Max tire width FM936 & FM909

[6speed]

Carbonda lists the max tire width as 2.35" for both the FM936 and FM909...but 2.4" for FM1001.  Tire widths are nominal, and there is a lot of variation in how wide they inflate on rims of differing widths.  For anyone running 2.4s, which tire are you using, what (interior) width rim, and how much clearance do you have to chain and seat stays?

[zilcho]

On my FM936 I started with a 2.35 Maxxis Ikon in the rear with a 30mm inner width rim, never measured but it was giant and still had a few mm of clearance. After that I've been using 2.4 Maxxis Rekon in the rear on the same 30mm inner width rim and it has a little more clearance even though it is marked as wider. If you're riding through peanut butter mud you'll have an issue, otherwise nothing to worry about.

On my FM1001 I'm using a 2.4 Maxxis DHR II with a 30mm inner width rim and could probably get away with a 2.5 or maybe even a 2.6, plenty of clearance in there.

[FullCarbonAlchemist]

That’s very odd that they list the FM1001 as limited to 2.4 since both it and the 1002 share the same linkage/rear triangle and the 1002 can very comfortably clear a 2.6 on 30-35mm rims…

[zilcho]

That’s very odd that they list the FM1001 as limited to 2.4 since both it and the 1002 share the same linkage/rear triangle and the 1002 can very comfortably clear a 2.6 on 30-35mm rims…

I thought they did at one point, I had to double check the site that it only said 2.4 now

[Eneen]

From drawings 909 has bit more clearance than 936. When I get my 909s I can check it thoroughly.

[6speed]

Wing at Carbonda sent me these dimensions for FM936 and FM909 frames.  They list some dimensions around the tire area for both seatstays and chainstays, but most of the widths are missing, and it is unclear what the clearance is expected to be above the tread.  Wing said the standard is to allow for 6mm of clearance to the tire, which is where their max widths come from.

2.35" = 59.69mm
2.40" = 60.96mm
Diff  =  1.27mm

[6speed]

From drawings 909 has bit more clearance than 936. When I get my 909s I can check it thoroughly.

Did you receive your 909 yet?

[lukwy]

In my FM936 bike the rear tire for XC is Kenda Saber 2.4" (60mm real width) and there is a lot of room arround. In future I will try Kenda 2.6 (supposed 65-66mm) for long mountain riding. In my opinion it should fit. Maybe someone mounted 2.6 tire, and could shere with us his thoughts?

[Eneen]

Did you receive your 909 yet?

Yes, I've got it here, but have only 27.5 wheels. To properly check this I need to design and print adapter, however due to race season I've got no spare time to do this right now, maybe in 2-3 weeks.

[qwerty]

I run Wolfpack 2.4" tyres on i28mm Arch rims and have loads of room.

[6speed]

On my hardtail, I just replaced a Racing Ralph rear tire with a 2.25" Wicked Will and it was a good upgrade.  No noticeable decrease in speed, and much more traction climbing and cornering.  If I get an FM909 or 936, I want to fit the 2.4" (ETRTO 62-622) version front and rear.  If I instead decide to go with an FM1001, then clearance won't be a concern.

[Eneen]

Here're images of Kenda Booster 2.6 tire on i36 rim. I don't own 29 wheels yet, pictures show 27.5 wheel installed using 19mm 3d printed offset adapter to mimic 29. As you can see 4mm allen key fits well, so it's about 4-4.5mm of clearance. Kenda Booster is about 64.5 on knobs, but it has quite round profile, more square/knobby tire won't fit for sure.

[ChinaCruz]

And then a pebble gets stuck in the side knobs and shreds the carbon on your chainstay.

[Eneen]

This tire model has quite large side knobs spacing, about 12mm or so, but indeed. with e.g. wicked will it wouldn't be hard to do...