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Pics of a problem with mounting my chain device + questions

coursemyhorsecoursemyhorse Posts: 192
edited April 2013 in MTB workshop & tech
Hi all.

Setup:
Stumpjumper 2007 FSR Comp
SM-BB51 Bottom Bracket
E Thirteen 32 tooth front chainring
E Thirteen XCX Chain Guide (bottom bracket mounting type)
Shimano Deore/(SLX?) FC-M552 Crank Arms
KMC 93 chain 10 spd
Zee Rear Derailleur 10 spd
XT 11-36 Cassette

Problem:
The E Thirteen XCX chain device states it is compatible with a 32 tooth ring, which it is on the lowest setting. If I put it down this low on my setup, it fowls the spider arm. I have to run it in about the 34 tooth position for it not to do this. My concern is that it will not be low enough to do its job effectively. Maybe you can see in the pics and tell me if you think it is low enough to still do its job?

Solution:
1: Machine a mm or so off the outside tip of the spider arm (don't want to do this)
2: Run a 33 or 34 tooth chain ring (don't want to run 34, but could live with 33 - still not convinced it would be able to sit low enough)
3: Change my cranks to ones with a removable spider and run a chain ring that mounts directly to the crank spindle.

In option 3 above I want to know:
A) What type of bottom brackets fit my bike, I think it originally had a Truvatix GXP one and now has a Shimano Hollow Tech SM-BB51 one. Does this have a generic "type" of name to find other bottom brackets that fit.
B) What are some cheap cranks that fit my bike that have a removable spider arm? SRAM X7/X9? Shimano?
C) Can I buy said cranks without all the chain rings that I won't use?
D) Where can I get a direct mount chainring and what manufacturers sell them and what are they called/refered to as?


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Posts

  • The RookieThe Rookie Posts: 27,804
    Clearly it can go lower than that with fowling the spider, so set it as low as you can.

    That will probably be fine anyway, it can't come off the sides!
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • I must admit in that pic it does look like it can go lower. Hmm, let me go snap another one hang on...
  • I just checked and maybe in the above one I put it back up a bit. Anyway now, with it mounted as low as I could get it it looks like the below. It seems to have moved actually since putting it on as it literally JUST rubs the arm. I know it will easily prevent chain from coming off the sides, but wondered if the gap vertically (between chain and top of guide) matters to keeping it from dropping at all.
    Thanks

    %5BUNSET%5D
  • *AJ**AJ* Posts: 1,080
    Buy a 34T chainring. :lol:

    In all honesty though, its probably the only answer if its bothering you. I cant see that it wont work how it is though like 'The Beginner' said the chain can't move side to side, which it needs to to come off.
  • Hmm. Yeah. Any thoughts on the above where I mentioned spiderless crank options anyone? OTT?
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