[emptybe_er]

. . .running dual-rings and 2.1's on an '05 Heckler - there's less than 1/4" clearance between the chain and side-knobs when in the lowest gear. This has only presented problems during muddy rides where the side-knobs pack with mud and, consequently, transfers said mud to the chain and drive-train. How's the clearance on your Heckler?

 

[DrWheels]

Very tight - this is common to the 2004-2007 Hecklers, not sure if it was revisited in the new ones. You can get a little more clearance by running a BB that fits 68-73mm shells and then put the 5mm spacer on the drive side. (That generation Heckler has a 68mm BB shell.)
Tire choice also seems to matter, as square profile tires are more likely to rub. When I ran 2.5 Panaracer Fires (big square shoulder blocks) the chain always rubbed in the lowest gear combo, but when I switched a 2.4 WTB MotoRaptor (rounded shoulder blocks) the rubbing went away. A friend of mine actually trimmed the drive-side shoulder blocks on his rear tire so he could keep running 2.5s, but that's too much work for me.

 

[emptybe_er]

Thanks. Yesterday was a sloppy ride and staying in the 36T kept things from clogging. . . guess I'll just have to man-up.

 

[spacoli]

I had the same problem. I tried a 2.35 tire once and it had a slight wobble and rubbed heavy when climbing in the granny. Back to a 2.1 tire.

 

[mountainbyte]

Damn I was hoping someone would've answered...

Buying an new BB for my 07ish Heckler. Santa Cruz has posted the wrong size for this model. So now I am offered a variety of chainlines on the 68mm bb....

Anyone know? My guess is 51mm...

 

[rglsr]

What type of cranks are you running?

I've got an 06 Heckler with XT FC-M760 cranks, 2 X 9 set up. No tire rubbing probs at all, even in the granny, and I run 2.35 to 2.5 tires. With Shimano integrated cranks run 2 spacers on drive side, 1 on non-drive side. Chain line appears to be 50-51mm or so.
(no poor shifting or crazy chainline issues either after 2.5 years)

If you have 3 piece cranks (non-integrated bb) and you're reusing your existing cranks (and the chainline is OK) pull the bb and see what you've got. If you've got tire rubbing probs try the next (longer) available spindle length to move the chain outwards some.

 

[mountainbyte]

So I measure what, the spindle to the 32 tooth ring? Or the entire spindel width... I'm starting to think it would be a safe bet just to go with the 51mm...

 

[mountainbyte]

chainline bb 06/07 Heckler

So I measure what, the spindle to the 32 tooth ring? Or the entire spindel width... I'm starting to think it would be a safe bet just to go with the 51mm...

 

[rglsr]

Can't help much w/o knowing what cranks we're talking about

If you have non integrated bb find out existing bb spindle length (end to end w/o crank arms, typically 68mm X 113 or 118mm on a Heckler, usually labeled on bb) and determine what your existing chainline is, (before tearing it all apart) 32 tooth ring to centerline of seat tube/frame. Chainline adjustments can be made with different spindle lengths.

With an integrated bb (spindle attached to drive side crank) chainline adjustments can be made via spacers. BB replacement on integrated cranks does not include the spindle.

 

[mountainbyte]

thank you!

...determine what your existing chainline is, (before tearing it all apart) 32 tooth ring to centerline of seat tube/frame. Chainline adjustments can be made with different spindle lengths.

I have a giga-pipe gxp on there now going to a tru-vativ holzfeller oct.

I imagine this measurement from centerline to middle ring will work.

It does have a tendency to skip a tooth, or drop the chain on granny when shifting under climbing duress....