Bicycle Mechanics - threadless 853 steerer tube, star fangled nut?
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12-06-10, 09:38 AM
I have a frame to build up, the fork has a steel 853 steerer (1 1/8) as the title suggests, I have a few star fangled nuts laying around but they don't stay-put cause of the thinner tube, likewise a compressor plug cannot be expanded enough to grab on, is there a special plug or insert made for these steerers, where can I find something that will work? thanks for any leads
12-06-10, 09:52 AM
How about a ring of rubber tape inside the steerer, say, wrapped around the expansion plug?
the actual tension needed to adjust the pre-load on the headset is not much.
when you tighten the stem around the steerer tube
the top cap , and the bolt thru it, ... it's job is done,
until next adjustment.
You could buy a BBB BHP 21.
It's a quill based stem riser, wedge secured,
inside the steerer tube,
but it can also be buried inside the whole steerer,
by leaving off the shim spacer set..
I got one for the too short a steerer problem,
but was impressed by its potential versatility.
wedge bolt is internally threaded at the top, inside the 6mm hex
to accept the common M6 bolt, to adjust the headset as usual.
12-06-10, 09:53 AM
Hi, if the lbs doesn't have one, maybe use 1 1/4" or go to a furniture repair store. I was told as this is what they use for the feet of the couches ext to adjust the legs and should have a lot of different sizes.
12-06-10, 10:18 AM
There are different star nuts for aluminum and steel steerers. I'll bet you have one for aluminum steerer, as I din't think there is alot of variation between tube wall thicknesses of different steel steerers. Is the inside diameter of your steerer 25.4mm?
Yeah, that can be and issue with those steerers....also with the True Temper MSDLT lightweight 1 1/8" steerers. They only have a wall thickness of 1.1 mm at the top, as apposed to the 1.6mm of a typical steel steerer, so the ID of the steerer is quite a bit larger than normal. What has worked for me is to "spread" the "fingers" on the star fangled nuts out farther. I flip one upside down on a hard flat surface and hit the threaded center section with a hammer, which flattens out the top "finger" section a little.....pushing them out farther. For bottom section, I slide it between a notch cut out of a piece of steel plate and hit it again, rotate it and then hit it again, so all of the fingers are even. I don't flatten them out completely, but only enough to spread the fingers enough for a firm seating into the steerer, etc.
12-06-10, 12:53 PM
Different nuts will likely be different enough that if you take your fork into a couple of LBS's you'll almost certaily find one that fits and grabs well. And if you can't get one that actualy fits correctly then get the closest you can find and slightly flatten the petals out a bit before inserting to get more bite. I'd also suggest that you use the correct tool if you didn't on the first one. Otherwise the typical angle correction as it goes in from using makeshift tools might have bent the petals too much and now it isn't biting correctly.
Lardasse, I agree with the issue between steel and aluminium start nuts. But aren't the aluminium ones so small that they would rattle in a steel steerer? I know the one time I checked this would have been the case.
12-06-10, 01:14 PM
Most expansion plugs are made for carbon steerers with thick walls but Profile Designs makes (or made) one for steel steerers, albeit with 1.6 mm wall thicknesses. However, mine looks like it would expand enough to work with a thinner wall steerer and could be shimmed to fit if needed.
12-06-10, 02:18 PM
If you get the steering tube to a length that you're not likely to change, then you can glue in an expanding plug. I've even made my own glue-in plugs from some epoxy putty and an M6 thread insert.
12-06-10, 06:59 PM
Dave A: I thought about trying that actually, but figured it would be difficult bending the bottom ones evenly enough, maybe I'll have a go at that though. This is a TT bike so I dont think I'll ever be that aggressive on the bars to worry about anything.
The s-fangled nuts I have are for steel steerer, but as mentioned the wall thickness of these tubes are only about 1mm. I dont have digital calipers but it looks like the inner diameter is around 25.8.
12-06-10, 07:22 PM
I like the 'If the steerer is the right length".. ..Then a plug that is bonded in will work..
A Loc Tite product could be used to put an aluminum plug in, and given Loc Tite breaks down when heated
If removal is needed, it's possible, which is more difficult with Epoxy.
anyone with a lathe can turn a plug down to fit , and M6 thread the inside of the plug
for the pre-load adjustment bolt. for a Time trial bike It will be light and simple.
12-06-10, 11:08 PM
DONT HAMMER A 1 1/8 star nut to flatten out the fingers.
or try to shim a compression plug, lol.
just use a 1 1/4 nut and be done with it.
12-07-10, 07:32 AM
Or you can leave out the nut entirely - set the bearing preload with some other method (a long bolt and some washers, or a mallet), clamp the stem and leave the hole open. You can tell people it is a view-port to check wheel alignment or something :D
12-07-10, 11:04 AM
.....leave the hole open. You can tell people it is a view-port to check wheel alignment or something :D
If it's a carbon bladed fork with the steerer closed at the bottom, you can stick a straw into it and use it as a water bottle.
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