Author Topic: Max height of steerer tube above head tube?  (Read 2820 times)

Phil W

Max height of steerer tube above head tube?
« on: 07 June, 2018, 05:14:03 pm »
I have started building up my warranty replacement frame.

I do not know what height I want the handlebars yet.  So I have got a local bike shop to insert a star nut in the uncut steerer. The intention is then to ride the built bike for a month and move the stem height around  till I decide on bar height.

Other than ugliness quotient is there a maximum height the steerer should rise above the head tube from a safety point of view? I don't intend to leave the steerer uncut forever, just long enough to decide on stem / handlebar height.

citoyen

  • Occasionally rides a bike
Re: Max height of steerer tube above head tube?
« Reply #1 on: 07 June, 2018, 05:20:16 pm »
Is it a carbon or metal steerer? If carbon, you don't want the stem to clamp below the bottom of the bung.
"The future's all yours, you lousy bicycles."

zigzag

  • unfuckwithable
Re: Max height of steerer tube above head tube?
« Reply #2 on: 07 June, 2018, 05:51:44 pm »
recommended height of spacers is ~40mm or less. (for thorn bikes 40cm or less)

Re: Max height of steerer tube above head tube?
« Reply #3 on: 07 June, 2018, 06:01:28 pm »
Is it a carbon or metal steerer? If carbon, you don't want the stem to clamp below the bottom of the bung.

If the shop inserted a star nut, I hope the steerer is metal, not carbon. Otherwise, ask for a replacement fork immediately!

Phil W

Re: Max height of steerer tube above head tube?
« Reply #4 on: 07 June, 2018, 06:18:05 pm »
Steerer is metal

Phil W

Re: Max height of steerer tube above head tube?
« Reply #5 on: 07 June, 2018, 06:18:46 pm »
recommended height of spacers is ~40mm or less. (for thorn bikes 40cm or less)

40cm,  ;D  ;D

Nick H.

Re: Max height of steerer tube above head tube?
« Reply #6 on: 07 June, 2018, 07:20:59 pm »
I have 100mm of spacers. Is this bad? https://s19.postimg.cc/vihuerrs3/steerer.jpg

Re: Max height of steerer tube above head tube?
« Reply #7 on: 07 June, 2018, 07:27:42 pm »
I have 100mm of spacers. Is this bad? https://s19.postimg.cc/vihuerrs3/steerer.jpg
Ummm.....
Interesting link....

Tim Hall

  • Victoria is my queen
Re: Max height of steerer tube above head tube?
« Reply #8 on: 07 June, 2018, 07:40:21 pm »
I have 100mm of spacers. Is this bad? https://s19.postimg.cc/vihuerrs3/steerer.jpg
Ummm.....
Interesting link....
Your flirty steerer makes my head spin.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Nick H.

Re: Max height of steerer tube above head tube?
« Reply #9 on: 07 June, 2018, 07:59:10 pm »
Qué?

citoyen

  • Occasionally rides a bike
Re: Max height of steerer tube above head tube?
« Reply #10 on: 07 June, 2018, 08:04:38 pm »
If the shop inserted a star nut, I hope the steerer is metal, not carbon. Otherwise, ask for a replacement fork immediately!

I assumed it would be metal but thought it was worth mentioning anyway.
"The future's all yours, you lousy bicycles."

Phil W

Re: Max height of steerer tube above head tube?
« Reply #11 on: 07 June, 2018, 09:14:09 pm »
Been through the head tube length, headset stack, stem height, and pretty sure it will be well within 40mm of spacers even uncut.  So looking good on that front.

rogerzilla

  • When n+1 gets out of hand
Re: Max height of steerer tube above head tube?
« Reply #12 on: 09 June, 2018, 05:06:16 pm »
The diameter of the steerer, so 31.8mm, for carbon or alu steerers.  More for steel but no-one knows how much more.  Twice this seems prudent.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Re: Max height of steerer tube above head tube?
« Reply #13 on: 09 June, 2018, 05:20:46 pm »
When sorting out my first Van Nic, Paul Smith (OTP) suggested that the stack shouldn't exceed 50mm - which falls between the above two suggestions.

IanDG

  • The p*** artist formerly known as 'Windy'
    • the_dandg_rouleur
Re: Max height of steerer tube above head tube?
« Reply #14 on: 09 June, 2018, 05:26:19 pm »
My thoughts were (not necessarily right) that if the manufacturer sold you forks of x column length with a certain size frame then the stem clamped at the top should be safe - if that wasn't safe and you had an accident would the company be open to litigation?

My Genesis Equilibrium has an alloy cloumn and there are 3cm of spacers with the stem at the top of the steerer. My Surly Cross-Check with steel column with 5cm of spacers and a 1cm spacer above the stem clamp.

Re: Max height of steerer tube above head tube?
« Reply #15 on: 09 June, 2018, 05:39:59 pm »
When sorting out my first Van Nic, Paul Smith (OTP) suggested that the stack shouldn't exceed 50mm - which falls between the above two suggestions.
In what material?
For steel it's hard to see what would be too much and why, other than aesthetics. 

Phil W

Re: Max height of steerer tube above head tube?
« Reply #16 on: 09 June, 2018, 07:05:07 pm »
I have done some calcs with the head tube length, headset stack, stem height and reckon the stack of spacers will be about 27mm.  So sounds like it will be fine based on what is being said.

Re: Max height of steerer tube above head tube?
« Reply #17 on: 10 June, 2018, 10:00:20 am »
When sorting out my first Van Nic, Paul Smith (OTP) suggested that the stack shouldn't exceed 50mm - which falls between the above two suggestions.
In what material?
For steel it's hard to see what would be too much and why, other than aesthetics.
The steerer, in this instance was ally, the frame Ti.

Nick H.

Re: Max height of steerer tube above head tube?
« Reply #18 on: 10 June, 2018, 11:00:31 pm »
I don't see anything wrong with my 100mm of spacers. Apart from the aesthetics.


Re: Max height of steerer tube above head tube?
« Reply #19 on: 11 June, 2018, 08:59:32 am »
My thoughts were (not necessarily right) that if the manufacturer sold you forks of x column length with a certain size frame then the stem clamped at the top should be safe - if that wasn't safe and you had an accident would the company be open to litigation?

Bare framesets normally come with a generic fork (i.e. not frame size specific) with a very long steerer like this that's well beyond anything you should be riding.

(I've previously raided every bike I own for spare spacers to build up a new frame I didn't want to cut yet)

IanDG

  • The p*** artist formerly known as 'Windy'
    • the_dandg_rouleur
Re: Max height of steerer tube above head tube?
« Reply #20 on: 11 June, 2018, 12:01:49 pm »
My thoughts were (not necessarily right) that if the manufacturer sold you forks of x column length with a certain size frame then the stem clamped at the top should be safe - if that wasn't safe and you had an accident would the company be open to litigation?

Bare framesets normally come with a generic fork (i.e. not frame size specific) with a very long steerer like this that's well beyond anything you should be riding.

(I've previously raided every bike I own for spare spacers to build up a new frame I didn't want to cut yet)

I know frames come with generic forks but what I'm trying to say is that if greater than x mm of stack was dangerous then manufacturers wouldn't sell a frame with a column that was too long for the size of frame for fear of litigation (would they?). I've bought two new frames in the last few years and don't remember there being a warning/disclaimer on the column relating to maximum stack height and risk of accident.


citoyen

  • Occasionally rides a bike
Re: Max height of steerer tube above head tube?
« Reply #21 on: 11 June, 2018, 12:23:13 pm »
I don't see anything wrong with my 100mm of spacers. Apart from the aesthetics.

I can't help thinking that if you need that many spacers, then maybe your frame is the wrong size for you.

But if it works for you, that's all that really matters.
"The future's all yours, you lousy bicycles."

Re: Max height of steerer tube above head tube?
« Reply #22 on: 11 June, 2018, 03:53:41 pm »
It does seem that, in contrast to the 1960s, when the fashion was to ride the largest possible frame (which lead to inverted saddle clips and suchlike), these days the fashion is to use the smallest possible frame, with a 160mm stem is required.

Nick H.

Re: Max height of steerer tube above head tube?
« Reply #23 on: 11 June, 2018, 06:46:49 pm »
I can't help thinking that if you need that many spacers, then maybe your frame is the wrong size for you.

But if it works for you, that's all that really matters.
It's made to measure on a Dave Yates course. It wasn't meant to have that many spacers but I've been indecisive about cutting it because of all the choices of hand positions. It seems to me that for aero reasons the cruising position for a touring bike should be on the drops. Although the drops are really intended for sprints on a racing bike. And everyone cruises on the bar tops or the hoods. Maybe the cruising position has changed over the years because Shimano brifters have become so long that they really constitute bar extensions.

To confuse things further I fitted tri bars. They turned out to be my favourite cruising position...so comfy that I almost doze off. And they could be very aero, but they're probably not because they're too high.

Then there's the safety-in-traffic question. Got to be able to brake instantly. So maybe I need extra brake levers on the bar tops.

I am no nearer a decision.  I need to rethink the entire handlebar question. Maybe dropped bars are not for me.

Re: Max height of steerer tube above head tube?
« Reply #24 on: 11 June, 2018, 07:59:00 pm »
I can't help thinking that if you need that many spacers, then maybe your frame is the wrong size for you.

But if it works for you, that's all that really matters.
It's made to measure on a Dave Yates course. It wasn't meant to have that many spacers but I've been indecisive about cutting it because of all the choices of hand positions. It seems to me that for aero reasons the cruising position for a touring bike should be on the drops. Although the drops are really intended for sprints on a racing bike. And everyone cruises on the bar tops or the hoods. Maybe the cruising position has changed over the years because Shimano brifters have become so long that they really constitute bar extensions.

To confuse things further I fitted tri bars. They turned out to be my favourite cruising position...so comfy that I almost doze off. And they could be very aero, but they're probably not because they're too high.

Then there's the safety-in-traffic question. Got to be able to brake instantly. So maybe I need extra brake levers on the bar tops.

I am no nearer a decision.  I need to rethink the entire handlebar question. Maybe dropped bars are not for me.

There is always the possibility of having less spacers, a shorter steerer and gaining the height with a more angled stem (pointing upwards of course); although, when I tried this idea with a quill mtb stem on the Gitane to raise the bars, it really didn't work for me and now I'm back to the old-fashioned horizontal stem extension.