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  1. #1
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    Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur

    So, I bought a pair of 2.4 Kenda Telonix tires to get something more substantial than the 2.3 Kenda Kiniption stock tires. On the trail, I find out when shifting to the granny gear, the front derailleur rubs against the new rear tire. Bummer. So much for the Surly slogan "fatties fit fine". The slogan would probably hold true if I ran a singlespeed setup with no front derailleur?

    Anyway, after the ride, I went to the LBS to see what advice they would give. Their recommendation? Get a smaller tire size in the rear. So I left with a 2.2 Continental Mountain King rear tire and all is well again. I can shift to my granny gear and the front derailleur does not rub the rear tire. Lesson learned.

  2. #2
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    This sounds odd. Do you have any pictures of the problematic setup? What front derailleur and cranks are you using.

    Curious, because I have a meaty Continental Trail King 2.4" on MTX33 rims with SLX cranks and an older XT front derailleur (pre-spacers) with no rub issues (wheel full forward or with Monkey Nutz). Just checked mine, the cage doesn't go further in than the chainstay.

  3. #3
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    I have the stock Shimano Deore, model 590. 28.6mm. Top pull derailleur and the stock Andel RSC6, 24/34/46t. Black cranks. Sorry, I didn't snap close up pictures. I do have a before and after pic that was taken from a distance.

    I did read from reviews that the Continental sizing is smaller than they actually are. So maybe their 2.4 is narrower than the Kenda 2.4?
    Attached Thumbnails Attached Thumbnails Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur-imag0411.jpg  

    Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur-imag0412.jpg  


  4. #4
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    With regards to your wonderful Troll, Surly say "room for
    26 x 2.7˝ tires". In their "Frame Hightlights" page they offer: "26 x 2.5" with rear wheel fully forward. Clearance for 2.7" tire with wheel farther back".
    Where is your rear wheel in the drop outs?
    Your Top pull derailleur sounds right.
    Did you build up a frame or buy a complete bike? I ask as I'm wondering about the length of your BB spindle and if your crankset rings may be a little close to the frame?
    I'm suspecting that your build has somewhere strayed from Surly's spec but dont yet have the detail of your build to suggest where you might begin to look first.
    Hope this is of some help.

  5. #5
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    Quote Originally Posted by rifraf View Post
    With regards to your wonderful Troll, Surly say "room for
    26 x 2.7˝ tires". In their "Frame Hightlights" page they offer: "26 x 2.5" with rear wheel fully forward. Clearance for 2.7" tire with wheel farther back".
    Where is your rear wheel in the drop outs?
    Your Top pull derailleur sounds right.
    Did you build up a frame or buy a complete bike? I ask as I'm wondering about the length of your BB spindle and if your crankset rings may be a little close to the frame?
    I'm suspecting that your build has somewhere strayed from Surly's spec but dont yet have the detail of your build to suggest where you might begin to look first.
    Hope this is of some help.
    Thanks for your input, rifraf! My rear wheel is fully forward when I had the Kenda Telonix 2.4 tire. I guess the Surly statement "room for 2.5" with rear fully forward may only apply if no front derailleur is present? With the 2.4 rear tire, there was enough clearance for it to rotate with no frame rub. I was able to shift from the middle to big rings with no issues. The only issue was when the derailleur tries to go to he smallest chain ring. The derailleur body rubbed against the Kenda Telonix 2.4 rear tire.

    I bought the complete bike as spec'ed by Surly. I haven't changed anything except for the tires so far. Maybe later I can try a "narrower" 2.4 (or even a 2.5) tire from another manufacturer. For now, I'm good with the Continental Mountain King 2.2 rear tire.

  6. #6
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    Konadude -

    You have your axle slammed forward in the drop outs. You need Monkey Nuts or a Tuggnut to move it rearward for more clearance.

    Read up...
    Blog | Surly Bikes

  7. #7
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    Quote Originally Posted by Belatu View Post
    Konadude -

    You have your axle slammed forward in the drop outs. You need Monkey Nuts or a Tuggnut to move it rearward for more clearance.

    Read up...
    Blog | Surly Bikes
    Wow. I guess I missed that Surly article/blog about fat tires and front derailleurs. Thanks for providing the link. Now I know that I can use Monkey Nuts to move the wheel back in a consistent manner and be free of front derailleur interference!

    After riding the 2.2 Continental Mountain King rear tire though (vs. the 2.4 Kenda Telonix), I think I'll stick with the lighter (and better/lower rolling resistance) 2.2 tire for now.

    It's good to know that later on, I can put a 2.4 (or even 2.5 rear tire) and use the Monkey Nuts to clear the front derailleur. Thanks again!

  8. #8
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    Yeah, most of the Conti's are pretty undersized. The Trail King (a.k.a. Rubber Queen) tires are correctly sized for a change. Shiggy's tire spec site gets them right in the 2.4" actual measurement range. Not sure about the Telonix, Shiggy's site didn't have them and I have no experience with them. But, I'd bet their tread is in the 2.4 range at least. As mentioned, my derailleur cage does not come in any further than the chainstay. So, if a tire of mine was hitting my cage it would be hitting my chainstay. Something sounds off.

    Check your wheel alignment within the stays and check that your derailleur is correctly adjusted. In low/low gear setting the cage should be just missing the chain (and parallel to the chain line). No excessive gapping, or when you shift to granny you have a higher chance of dropping the chain.

    As reference, there are a few people running a triple front with larger tires and no problems on the Troll picture thread. Most notably is on page 19, a blue repaint Troll running 2.6 Maxxis Ardents where the tread is in line with the tail of the derailleur cage.

    Seems like the bike shop didn't look real close at things and maybe, just maybe, wanted to sell a set of tires.

    Edit: What part of the derailleur was rubbing? The cage or part of the body? That would make a big difference if something is adjusted incorrectly, or if the tire just needs to be pulled back some. It seems some of the newer front derailleurs have quite a large body.
    Last edited by Turtle01; 02-17-2013 at 08:54 AM.

  9. #9
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    Something does sounds off...

    Quote Originally Posted by Turtle01 View Post
    Yeah, most of the Conti's are pretty undersized. The Trail King (a.k.a. Rubber Queen) tires are correctly sized for a change. Shiggy's tire spec site gets them right in the 2.4" actual measurement range. Not sure about the Telonix, Shiggy's site didn't have them and I have no experience with them. But, I'd bet their tread is in the 2.4 range at least. As mentioned, my derailleur cage does not come in any further than the chainstay. So, if a tire of mine was hitting my cage it would be hitting my chainstay. Something sounds off.

    Check your wheel alignment within the stays and check that your derailleur is correctly adjusted. In low/low gear setting the cage should be just missing the chain (and parallel to the chain line). No excessive gapping, or when you shift to granny you have a higher chance of dropping the chain.

    As reference, there are a few people running a triple front with larger tires and no problems on the Troll picture thread. Most notably is on page 19, a blue repaint Troll running 2.6 Maxxis Ardents where the tread is in line with the tail of the derailleur cage.

    Seems like the bike shop didn't look real close at things and maybe, just maybe, wanted to sell a set of tires.

    Edit: What part of the derailleur was rubbing? The cage or part of the body? That would make a big difference if something is adjusted incorrectly, or if the tire just needs to be pulled back some. It seems some of the newer front derailleurs have quite a large body.
    Anyway, so today, I ride the Continental Mountain King 2.2 on the rear going up Caballero Canyon (a local trail here). No rubbing issues on the flats when shifting to the granny gear when testing. As soon as I torque that granny gear though going up an incline, there is a very slight rubbing! Damn. I inspect it while riding up and notice that the 'hairs' of the tire touches the derailleur cage when on the granny gear. Check out the pics I attached of the clearance between the derailleur cage and the 2.2 tire. I think there is definitely something amiss here if I can barely clear a 2.2 tire in the rear. Considering that Continental 2.2 tires are usually narrower than typical 2.2 tires.

    Thanks for telling me about page 19 on the Surly Troll pic thread. That custom blue Troll does look like it has a triple-ring setup, 2.6 Ardents AND his axle moved all the way forward! Now how come I can't do that with a 2.4 Kenda Telonix in the rear??

    One thing that is very noticeable is that the Continental Mountain King 2.2 rear tire is definitely 'lighter' in feel and accelerates easier than the 2.4 Kenda Telonix rear tire. The 2.4 front tire, though has a bit more rolling resistance, is worth the extra weight and rolling resistance given the pros of added traction and grip-giving confidence especially going downhill. I think I'll just stick with this setup for a while: big tire up front and skinnier tire in rear.
    Attached Thumbnails Attached Thumbnails Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur-imag0415.jpg  

    Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur-imag0416.jpg  

    Surly Troll and Rear 2.4 Kenda Telonix Rubbing Against Front Derailleur-imag0414.jpg  


  10. #10
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    Something that I've noticed these last few years is that we have a definate shortage of bike mechanics, people that can think outside of the box sometimes. We are stuck with techs that simply install parts. First of all front derailleurs can be rotated on the seat post, secondly they are made out of flat metal that is easy to bend. The first thing I would have looked for is the position of the deralleur, position, move and or bend it to clear the tire. If the tire clears the chainstay the derailleur can also be mounted to clear. Fatties do fit fine, I've never had clearance issues on the back of my Troll. It's not uncommon for 'mechanics' to manipulate a front derailleur to fit.

    With the limts set properly and a little bending and shaping of the cage I don't see any reason for the deralleur to extend inward any farther than the chainstay itself.
    Last edited by Saddle Up; 02-18-2013 at 07:49 AM.

  11. #11
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    When researching my recent Troll build, I read several accounts of this scenario, and it's one of the main reasons why I decided to go with a 1x10 setup on mine. Aside from the obvious simplicity, I wanted to be able to run the fattest possible tires on my Troll, while still having the wheel all the way forward in the track dropouts, to make removing and replacing the rear wheel as simple as possible.

  12. #12
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    In my opinion, it appears that the limits need to be adjusted on your FD, and it may need to be slightly rotated away from the tire.

  13. #13
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    I have to wonder if they even put it in the stand to check it over and adjust the limit screws like CycleAddict said. The derailleur just looks poorly adjusted.

    And as Saddleup said, there is a serious lack of good bike mechanics in some areas and shops. The shop I worked at was a mixed bag.

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