Spacers under the stem

[cnw20]

Recently picked up 2010 Classique Ti - oh yea, love it! I was riding a Fuji Touring and got used to a more relaxed geometry so I moved all of the spacers (about 5) under the stem on my Chris King - is this OK?

[Bruce K]

Depends on total thickness of spacers and what kind of fork you have

BK

[Mike748]

Which fork do you have and how tall are the spacers?

[AngryScientist]

Is the fork steerer carbon or alloy? A positive rise stem might be another good option.

[cnw20]

I have S3 forks and the stack of spacers under the stem total 1 inch

[dave thompson]

1" of spacers? You're good, no issues.

[Bruce K]

I believe that common practice for most carbon steer tubes is 40mm of spacer maximum.

You are at 25mm so you've got room "to grow"

BK

[FastforaSlowGuy]

Stupid question perhaps, but what happens if one exceeds the max? Is it a structural thing (too much leverage too high on the steerer tube = breakage) or is it flex and responsiveness?

[rwsaunders]

The number and placement of spacers does have an effect on the fatigue life of an aluminum steerer tube. Running less than 5mm of spacers under the stem can concentrate or "point load" a great deal of stress in one spot on the steerer. Therefore, Bontrager recommends a minimum of 5mm, and a maximum of 40mm of spacers between the stem and the headset to maximize the fatigue life of the steerer.

Scott Daubert Trek Bicycles

[gearguywb]

Stupid question perhaps, but what happens if one exceeds the max? Is it a structural thing (too much leverage too high on the steerer tube = breakage) or is it flex and responsiveness?

You nailed it. Particularly with carbon steer tubes you can end up with far too much leverage (weight) on the tube causing a potentially hazardous situation.

[cnw20]

I assume it's OK to stack spacers or is it better to get 1 or 2 larger ones? Thanks for all the info.

[soulspinner]

I assume it's OK to stack spacers or is it better to get 1 or 2 larger ones? Thanks for all the info.

Doesnt matter................long as u dont exceed the max by fork manufacturer.

[biker72]

I assume it's OK to stack spacers or is it better to get 1 or 2 larger ones? Thanks for all the info.
My own personal preference would be one.
Trek has had a number of service bulletins out about carbon steerer tube failures on their Madones. The alloy steerer tubes are much more durable.