Confused with Headtube diameter.

[mikesf]

Been on the market for a fork upgrade. Have a Gen3 turbo levo alloy comp s3 and I want to replace the 36 rhythm with a 38 gripx2 fork. I find two versions, 58 and 68 headtube diameter ones.

As it is a respectable amount to invest, I want to avoid getting a fork that will not fit and start a slow return process, and I want to avoid also getting a fork with a weaker crown.

Can anyone help?

Thanks,

Mike

 

[HeathenRides]

Been on the market for a fork upgrade. Have a Gen3 turbo levo alloy comp s3 and I want to replace the 36 rhythm with a 38 gripx2 fork. I find two versions, 58 and 68 headtube diameter ones.

As it is a respectable amount to invest, I want to avoid getting a fork that will not fit and start a slow return process, and I want to avoid also getting a fork with a weaker crown.

Can anyone help?

Thanks,

Mike

I got a levo to but it doesn't matter the diameter you been looking at is head tube bearings diameter and not the diameter of the fork the diameter of the fork is the same on all tapered forks which is 1.1/8 1.1/5 inches and you don't need to care about the bearings because you already have a headset just take out your fork easier to do it nicely if you remove the front wheel first. Then insert your new fork put on all the spacers and the stem make sure it's all the way in as you have no top cap yet then make a mark where to cut. It's better to make it too long than to short you can use spacers on top of the stem if it's too long and it will fit your next bike which might have a longer head tube. Go back with this information check make sure you are reading only about the fork not your headset and you will get the confidence to buy your new fork it's very simple as you already have a fox fork you don't need to think about anything like torture caps etc the parts you have will fit like hand in a glove.. You're bike will be super awesome

 

[mikesf]

Thanks for the reply, appreciate the feedback. I am still unsure what to buy, the 58HT or the 68HT version of the fox 38…

 

[Money Pit]

I believe the 68 will have a larger crown to look in line with larger head tubes on ebikes.

Think it's just an aesthetic thing.

 

[Frankenbetty]

The 68 is for bike frames with a 1.8 inch tapered head tube and the 58is for frames with a 1.5 inch tapered head tube. The 68 fork won’t physically fit into a 1.5 inch frame and you need a new lower headset cup to fit a 58 into a 1.8 (68) frame. The 68 is a new standard adopted by some manufacturers for their E-Bikes to improve frame stiffness but most just stuck with 1.5 as in reality it makes bugger all difference!
Levos have a 1.5 tapered head tube frame so you’ll need the 58 to fit as the 68 won’t and you’ll be sending them back. I’ve just gone the other way as my Giant Reign has a 68 (1.8 inch) head tube and the 38s I got were 1.5 tapered steerer so I had to get a new lower headset cup to make em fit.
Merlin Cycles (I have no connection) have some killer deals on E-bike optimised Fox 38s at the moment which are pretty much half price. E-bike versions are different to non E-bike versions to cope with the increased weight of the bike

Fox 38 Float Factory GRIP2 E-Optimised Boost MTB Forks - 29" | Merlin Cycles

Buy your Fox 38 Float Factory GRIP2 E-Optimised Boost MTB Forks - 29" at Merlin. Free worldwide delivery available on most items!

www.merlincycles.com

one last thing is the 38’s are a 180mm post mount for the brakes so you might need a new brake mount adapter depending on what size your current forks are as they aren’t all the same. RockShox Zebs and Domains for example are a 200mm post mount so the change would need a +20mm adapter to make the brakes fit though youll be ok coming from 36’s

 

[HeathenRides]

The 68 is for bike frames with a 1.8 inch tapered head tube and the 55 is for frames with a 1.5 inch tapered head tube. The 68 fork won’t physically fit into a 1.5 inch frame and you need a new lower headset cup to fit a 55 into a 1.8 frame. The 68 is a new standard adopted by some manufacturers for their E-Bikes to improve frame stiffness but most just stuck with 1.5 as in reality it makes bugger all difference!
Levos have a 1.5 tapered frame so you’ll need the 55 to fit as the 68 won’t and you’ll be sending them back. I’ve just gone the other way as my Giant Reign has a 69 (1.8 inch) head tube and the 38s I got were 1.5 so I had to get a new lower headset cup to make em fit.
Merlin Cycles (I have no connection) have some killer deals on E-bike optimised Fox 38s at the moment which are pretty much half price
one last thing is the 38’s are a 180mm post mount for the brakes so you might need a new brake mount adapter depending on what size your current forks are

Å tapered fork is 1.1/8 on the top of the steerer and 1.1/5down at the crown or bottom of the steerer.. I don't understand this forks I always get the right fork without thinking about that stuff. Just make sure it's not for fat bike's and that it's tapered.. I just bought a new fit grip 36 and you can't choose it was only in tapered tapering from 1.1/5 and into 1.1/8... Anyways to the buyer who are worried about the measurements measurement make sure it's for boost wheelsize if you have boost sizing 110mm and take out your fork and measure it or read the owners manual maybe both then search on YouTube.. All my forks fit on all my bike's I can switch them around from the sensor to the levo or from the exf to the sensor etc etc without measuring anything the all tapering from 1.1/5 and into 1.1/8.. Maybe these forks has different length on the steerer maybe one is for fat bike's i have no clue i been riding emtbs since 2018 (levo) (cube perf) sup exf) and also has a GT sensor the cube has a adapter because it's tapered headtube and straight fork the rest is all tapered tube headsets and steerers and they all fit each other including the new fit grip 36 I just fitted to the exf yesterday.. Anyways when you find out what's the actual difference between these two please tell us. Anyways if both is tapered both will fit your headset. If not it's something new that has just entered the market and if it is it's probably already a YouTube video about it. Good luck

 

[HeathenRides]

I just saw your picture again only one of those is tapered.. When it's not mentioned tapering it's not tapered but they should write straight.. The other one says tapered and that's what you need. Tapered ones are thicker at the bottom of the steerer they measured it in mm instead of inches that's all.. They should have wrote it in inches

 

[Frankenbetty]

They’re all 1.18th at the top of the steerer the difference is the bottom. As I said some are 1.8 (1.8 to 1.18th)some are 1.5 (1.5 to 1.18th)
1.8 tapered is a new standard for some but not all E-bikes. The Levo is a 1.5 tapered steerer head tube not 1.8
you can’t get straight steerer Fox 38’s

 

[HeathenRides]

They’re all 1.18th at the top of the steerer the difference is the bottom. As I said some are 1.8 (1.8 to 1.18th)some are 1.5 (1.5 to 1.18th)
1.8 tapered is a new standard for some but not all E-bikes. The Levo is a 1.5 tapered steerer head tube not 1.8
you can’t get straight steerer Fox 38’s

Tapered isn't very new my levo bought in 2018 have a tapered fork and it wasn't really new back then either the previous levo also had tapered head tube and I think the 2015 sensor pro also had tapered headtube and I guess it started become popular in 2016 stump jumper had it then.. So it's about a decade since it was new.. It's the straight one's that are antique anyways if he should have posted the pictures right away and I would tell him that it's one straight and one tapered fork and it's never been a levo with straight fork.. Anyways my first reply first comment at all would more than enough info. He probably just didn't notice that only one of those forks were tapered.. Anyways good that he noticed that they were different somehow so he didn't buy a straight fork even you can use a straight fork in a tapered headtube like on my cube but then he would also need to get a adapter headset it's better with the good old and proven tapered one. He's bike is going to be supernice I want one myself but I just fitted a new 36 yesterday and I have a new zeb reason I'm not using it is because my hope wheels does not have torque caps so I'm going to put it on the levo because my rovals has torque caps.. The hope was supposed to come with it it says so on YouTube but I have four new hope hoops two f wheels and it's only tubeless tape and valve in the box no extra end caps

 

[Tooks]

This topic is getting wrapped around the axles a bit!

58HT vs 68HT is answered here;

FOX38 Factory CROWN DIMENSIONS STD VS EBIKE-VERSION

Hello, I am having difficulty locating the dimensions of the FOX 38 Factory crown on the FOX website. Could someone please provide me with a comparison of the dimensions of the FOX 38 Factory crown and the FOX 38 FIT Perf Grip Air crown? I currently have a FOX 38 FIT Perf Grip Air fork in Patron...

www.emtbforums.com

This is a picture of a 68HT crown fork on a Kenevo Gen1.

Kenevo Gen1 - 29er Front and Rear Kenevo

How in earth have you done that? If you have raised the front & back by the same amount, it cant be 60 degrees. My mullet is 62.5 degrees or so with a fox 40 at 200mm. Going from the boxer tripple clamp to the fox 38 it raises 30mm plus, but I have no idea I thought I’ve done everything same...

www.emtbforums.com

Steerer tubes are still 1.1/8 to 1.5, but the crown is bigger/wider to accommodate fatter head tubes on some e-bikes.

For the Gen3 Levo, you want the 58HT unless you want it to look like the Kenevo pictured.

 

[Tooks]

Fox38 58HT

Fox38 68HT

Both same size steerer tube, both will fit the Levo Gen3, but different sized crowns and the 68HT where the crown race fits will stick out further than the Levo head tube.

 

[Mikerb]

Glad someone got this right!!
58mm or 68mm refers to the outer diameter at the bottom of the head tube of any particular bike.

 

[mikesf]

Thanks for all the replies. The topic is answered from all sides!

Cheers!

 

[Money Pit]

I noticed this when riding my levo yesterday compared to my mates whyte rsx180. The head tube on the whyte is way bigger than on the levo.