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I'm a dummy and need help with wheels
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Okay so I have two bikes
https://www.specialized.com/...earchText=94419-5549

And
https://www.backcountry.com/...series-105-road-bike
And I'm wondering if I can use the same wheelset across both bikes?
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Re: I'm a dummy and need help with wheels [duganator99] [ In reply to ]
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Yes

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Re: I'm a dummy and need help with wheels [duganator99] [ In reply to ]
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Yes.

From what I can find the Cervelo is 12x100mm front and 12x142mm rear. Cervelo does not list this on their page, but my search came up with: https://www.sigmasports.com/...thlon-Bike-2021/RLYX

*Take this with a grain of salt as I don't know this for a fact. I'm going by what they listed. You can always measure yourself or contact Cervelo directly.

The Specialized page lists as 12x100mm and 12x142mm thru-axel.
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Re: I'm a dummy and need help with wheels [GingerAvenger] [ In reply to ]
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GingerAvenger wrote:
Yes.

From what I can find the Cervelo is 12x100mm front and 12x142mm rear. Cervelo does not list this on their page, but my search came up with: https://www.sigmasports.com/...thlon-Bike-2021/RLYX

*Take this with a grain of salt as I don't know this for a fact. I'm going by what they listed. You can always measure yourself or contact Cervelo directly.

The Specialized page lists as 12x100mm and 12x142mm thru-axel.
Will I need to change the rotors when I move the wheel from bike to bike? I'm absolutely clueless about this stuff
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Re: I'm a dummy and need help with wheels [duganator99] [ In reply to ]
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Why would you need to change the rotors? Are they different diameters?
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Re: I'm a dummy and need help with wheels [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
Why would you need to change the rotors? Are they different diameters?

He doesn’t know; he openly said he’s clueless. Why can’t you just accept that others don’t know as much about bikes as you and provide a helpful response to their question in a non-condescending manner?
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Re: I'm a dummy and need help with wheels [DFW_Tri] [ In reply to ]
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Wouldn't you just measure the rotors to see if they are the same?
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Re: I'm a dummy and need help with wheels [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
Wouldn't you just measure the rotors to see if they are the same?

Wouldn’t you just provide a helpful response?
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Re: I'm a dummy and need help with wheels [duganator99] [ In reply to ]
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So to give you a bit more information than jimatbeyond, road bike rotors typically come in two different diameters - 140mm or 160mm. So best case both bikes use all the same size front and rear, in which case yes the wheels can easily be swapped.

It looks like your P-Series has 160s, and the Roubaix doesn't actually say... but from the picture it looks like 160 to me. You can easily tell by either measuring the diameter or physically attempting to swap the wheels. If it fits, you are good to go.
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Re: I'm a dummy and need help with wheels [duganator99] [ In reply to ]
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The simple answer to your original question is yes both bikes will accepted the same wheels. The longer answer which you have picked up in the follow-up about rotors is that there are some nuances to compatibility.

Rotors come in a couple of sizes and the easiest set-up in terms of compatibility is to run both bikes with the same size rotor. I think you have 160mm rotors on both bikes so are good to go, but you can also easily move between 140 and 160mm rotors without messing with the wheels. You have flat mount brakes on both bikes so they are already fit with a little shim/wedge that looks something like this (Shimano Rear Mount Adaptor Flat to Flat Road | Chain Reaction Cycles). By flipping this wedge you convert between 160 and 140mm. The wedge will be labelled with a direction to tell you which way it is installed. You are almost certainly going to have to fiddle with the brake alignment every time you move wheels between bikes. Disc brakes have a small tolerance and that means you need to align the brake and rotor every time you do a wheels slot. Adding the wedge flip to this is a trivial time difference so you can easily move between rotor sizes on a bike without changing the rotors. I honestly can't tell any difference between 140mm rotors and 160mm rotors. I have a gravel bike that accepts two different wheel sizes and I bought used wheels so the rotor sizes differ between the wheels. The time required to adjust the bike between setups is so small I haven't bothered with the cost of buying new rotors.

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.
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Re: I'm a dummy and need help with wheels [scott8888] [ In reply to ]
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scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.

I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??
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Re: I'm a dummy and need help with wheels [SBRcanuck] [ In reply to ]
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While the length and width may be standard the threading on the thru axle may be different between brands.

Just keep the same axles and bikes paired.
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Re: I'm a dummy and need help with wheels [SBRcanuck] [ In reply to ]
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SBRcanuck wrote:
scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.

I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??

You have to make sure the threads are the same too.
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Re: I'm a dummy and need help with wheels [Tri.Tony] [ In reply to ]
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I have a Specialized Tarmac and a P-Series. I can try swapping the thru-axles to see if they're compatible (which I think they are). My Tarmac has an eTap groupset and the P-Series is Di2 with the TRP brakes. I'll swap the front wheel to see if it works.
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Re: I'm a dummy and need help with wheels [Th4ddy] [ In reply to ]
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Th4ddy wrote:
I have a Specialized Tarmac and a P-Series. I can try swapping the thru-axles to see if they're compatible (which I think they are). My Tarmac has an eTap groupset and the P-Series is Di2 with the TRP brakes. I'll swap the front wheel to see if it works.

Or compare the threads of the thru axles. You don’t want to attempt to tighten with the wrong tpi. I’m not sure but you could strip the thread in the fork.
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Re: I'm a dummy and need help with wheels [Th4ddy] [ In reply to ]
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I would not try and force a through axel from specy into a cervelo or vice versa. It should be pretty obvious when you try and put the wheel from one bike onto the other.

To the OP, you might have to change cassettes if you have a medium cage on one and short on the other. Looks like the roubaix comes with a 11-34 and the P series an 11-30.

You should not have to measure any brake rotors, they are all clearly labeled with their diameter.

The other thing to watch for is hub spacing, while they are pretty universal, 1 mm out is going to impact chain rotor clearance and shifting performance. Once you are set across both bikes you shouldn't have to make any changes.

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Re: I'm a dummy and need help with wheels [SBRcanuck] [ In reply to ]
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SBRcanuck wrote:
scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.

I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??


Yes.
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Re: I'm a dummy and need help with wheels [Tri.Tony] [ In reply to ]
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Tri.Tony wrote:
SBRcanuck wrote:
scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.

I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??

You have to make sure the threads are the same too.


No, you don't have to make sure the threads are the same.

Wheels don't have threads.
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Re: I'm a dummy and need help with wheels [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
Tri.Tony wrote:
SBRcanuck wrote:
scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.


I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??


You have to make sure the threads are the same too.



No, you don't have to make sure the threads are the same.

Wheels don't have threads.

I assume he meant the threads on the thru axle vs the threads in the frame/fork, no? Googling seems to indicate these can differ between bike brands?
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Re: I'm a dummy and need help with wheels [SBRcanuck] [ In reply to ]
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SBRcanuck wrote:
jimatbeyond wrote:
Tri.Tony wrote:
SBRcanuck wrote:
scott8888 wrote:
.........

The thing that probably isn't compatible between the bikes is the thru-axles. There are an absolute ton of thru-axel standards and while some compatible between frames I would never assume this to be true.


I'm new to the disc brake world as well.....
If both bikes say '12x100mm and 12x142m', doesn't that mean they should be perfectly compatible??


You have to make sure the threads are the same too.



No, you don't have to make sure the threads are the same.

Wheels don't have threads.

I assume he meant the threads on the thru axle vs the threads in the frame/fork, no? Googling seems to indicate these can differ between bike brands?


You keep the thru-axles with the bike.

Only the wheels get moved from bike to bike.
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Re: I'm a dummy and need help with wheels [jimatbeyond] [ In reply to ]
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exactly. what jim said. every bike comes with its own thru axles. so, when you take a wheel out of a bike, you put the thru axle back into the bike. even if you take a wheel out, and don't put another wheel in for whatever reason, i always put the thru axle back into the dropouts, so that i don't lose it or get it mixed up with other thru axles. so, the thru axle thing really isn't or shouldn't be anything to be concerned with.

what i really try to do these days is make sure all my bikes are set up for 160mm rotors. if it came shipped for 140mm i see if i can turn the mount around or get another mount to make it 160mm. and, i won't buy any wheel that doesn't have a centerlock hub. that way, a wheel is a wheel is a wheel. wheels are getting very good at being just... wheels.

i was in between road bikes for a couple of months, and had to purpose a gravel bike as a road bike. the only road wheels i had for this bike that were compatible - 160mm rotors, 12sp, XDR driver - were a set of zipp 808s off a tri bike. so on they went, and that was my road bike for a bunch of rides.

Dan Empfield
aka Slowman
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Re: I'm a dummy and need help with wheels [Slowman] [ In reply to ]
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Slowman wrote:
what i really try to do these days is make sure all my bikes are set up for 160mm rotors. if it came shipped for 140mm i see if i can turn the mount around or get another mount to make it 160mm. and, i won't buy any wheel that doesn't have a centerlock hub. that way, a wheel is a wheel is a wheel. wheels are getting very good at being just... wheels.
Wheels used to be very good at being just wheels. As this thread shows, that is no longer true! (And just wait for Shimano 12 speed road...)
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Re: I'm a dummy and need help with wheels [lanierb] [ In reply to ]
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Shimano 12 speed road cassettes will probably use Microspline freehub bodies.
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