10 Common Mistakes Made When Replacing A Mountain Bike Fork | How To Fit A New Fork

From cutting the steerer tube too short to using a track pump to set the pressure; there are a few common mistakes that can be made when fitting a new set of forks. Heres Doddy showing you how to avoid them 🔧
Subscribe: gmbn.tech/subscribetogmbntech
The GMBN Shop: gmbn.tech/mZ
When did you last upgrade your forks?
If you'd like to contribute captions and video info in your language, here's the link 👍 gmbn.tech/mY
Watch more on GMBN Tech...
📹 gmbn.tech/5traveling
📹 gmbn.tech/suspensionbasics
🎵 Music - licensed by Epidemic Sound
JuiceBox - Dylan Sitts
Just My Luck - Mattias Hedbom
Midnight Vibe - Yomoti
Motor Town - Da Tooby
Submit your content here:
upload.gmbn.com/tech
Brought to you by the world’s largest mountain bike channel, the Global Mountain Bike Network (GMBN), GMBN Tech goes deeper into the bikes, kit and technology stories that help fuel your rides.
Our mission is to help you discover, dial-in and get the best from the latest cutting edge bikes and technology available.
With news and rumours, first ride exclusives, how-tos, the weekly GMBN Tech Show wrapping up and showcasing the week’s biggest tech stories, and more besides, if it’s off-road tech, it’s in.
Every week, of every month we seek out, showcase, and ride the newest gear and innovations from across the globe in an authoritative, inspiring and entertaining way to help you get the best from your rides. And when we’re not riding, we get geeky in an accessible, easy-to-understand way about forks. And shocks. And more to help you setup and maintain your bikes perfectly.
Engage with us every week on the channel and across social media - we’re here to answer every question you’ve got on mountain biking tech.
Facebook - gmbn.tech/gmbntechfb
Instagram - gmbn.tech/gmbntechinsta
Twitter - gmbn.tech/gmbntechtwitter

[@gmbntech]

When did you last upgrade your forks?

[@meinefresse94]

Never

[@charlesb7831]

Couple seasons ago, picked up a set of Rockshox SID 29ers for my XTC.

[@reggin_spelt_backwards]

Just got a fox float 32 performance. Im shitting my pants about fucking up the installation lol

[@dombmtb]

Stephen do you even bike?

[@dombmtb]

Stephen I know what tapered is, I just don’t wanna take out my fork

[@GlidingTobster]

I diligently followed your recommendation not to use the old tube as a measurement datum. Instead I measured the crown spacers; three times, to be absolutely sure. I then cleanly cut the tube with a pipe cutter. ...And then remembered that the handlebar stem is supposed to go on as well 🤦‍♂️

[@newttella1043]

If you buy your own forks, listen to Doddy. If you get free forks, listen to Sam Pilgrim.

[@user-bz6sg7sj4s]

Newt Tella gfbn no Koch. Ccgggggghhgyyyyyyuuuuui has iOS been the ioiohbhhhhhhyyuuuuiiiej)hJ&jKKIIzziziziziziuziJObnhihjhlhvlug pivyybihoh bbjuh bbbhhhh

[@jrbechthold]

🤣

[@GiliD_Aki]

This needs GRINDING

[@robertturnip7850]

I wouldn't even do that with free forks. Who knows if your next forks will also be free. Always look after your equipment no matter what.

[@mrjagriff]

Robert Turnip 😴

[@glenvaal3651]

Great video. Especially the bit about not cutting the steered tube too short. My tip, before cutting, compare the length of your old fork to the proposed length, if the latter is shorter, something's not right! I'm my case, I forgot to accommodate the handlebars....really stupid I know, but thank goodness I remembered "measure twice...."

[@Ricochetmex]

No thanks, I’ve already watch enough Sam Pilgrim videos, and he is a pro...

[@Dan23_7]

An adjustable pipe cutter from the plumbers merchant is better than using a hacksaw to cut your steerer tube, plus you don't get burr at the cut 👍🏻

[@mtbboy1993]

using a file to make it smooth takes few seconds up to 1 or 2 min, I guess, just use a smooth file.

[@mtbboy1993]

another mistake with Star Nut, is to install it on a carbon steerer tube, only compression plugs can be used on carbon steerers.

[@FalcoBikes]

Tip on lining up the stem angle: place the bike over some floor tiles, and use the square seams between tiles as reference.

[@herculesmclovin]

Re: star nut; use the topcap. Once you hammer it 2mm in, unscrew the bolt and fit the topcap in, rescrew the bolt back in, hold the topcap in place and start hammering again. Not magical but certainly helps a little 👍

[@alexnicolas9135]

bold of him to assume I have friends

[@martinjflanagan6522]

I use a ruler for aligning the handlebars, gently lay it across the fork stanchions and eyeball the handlebar with the ruler.

[@timndel]

The best way for most of us, is to have a knowledgeable and experienced bike mechanic do it. That will remove the idiot factor.

[@charliehugo]

Tim Dunn and make you broke

[@tankizoltan1752]

@@charliehugo I'd give a mechanic one day worth of my salary to spare that hassle.

[@wordreet]

Ah, but if the idiot isn't allowed to screw up, it'll never learn. 😉

[@jackkelly324]

rather not be poor thanks

[@akkatonezapkin536]

"If you want something to be well done, do it yourself" (as long as we are talking about bikes and not quantum mechanics, heart surgery etc.). I prefer taking responsibility to myself for my own mistakes instead of feeling anger for mistakes done by someone else. It could be unbearably frustrating to pay to some idiot and have the job messed up.

[@j_white1305]

Perfect video to pair with your How-to video, I'm glad I found it. Thanks!

[@carloswithac]

Doddy is back!

[@desmond5593]

Thank you so much for making this video so easy to follow and understand. Looking forward to rebuilding my bike of 20 years old ( sentimental value).

[@uessaloniki]

Good stuff Dody! Thanks!

[@joeday6029]

Love the handlebar alignment trick ...!

[@JOE-hu9qk]

'Filing streerer tube' Sam pilgrim: a pavement will do

[@thegrantclan]

Spot on information 🧐

[@pierretruchon4353]

great video, thank you

[@BarryJTaylor]

I recently put 180mm bombers on my 150mm Trance. Best move I ever made. Fixed the low bb and slackened off the head. What a weapon now. I cant see a use for anything under 160 now lol. PS. I used Sam pilgrims vid as an example of what not to do.

[@livinlarge1247]

Great videos. Thx!

[@MrJakeepooh]

Doddy, my brother, I freaking love your videos! I just have a small quibble with this one. You got me all excited to learn the best way to install the star nut if you don't have the specific tool, but you just showed how not to do it? Did I miss something?

[@rustinchole2357]

I use a 15cm srew/bolt for installing the starnut. Works great!

[@user-ol6zp4fz3e]

Used this to fix an Oset. Thank you.

[@aka4146]

Thank you great info

[@stiingya]

Good tips! when you use a stem as your cutting "guide" if you put a spacer on it you can keep from scratching up the stem. Plus the spacerr "spins" as you cut and works well. (still gets all scratched up and you won't want to use it again! :)

[@Toots-yf7fb]

Been there. My star fangled nut has a slight tilt making changing cockpit adjustments a pain in the ass.

[@rupedog]

Love the no no 'waggy finger of dodd' 😁

[@M3PH11]

From experience I can say always use a hacksaw and get yourself a cutting guide from park tools or x-tools. As long as you don't screw up the measurements you can not do wrong using those 2 tools. 4:35 After spending a few hundred quid on some forks £20-£30 for a guide is always justifiable when the consequences for screwing up are so high. Sure you can go to the the LBS but they will charge you more than £30 to install some forks. 5:24 A dremel on the lowest speed with the grinding bit inserted also works. Just don't press very hard at all and dab it on to the surface, only making contact for a tiny fraction of a second each time. Works fine. Also works great at getting surface rust of cast steel steerers. 6:30 I lay mine out flat on a work surface with the part i'm working hanging off the end. So the filings/shavings can only end up on the floor.

[@geraldmaybebaby1585]

Please make a vid on fork purchasing errors. Variations in steelers, tapered, etc. Extra costs of compatible headsets. Whether fork travel suits frame geometry, etc. I have an old marin quad Tara. And an adjustable travel fork to match the rear travel adjust is a perfect match.

[@mtbboy1993]

3:02 I also recommend using lube, so the saw can move smoother, the particles don't fly everywhere. also having fork in a repair stand, and cutting using a saw, is a good idea, this way things don't go anywhere near the seals.

[@Chromedome-ss6mg]

I got my star nut crooked. I think I'm going to drill it out and get one of those that you tighten up and it spreads open. Much better imo.

[@Semprefi]

Most of the big chain hardware stores sell a plastic mitre box and cheap saw designed as an inexpensive alternative to a compound mitre saw . The box has slits for cutting 90 & 45 degree angles. Your hacksaw will work fine in the slits and give you a perfect cut every time for around $7 w/o the hacksaw

[@matteobettola7504]

Guys there was an even easier way to fit the star nut! Just use a suuper long screwdriver that fits inside the thread of the starnut itself and start hammering! Love the channel, got me into mountain biking!

[@GokkunGuru]

Great video. How often do I need to pump air into the suspension?

[@christianpeters6579]

So, I’m supposed to cut the steerer tube a bit too short so the top cap presses on the stem?

[@jackdaniels2127]

Dodi, how do you install a star nut if you don’t have that specialized tool?

[@Pshpshpshpshpshpshpsh]

I use a corner of a wall to level out each handlebar but either eyeballing it or using the equal distance of bar to the wall to level out.

[@sam-ww1wk]

Great vid. Quick way to cut the tube is with a cut off wheel, then sand flush and clean with a random orbital. Mark all the way around and cut a mil long, then sand to your mark. Finish with a finer grit. Much faster and cleaner than using a hacksaw. But, you have to know what you're doing.

[@MasterChronometer]

#askgmbn I was servicing my pike the other day when I ran into a bit of an issue. The bolt on the damper side wouldn’t come free as the rod inside was just turning. Is this an issue in new rockshox forks and how can I stop this happening in the future?

[@fhehle]

The steerer on my bike is wider on top, so I cannot pull and remove the fork. Any idea what could be done from there ? Cut it ? Thank you kindly

[@dosetti]

Easy way to put in and align the star nut is with long bolt, like 10-15cm. At least easier than with very short one.

[@desertrider325]

You said to leave a 4mm gap on the stem in your other video. I did that. But now you say be above the stem and add a extra spacer. So which Is correct? I have a 2015 specialized enduro.

[@Alan-75]

I want to remove a spacer as I've got 4 of them on (newish bike) and only need 3.. I've got the correct tool for installing a star nut my question is when I cut off 10mm will I have any trouble pushing that nut down the correct distance.

[@ManuelMartinez09]

Yesterday I did a test: Mounted the new Fork with new headset with no lubrication at all (I was going to change the spacers and deciding if cutting or not the steerer tube) and it felted awful. Grease is the most important here.

[@guitarrocker0991]

I have made the mistake of hammering in my star nut just barely too far. Luckily I was being very conservative with my steer tube length, so I all I had to do was cut off a few more mm and all was well.

[@sam-ww1wk]

The easier way is just to use a longer bolt.

[@kizmack7772]

noob question here, im about to get a Zeb charger designed for Emtb, can i still use it on a standard hardtail (non Emtb) frame?

[@errolflynn7166]

When changing from a ridgid fork to a suspension fork, what would be the right Crown to Axle measurement. My ridgid crown to axle measurement is 375mm, what suspension fork would be the right measurement?

[@ianmangham4570]

I'm just under the top nut on my stem, I've found a longer top cap bolt and tightened up the bottom bolt, I'll go slow until I can find an extension or a smaller in height stem if they do them anyone?

[@Musashi-_-]

Sam Pilgrim ?

[@lizardmechanic8785]

You didn't mention getting the bearing crown race off the old fork and installing on the new one. I have seen some people hack that up for sure. If you do mess up a star nut you can just drive it down a bit and install a new one, leaving the old one as reminder to be more careful. Getting it all the way down and out the bottom is challenging, it also leaves deep scratches all the way down the tube.

[@jtperez657]

11. Don't forget the crown race

[@lastpme]

I just learned one the hard way. After wasting hours try remove the Crown Race from my old fork and installing it on my new bike. I am almost at the finish line but my tire not fitting in the fork. My tire is a 29er…and when I went back and looked at my new fork info…it fits a 26 inch wheel. I needed a moment alone 😑. I also don’t understand why some fork companies don’t provide the Crown Race with the fork since it so hard to remove safety. That makes no sense.

[@hedemalmcarl]

can i use the top cap to hammer the starnut in? since it could work as a guide

[@DeepakKumar-lv4te]

he didn't tell us how to do it other than use that tool. recommend looking at other vids.

[@przemokbh8079]

I want to buy fork to retro mountain bike but is 16cm dont know if that is not to ahort ?

[@hedemalmcarl]

I actually dont have the spacer on top, sure safety but the positioning of the bolts on my stem makes so it doesnt really matter. I used to have that extra but then i removed it because i had no need going higher, i was maxed out but 3mm difference wouldnt affect so much and im more likely to change my bars because id need them wider and higher rise aswell.

[@icebreakertech]

9:36, so obvious, that I didn't think of that :P

[@drewgilker417]

i love classics

[@Gabo112310]

What is up with Doddy's tan? Where did you go on vacations my friend? haha

[@rorybissmtb]

How do I know if my bike has a tapers head tube

[@chyu89]

Nice suggestion. Use your friend's stem 😂

[@Heleninhalinda176]

Yeah, my steerer tube ends in the middle of the 2 stem bolts. 0 spacers, low stack stem. Good thing I'm a lightwheight guy

[@keithchurulich7900]

What about threaded forks?

[@mtbboy1993]

6:51 I just drop that altogether and install a compression plug.

[@roythearcher]

Was that thunder @ 08:40 ?

[@mattgies]

At 2:51, during the segment titled "USING THE WRONG TOOL", is that not a clip of using the Park Tool SG-8 (saw guide for thick carbon fiber hacksaw blades) with a standard metal hacksaw blade--a case of using the wrong tool? The correct tool, unless my eyes are deceiving me, would be the SG-6.

[@r.c.r.rproductions8462]

The star nut, metal shavings, cutting it wrong, that I understand. But not lining up your bars and stem and greasing your headset? How do you mess that up

[@justingiassonmountainbike3346]

Sam pilgrim did all of the mistake you said 😂

[@rahakadesh]

Need to replace my fork...please help

[@noahfence4969]

So, any tips for people who have stripped the thread on the cable clamp ? ☹️ Have been using a cable tie, but there must be a better bodge !

[@dosetti]

Drill and tap new bigger threads?

[@mtbboy1993]

it can be tapped, but you can just put zip ties there in the mean while.

[@_Steven_S]

My braided hose doesn't even fit in the retainer to begin with! Cable tie for me also 😢

[@acbrown8201]

Steven S ask an electrician for a 'p-clip'... same from commercial fire alarm installer. 'pyro' is a tiny bit bigger than most braided, so easy fit added bonus; p-clips are in diff colours, just red, orange, black and white are most common, green and blue bit rarer. also, SOME clips are plasticcoated metal; others are... plastic!

[@paulhead9075]

!!!!!!!!!!Doddy! Amateur tip for lining up your stem/bars.!!!!!!!!! I take a handlebar sized length of STRAIGHT timber and zip tie it to the stanchions beneath and flush with the crown. Then eye the handlebars to the timber as you have a much longer area to eye through against. Works well! Then I put a small scratch on the stem and steerer tube to make future aligning easy.

[@ashleyscarth8363]

Use 8mm drill bite drill the 🌟 nut centre out

[@rupedog]

A pole and hammer it down and out the bottom!

[@josereneducharme142]

Does Park Tool have a fork/bars alignement tool?

[@bobbyhempel1513]

Don't give them any ideas.

[@acbrown8201]

yeah; under development since you mentioned it. a custom built workshop wall. park toolz are trying to organize overnite shipping to meet the expected crazy high demand. get in line...

[@sam-ww1wk]

Yeah, it's usually on the shelf next to the tube stretchers. Great tools.

[@stefanthegerman3575]

You never see a Video from sam pilgrim. Thats the way to change a fork🤣

[@31acruz]

how do you measure your fork's travel?

[@sam-ww1wk]

zippy around the tube.

[@TheKooster31]

also it's best to use a dedicated tool to install a star nut for your new fork, way better than banging it with a screwdriver yourself. if you dont have one ALWAYS borrow one from your friend that have one boom, 1 more tip for money saving tips segment :D

[@Dan23_7]

TheKooster31 When I replaced mine a few months ago I screwed the screw in a few threads and tapped it in with a hammer. Might sound bodgy but it worked 👍🏻

[@TheKooster31]

@@Dan23_7 ah you must have a delicate touch. my hand is more like a sledgehammer lol

[@Dan23_7]

TheKooster31 Haha 😂

[@jackmaddesty]

If you cover your file with gorilla tape before filing, you won´t get metalfilings on your fork legs when filing. Another great hack is to remove the blade on your hacksaw before cutting. It´ll take a tiny bit longer to cut but that way you´ll have the cleanest fork legs ever🤓👍

[@reinholdachleitner2069]

Great common mistakes when replacing a mtb fork guide.Your statement is not true when removing a star fangled nut.They can also be drilled out with the appropriate drill or drill press not only hammered through.Cheers.

[@onelove8062]

When I upgrade my fork maybe I can make it so my bars arent below my seat 🤔 and get some different handlebars that are more upright and sweep more...hands go dead numb I cant uncrumple a bill to pay someone at the store I'm like arthritic from biking 10,000km

[@sebastienhintz2349]

Hey, is there a safe way to extend the steering tube?

[@nickadams8952]

No I'm afraid not. If its cut too short you will have to get a new CSU for your fork and it will be pricey.

[@sebastienhintz2349]

@@nickadams8952 Cheers mate

[@BarryJTaylor]

How much short is it?

[@sebastienhintz2349]

@@BarryJTaylor around 2 cm

[@BarryJTaylor]

@@sebastienhintz2349 a local machineshop could turn you up an insert that could be bonded inside the existing steerer. The top of the inser would be the same diameter as the outside of the steerer. Like a stepped cylinder of aluminium, with say 25mm at the ID of the steerer and the top 20mm at the OD. You would need a 10mm hole right through so that you could use a long 6mm bolt to reach the star nut. The star nut would need to be inserted before the insert was bonded in. Easy job if you know someone with a lathe. Engineering epoxies are so good these days you could do that bit at home. Just saying its quite an achieveable fix.

[@TM-lw8wn]

use a standard pipe cutter and de-burr after

[@alexanderpeckham8105]

After watching this if I get new forks I will be taking it to a professional to install it.

[@f1j11slander4]

🤣🤣💯

[@wigma]

better hack if you dont have the saw guide is to tape a headset spacer to one side of the mark and one the other side. just cut between the 2 spacers. once you're cutting the saw cant drift

[@DeepakKumar-lv4te]

or use a jubilee clip

[@bradleydegraaff7574]

Dam it Blake get it right

[@ysmir6065]

today I got my carbon fork for my bike that I converted to gravel bike , I measured 3 times , and still managed to cut it too short , I have no idea how it happened , I am currently looking for a solution to fix this , cuz I dont have another 300 euros to spend and my bike is unusable and I need it for work -.-

[@underbikedoverconfident1142]

Something I learnt is to use masking tape to mark the cutting line. Why? Well its thin enough to get spacers over and creates a great cutting guide line if you don't have that fancy Park Tool. Its also easy to remove/move.

[@julespoor6359]

What fork is this

[@gmbntech]

Hey Jules, this is a SID from Rockshox.

[@mkimlicka]

good video, but there are only 9 mistakes mentioned in it :)

[@emilianoromerocepeda5071]

Love the bike design kzbin.infoUgkxHL1v1R3NE5x4KiYfyt8dnQmyNYz7qi5L and functionality. It is hard to align the front tired to center the disk brakes. The brake wheel touches the stationery side of the brake caliper and pad. I aired the tire up to 40 psi as the markings say 40-60psi. Left the house for a few hours and came back to an exploded innertube.All in all it seems to be a good bike. Have not ridden it yet though so that's the max of my knowledge. Update, put a new innertube made sure the tire was set properly and it did the same thing in under 20 minutes as second pic shows.

[@BarryJTaylor]

Never heard it called a "star fangled nut" before!! Where did that come from? Does it need a "star fangled spanner" to be tightened? Lol.

[@gmbntech]

Hey Barry, a "star fangled nut" or "star nut" is the name of the nut that is pressed into the steerer tube. The arms are angled so that it can be tensioned. We suggest you use the tool used in this video to ensure that it's inserted correctly.

[@sam-ww1wk]

That knick name was first used as slang by shop techs back in the day when they first came out, and still in use.

[@MrGruzefix]

Just let a professional do it. I have seen so many stupid mistakes our customers have made when replacing their forks, like: - put both bearings on top (or bottom) - forgot to transfer the headset ring to the new fork (or used two of them stacked on top of another) - mounted the star-nut up-side down (it must have been a pain to get it in there like this) - used a carbon star-nut replacement on a steel fork-shaft (or used a star-nut on a carbon shaft) - put the fork in facing backwards - and no, it was not a Manitou fork... - bought the wrong fork in the first place and realized half way through mounting it, that a key feature, like a disc brake mount, is missing. - bought forks for the wrong wheel-size and wondered why the tire was not able to fit But the prize for biggest idiocy goes to a guy who came in one day, with two rigid forks in hand, one that was bent because of an accident, with a 1" screw-on shaft and the other one new with a new 1 1/8" screw shaft. "Can you replace this for me?" "No, sorry, that's the wrong size for your bike, the shaft will not fit, as it's too big" "No, I meant the shaft, can you cut it off and weld it onto the other fork?"

[@jackkelly324]

you are exactly the reason i dont go to bike shops

[@MrGruzefix]

@@jackkelly324 elaborate please?

[@jackkelly324]

@@MrGruzefix your attitude, as if your better than everyone else. the look LBS employees always gives you. You rip people off and treat your customers like shit. There's loads of videos explaining this

[@rupedog]

Its called a crown race...not a 'headset ring'.

[@rupedog]

Its not a hard job to do. But the idiots will bring lbs more business, so u should encourage it!

[@Pienimusta]

Filing with actual file? Somone missed this one.

[@glennpettersson9002]

Oops😳

[@Panslapper]

...otherwise 35 degree 70-90mm riser stem and 30-50 degree riser bars will get you back on the road/track. Lol.

[@DeepakKumar-lv4te]

it's all very well saying leave 3mm between the steerer and stem, but 3mm which way? Us peasants ain't gonna do this more than once (?) if at all so it's not like we're going to be experts in this. I liked the tip re using an old stem as a cut guide, also a jubilee clip can do it (thx oz). Also, what about using a power circular saw? More teeth, high rotation speed , does that give a cleaner cut? What about on carbon? This vid lacks advice on road bike forks / non suspension setups (ok, maybe not the vid for it), max spacers recommended, and also the idea of doing it twice - first with an extra 10mm spacer, ride it and then cut it down a second time to the exact length after assessing it. So could have had a lot more tips in it.

[@Chromedome-ss6mg]

You can mark your fork on the steerer tube so you know your straight.

[@1brokenspoke189]

Why doesnt Neil fit his own forks lol ?

[@olegpetelevitch4443]

And i have done so with carbon forks cost me another $1500 not happy JAN !!

[@thiosemicarbizidebenzoylal2921]

None of these tools are expensive anymore, and a star nut tool is 11 francs on Aliexpess Doddy. Why none of this isnt discussed is still bewildering and makes this channel about 10 years behind in the cycling world. This trade war tariff sceneraio isnt real because everything in cycling is made in China, at least all the good stuff.