Ok humour me on this one for a bit. Is there any difference between the material used for a seatpost and that for a steerer tube? I need a 1" steerer tube for a pair of forks with a bolt in crown. The old steel tube is basically a straight piece of tube with a groove for a spring clip and it is threaded. I tried to get a new tube from a frame builder but its coming in around £30 which for that money could buy a pair of forks and cut of the steerer, though it feels like any awful waste of a pair of forks. I next thought of using a 25.4 mm seat post which for some reason don't feel as bad about chopping up, so the question is is there any reason not to do this? I also could machine a bit of pipe to the correct size but it would probably weigh a ton. Any thoughts or insights or ridicule welcome :roll:
Seatpost for a steerer tube
- Thread starter kaiser
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kaiser":1mvsjsaa said:
I would have thought that the old steerer tube wasn't just a straight 1" diameter over the whole length but surely has a section at the fork crown end which is machined to be a press fit inside the inner race of the lower bearing? If you have machining facilities then you could, of course, make one from scratch - from either a length of 4130 if you want a steel steerer tube or something like 6061 T6 or 7075 T6 for an alloy version. In other words, not just a bit of pipe........
Either will cost you a lot more than £30 in materials and time though, and I would have thought that trying to source a genuine replacement steerer was a better option. What make/model of forks are they?
If I were you (and I was still working in the engineering industry and therefore had the facilities) then yes, I would source some suitable material and make one - I don't think I'd use a seatpost though.
Cheers Andy. Part of the problem was going to be sourcing a piece of the correct material, thus the seat post :idea: . The fork is an anti gravity one which I think is basically a tange shock blade so not exactly an abundant amount of spares especially when looking for an 1" threadless tube :? The tube pretty much is just a straight piece of tube with a machined crown to give the rake.
Well. the seatpost idea (steel or aluminium ?) is probably fine as far as the material spec. goes - after all, the loading on a long seatpost is probably as high as on a steerer tube, and the consequences of failure almost as unpalatable :cry: :cry:
If the original tube is actually a constant 25.4mm dia. for its whole length then that makes it easier, but are you sure that it isn't reduced after where the crown race fits? (Otherwise the race would have to be pressed on over the whole length of the steerer....)
Of course, if you have access to cylindrical grinding facilities then you could easily deal with this too.
BTW - is the new steerer going to be threadless?
Another thing to consider is the wall thickness of the tube you intend to use - is it sufficient to allow machining the groove for the locating circlip?
Get the bore gauges or verniers out and check this on the old tube to make sure.
If the original tube is actually a constant 25.4mm dia. for its whole length then that makes it easier, but are you sure that it isn't reduced after where the crown race fits? (Otherwise the race would have to be pressed on over the whole length of the steerer....)
Of course, if you have access to cylindrical grinding facilities then you could easily deal with this too.
BTW - is the new steerer going to be threadless?
Another thing to consider is the wall thickness of the tube you intend to use - is it sufficient to allow machining the groove for the locating circlip?
Get the bore gauges or verniers out and check this on the old tube to make sure.
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Hi kaiser,
bit of a tangent here :roll: but...............
Windwave (marzocchi service agents) sell specific steerers 1'' and 1 1/8.
Okay they dont have the reinforcement/support ring at the bottom but from memory are only about £17.50 :?
Just thought I would mention it in case
Mark
bit of a tangent here :roll: but...............
Windwave (marzocchi service agents) sell specific steerers 1'' and 1 1/8.
Okay they dont have the reinforcement/support ring at the bottom but from memory are only about £17.50 :?
Just thought I would mention it in case
Mark
South Bound
Senior Retro Guru
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Surely there is enough chopping and changing of Pace steerers to throw up a 1" that you can slap in there??? Justbackdated must have one kicking around???
Cheers folks
SB somewhere in the midsts of time I'm sure justbackdated offered to help me and I've forgotten will be my first port of call
LMTTM top tip should JBD be unable to sort us out
dyna-ti already have an 1" rigid fork sitting but for some reason can't bear to cut it up for a steerer :roll:
SB somewhere in the midsts of time I'm sure justbackdated offered to help me and I've forgotten
will be my first port of callLMTTM top tip should JBD be unable to sort us out
dyna-ti already have an 1" rigid fork sitting but for some reason can't bear to cut it up for a steerer :roll:
