Distance between top bearing and the stem
Moderators: Bearbonesnorm, Taylor, Chew
Distance between top bearing and the stem
Iv put new forks on the camino, and i want to leave the steerer fairly long that way if i ever change my mind and sell the forks are more use to someone else ( AND IT KEEPS MY FRONT END A BIT HIGHER ) iv got 55mm of spacers though is this abit excessive or ok
The fork website says max 30mm spacers
Does it really make much difference to the leverage on steerer etc?
The fork website says max 30mm spacers
Does it really make much difference to the leverage on steerer etc?
- Bearbonesnorm
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Re: Distance between top bearing and the stem
Carbon steerer?
May the bridges you burn light your way
Re: Distance between top bearing and the stem
I don't pay too much attention to these things, it will be fine.
Even if we assume they somehow calculated the 30mm they would have to use the worst case figures and then apply a factor of safety to allow for manufacturing tolerances. So they would have assumed say a 20+ stone rider battering down a potholed alpine descent for hours.
Given most of the fork manufacturers recommend about the same max height of spacers I think they just pick a figure that looks about right.
Even if we assume they somehow calculated the 30mm they would have to use the worst case figures and then apply a factor of safety to allow for manufacturing tolerances. So they would have assumed say a 20+ stone rider battering down a potholed alpine descent for hours.
Given most of the fork manufacturers recommend about the same max height of spacers I think they just pick a figure that looks about right.
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- Bearbonesnorm
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Re: Distance between top bearing and the stem
Don't listen to Sean. It seems quite obvious that while 30mm will result in every ride being ridden through sunny, flower covered countryside, 31mm will result in a certain and painful death ... don't say I didn't warn you.
May the bridges you burn light your way
- Cheeky Monkey
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Re: Distance between top bearing and the stem
Try 30mm of spacers below and 20mm above stem?
I have an enormous stack of spacers on the Gryphon (all below the stem) and haven't died yet.
I have an enormous stack of spacers on the Gryphon (all below the stem) and haven't died yet.
Re: Distance between top bearing and the stem
Of course if you follow "The Rules" then #45 applies
A maximum stack height of 2cm is allowed below the stem and a single 5mm spacer must always – always – be stacked above. A “slammed down” stack height is preferable; meaning that the stem is positioned directly on the top race of the headset.
I've had 35mm under my stem and 10mm on top with a carbon steerer and survived.
A maximum stack height of 2cm is allowed below the stem and a single 5mm spacer must always – always – be stacked above. A “slammed down” stack height is preferable; meaning that the stem is positioned directly on the top race of the headset.
I've had 35mm under my stem and 10mm on top with a carbon steerer and survived.
Adventure without risk is Disneyland - Bikemonger
Re: Distance between top bearing and the stem
Rode with this for a couple of years without problem.
Uncut Reba on ti Stooge.
P1150534 by michaelwex10, on Flickr
Waiting for another ti frame and will probably just rebuild to same set up but with a 120mm Reba.
Uncut Reba on ti Stooge.
P1150534 by michaelwex10, on Flickr
Waiting for another ti frame and will probably just rebuild to same set up but with a 120mm Reba.
Zazen - nothing happens next this is it.
- In Reverse
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Re: Distance between top bearing and the stem
I ran a carbon steerer with about 40mm of spacers on the Spanish C2C and didn't die Mike. Don't even think I fell off.
edit: I did fall off thinkiing about it - I went otb about 2 minutes after we set off from the airport.
edit: I did fall off thinkiing about it - I went otb about 2 minutes after we set off from the airport.
Re: Distance between top bearing and the stem
Well just taken the camino out with the new lauf true grit sl fork on and its made such a difference to what was a super harsh ride over roots n rocks into a very enjoyable ride with no achy wrists or arms on my return. Iv been fighting them off for awhile as i thought they looked ugly..... but actually i think they look mint on the ti
Re: Distance between top bearing and the stem
Don't worry, that's just confirmation bias. They still look ridiculous
I'm sure they're more comfy though!
I'm sure they're more comfy though!
Re: Distance between top bearing and the stem
The problem I have with that setup is the spacers above the stem. Assuming you're using the correct bung, the bung is designed to pop into the steerer at the same level as the stem, then when tightened to tension the headset, the bung expands inside the steerer. This gives the stem a solid piece of steerer to clamp onto. With that amount of spacers the stem will clamp onto a hollow part of the fork and the bung will expand into an unsupported piece of steerer. Have you checked the steerer for cracks?In Reverse wrote: ↑Tue Nov 05, 2019 2:04 pm I ran a carbon steerer with about 40mm of spacers on the Spanish C2C and didn't die Mike. Don't even think I fell off.
edit: I did fall off thinkiing about it - I went otb about 2 minutes after we set off from the airport.
- Cheeky Monkey
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Re: Distance between top bearing and the stem
But the bung is just to pre-load the bearings so if you've whanged it that tight (to split a steerer) shirley operator-error
- stevenshand
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Re: Distance between top bearing and the stem
I thought the same but after re-reading, I think the point he's making is that the bung provides additional support for the steerer when the stem is tightened. In this example, there is no bung at the same point the stem is clamping the steerer.Cheeky Monkey wrote: ↑Tue Nov 05, 2019 4:43 pm But the bung is just to pre-load the bearings so if you've whanged it that tight (to split a steerer) shirley operator-error
FWIW, I think the notion that the steerer is designed to have a bung in place to handle the (over)tightening of the stem is bunkum.
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Re: Distance between top bearing and the stem
Carbon steerer.
Something inside the stem pushing the tube outwards just above something outside the stem pushing the tube inwards.
I wouldn't.
But then I'd also not ride a bike that fitted so badly I needed all those spacers....
Something inside the stem pushing the tube outwards just above something outside the stem pushing the tube inwards.
I wouldn't.
But then I'd also not ride a bike that fitted so badly I needed all those spacers....
Re: Distance between top bearing and the stem
The bike fit is fine, im just leaving the steerer longer so if i ever sell the fork im not limiting my sale to just short arses like me
- BigdummySteve
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Re: Distance between top bearing and the stem
Another option is the woolftooth headset
https://www.wolftoothcomponents.com/pro ... d-standard
I have one on the Fargo in the 25mm stack height, gets rid of a few spacers and looks like it would spread the load better.
Also very nice headsets
I’m not convinced that a stack of spacers means a badly fitting frame, low front ends may be great for speed but maybe not so good for comfort.
As an additional temptation I’ve just this moment received an email from woolftooth announcing limited edition nickel components
Would look mint on a Ti frame
https://www.wolftoothcomponents.com/col ... f1c9250d2d
https://www.wolftoothcomponents.com/pro ... d-standard
I have one on the Fargo in the 25mm stack height, gets rid of a few spacers and looks like it would spread the load better.
Also very nice headsets
I’m not convinced that a stack of spacers means a badly fitting frame, low front ends may be great for speed but maybe not so good for comfort.
As an additional temptation I’ve just this moment received an email from woolftooth announcing limited edition nickel components
Would look mint on a Ti frame
https://www.wolftoothcomponents.com/col ... f1c9250d2d
Last edited by BigdummySteve on Tue Nov 05, 2019 10:44 pm, edited 2 times in total.
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- fatbikephil
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Re: Distance between top bearing and the stem
A large stack of spacers below your stem is a sign of age and wisdom - you want a nice comfy riding position which also allows to to negotiate harum scarum descents without fear of face plants
Re: Distance between top bearing and the stem
To be fair it is unlikely you will ever ride a childs bike and that is the only wqy you would ever need that many spacersBut then I'd also not ride a bike that fitted so badly I needed all those spacers..
Re: Distance between top bearing and the stem
In fairness you did try a no-handed bunnyhop whilst taking a pictureIn Reverse wrote: ↑Tue Nov 05, 2019 2:04 pm I ran a carbon steerer with about 40mm of spacers on the Spanish C2C and didn't die Mike. Don't even think I fell off.
edit: I did fall off thinkiing about it - I went otb about 2 minutes after we set off from the airport.