Steerer Length question

[okie]

Hi Hubbers,

I am building a new MTB and I need some advice as I am new into Mountain biking and don’t know much.

I bought a frame that has a 118mm head tube length including the headset bearing cups.

I dint know what the total length of the headset is. I also don’t know what the average length of a stem is and how much spacers I have to get.

Any help would be appreciated as I am a bit in the dark and dont know what steerer length I need to get when looking for forks.

[SteveS]

Most Suspension forks come with uncut steerer tubes. The best would be be to install the fork without cutting the steerer tube. You then have a few options. The best would be to take your bike to a specialist bike fitter and let them measure you up and install the necessary spacers and when you are happy only then cut the steerer to size. Alternativley you could play around with the spacers until you feel happy with the set up.

 

I have a simple solution that works for me. It is not very scientific. I have a specific seat height that I set all my bikes too. When I get a new fork or bike, I first get the seat to the correct height and then take a spirit level and then set the spacers on the fork to make sure that the stem and the seat are completely level.

[okie]

Tanks SteveS

I will definitely take my bike for a professional setup, but my problem is that I am looking for a second hand fork to save some costs and most second hand forks have already been cut. Is there any way in witch I can calculate what minimum steerer length I should look at?

This looks more complicated than I thought.....

[SteveS]

It is difficult to say. Stay clear of anything shorter than 200mm. There are loads of variables here, like the length of the fork (80 vs 100mm vs 120mm) the size of the frame the fork came from (the bigger the frame the longer the steerer would be) etc

[Tankman]

...I have a specific seat height that I set all my bikes too. When I get a new fork or bike, I first get the seat to the correct height and then take a spirit level and then set the spacers on the fork to make sure that the stem and the seat are completely level.

 

I dont think there are uncut steerer tubes long enough for me to try that, it would look a bit silly

 

[Guest coenie]

Johan might be able to help more, but as far as I know you should work on the Headtube lenght + 4 cm of spacer + your stem with and that is the Max lenght that your steerer tube can be....well on most bikes.

 

It might be carbon that I am refering to but as I far as I know the 4 cm is the max recommended by most manufacturers.

[okie]

It is difficult to say. Stay clear of anything shorter than 200mm. There are loads of variables here, like the length of the fork (80 vs 100mm vs 120mm) the size of the frame the fork came from (the bigger the frame the longer the steerer would be) etc

 

Ok thanks, at least I now have something to work from.

[okie]

I dont think there are uncut steerer tubes long enough for me to try that, it would look a bit silly

 

LOL

[okie]

Johan might be able to help more, but as far as I know you should work on the Headtube lenght + 4 cm of spacer + your stem with and that is the Max lenght that your steerer tube can be....well on most bikes.

 

It might be carbon that I am refering to but as I far as I know the 4 cm is the max recommended by most manufacturers.

Sounds easy enough, do you perhaps know what the length of the average stem is where the fork goes through?

[Minion]

Johan might be able to help more, but as far as I know you should work on the Headtube lenght + 4 cm of spacer + your stem with and that is the Max lenght that your steerer tube can be....well on most bikes.

 

It might be carbon that I am refering to but as I far as I know the 4 cm is the max recommended by most manufacturers.

The general rule of thumb is that the spacer height between the top of the headset and the bottom of the stem is 1.5 x steerer diameter. The top of the steerer tube should be about 3mm below the top of the stem or the top of whatever spacers you have above the stem.

 

For an integrated headset with 1 1/8" steerer, this would be:

 

Minimum length = Head tube length + headset dust cover thickness + 43mm + stem thickness - 3mm

 

Parktool article with pictures

[Minion]

Sounds easy enough, do you perhaps know what the length of the average stem is where the fork goes through?

40mm or so.

[Noshow]

Mtb stems are usually around 41 mm and don't vary much (up to around 45mm for DH stems), but you need the stem (or top spacer) about 3mm above the top of the steerer for the top cap bolt to properly grip the star nut.

 

You should allow for at least 20mm of spacers for adjustment, preferably up to 40mm. You can then play around with the height (spacers above or below stem) until you find the perfect height for you and cut to fit.

 

For this bike you need a steerer at the very least 160mm, but wouldn't recommend less than 180mm, and preferably 200mm.

[okie]

Thanks a lot guys, this helps me tremendously. I will measure the head set tonight to get a better idea of where I am. I think the frame being a medium is a bit of a advantage in terms of finding second hand forks.

Thanks for the external link Edman

[Edge_Design]

I think you should buy my Sid World Cup fork with 205mm steerer for R3k and then we're all happy! (Not so undercover advertising going on here!)

[SteveS]

Tankman, All you need is a steerer similar to this one

[okie]

I think you should buy my Sid World Cup fork with 205mm steerer for R3k and then we're all happy! (Not so undercover advertising going on here!)

LOL dont worry a "white fork wanted" add will be coming from my side soon.