Results 1 to 10 of 10
  1. #1
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    760

    Going 1 X 9 with SLX triple crankset....

    Hi,
    Would like some advice please. I want to strip the chainrings off of my triple SLX crankset that I have been happy with and install a non ramped/non pinned 42t middle ring only.
    Can someone suggest where I can purchase such a middle ring with 104 bcd that will be compatible with the SLX cranks in the middle ring position? I want to use the middle position because its the best compromise chainline across the cassette in back.
    Many Thanks.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Aug 2005
    Posts
    153
    Any 104 bcd chainring will work. Mrp, e thirteen, surly are some of the main brands but there are a bunch out there. Look on jensonusa.com or bikebling.com or any online retailer. You're also gonna need shorter chainring bolts unless u use a bashguard and some sort of chain guide to keep the chain from jumping off. The options are endless honestly.... Depending on the type of riding u do

  3. #3
    mtbr member
    Reputation:
    Join Date
    Oct 2010
    Posts
    15
    Another thing to consider is will the 42t fit in the middle ring position? it may hit the chain stay. Unless of course you actually ment to type 32t, which is more common and not a problem regading the chainstay.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    760
    Thanks a lot guys....appreciate your help.
    Man...a big middle ring hitting the chainstay went right over my head. Thanks for saving me a lot of grief. Eyeballing it...a 42t in the middle position would hit the chainstay...doh. Maybe could go 38t in the middle position...but that is a bit tight on gear inches for higher speed riding.

    An explanation of what is going on with my 29er... The trail near my house which was a mess for many years has just been asphalted. So its smooth and my 29er is going under the knife to make it more of fast smooth training bike. I prefer flat bar to drop bar for in town riding but still like the speed if not riding on the bumps. I don't need a lot of short gears for climbing as the terrain I ride is flat...but no...no single speed for this oldster...I like my gears coming from the road. My CF road bike is getting less use tho with the new trail. So what is up is...
    Going to a Salsa Cromoto rigid fork to replace the Reba as really don't need suspension now, 700 X 32 tires to replace the Nanos and would like a fairly big middle ring as I hang out a lot on the 44t big ring now on my triple which would really cross chain to the big cogs in back if I tried it. I now cruise on this bike with low volume skinnier tires at the 15-20mph mark depending on wind and don't need the short gear inches...mostly need gearing for higher speed.
    But now that Tim saved me from trying to paste a 42 in the middle position which would hit the chainstay it appears....and I believe putting a 42 in the outside position would be too cross chained for the inboard big cogs in back if only having one ring...maybe now best I just remove the granny which I don't use, adjust the limit stop on my FD and call it good...shifting to the big ring when I ramp my speed up instead of running a single ring which is always a compromise to chain line anyway.
    Guys, I run a single 2.5mm Shimano plastic spacer on the drive side of my BB. If I remove the granny, should I put the spacer on the non drive side of the BB to move the 2 chainrings in to promote a better chainline with middle ring for big cogs in back?

    As to sticking with a 42t middle ring only, can I put one or two more 2.5mm plastic spacers on the drive side of the BB to space it out just enough to clear the chainstay? Again, I only have a single spacer installed now and not sure if the SLX cranks can be spaced further outboard as this would effectively 'widen the BB shell with more spacers' and not sure if the crank spindle length would accomodate this.

    Thanks for any further advice.
    Last edited by dirtrider7; 06-18-2011 at 05:09 AM.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Oct 2010
    Posts
    15
    Sounds to me like you will either have to run a slightly small front ring or keep the derailleur, both of which you have obviously though of. Not much help I know, sorry. I'm not even sure what I would do in your situation either, you sound like a good candidate for running a single ring, but it also sounds like you will loose too much top end for the type of riding you do with a 36 or 38 single ring.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    760
    Thanks for your honest comments Tim...appreciate it. Believe I can make due with a 38t for my top end. I am no beast of a rider nor rarely ride faster than 22mph or so on the flats. This bike is pretty fast tho with 700 X 32 tires at 75 psi and why I need more gear inches than 36 or I would be living on the 11t cog in back I believe on the flats...at least down wind. So a single 38t ring may work fine but maybe a tight fit to my chainstay in back in the middle position of the cranks as you advised. A thought is....I could run the 38t ring on the outside position and remove the 2.5mm plastic Shimano spacer I have on the drive side of the BB and put it on the non drive side. This would help the chainline for the large cogs in back when running just an outside ring. Further...the big ring of the SLX crank is dished or offset outboard which allows Shimano to mfr this crankset without spacers between big and middle ring. If I paste a flat (versus Shimano dished) non ramped/non pinned 38t chaintring to the outside of the cranks....which will be a more favorable all around chainline compared to just running on the big 44t stock ring which doesn't work with the large cogs in back...too cross chained....AND switch the spacer to the other side, I may get a suitable chainline in the outboard position across th cassette...close to the middle position which maybe too tight to the chainstay.
    I wouldn't know this without experimenting unless somebody will weigh in with their experience.
    Other than that...just run what I have ...maybe remove the granny which I don't need now and move the 2.5mm spacer to the non drive side which will improve the chainline for the mid ring to the biggest cogs...which works right now but that 2.5mm offset would help the middle ring to the biggest cogs in back. Decisions decisions.
    If I do run a single ring in the outboard position....and no bashguard nor N-Gear stop inboard, can you suggest a good chain guide that would keep the chain on a single ring?
    Thanks again.
    Last edited by dirtrider7; 06-19-2011 at 08:51 AM.

  7. #7
    Nouveau Retrogrouch SuperModerator
    Reputation: shiggy's Avatar
    Join Date
    Dec 1998
    Posts
    47,279
    Quote Originally Posted by dirtrider7 View Post
    Thanks for your honest comments Tim...appreciate it. Believe I can make due with a 38t for my top end. I am no beast of a rider nor rarely ride faster than 22mph or so on the flats. This bike is pretty fast tho with 700 X 32 tires at 75 psi and why I need more gear inches than 36 or I would be living on the 11t cog in back I believe on the flats...at least down wind. So a single 38t ring may work fine but maybe a tight fit to my chainstay in back in the middle position of the cranks as you advised. A thought is....I could run the 38t ring on the outside position and remove the 2.5mm plastic Shimano spacer I have on the drive side of the BB and put it on the non drive side. This would help the chainline for the large cogs in back when running just an outside ring. Further...the big ring of the SLX crank is dished or offset outboard which allows Shimano to mfr this crankset without spacers between big and middle ring. If I paste a flat (versus Shimano dished) non ramped/non pinned 38t chaintring to the outside of the cranks....which will be a more favorable all around chainline compared to just running on the big 44t stock ring which doesn't work with the large cogs in back...too cross chained....AND switch the spacer to the other side, I may get a suitable chainline in the outboard position across th cassette...close to the middle position which maybe too tight to the chainstay.
    I wouldn't know this without experimenting unless somebody will weigh in with their experience.
    Other than that...just run what I have ...maybe remove the granny which I don't need now and move the 2.5mm spacer to the non drive side which will improve the chainline for the mid ring to the biggest cogs...which works right now but that 2.5mm offset would help the middle ring to the biggest cogs in back. Decisions decisions.
    If I do run a single ring in the outboard position....and no bashguard nor N-Gear stop inboard, can you suggest a good chain guide that would keep the chain on a single ring?
    Thanks again.
    Do not put the spacer in. The chain line is already too far outboard. Much more likely to have the chain drop off the inside of chainring when using the larger cogs.

    Even with a 32t ring you are only losing two higher ratios without the 42t.
    mtbtires.com
    The trouble with common sense is it is no longer common

  8. #8
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    760
    Quote Originally Posted by shiggy View Post
    Do not put the spacer in. The chain line is already too far outboard. Much more likely to have the chain drop off the inside of chainring when using the larger cogs.

    Even with a 32t ring you are only losing two higher ratios without the 42t.
    Not sure what you mean Shiggy. Moving the 2.5 BB spacer from drive side to non drive side moves the chainrings in...or less outboard. As you say the chainline is too far outboard.

    As to difference in gear inches between 32 and 42t ring....32/x = 42/11....x= 8.4t So technically 2.6 cogs if running max gear inches or on the 11t in back with a 42t chainring.

  9. #9
    Nouveau Retrogrouch SuperModerator
    Reputation: shiggy's Avatar
    Join Date
    Dec 1998
    Posts
    47,279
    Quote Originally Posted by dirtrider7 View Post
    Not sure what you mean Shiggy. Moving the 2.5 BB spacer from drive side to non drive side moves the chainrings in...or less outboard. As you say the chainline is too far outboard.

    As to difference in gear inches between 32 and 42t ring....32/x = 42/11....x= 8.4t So technically 2.6 cogs if running max gear inches or on the 11t in back with a 42t chainring.
    Misread it. With a larger "middle" you may not have the clearance to move the chain line inboard. I read it as wanting to increase clearance. If you do move the spacers as you said and used the ring in the outer position the chain line is still much worse than the middle, so my reasons above apply.

    Never seen 0.6th of a cog.

    I mean there are usually only two ratios with the 42t that are higher than you have with the 32t.
    mtbtires.com
    The trouble with common sense is it is no longer common

  10. #10
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    760
    Quote Originally Posted by shiggy View Post
    Misread it. With a larger "middle" you may not have the clearance to move the chain line inboard. I read it as wanting to increase clearance. If you do move the spacers as you said and used the ring in the outer position the chain line is still much worse than the middle, so my reasons above apply.

    Never seen 0.6th of a cog.

    I mean there are usually only two ratios with the 42t that are higher than you have with the 32t.
    Thanks. Yeah...having a single ring on the outside doesn't work very well for the big inside cogs in back...to be sure. Point about the calculation if rounding up is...its almost a 3 cog diff between 32 and 42t ring size...but close enough for horseshoes.
    The 44 in front is a bit more than I need...maybe 38 would be the best and it may fit in the middle position with clearance to the chain stay...only way to know I guess would be to try.
    Thanks again for your comments as I have learned alot about my options.

Similar Threads

  1. SLX Crankset-Double or Triple?
    By angelo in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 3
    Last Post: 03-11-2011, 05:40 PM
  2. FSA SLK carbon MTB triple crankset
    By mtbiker3995 in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 0
    Last Post: 11-18-2010, 08:52 AM
  3. CARBON crankset TRIPLE
    By eliflap in forum Cannondale
    Replies: 5
    Last Post: 11-05-2008, 10:08 PM
  4. double Vs Triple crankset?
    By Ivo Suarez in forum Beginner's Corner
    Replies: 2
    Last Post: 11-16-2007, 06:05 AM
  5. Q: Using a Triple Crankset for singlespeeding
    By os2 in forum Singlespeed
    Replies: 6
    Last Post: 12-05-2004, 04:46 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •