changed the way that they did things as well to shake things up even more.

slcoldstone

Thats not really answering his question... If you read his original post he states that he is running a Truvativ Firex 3.3 GXP which is pretty standard as far as shoulder heights go... so he will be fine running a 42t single/middle/dh chainring.
Whats with your replies? they seem to drift from the original question. Why do you question why he wants to run a 42t? or that he doesnt use his gears properly? i pretty much only use my 42t ring and do XC and light DH, and a bash ring wouldnt go a miss for ripping over logs etc though its not vital right now.