Crux 2021

The spirit of Grav-lo-cross. No but seriously, cyclocross and gravel go here!

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takolino
Posts: 340
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

No reason to remove the cups, especially on a new frame. If LBS is doing the install, either one piece or the threaded insert will work. The advantage of using the threaded sleeve is that you can use Shimano BSA bb and replace cheaply and easily when they wear out. The one-piece bb will require an extractor and a press to swap out the bearings. No big deal if you already know how and have the tools.

rothwem
Posts: 211
Joined: Wed Jul 09, 2014 4:45 pm
Location: Asheville, NC

by rothwem

Fwiw, I've got a 2021 Crux and I'm running a Sram bb30 crank and just the bare bearings pressed into the glued in sleeve. I've got zero creaking despite some hard treatment, mud and minimal washing. I'd just run a bb30 crank and not worry about it.

As for a long term review--I really like the bike. I went with the cheapo Apex build and I hate the brakes, but the frame itself has been great. I wish it had a smidge more tire clearance, but realistically I wouldn't run much more than a 40 anyways.

The handling is really quick for a gravel bike, which is refreshing considering that around 2018ish, the trend was to make a gravel bike as boring as possible to ride.

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steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

rothwem wrote:
Fri Dec 23, 2022 10:10 pm
Fwiw, I've got a 2021 Crux and I'm running a Sram bb30 crank and just the bare bearings pressed into the glued in sleeve. I've got zero creaking despite some hard treatment, mud and minimal washing. I'd just run a bb30 crank and not worry about it.

As for a long term review--I really like the bike. I went with the cheapo Apex build and I hate the brakes, but the frame itself has been great. I wish it had a smidge more tire clearance, but realistically I wouldn't run much more than a 40 anyways.

The handling is really quick for a gravel bike, which is refreshing considering that around 2018ish, the trend was to make a gravel bike as boring as possible to ride.
Thanks! If I didn't want to run it with Shimano cranks, I wouldn't even worry about the BB at all. But in any case, it's reassuring to hear that the BB30 tolerances on your frame are decent

rothwem
Posts: 211
Joined: Wed Jul 09, 2014 4:45 pm
Location: Asheville, NC

by rothwem

steveadore wrote:
Sat Dec 24, 2022 12:25 pm
rothwem wrote:
Fri Dec 23, 2022 10:10 pm
Fwiw, I've got a 2021 Crux and I'm running a Sram bb30 crank and just the bare bearings pressed into the glued in sleeve. I've got zero creaking despite some hard treatment, mud and minimal washing. I'd just run a bb30 crank and not worry about it.

As for a long term review--I really like the bike. I went with the cheapo Apex build and I hate the brakes, but the frame itself has been great. I wish it had a smidge more tire clearance, but realistically I wouldn't run much more than a 40 anyways.

The handling is really quick for a gravel bike, which is refreshing considering that around 2018ish, the trend was to make a gravel bike as boring as possible to ride.
Thanks! If I didn't want to run it with Shimano cranks, I wouldn't even worry about the BB at all. But in any case, it's reassuring to hear that the BB30 tolerances on your frame are decent
I guess going to a non-Shimano crank isn't an option? The plain bearings are way lighter (and cheaper) than any adapter/thread together setup will be.

takolino
Posts: 340
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

Agree. I was using a Hollowgram SiSL with 46-30 spidering which gave me the low gearing I needed and never a creak. Native bb30 cranks would be my first choice. Outboard bb on a narrow shell press fit is asking for trouble unless you go with a one piece retrofit like the bbinfinite. But this is adding weight along with the longer than necessary spindle and a wider crank. I miss the ample ankle clearance.


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steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

I'm more of a brand purist (and less of a WW) when it comes to cranksets and prefer Shimano (I've tried Praxis and went back to Shimano GRX). It's just an irrational thing with me, which has to do with perceived shift quality.
The Hollowgram looks great (though C'dale on a Spec?) and is light too, but no, thank you :D
My real question, however, is why is the outboard bearing and longer crank axle a problem? Disregarding the extra weight added by either a FSA sleeve+Shimano BSA HTII BB or pressing in a one-piece Hambini/BBinfinite-style BB (both used with a Shimano HTII crankset), why would this be technologically or structurally inferior to pressed-in BB30 (42mm outer, 30mm inner bearings) used with a 30mm axle BB30 crankset?

rothwem
Posts: 211
Joined: Wed Jul 09, 2014 4:45 pm
Location: Asheville, NC

by rothwem

steveadore wrote:
Mon Dec 26, 2022 9:40 am
I'm more of a brand purist (and less of a WW) when it comes to cranksets and prefer Shimano (I've tried Praxis and went back to Shimano GRX). It's just an irrational thing with me, which has to do with perceived shift quality.
The Hollowgram looks great (though C'dale on a Spec?) and is light too, but no, thank you :D
My real question, however, is why is the outboard bearing and longer crank axle a problem? Disregarding the extra weight added by either a FSA sleeve+Shimano BSA HTII BB or pressing in a one-piece Hambini/BBinfinite-style BB (both used with a Shimano HTII crankset), why would this be technologically or structurally inferior to pressed-in BB30 (42mm outer, 30mm inner bearings) used with a 30mm axle BB30 crankset?
Hey if you want to be irrational that's fine. However a Bb30 crank in a good native BB30 frame is the best thing to use. Lighter, simpler, better.

If you really want to use Shimano rings for the shifting, you can get a quarq or a power2max power meter for Shimano rings and use that. And you get power measurement!

allrandomletters
Posts: 67
Joined: Thu Jul 15, 2021 2:46 pm

by allrandomletters

The frame is NOT a native BB30 frame. The frame is OSBB (46mm x 61mm) - a narrower version of PF30 (46 x 68). That is why Specialized has epoxied cups into the frame. The epoxied cups convert the OSBB frame to BB30. There is no connection laterally between the two epoxied cups, which introduces the possibility of creaking or premature bearing failure from lateral misalignment between each side.

My stock previous-gen Crux came installed with the 2 cups, plus a 2 piece Praxis M30 threaded bottom bracket, and the Zayante carbon crankset. The simplest, best, most robust and possibly even the lightest solution would be to remove the threaded bottom bracket and the 2 cups, and replace it with a single piece bottom bracket like the Hambini or BB-infinite, which would have the bearing directly mounted. This solution eliminates the 4 more complicated pieces (2 cups plus 2 piece threaded BB).

The spindle and cranks are standard road, not wider/longer. Hope this clears up some of the misconceptions about the frame and it's BB that I am seeing from people who seem to have no actual experience with it. More information can be found here - would apply to any other 1 piece solution.

https://www.bbinfinite.com/blogs/news/s ... val-solved

takolino
Posts: 340
Joined: Sun Nov 13, 2016 9:11 am
Location: USA, SF Bay Area

by takolino

allrandomletters wrote:
Tue Dec 27, 2022 4:47 pm

...The spindle and cranks are standard road, not wider/longer. Hope this clears up some of the misconceptions about the frame and it's BB that I am seeing from people who seem to have no actual experience with it. More information can be found here - would apply to any other 1 piece solution.

https://www.bbinfinite.com/blogs/news/s ... val-solved
Perhaps my statement was a bit unclear. When I said "longer" I meant longer than spec on a bb30 frame. People are free to use whatever crank they like but in general, it's best to stick to the BB type that the frame was designed for. There are many reasons but I won't go into it here. The video you linked has already been discussed. I don't recommend this for new frames or anyone uncomfortable with using a hack saw on a frame.
steveadore wrote:
Mon Dec 26, 2022 9:40 am
I'm more of a brand purist (and less of a WW) when it comes to cranksets and prefer Shimano (I've tried Praxis and went back to Shimano GRX). It's just an irrational thing with me, which has to do with perceived shift quality.
The Hollowgram looks great (though C'dale on a Spec?) and is light too, but no, thank you :D
My real question, however, is why is the outboard bearing and longer crank axle a problem? Disregarding the extra weight added by either a FSA sleeve+Shimano BSA HTII BB or pressing in a one-piece Hambini/BBinfinite-style BB (both used with a Shimano HTII crankset), why would this be technologically or structurally inferior to pressed-in BB30 (42mm outer, 30mm inner bearings) used with a 30mm axle BB30 crankset?
The reason I would not go with a two piece outboard bb is because of my design background and obsessive nature. If the tolerances are good and the press fit has sufficient tightness, it should be fine. But for the crux, there's already a cup. Then if you add another outboard cup, you've added another tolerance layer. And the outboard placement of the bearing (this is my main concern) puts shear force into the mix. So, to me, there's more that can go wrong in this configuration. It could still work. But if I hear a creak, I'd be kicking myself.
As for spindle length (longer than spec for the BB30), I personally appreciate the narrower BB30 cranks (at the crank bolts) for reduced foot and ankle rub in addition to the typically lighter weight.

steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

Just to double check: Isn't the Crux BB30 regular 68mm width rather than the old, narrower 61mm width OSBB? I thought that was discontinued by Specialized around the time the Tarmac SL5 was launched. I am well familiar with the issues of that old, proprietary OSBB, but that surely doesn't apply to this 2021 Crux, does it?
As for native vs non-native, I'm not sure. I have the alloy E5 Crux (2018 model) now, which has a proper (42mm diameter) BB30 (68mm wide btw) BB hole in the frame and I have had the cheapo FSA adapter sleeve with threaded BSA Shimano HTII bottom bracket installed for almost three years, since I wanted to use GRX cranks instead of the stock Praxis Alba (and the Praxis BB). Not a peep, not a creak, it's rock solid. Pressing in the FSA adapter sleeve was quite easy and tolerances on the frame seemed quite good (I have had major issues pressing in the same adapter into a different brand frame in comparison).
Now, of course, that's an alloy frame, and there are no extra epoxied cups between the adapter sleeve and the frame, that's precisely why I asked in my first post here about the pros and cons of using an adapter WITH the epoxied cups left intact in the frame. IF the epoxy bond is rock solid and the cups are well aligned, it should work, but that's two big questions marks in my book.
As I already mentioned in my first post, I'd rather not risk the hacksaw/removal option for the cups on a brand new frame. Besides, if the 46mm hole tolerances in the carbon frame turn out to be "less than ideal" (to quote Luescher) after the removal of the alloy cups, the installation of a Hambini/BBInfinite type BB could itself be a bit tricky. On my old Specialized mountain bike with native PF30 (46x73mm) I have a pressfit, thread together in the middle Hope BB (for 24mm Shimano cranks) installed in the carbon frame and I have not had any issues with it in 5 years. And I might try something similar in the Crux if it came with a regular PF30 carbon BB tube. But removing epoxied alloy reducer cups is really not sth. I fancy experimenting with.
Allrandomletters is right in pointing out that the BB30 is technically, not native on the Crux, as there's already one layer (glued in cups) in between the BB30 bearings and the frame (and this could, in principle, cause trouble too).
But why does the outboard placement of the bearings (with a Shimano conversion adapter installed with Loctite into the BB30 epoxied cups) create extra "shearing forces"? The unibody adapters (either the FSA sleeve or a Hambini BB) should not have a more negative impact on the epoxied cups than a 30mm axle spindle with pressed in BB30, right? This is the part that is not quite clear to me (I'm not an engineer, so I may well be wrong)

Petz
Posts: 29
Joined: Wed Apr 07, 2021 8:44 am
Location: Austria

by Petz

Image

First few rides done on my new Crux.
Just feels amazing both on the road and on gravel/dirt :D

Weight is around 8,1kg including a small light, saddle bag and a bit of mud.

Rival Shifters, Brakes, RD, FD
Force Crankset
Red 10-33 Cassette and Chain
Wheelset: Light Bicycle WR35 Rims, Hope RS4 hubs und Sapim CX Ray/Sprint spokes
Panaracer Gravel King Slick + 38mm
Newmen Stem and Pro Discover Alloy Bar

allrandomletters
Posts: 67
Joined: Thu Jul 15, 2021 2:46 pm

by allrandomletters

I am not sure what the BB is on the alloy Crux. My experience is only with the carbon model.

I *think* the issue with outboard placement of bearings is the additional leverage and torque that it will provide, causing more flexing and twisting in the frame.

If you've had no issues with your bearings, cranks or shifting, I would recommend spending effort on more tangible improvements. If it ain't broke. . .

steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

allrandomletters wrote:
Thu Dec 29, 2022 3:55 pm
I am not sure what the BB is on the alloy Crux. My experience is only with the carbon model.

I *think* the issue with outboard placement of bearings is the additional leverage and torque that it will provide, causing more flexing and twisting in the frame.

If you've had no issues with your bearings, cranks or shifting, I would recommend spending effort on more tangible improvements. If it ain't broke. . .
The Crux E5 (alloy) has native BB30 (42x68 mm). It came with Praxis BB originally, which I removed and installed the FSA adapter sleeve (which basically allows for the use of regular Shimano HTII threaded BSA bottom brackets.
Now I'm planning to replace this alloy Crux with a carbon 2021 Crux, so that's why I've raised the whole issue of cups, adapters etc.

rolfo
Posts: 113
Joined: Sun Apr 23, 2006 11:15 pm
Location: Netherlands

by rolfo

Hi Fellow bikers,

I'm want to go for a Specialized Crux and found a 52cm and a 54cm (pretty rare ;-).

I have a Specialized Aethos in size 54, so first choice would be a 54. But if I look at the stack and reach a 52 would also be possible:

- 54cm: 100 stem and 5 mm spacers under stem.
- 52cm: 110 stem and 15mm spacers under stem.

Should I go for the 54cm as adviced by Specialized (long reach short stem plan)? Or go for a 52cm as I'm looking for and Aethos with fat tires which rides as a road bike (which I ride a lot on the road ;-)

Thanks!

by Weenie


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User avatar
TheDoctor
Posts: 195
Joined: Sun Dec 17, 2017 9:56 pm

by TheDoctor

rolfo wrote:
Wed Jan 04, 2023 11:28 am
Hi Fellow bikers,

I'm want to go for a Specialized Crux and found a 52cm and a 54cm (pretty rare ;-).

I have a Specialized Aethos in size 54, so first choice would be a 54. But if I look at the stack and reach a 52 would also be possible:

- 54cm: 100 stem and 5 mm spacers under stem.
- 52cm: 110 stem and 15mm spacers under stem.

Should I go for the 54cm as adviced by Specialized (long reach short stem plan)? Or go for a 52cm as I'm looking for and Aethos with fat tires which rides as a road bike (which I ride a lot on the road ;-)

Thanks!
FWIW, I have a Tarmac SL6 and a Crux both in 54, saw no need to size down. In case you're looking at an S-Works frame that comes with the Alpinist seatpost, do consider your saddle height as well. The stock Alpinist post length on these frame sizes is "only" 300mm with an 80mm min. insertion. If you have a relative large saddle height that might be an issue with the 52.

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