gkamieneski

I have been looking at these new carbon frames with tapered carbon head tubes and steerers. Often these bicycles are shown with quite a bit of steerer below the stem taken up by spacers.

For me, I need 9cm of drop between the top of the nose of the saddle and the bars. The last carbon fork I had, had an alloy steerer and I cut it to size after deploying a conical shaped carbon spacer to get the bars to the right height. Are these current models, particularly those delivered through mail-order, coming without their steerers cut and with variable spacers to move the stem up and down. It used to be suggested that you leave enough room when cutting a carbon steerer to be able to place a spacer on top of the stem before pre-loading with the star nut cap.

On the other hand, for frames purchased at the LBS, is the LBS cutting the steerer and using the appropriate spacers to get the rider the correct fit?

AnkleWork

No doubt, they do.

HillRider

For frames and forks purchased at an LBS, you can certainly specify how the steerer is to be cut. For a mail-order purchase of just a bare frame and fork, no headset, the steerer is probably left full length and sizing it is up to the purchaser. For a mail-order complete bike, who knows, and you better ask before ordering.

fietsbob

1) They Dont grow Back.. If you want the stem lower , take some spacers from under the stem and put them above the stem.
think long and hard before sawing off steerer tube.. see Number 1 again..


Cartoned bikes get the fork cut to a sizing Formula, before they are shipped across the Sea, to Distributor's warehouses.

alcjphil

Most pre built bikes have the steer tube cut to the maximum recommended height. If you need the bars higher, you flip the stem, it that isn't hight enough, either you should be looking at a frame with a higher head tube or you change to a stem with more rise. If you need the stem lower, you move spacers from below to above the stem. Once you get the fit dialled in, it is up to you whether you cut the steer tube or not

Andrew R Stewart 

The last four shops I've worked at (alright just three I worked at, the fourth I owned and did much of the wrenching) Take a lot of time to make sure that the cust provided steerer cutting request is done right. Suggesting that the steerer is cut to a longer length then first asked for and the offer to recut to a shorter length for free after the cust rides the bike a while. On new build ups we've sold we would do this as a mater of course. The recutting is usually done at the free bike check up if we sold it. More then a few times each year we would have a cust want a different stem position after living with the bike a while. Some of these times we were glad that we had extra steerer to work with. Andy.

HillRider

As fietsbob noted, they don't grow back. Don't be the guy who says; "I've cut it twice and it's still too short".

leob1

A hard lesson.

mconlonx

All Trek roadbikes come in with 3 10mm spacers below the stem, one 5mm spacer above the stem on carbon steerer models. We set them (3 10mm spacers) up under the stem, the thin spacer above the stem, and flip the stem up for display. On 99% of road bikes sold, they either stay that way, or we get a customer asking for a shorter stem with more rise.

Unless a buyer is extremely knowledgeable and a very experienced rider, we'll tell people to try things out first for a while before cutting a steerer.

gkamieneski

That's very helpful all. The last steerer I cut was an alloy steerer mated to a carbon fork. With the 120mm 3TTT Forgie stem I spec'd out, I was able to exactly duplicate the position of the previous Columbus bicycle that this frame replaced. So, yes I measured twice (at least) then cut. Because the position measured identical to my previous fit, no test riding was required. I would expect to do the same with a new carbon frame I may get. I was just wondering what to expect from the steerer as received and how easy it would be to cut it to the size required, whether to leave some room above the stem and how cutting it with my miter box and hacksaw.

Andrew R Stewart 

As I already said, leaving the steerer a bit longer and riding the bike (with spacers above the stem, needed if the steerer is a carbon one) is a smart method to not get caught with your steerer down around your ankles You can always cut a second time a week+ later after confirming everything is just right. Andy.

HillRider

The general rule for cutting carbon steerer is to leave them at least long enough to require a thin (say 5 mm) spacer above the stem to assure the stem's clamp is all below the top edge of the steerer.

You can cut it with your hacksaw using a fine tooth (32tip or more) and a miterbox or use a hose clamp as a cutting guide and let the weight of the saw make the cut. Don't press on it and go real slow near the end of the cut not to splinter the edge as you finish, or rotate the steerer so you cut all around the circumference.