Bicycle Mechanics - Fixed wheel is slipping forward on the drive side

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alexgate
10-04-09, 02:21 PM
No matter how tight i tighten my wheel, it keeps slipping forward on the drive side. I did a quick search and came up with nothing. This happens in as little as half a mile into a ride. The problem started out as going up steep hills the wheel would completely torque to one side and start rubbing against the frame. My bike mechanic just joked around and said you are a beast. This happened twice. Any help is appreciated.
http://img21.imageshack.us/img21/2826/picture1585.jpg
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http://img7.imageshack.us/img7/8641/picture1583.jpg
http://img74.imageshack.us/img74/3892/picture1581.jpg
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There's a reason track hubs have traditionally been bolted on with 10mm fine threaded nuts. Holding power. The shallow ramp angle of a 10x1 thread ensures a compression force of nearly 30 times the torque, or almost double that of a 6mm thread. Combined with the higher maximum torque of 10mm hardware the system assures a solid mounting.
If there's a way to replace your axle set, I suggest you consider going to a traditional solid axle system. Otherwise look for a hardened steel serrated washer with sharp points which will bite into the dropout and hold with the lighter compression force of the hex cap screws.
griftereck
10-04-09, 02:51 PM
chain tensioners maybe hold the wheel from moving forward
what kind of skewer is that?
honestly, it doesn't seem strong enough to hold the wheel in place along hardened steel.
if you can use a QR with that wheel, try a shimano closed cam QR with it.
Bianchigirll
10-04-09, 03:00 PM
I don't think it is a skewer. I think it is two allen bolts that thread into the axle.
alexgate
10-04-09, 03:23 PM
Yes it is two allen bolts threaded into the axel. Currently I do have serrated washers on the wheel, although it may be hard to see in the poor quality pictures. This is the wheel if it is any help.
http://www.amclassic.com/products/roadwheels/420track.php
let me know if there is any other info or pictures needed. Thank you for the the help so far.
Traditional track nuts are better. Get better serrated washers or go old school and add Chain Tugs. Those allen bolts don't look like it's applying enough pressure on the entire surface of the washer, just the center. Wouldn't be surprised if the washer was concave in the middle. would have to add 2 flat washers of different diameters (same size, smaller washer, then allen bolt) to get more even pressure and gripping power if you stay with the allen bolts.
alexgate
10-04-09, 03:28 PM
Traditional track nuts are better. Get better serrated washers or go old school and add Chain Tugs. Those allen bolts don't look like it's applying enough pressure on the entire surface of the washer, just the center. Wouldn't be surprised if the washer was concave in the middle. would have to add 2 flat washers of different diameters (same size, smaller washer, then allen bolt) to get more even pressure and gripping power if you stay with the allen bolts.
Thank you I will go to the hardware store and see what I can round up.
How hard would it be to switch to a traditional track nut?
operator
10-04-09, 03:53 PM
There's a reason track hubs have traditionally been bolted on with 10mm fine threaded nuts. Holding power. The shallow ramp angle of a 10x1 thread ensures a compression force of nearly 30 times the torque, or almost double that of a 6mm thread. Combined with the higher maximum torque of 10mm hardware the system assures a solid mounting.
If there's a way to replace your axle set, I suggest you consider going to a traditional solid axle system. Otherwise look for a hardened steel serrated washer with sharp points which will bite into the dropout and hold with the lighter compression force of the hex cap screws.
Wow wtf, did you even look at the pictures? It shows a giant serrated washer on top of a bolt. The slick chromed/stainless dropout surface of the OP's bikes dropouts don't help in holding power - are the inside locknuts facing the dropout serrated? If they're not that's another thing you can try.
operator
10-04-09, 03:56 PM
Thank you I will go to the hardware store and see what I can round up.
How hard would it be to switch to a traditional track nut?
At least requires changing the axle since your hub was designed to use allen bolts. Track nut style hubs use solid axles which you don't appear to have. Could you place take the wheel out, remove the bolts and shows us the locknut face that would be pressed into the side of your dropout if the wheel was attached?
From the picture it looks like a silver type washer that wouldn't be serrated. I hate to admit that you might actually need to install a chain tug on the driveside if nothing works.
roadfix
10-04-09, 03:58 PM
I would install a chain tug on the drive side.
JohnDThompson
10-04-09, 09:26 PM
Wow wtf, did you even look at the pictures? It shows a giant serrated washer on top of a bolt. The slick chromed/stainless dropout surface of the OP's bikes dropouts don't help in holding power - are the inside locknuts facing the dropout serrated? If they're not that's another thing you can try.
Those look like cheap stamped serrated washers; they may well be to soft to bite into the stainless steel dropout faces. IMO the OP should try and find some quality track nuts with captive washers. These seldom have problems holding the wheel securely. The OP would have to replace the current axle with a longer one in order to use track nuts, though.
fuzz2050
10-04-09, 10:59 PM
Ok, here's a thought. Reputable manufacturers, like Phil Woods and American Classic wouldn't make a product with such an obvious failing. There must be a way to get them to work.
Now think of this, how long is your average 15mm box wrench? A good 10 inches or so, at least.
Your average 6mm allen wrench? You lucky if you have 3 inches or so. You need more torque, and a bigger wrench.
chummdizzle
10-05-09, 01:21 AM
+1 on the chain tensioner. These are only $11 and come in pairs for both sides
http://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=105
Next time buy a decent hub with a threaded axle for bolts. I can't imagine why that hub has a bolt on skewer.
Funny thing, I was looking at a motorcycle next to me at a traffic light today. Yamaha R1000 I think. Anyways, it has horizontal drops and a chain tensioner on the rear axle.... thought that was pretty cool.
chummdizzle
10-05-09, 01:23 AM
wait a second. Is that an AC wheel? is it the stock AC hub? whats going on?
Get a set of proper track nuts and a set of MKS tensioners. Problem solved.
joejack951
10-05-09, 07:11 AM
What is the recommended torque spec for the bolts on that hub? What torque are you using? If you don't know, that's likely where your problem lies.
due ruote
10-07-09, 10:12 AM
Sorry if this is too obvious but are you sure you have a short enough length of axle showing on the drive side? If the axle extends all the way to the outside edge of the drop it won't matter how much you torque down the nut.
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