My wife's CS-041 29er hardtail

[cmh]

Starting a build thread for her new bike - ordered from Peter at XMCarbonSpeed she picked it up from the post office today. It's going to be a backup for her Scott Scale 910, which is perfect since the geometry is almost a direct copy. Have all the parts on her old 26er which was a great bike, but she has decreed the 26er to be "dead like Elvis", so it becomes a part donor.

[cmh]

Unpacked the frame last night. Looks good, weight is excellent, 960g - lighter than her Scale! Finish looks to be great, and when I pulled the bolts holding the derailleur hanger in place, I discovered that they already had a blue thread locker applied. Nice touch. Included covers for the frame holes look good.

Biggest problem I've encountered so far is I just cannot get the lower headset bearing installed. Should drop in, be a light press fit at most, but it just won't go in. Pulled out the calipers, the bearing measured 51.99mm (same number over about 10 measurements) but the bearing race (molded directly into the carbon frame) measured anywhere from 51.6mm to 51.8mm. I had one measurement of 51.5mm that I couldn't replicate. That's just too small, and would result in an interference fit. I don't think a press should be needed to install the headset bearings, especially since I'm not sure how the bearing would be removed when necessary. Park's page on headset standards and sizes specifies 52.1-52.15mm for this cup diameter as well as a "slip fit", so it's pretty far off. I'll be contacting Peter but am afraid this frame may have to go back.

[MTB2223]

Biggest problem I've encountered so far is I just cannot get the lower headset bearing installed. Should drop in, be a light press fit at most, but it just won't go in. Pulled out the calipers, the bearing measured 51.99mm (same number over about 10 measurements) but the bearing race (molded directly into the carbon frame) measured anywhere from 51.6mm to 51.8mm. I had one measurement of 51.5mm that I couldn't replicate. That's just too small, and would result in an interference fit. I don't think a press should be needed to install the headset bearings, especially since I'm not sure how the bearing would be removed when necessary. Park's page on headset standards and sizes specifies 52.1-52.15mm for this cup diameter as well as a "slip fit", so it's pretty far off. I'll be contacting Peter but am afraid this frame may have to go back.

Use a sanding paper to make it fit. I had to do this also on the frame of my daugther. It won't damage anything.

[cmh]

Use a sanding paper to make it fit. I had to do this also on the frame of my daugther. It won't damage anything.

I'm sorry, but I've got no interest in sanding a half millimeter off of a frame to get it to the proper spec. I gave it a light sanding before I measured with the calipers, then discovered how far off it was and stopped. I also discovered that it's not quite circular. The bearing is 51.99mm wherever I measure, but the cup in the frame was ~51.8 in one spot and ~51.6 in another.

This is something that should be a precision fit. Hand sanding won't guarantee it's either circular or concentric to the axis of the steerer tube. I'd also be modifying the frame in such a way that I couldn't expect any type of warranty support if it were necessary. Sanding would probably work, but I didn't buy a frame expecting to have to do extra finishing work that should have come from the factory.

[Vipassana]

Perhaps I missed it, but what size is this one?

Also, bummer about the headset.  I've heard this complaint from others time to time, but never on the 041 frame.

[trekcarbonboy]

Well that sucks! There's no way you should be expected to make that work. I see no good option but to request another.

[carbonazza]

I remember to have to press the bottom bearing. It didn't go manually.
I did not measure it though.
The top was snug but easy.

But before the brute force, it is probably better to wait for Peter.
Unfortunately it is the holidays over there.

[cmh]

I remember to have to press the bottom bearing. It didn't go manually.
I did not measure it though.
The top was snug but easy.

But before the brute force, it is probably better to wait for Peter.
Unfortunately it is the holidays over there.

Yeah, this one feels like it would be a *tight* press fit, like I'd need a hammer or press to get it in there.

Forgot about the holidays. No worries on that, this is to be a backup bike, so I can wait.

[bxcc]

I remember to have to press the bottom bearing. It didn't go manually.
I did not measure it though.
The top was snug but easy.

But before the brute force, it is probably better to wait for Peter.
Unfortunately it is the holidays over there.

Yeah, this one feels like it would be a *tight* press fit, like I'd need a hammer or press to get it in there.

Forgot about the holidays. No worries on that, this is to be a backup bike, so I can wait.

One thing you could try is to throw the bearing in the freezer for a half hour or so. I have to do that on some bearings at work. Especially when it's a steel bearing going into an aluminum or magnesium housing. Normally the housing is also heated to 150 degrees. Bell Helicopter's technical term is "thermal fit".

As far as a QC standpoint, it definietly isn't right. That seems way off. Sanding down a burr or paint drip is one thing, sanding to change a dimension is something else. Good luck either way.

[cmh]

One thing you could try is to throw the bearing in the freezer for a half hour or so. I have to do that on some bearings at work. Especially when it's a steel bearing going into an aluminum or magnesium housing. Normally the housing is also heated to 150 degrees. Bell Helicopter's technical term is "thermal fit".

Yep, have heard of/seen that done - probably f*ked the math but going from ~60F to ~0F would bring me from 51.99 to 51.94mm - still well shy of the 51.6mm ID.

As far as a QC standpoint, it definietly isn't right. That seems way off. Sanding down a burr or paint drip is one thing, sanding to change a dimension is something else. Good luck either way.

Thanks - got a reply from Peter who mentioned that they were on holiday but suggested I check here as well.

Looking at that Park Tool chart again, old-fashioned press-fit 1 1/8" headsets have 34mm cups, with the frame being 33.8 - 33.9mm. So something designed to be pressed in has a 0.1-0.2mm interference fit - vs. 0.3mm mismatch with this bearing. Wups.

[cmh]

Might as well share some of the photos...


Looks nice!


Weight is right on the money.


Derailleur hanger screws came with threadlock already!


...and here's the problem. The Park Tool site says this diameter should be 52.1-52.15mm. I measured around the circumference and got no dimension more than 51.8mm. That's an interference fit. It looks like the calipers are tilted, but they're not. The measurement is legit - and either way, the headset bearing does not fit in there.

[RS VR6]

Thats a good looking frame...bummer about the bearing.

[cmh]

Thats a good looking frame...bummer about the bearing.

Yeah, it sure is. Spent some more time with it today, and I sure hope we can get this ironed out, because it's damn nice looking. I took the time to check the upper bearing today (which fits) and I don't remember the numbers, but the diameter of the cup is only 0.1mm larger than the bearing - so that makes the amount that needs to be increased not quite as much... but I'm not doing anything else in the way of modifying the frame without the ok from Peter that the warranty would remain intact... and that'll have to wait until they're back from holidays.

One thing that irks me a little is that the cable entry for the rear derailleur housing is on the right (drive side) of the frame - same side as the shifter. I much, much prefer having the cables run from the shifter to the opposite side of the frame as it makes for a much nicer routing. Also, the replaceable cable entry ports are cool, but the ones that allow for the full-run housing that I'll want to run are just slightly oval holes, so the angle they make going into the frame is nowhere near what I'll want. Once I sort out the headset issues, those parts are going to have to be heavily modified to improve the cable entry angle. One guess regarding those stops is they're designed around Di2, which would handle sharper bends with less issue. The frame must have Di2 in mind, as there's a hole above and slightly ahead of the bottom bracket that can only be a battery hookup - it has no purpose in a mechanically shifted bike that I can imagine.

FWIW, the Scott suffers the same shifter/cable side issue, but I wind up using the front derailleur stop on the non-drive side. The FD stop on the 041 is not one of the replaceable covers, but similar to the brake hose routing, and it's mounted up on the top tube, so even if I ran the RD housing in there, it would have to take a strange angle after entering the frame to head towards the down tube. If I could have run it down the top tube and exited from the top of the drive-side seat stay, that would have been pretty cool, but there's no holes for that.

Sounds like I'm nitpicking, and I am, but I can be a fussy bitch about bike stuff, and this is what I'm noticing even before the build starts. I still think it's gonna make a wicked bike.

[cmh]

So I haven't done anything else with the bearings, but did spend some time with my good camera and the frame today, and took some better photos:

XM CarbonSpeed CS-041 album

The design of this frame is really starting to win me over. I have become such a fan of the seat cluster:



As I said in the album description:

"The seat cluster on this bike is gorgeous. The top tube is flattened, and takes a straight path to the rear wheels. The top tube splits into the seat stays in a very fluid way - it almost looks like the top tube was poured down over the seat tube, and the flow splits evenly into the two seat stays which mirror the profile of the top tube. Plus, the extra reinforcing rib running from the top tube to the seat tube, it just makes for a really, really pretty junction. I love the visual design of this frame."

Also, I complained about the cable routing, but while taking photos, I noticed something I hadn't noticed before:



There is a housing running through the frame for the shift cable that should make running the cable much easier. Get the shift cable inside the orange tube, and push it through until it comes out by the rear derailleur, easy peasy. I still prefer a full run of housing, but this looks to be bonded in place, so won't rattle. I still wish it was run on the non-drive side of the frame, as well.

[Carbon_Dude]

Looks like a really nice frame.