I installed a new 21in front rim with new chrome rotors on my 07 SG, but the brake padswere so snug on the rotors than it wouldn't turn without A LOT of force. I thought the rotors just needed to be 'worn in' but after a short ride, they got so hot from rubbing they discolored. I switched back to the stock rotors on the new rim and there's WAY less resistance but the wheel doesn't spin freely. any ideas? i used both stock spacers and new chrome spacers as well.(both with the longer spacer on the right side and left)

fyi- The wheel spins normal without the brake calipers installed.

 

Sounds to me that as you attach the calipers to the fork legs and tighten them, they aren't being centered over the rotors, either due to wheel spacers (wheel too far left or right) or caliper mounting. (wheel and rotor pair too wide, or not wide enough)

First, I think you'll have to determine which brake pads on each caliper are hanging up on the rotors so you can decide whether this is a wheel spacer thing, or a caliper thing. If the spacing is wrong, I'd think the same side brake pad on each caliper would be hanging up on the same side of their respective rotor, either to the right, or left. (wheel too far to one side or the other)
You say it spins freely with the calipers off? How about trying each caliper by itself to see if BOTH of them are hanging up. (leaning towards corfirming a spacer issue, providing the same side brake pads hang up in each case)
You might not need to dis-assemble everything to determine this with some judicial use of feeler gauges.

If it's a caliper thing; I'm guessing that as you tighten up the caliper bolts in the fork legs, (moving the calipers outboard on each side as you go) the inner pads in each caliper would try to pull the inside faces of both rotors outboard too far. To my thinking this would require shimming all caliper bolts to move the calipers back inboard to relieve this pressure.

Does this make any sense? I've tried to explain my way of thinking best I can.

CN

 

After re-reading your post; With the stockers, the wheel will not spin completely freely, but rather, the pads will hang up slightly, so what you're seeing going back to the stockers might be normal.

How do the overall widths of the new wheel plus new rotors compare to the stock wheel with old rotors compare? (from outer face of the left rotor to the outer face of the right rotor?)
Are the new rotors thicker than the stockers?
Is the new wheel wider at the hub than the one before?


CN

 

[quote]ORIGINAL: Comfortably Numb

Sounds to me that as you attach the calipers to the fork legs and tighten them, they aren't being centered over the rotors, either due to wheel spacers (wheel too far left or right) or caliper mounting. (wheel and rotor pair too wide, or not wide enough)

First, I think you'll have to determine which brake pads on each caliper are hanging up on the rotors so you can decide whether this is a wheel spacer thing, or a caliper thing. If the spacing is wrong, I'd think the same side brake pad on each caliper would be hanging up on the same side of their respective rotor, either to the right, or left. (wheel too far to one side or the other)
You say it spins freely with the calipers off? How about trying each caliper by itself to see if BOTH of them are hanging up. (leaning towards corfirming a spacer issue, providing the same side brake pads hang up in each case)
You might not need to dis-assemble everything to determine this with some judicial use of feeler gauges.

If it's a caliper thing; I'm guessing that as you tighten up the caliper bolts in the fork legs, (moving the calipers outboard on each side as you go) the inner pads in each caliper would try to pull the inside faces of both rotors outboard too far. To my thinking this would require shimming all caliper bolts to move the calipers back inboard to relieve this pressure.

Does this make any sense? I've tried to explain my way of thinking best I can.


Yeah bro, this does make sense. The outside of the rotors are rubbing evenly, as per the wear marks on the new rotors, but the insides of both rotors are only wearing halfway. Shimming sounds like it should fix the problem. I did try one caliper at a time and the single caliper did bind it up. Thx!

 

[quote]ORIGINAL: Comfortably Numb

After re-reading your post; With the stockers, the wheel will not spin completely freely, but rather, the pads will hang up slightly, so what you're seeing going back to the stockers might be normal.

How do the overall widths of the new wheel plus new rotors compare to the stock wheel with old rotors compare? (from outer face of the left rotor to the outer face of the right rotor?)
Are the new rotors thicker than the stockers?
Is the new wheel wider at the hub than the one before?


CN
[/quote

i was thinking the new rotors were a bit wider but according to the manufacturer, the specs are exactly the same as stock. i do know that installing the new or stock rotors onto the new rim was a B*tch to get off and put on once all the bolts were removed...they were on so snug i thought they were glued on!

 

You have got a big problem that you need to work out. I am doing a bike right now and I will take photos of how to do it. You need to hang on a few hours and under no circumstances ride a bike in that condition. I will try and get back to you this evening with a how to w/photos.

I am converting this 1967 FL over to 2X disk rotors/calipers & trying to keep it some what stock looking. This is the before photo.


[IMG]local://upfiles/29413/DE3CCF5958BD4C719C1E5F998242C27C.jpg[/IMG]

 

there are a couple issues that may be happeing. Either your wheel spacers are slightly off, or you need to shim your calipers. if the measurement from face to face of the aftermarket rotors compared to your stock set up, chances are your hubs are fine. when dealing with dual disk set ups, the hub offsets are critical. if the rotor offsets are the same, you will need to check your wheel spacing, since you mentioned that you switched to chrome spacers. if those are the same, you will need to shim your calipers to center them on the rotors. let me know if you need more help. call me if necessary. good luck

 

Here is how to do it. I just did it on the 67 FL listed above.
I took a set of stock 67 triple trees so I could retain the stock tins & look. I am not a big fan of modifying a classic like Frankenstein, however,due to the drivers in Ft. Lauderdale, drum brakes are not an option. This is how I did this one.

NOTE* {When making designing and making my inverted front ends, we used a surface table and gauges to measure} You can use whatever method you have available to determine : [ol][*]The wheel (width from outside sealed bearing to outside S.B.}[*]Measure the hub width from flange to flange[*]Measure what thickness rotor you are using & yes, they are different[*]Mount both rotors & measuring outside to outside with a Veneer (caliper).[*]Take the total outside to outside measurement than minus the hub width. The answer is total rotor width.[*]Add the hub width to ½ both rotor thicknesses.[*]align the front wheel as per instructions on my site [HERE].[*]Mark the exact center of each caliper via tape & a “sharpy” . you may than use that center mark to center the thickness of the rotor (as shown in the photo).[*]With the front wheel properly aligned,[*]Make spacers by measuring between the two forks by:[*]See the photo as I uses a thinner (known length) spacer to help with the measurement.[*]Measure to the wheel bearing on either side of the fork (see Photo). NOTE* your front wheel must stay alighned, it is in a fixed position. (This is excluding some models like the 07 Softail where an offset was built in and than corrected in 08)[*]Your wheel must be aligned (see not above) if you want your bike to track straight and handle properly.[*]Install the calipers with the rotor center marks in view.[*]Shim or mill the calipers to the center of the rotors when mounted. [/ol]If you can not do this, you may wish to get someone who can.

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