when to cut a new steerer
 

I'm finishing up a build of a new frame, and the steerer is uncut. I don't want to cut it too short and have to resort to a stem that rises to make the cockpit correct.

I think I've got the spacers correct, using another bike that fits well as a measuring guide, but the new frame has a sloping top tube so I'm not certain about the fit until I ride it.

Seems reasonable that I tighten the stem bolts to spec, and then ride it with the steerer uncut to check the fit. Once it's good, then mark it and cut the steerer.

I guess I'm asking if riding it without the plug in place inside the steerer is OK, for just a short while to check the fit.

2 years of riding and shuffling spacers to try different heights after long rides over weeks..

Put more spacers over the stem to try out lower bar heights ..

I got a used bike it was a challenge to get it high enough with a sawn off short fork.

they dont grow back.



Threadless once the stem is tight , after setting the HS pre load, the cap bolt has done its job until the stem is loosened.




..

I'll usually suggest about 1cm more steerer then what takes to get a nice fit. Use spacers above the stem as needed. After a long time some might take that cm off but two of my bikes still have that 1cm stack above the stem and about 10,000 collective miles. I can't say that any of those miles were hampered by the extra steerer and spacers. Andy

Without the plug (carbon steerer?) or a starnut you won't be able to adjust the headset properly so you will either have to improvise the adjustment or place a stack of spacers above the stem to let you use the plug or a temporary starnut. Once you determine the right height, remove the plug or drive the starnut down and cut the steerer to length.

BTW, I recommend leaving the steerer long enough to require a 5 or 10 mm spacer above the stem after the final length cut. That assures the stem is fully supported by the steerer (highly recommended for a carbon steerer) and gives you some height adjustability for future changes.

That's why I'm asking - I want to give myself the best chance to get it cut correctly - and most importantly, not too short.

Yes, I'll have to improvise the initial adjustment until the plug is in place. I plan to have a spacer above the stem.

ride a lot first .. a touring ride needs comfort more than speed.. I like tall, I had to add a stem raiser..
because fork was pre cut , short ....

http://www.cyclofiend.com/working/im...-1P1010007.jpg

you never said what kind of riding goals you had in mind.

This is exactly what I'm trying to avoid. This is my go-fast bike, not touring or riding trails.

Yes. I would do that. Last time I built a drop bar frame it was a Salsa Fargo. I ran it with two to three inches of spacers for a few days. It looked crazy :thumb:. I put a star nut in, threw on the stem and all those spacers, and rode the bike and played with stem height until I felt good about it. Then I cut the steerer, which got rid of the old star nut, set a new star nut, and I was good to go.

Edit: I realize now that you might have a carbon fork. I lack experience w/those, but am pretty certain I'd want the expansion plug in place where it would support the stem clamp.

The expansion plug supports the stem. I would not tighten the stem without the expansion plug in place. It is very easy to crush the steerer to the point where the carbon delaminates and cracks.

People are free to make their own choices but please watch this video before you decide. At least watch the first two minutes.

Well, it seems a better idea is to cut the steerer 10-15mm above where I think the final cut will be, insert the plug, and use spacers to position the stem. Clamp it down and check the fit. Move spacers from below to above the stem to lower it and repeat until the fit is good. Then allow for a 5mm spacer above the stem, and cut the steerer 1-2mm short of the top spacer to allow for the compression cap.

When I ordered my Airborne (years ago), I did not think of requesting that the steerer be left a bit long. An extra couple of centimeters would have been nice to allow for changes in stem geometry as I get older and less flexible. :eek:
So far so good though! :D
Steve

Cut it down enough so you're within 2cm of what you think your final height will be and cut/install from there. If you think you'll need more steerer than that, I'd suspect you bought the wrong bike/size....

When I ordered my Litespeed frame, fork and headset package deal from Colorado Cyclist in 2006 I specified that the steerer was to be left full length and I would cut it to size when I completed the build. I had to argue with the order taker quite a bit to convince him I really wanted it that long and that I knew what I was doing. He was afraid I'd leave the steerer (1-1/8" carbon) dangerously long as Easton's maximum recommended spacer stack under the stem was 50 mm. I assured him I wouldn't need that much.

Mine is a steel steerer... the fork is actually a Co-Motion Americano fork, made of Cr-Mo. I thought it would ride like a truck, but it's actually quite compliant. :)
Steve

Ride it with the plug for sure. You should be able to install the plug and remove it later - or get a $10 non-star plug that just expands that is easier to remove. The manual for my new Specialized with a carbon steerer says:

"Warning! Do not install more than 40mm (1.5") of stack height of headset spacers" and "Do not permanently place stem spacers above the stem [...] defeats the purpose of the expander plug's ability to support the steerer tube and stem."

An inch and a half is quite a lot of wiggle room. I'm basing my measurements off my old bike and will probably ride with a couple spacers above the stem for a week or so to get the fit right.

Nice bike. What do you call that kind of handlebars? I can't tell but it looks like there's a full semicircle on each of of the bar. Maybe those are trekking bars with extra gear attached?

That's pretty tall! :eek:

an ITM product, butterfly/trekking bar in 4 parts, 2 D shaped wings,

a yoke to hold the two, and where the stem grips the whole thing,

and a T to fit the bar bag mount, if you wanted it that high up.

It's not silent.. creaks a bit.



:innocent:

standover clearance to the top tube is just right..




.....

I cut it 1", Oh! I'm sorry, I meant 2.5 cm longer than what I normally ride (as far as effective handlebar position not steerer length) , and after a season, and fine tuning, make the final cut.

Thank you very much! That must be the same one you mentioned here: https://www.bikeforums.net/17728280-post10.html

http://www.rodbikes.com/catalog/6-pa...erfly-bars.jpg