|   Correct dish on a front 'disc' wheel. | wecked out
Dec 10, 2001 7:54 PM | | I just got a new wheelset and I have a question about the correct "dish" the front wheel should have. Obviously the wheel needs to be built to allow space for the adapter and rotor... and to clear the caliper, but it appears that the wheel is about 1/8 inch off center (to the right) relative to the fork legs. Didn't notice this with my original wheelset. Is this a case of a careless build or is it correct for my new set-up? How does spoke length factor in?
I am running CK disco's with Mavic 317 and a year 2000 Marzocchi Z3 Flylight 100 fork. Thanks for your help! |
| Lookie here.... | Monte
Dec 10, 2001 10:04 PM | | There is a thread over on the brakes page, same thing. The rim is supposed to be centered in the fork. Spoke length doesn't change the way the wheel is centered, or dished to use the correct term. The wheelbuilder will choose the proper spoke lengths and build the wheel with the correct dish so the wheel is centered in your fork or frame. Did someone build the wheels for you? Or how did you buy them?
Monte
http://forums13.consumerreview.com/crforum?viewall@@.ee9c0bc |
| Brake Board.... didn't think to look there | wecked out
Dec 11, 2001 4:55 AM | | but it sounds like I have a similar problem. So what you're saying is the distance from the knurled surface on the hub axle to the rim should be the same so that the rim is centered in the fork. The spokes will be flatter on the rotor side to leave clearance so the caliper body doesn't get into the spokes. Right?
I ordered the wheels from Universal Cycles. It took them a month to get them to me so there is no way in heck I'm sending them back. It was my first and last time using them.
I have a buddy with the tools and know how to move the thing over (I hope)and fix it. Assuming the right spokes are in there. He's never built a disc wheelset before though and didn't know for sure how it was supposed to be. |
| disk wheel dish...... | heff®
Dec 11, 2001 5:15 AM | | .....your rim should be centered between the ends of the axle (or your fork legs). Standard front wheels will be over the middle of the hub, but disk wheels need different length spokes on one side, to compensate for the offset of the rotor. Once the wrong size spokes are used, it's kinda hard to move it over far enough. Depending on the hub, you may run out of thread on the rotor side before the wheel is properly dished.
I'd be concerned if your friend couldn't figure that out on his own.
heff® |
| To fix..... | Monte
Dec 11, 2001 8:32 AM | | If you aren't into building your own wheels, and don't want to send it back to UC, take it to your LBS and have them re-dish the wheel. If it's only off a little, the spokes may be okay. Take the rim tape off and look down at the top of the nipples. How far down is it to the top of the spokes?
Monte |
| Wheel centering in frame | Calvin Jones-Park Tool
Dec 11, 2001 6:12 AM | | The idea of dish or wheel centering is to end up with the rim centered in the frame. Front or rear wheels secure in the frame against the faces of the hub locknuts (ignoring the 20mm axle types). This is why dishing tools check centering using the locknut faces. If your wheel is showing off center when correctly mounted in the fork, it is simply dished wrong. It should center.
Non-disc front hubs usually have both flanges set symmetrically to the locknuts, so the spoke tension is the same on both side. Mounting a disc on the front hub does move the left flange inward. Looking at one disc hub here, the right flange is 20mm from the locknut, but the left flange is almost 30mm from the left locknut. The left side will end up being tighter than the right. Depending upon your exact rim and hub, there may be a 1mm difference is spoke length. However, building both side with only one length will not prove an issue. Simply center the rim in the fork, and tension will take care of itself.
Click here for use of a dishing tool. |
| Bring it over - and we'll check it out. | Fast Freddy
Dec 11, 2001 11:43 AM | | Bring the wheel over and let me see what is exactely going on here.... I have the Park dishing tool (stand, tensionometer, etc.) - to see if it's out and by how much. If the spokes are the right length they will be deep/shallow in the nipples (under the tape- as someone else said). My guess is with the incompetence you've delt with so far the spokes may be wrong lengths. We can pull them out and see... According to my calculations... King Disc hub, Mavic 317 rim, 32 spokes 3x (Wheelsmith) - spokes should be... 262 and 261 (anyone else come up different?) So we can pull it apart and see what's up - my guess is the goobers at Universal used the same spoke on both sides. If that's the case we should be able to fudge it enough to make them right (being that it's only 1mm difference).
Later
Fredman |
| |
