Caliper won't fit right on new fork

[tonyride]

I replaced the existing fork on my bike with 140mm of travel to one with 160mm travel, both are Fox. The old one is a Fox 34 Float Performance and the new one is a Fox 36 Float Factory. Both are 29er and boost. The bike came with a 180mm rotor on the 34 Float Performance fork. I increased the rotor to 203mm with an adapter for the caliper on the old fork. Today I put the new fork on and when I tried to put the adapter and caliper on and it is too far out, meaning only a small amount of the pads is touching the rotor. The new fork as 44mm offset and I think the old one is the same but would that make a difference if the offsets are different? I mean when you get an adapter for the caliper to go up in rotor size they don't ask what your fork offset is, right? So what could be the problem?

 

[BPaze]

It is upside down?

 

[w_b]

The 34 uses a 160 post mount and the 36 uses a 180 post mount. So in theory you need the original 34 to 180 adapter on the 36 for the 203.

 

[Mr.Moto]

The 34 uses a 160 post mount and the 36 uses a 180 post mount. So in theory you need the original 34 to 180 adapter on the 36 for the 203.

This.


34mm forks use a 160mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 160mm rotor.
36mm 15mm/20mm thru-axle or 15QR forks use a 180mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 180mm rotor.

 

[MadisonDan]

Because it’s made to fit on your forks.

 

[serviceguy]

This sounds like deja-deja-vu...

https://www.mtbnj.com/forum/threads/disc-brake-adapter.49560/#post-987678

 

[tonyride]

It is upside down?

It is upside down?

It is upside down?

I checked and it is not upside down. The adapter says up with an arrow and there's no way I can even try to mount the caliper upside down.

 

[tonyride]

The 34 uses a 160 post mount and the 36 uses a 180 post mount. So in theory you need the original 34 to 180 adapter on the 36 for the 203.

The 34 didn't have an adapter with the 180mm rotor. At least I don't think it did. I'll have to look in my parts bin.

 

[tonyride]

This sounds like deja-deja-vu...

https://www.mtbnj.com/forum/threads/disc-brake-adapter.49560/#post-987678

You have impeccable memory. Kinda scary. So that's the adapter I need for this application? LOL

 

[tonyride]

So it looks like SM-MA-F203P is what I need?

 

[w_b]

Dibs on the 34/140 if you gon put it up.

 

[serviceguy]

You have impeccable memory. Kinda scary. So that's the adapter I need for this application? LOL

Impeccable no. Scary yes. It's a dark place in there.

 

[tonyride]

Dibs on the 34/140 if you gon put it up.

It may be up for sale soon. New bike take-off with less than 100 miles on it. Steer is 6-11/16" if that's long enough for you.

 

[tonyride]

The 34 didn't have an adapter with the 180mm rotor. At least I don't think it did. I'll have to look in my parts bin.

As it turns out the 34 did come with an adapter for the 180 mm rotor. I'll try using that tomorrow.

 

[BPaze]

I'll take seconds on the 34 140 fork may need it soon although gotta check the steerer

 

[stb222]

The 34 uses a 160 post mount and the 36 uses a 180 post mount. So in theory you need the original 34 to 180 adapter on the 36 for the 203.

This.


34mm forks use a 160mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 160mm rotor.
36mm 15mm/20mm thru-axle or 15QR forks use a 180mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 180mm rotor.

This
34mm forks use a 160mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 160mm rotor.
36mm 15mm/20mm thru-axle or 15QR forks use a 180mm direct Post Mount that allows you to bolt your caliper directly to the fork and utilize a 180mm rotor.

 

[w_b]

As it turns out the 34 did come with an adapter for the 180 mm rotor. I'll try using that tomorrow.

Of course it did. To go from 160 post mount to 180 rotor you need a 10mm nominal thickness adapter. That should be what you had. That same adapter will get you from 180 post mount to 200 rotor.

Worst case with the 203 you off by 1.5mm (0.060”) and you can make that up with some Stainless flat washers if need be. Prolly won’t need em doe.

 

[w_b]

It may be up for sale soon. New bike take-off with less than 100 miles on it. Steer is 6-11/16" if that's long enough for you.

Will check. Tapered steerer I assume? Also can you confirm it is 44mm offset?

 

[tonyride]

Since this is my thread I'll let myself digress a bit and post the fork I'm selling. So the fork came off a 2021 Orbea Rise M20 which is an ebike purchased from Halter's in September. As stated, it has less than 100 miles on it according to Strava and the bike's app (yup, if you have an ebike there's an app for it). Here are some pics. It is a Fox 34 Float Performance 3-position 140mm travel 29er/27.5+ boost fork. Steer tube is 6-11/16" long with a star nut still in it. I have to think about a price but I'm looking at around $400. I was going to put it on my wife's bike as it would be an upgrade for it but since there's interest in the fork then I will consider selling it.

 

[tonyride]

Will check. Tapered steerer I assume? Also can you confirm it is 44mm offset?

Yes, it is tapered but I can't confirm the offset is 44mm. It came with the bike so the spec from the bike manufacturer didn't go into that level of detail. Here's the bike it came off of. https://www.orbea.com/us-en/ebikes/mountain/rise/cat/rise-m20-20mph