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Discussion Starter · #1 ·
Well I installed a RF Evolve XC X-type crankset on on my '05 Prophet 600, it's been on the bike for a couple of months and has been screwed up from the get go. The problem is I cannot get the front dérailleur adjusted properly so that it does not rub the chain with this crankset. I've tried just about everything and no matter how I tune the limit screws on the FD it always rubs the chain in certain gear combos. I can get the FD to not rub the chain in the smallest chainring, but then in rubs is the middle and large chain rings and vice versa. Furthermore I have to use all three chain line spacers with the crankset otherwise I get terrible side to side and vertical play in the crankset, your only supposed to use a max of two. One more thing, no matter how I adjust the chainline spacers it makes no difference in helping the dérailleur not to rub the chain. I do know how to work on the FD, and I just don't understand why I cant get this set up properly, I'm seriously considering re-installing the stock Truvativ blaze crankset that came with the bike as it worked properly. Please help if you can.
Thanks
-Nate
 

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MTB1986 said:
Well I installed a RF Evolve XC X-type crankset on on my '05 Prophet 600, it's been on the bike for a couple of months and has been screwed up from the get go. The problem is I cannot get the front dérailleur adjusted properly so that it does not rub the chain with this crankset. I've tried just about everything and no matter how I tune the limit screws on the FD it always rubs the chain in certain gear combos. I can get the FD to not rub the chain in the smallest chainring, but then in rubs is the middle and large chain rings and vice versa. Furthermore I have to use all three chain line spacers with the crankset otherwise I get terrible side to side and vertical play in the crankset, your only supposed to use a max of two. One more thing, no matter how I adjust the chainline spacers it makes no difference in helping the dérailleur not to rub the chain. I do know how to work on the FD, and I just don't understand why I cant get this set up properly, I'm seriously considering re-installing the stock Truvativ blaze crankset that came with the bike as it worked properly. Please help if you can.
Thanks
-Nate
Have you played with the derailleur position? Sometimes the clamp loosens a bit and either twists or move towards the cable. But in crosschaining situations chain rub can be expected.

First install the crank properly, using all three spacers in 73mm bottom bracket shell will f'up the spline on the crank and crush the bearings very quickly.

Second re-install the front derailleur properly.Shimano has a crappy instruction sheet, basically with the derailleur in the middle ring position you want the top of the derailleur to be 2mm above the largests chainring and aligned straight with it lengthwise. Having an alignment block helps, your LBS probably throws dozens away a week just ask them for one.

Good luck and keep coming back
 

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Limit screws have nothing to do with your problem. It's all about cable tension and fiddling with the barrel adjuster. I would also agree that, with a 73mm BB, you should never use more than two spacers. Have you tried all the combos:49, 50, 51mm? I'm not really sure just how serious this problem is, since I certainly can't stop my front derailleur from rubbing in certain gears. In the middle ring, it will rub at one extreme or the other (on the other hand, I did have to use a 51mm chainline just to get my front derailleur to clear a larger tire, so it may be somewhat screwed up).
 

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Discussion Starter · #4 ·
I thought the Prophet had a 68mm BB shell? I know it's not correct at all with having all three chainline spacers on the crank spline, but it was the only way I could cure the play issue in the crankset. If I run any less than three I get pretty serious play in the crankset. I did fool around with the barrel adjuster, but it didnt help much. I will try playing with the cable tension next to see if that fixes it. The chain rubs the most in the smallest front chainring.
 

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Did you try following the park guide to set it up? I've found it to be helpful.
 

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Discussion Starter · #6 ·
Vulcan said:
Did you try following the park guide to set it up? I've found it to be helpful.
Actually the Park guide is what I used to teach myself how to work on FD's. I found the guide very helpful, but my bike just wont cooperate with me.
 

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MTB1986 said:
Actually the Park guide is what I used to teach myself how to work on FD's. I found the guide very helpful, but my bike just wont cooperate with me.
How does the chainline differ with the Evolve vs the stock cranks?
 

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Discussion Starter · #8 ·
Vulcan said:
How does the chainline differ with the Evolve vs the stock cranks?
I honestly don't know. It's definitely a wider chainline I'm sure because of the external BB cups. I never really took the time to figure out the chainline on the stock cranks so I could transfer it to the RF's. I just went trial and error method like I did with my old bike the RF cranks were on, I had the crankset pretty well adjusted with the dérailleur on my old bike using the trial and error method. I just added/swapped the chainline spacers to and from each side of the spindle until I gained the best shifting performance, I couldnt get and still cant get anything to work using this method on the Prophet.
Thanks for the continued help.
 

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Are you sure you bottomed out the crankarm bolt? I have to use a piece of PVC pipe attached to my set of allen wrenches to get the leverage needed to bottom out the bolt. On a 73mm BB it's one large BB shell spacer and two chainline spacers. But you need to be sure that the bolt is completely bottomed out. Otherwise, you will get play and it will screw up the chainline.

The only other thing to try is cocking your derailleur at a little bit of an angle. I have to do this because my chainline is so off. We're not talking about a huge angle, just a couple of degrees. It's not the best solution, but it beats rub.
 

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Discussion Starter · #10 ·
^Does the Prophet have 73 BB shell? I had set the spacers up for a 68mm BB. I just used a normal allen wrench, and then put my body weight on to the wrench to bottom the bolt out, I'll check it again though. Also Guyechka, how sould go about cocking the FD?
Thanks.
 

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Discussion Starter · #12 ·
^I have the E-type derailleur, so I dont think thats where the problem stems from.
 

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Ok, cocking the derailleur a little is not going to happen if you have an E-type.

I'm not sure you can get the crank bolt to bottom out with just a regular allen. Have you got any pieces of pipe that would fit onto the handle of the allen? You will know when it bottoms out. You can feel it hitting, and there is absolutely no way to budge the bolt any further. And are you greasing the splines before you put the crank arm on? That helps a lot in actually getting the crank arm all the way on to the axle to the point where the bolt is bottomed out.
 

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Discussion Starter · #14 ·
^ Yep I greased the spindles. I'm almost positive I'm bottoming the crank bolt out, I felt it hit and it wont go any further. I just tried setting up the spacers according to RF's recomendations, and I'd say 49 and 50mm work the best. 51mm is just to much. But now I have the problem that the play may come back in the crankset as it did before.
 

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MTB1986 said:
^ Yep I greased the spindles. I'm almost positive I'm bottoming the crank bolt out, I felt it hit and it wont go any further. I just tried setting up the spacers according to RF's recomendations, and I'd say 49 and 50mm work the best. 51mm is just to much. But now I have the problem that the play may come back in the crankset as it did before.
If you have both spacers on there, it shouldn't develop any play. If it does develop play then the crank bolt is loosening up on you. Now, I've taken my crankset apart maybe seven or eight times. Each time I put it back together I make sure I'm bottoming out the bolt. I've never had the bolt back out on me. However, I have heard of bolts backing out when they weren't bottomed out to begin with.

If play develops, go back in there with your allen wrench and see if the bolt has started to back out. You may have to get some loctite to ensure that it doesn't budge, but that's a last resort.
 

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Discussion Starter · #16 ·
Guyechka said:
If you have both spacers on there, it shouldn't develop any play. If it does develop play then the crank bolt is loosening up on you. Now, I've taken my crankset apart maybe seven or eight times. Each time I put it back together I make sure I'm bottoming out the bolt. I've never had the bolt back out on me. However, I have heard of bolts backing out when they weren't bottomed out to begin with.

If play develops, go back in there with your allen wrench and see if the bolt has started to back out. You may have to get some loctite to ensure that it doesn't budge, but that's a last resort.
I think your right, as the play does not develop till after I have been riding for 30-40mins. Well, I'll try to get the crankset dailed in with two spacers instead of three. Thanks for all the help everyone, I'll keep ya updated on what I can find out.
 
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