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Discussion Starter #1
Good day,

I was replacing my chain and sprocket last night and noticed my axle runs above the eccentric, unlike the manual and online sources say.

The eccentric does not turn 360*, it seems the little locator pin that holds the brake caliper bracket limits complete rotation.
Can anyone comment on the easiest way to flip the eccentric around, or if it's absolutely necessary? The turn in never felt lazy or anything.
 

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Yes you will want to flip it the best way is to remove the brake bracket that is the stop. Then rotate it and re-install the bracket. Check the lower front part of your swingarm near the sprocket often it gets worn from being upside down. It got that way because some one put it in upside down either on purpose trying to lower the bike or by mistake but you will find the bike works much better when in the correct (lower) half.
 

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Discussion Starter #3
Thanks for your reply ducvet

Yeah I noticed the chain guard near the front was a little worn away. Nothing too noteworthy and ill get it welded up in the winter.

I will look into removing the caliper bracket, are the older sbk brackets different? Its my understanding that some models have full rotation and others, the later bikes, dont
 

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Discussion Starter #5
Hello Mr. Black, a pleasure to have you in my thread, haha!

I noticed on the brake caliper bracket, the slider seemed to have some material that was not machined which is where the locator pin was stopping.

What i decided was that more likely the reason my bike would not rotate fully is that the factory did not fully machine the casted bracket so I used a round file to slowly "machine" the slot.

Its noticeable that the casting was left on both sides of the slot, which results in the eccentric stopping at 9 and 3, but seeing as my goal is to only get the eccentric moved to the right location, I didnt care for full rotation.

I filed the material on the furthest side (from the hub) down until the eccentric would rotate essentially 350* as the stop nearest the hub has less room for a file stroke, a dremel would work perfectly here.

Ill post a small 'write up' tomorrow on how to do this. My eccentric now rotates fully from just above 3 to just below 3, on an imaginary clock, and down to the lower area of the arc. The amount removed seems to coincide with the original design.
 

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Discussion Starter #7
Ok so, after putting the rear on jack stands and removing the wheel and caliper. Begin by rotating the eccentric to the top most position so you can easily remove the brake bolts to the rear rotor. Set aside.

Note: This was done to a 748. The 848/1098 series bikes have an empty casting mark that can be used to drill and tap, then relocate the pin about 1 inch towards the hub, however 748-998 did not have this provision.

Looking at the Axle from the non-drive side, the caliper bracket slot will look like this. On these pictures, I had already filed down the right side but I did the left side for sake of a small write up.



Looking at where the file is pointed, you'll notice the slot has a small area near the edge that is not machined, evidently this area is smaller than the diameter of the locating pic and the rest of the slot. What this means is that as you rotate the eccentric, it will 'bottom out' on the slot despite there still being room for movement. The eccentric itself does not have any stops to limit movement otherwise, aside from chain length, etc.



I did not have a dremel or a drill bit large enough, so I went ahead and grabbed a round file and began working the metal down. The goal is to shave enough metal to make the diameter of the edge large enough to allow the pin to slide through as the eccentric follows its arc.

After about 15 minutes of filing, it will look like this. You can use dykem/marking grease to paint the slot and check if and where the pin is contacting. Using these contact points, file in small increments so you have a complete, obstruction free, movement. Taking small amounts will ensure that the slot is not enlarged past its required width.


Final results will allow the pin to move to this location:



Now, your eccentric should be able to turn a full 360* and allow you to move the eccentric to the correct spot. Be sure to move the eccentric to the top position and tighten the brake rotor bolts to 8ft-lb with some loctite before reassembly, once it is in the lower region you cannot access the bolts.
 

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The main reason it was made this way was to keep people from making a mistake and setting it wrong, I still see them assembled upside down every so often so some people try. One of the reasons I would just flip it is that it probably would take less time to do so than to modify a bracket and I cannot think of a need/want to have it upside down.

There are some bikes that get the eccentric flipped as a way to lower a bike and in some cases it does no damage to do so, on these bikes I often see damage from running this way. The swingarm wear on the bottom,lower chain slider as well as the tire hitting the exhaust cans.

I would also double check your torque figures on the rear brake rotor as the factory manual states 25Nm + or - 5% that's much tighter than 8 ft-lbs.
 

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caliper bolts/

using a 3/8" 9" extension the rear caliper mount bolts can be accessed in the correct eccentric position.
 

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Discussion Starter #10
I agree that the stop being there could prevent an inexperienced shop or owner from setting up the bike wrong, however I intend this method to be for someone who has identified the issue and wants to rectify it without disassembly.

I am not the first owner of this bike and unfortunately the dealer I bought it from hasn't been much help, but someone before me installed a quick change, so they probably installed it wrong at that time.

The torque values are for m6 allen heads, 25nm is for the m8. I should have specified, my apologies.
 
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