Max size for tire in an old Qx frame?

Hello y’all fellow unicyclists!

I have a Qx unicycle from 2016 running a 2"4 Maxxis High Roller II in a Qx frame - generation before the RGB model. It’s the squared frame, only compatible with disc brake. See these pics:


The tire is great for riding uphill - nice grip - but is too narrow to handle great drops. I’d like to go for a bigger tire but I can’t find how big this new tire can be. Would a 2"8 tire fit? I think a 3" tire would be too big.

Thanks for your help! :slight_smile:

Just thinking, your tyre doesn’t look centred in the snow image, so you are losing a lot of width available to you.

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Yes, it has been centered since this picture has been taken - two years ago. However, I don’t know how I have been able to ride with this decentered wheel. :upside_down_face:

Cool. Then the next concern I have for you is the vertical clearance - I am doubtful a 2.6" tyre will fit (unless your pic has your frame at an angle). You might be at the max already.

I think there’s an angle. As far as I remember, the photographer was lower than I was so the clearance is probably greater than what we see on this picture. I sadly can’t measure it ATM.
I was hopping that some of the members of this forum have already tried to put bigger tires in this frame… :slight_smile:

I have such a QX frame, a 29er frame with a 27.5 wheelset. It’s not exactly the same frame since mine has the magura mounts, but i think the overal geometry did not change in this time (maybe @qu-ax can tell). I run a Schwalbe Nobby Nic 2.8" on the QX rim (42mm?) in it. It’s fine as long as it is centered but i would not recommend on going any wider if you’re planning on doing uphill with it.

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Thanks @Eric_aus_Chemnitz yes, width is similar, however, if you run a 29" with a 27,5" clearance, there’s certainly more top-room - @Maxence seems to run a 27,5 wheel plus frame.
I know in the former forum there was a swiss guy who had put a wider tire in a 29" frame, too, but I am not sure if it’s here anymore.

A general clearance is hard to tell, since tyre width depends a lot on tyre makers. A 2,8" Maxxis is often as wide as a 2,5" Schwalbe etc.

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Thanks for you replies. So I won’t be able to know exactly which tire fits in my frame… Sad :frowning:
I’ll just try and send back the tire if it does not fit.

I think have a look at your top clearance again before buying, I don’t think you have a lot of space there.

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Sure. I’ll try and measure it before buying.

Nothing has gone lost during the migration.

You’re right, it’s here: Selling my Qu-ax 29x3.00, loc: Fin, Europe
On the last picture we can see there still a bit of clearance in the frame. Not much but still sufficient. I’ll probably go for a 2.8" tire which should fit.
Thanks all! :slight_smile:

On my 27.5 I changed the 2.4" High Roller II to a Specialised Ground Control 3"

Like Eric I have the frame with Magura mounts. And yellow Qu-Ax stickering, not “QX” as in your image.

If you like I can measure the frame width and clearance tonight.

Tanks @Quax1974. If it fits your frame, I don’t see why it would not fit mine. They probably have similar measurements. If you could measure it tonight, that’d be great :slight_smile:

Hi, 29x3.0 fits in my 29" QX frame.

But i ride nie the Schwalbe Bobby Nic 29x2.8 with better performance at higher speed as the Big Daddy 29x3.

Regards from germany,

Sven

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Thanks Sven. Looks like there’s not much clearance. I’ll probably go for a 2.8" tire. :slight_smile:

It works. But in my opinion, for my riding Style, 2.8 is better.

My frame is from 2018.

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Thanks @Fairlight, that was the photos I remembered.
The width from inner leg to inner leg of frame at tire-height is 86 mm +/-2 mm.
The high from center bearing-cup to inside of frame crown is 376 mm +/- 1,5 mm on the disc! QX

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@Maxence: in my 27.5 frame I have ~ 2.5 mm clearance, per side, with the 3" Ground Control tire.
Above the tire about 10 mm

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Cool! Thanks for your measurements :slight_smile:
Yesterday I have thought about it and I have measured my 27.5" x 3 wheel in my RGB frame and my older Qx frame. I had approximately the same values. I could certainly try and put my 27.5" x 3 wheel inside my Qx frame but I don’t want to mess up with my brake settings.
So I’ll get a 2.8" tire and it’ll work perfect!

Thanks again to all of you! :slight_smile: