Sensah Empire
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Re: Sensah Empire
Postby familyguy » Thu Jun 23, 2022 12:02 pm
The BB shell size is correct at 68mm. The spacers appear to be 2.5mm x 2 to allow the same cranks to fit a 68mm shell when used and a 73mm shell when not used.
Brings back shades of the multiple spacer systems I wound up going through to make the Force crankset (similar system, single bolt on NDS, no adjustment available) play happy with a slightly off-sized BB shell width.
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Re: Sensah Empire
Postby trailgumby » Thu Jun 23, 2022 1:04 pm
I'd call it production tolerances. While the BB shell is 68mm,is it 68.00mm, 68.05mm or 68.2mm?
When specifying bearing fit, for example, a difference of 0.05mm on the inside diameter of the bearing is the difference between the bearing being a firm fit, an interference fit, or unable to fit. It's why FSA 24mm Mega Exo crank spindles are incompatible with Shimano XT Hollowtech II bottom brackets, and you have to continue to use and frequently replace their overpriced rust magnets (in case you were unclear what I think about FSA drive train products ).
Given the way composites can move and misalign when they cool down, it's my view that some kind of method of compensation so that moving parts can operate at their correct tolerances is essential, and indeed this is why you see it on most reputable drive train manufacturers.
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Re: Sensah Empire
Postby 2wheels_mond » Fri Jun 24, 2022 7:30 am
Thanks for doing this - it's been good to follow along. I've been following the production of this groupset for a little while now and it seems like they've done some running changes over time of the major faults (eg the plastic lever is now aluminium, they've updated the hood rubber and they've stopped the lever digging in to the body) to the point now where it stands on its own reasonably well.familyguy wrote: ↑Thu Jun 23, 2022 11:12 amDespite all this sounding doom and gloom, if I can overcome these niggles, I think it's a worthwhile groupset, frankly. Feels good in the hand, does what it should, won't break your bank balance. With Di105 on the horizon that might leave Tiagra as Shimano's workhorse cable gruppo, this might make a 22s cable group like this more attractive to some people.
Keen to try it out, except I'll probably experiment with it in the Team Pro format (Shimano 11 compatible shifters) since I have a spare 5800 FD and RD lying around. Looks like there's some better Chinese brake options around too now (eg ZRace 700 for rim and ZRace BR 005 for disc), reviews of earlier Chinese brakes seem... less than ideal.
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Re: Sensah Empire
Postby nickobec » Fri Jun 24, 2022 9:07 am
The bearing preload is supposed to be handled by the wave washer, as the crank (less the 2mm step down on the non drive side) is the same as SRAM. That is assuming the spline on spindle to non drive side arm interface is a tapered like SRAM, if the spline is straight like Shimano, life gets interesting.trailgumby wrote: ↑Thu Jun 23, 2022 11:54 amAdjusting the cap clearance will have no impact on bearing preload - the room you're aiming to provide is on the wrong side, and will only impact what happens when you loosen the crank axle bolt.
I'd call the lack of end float/preload adjustment a design failure. Obviously it's designed to save cost, but it's quite inappropriate.
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Re: Sensah Empire
Postby familyguy » Fri Jun 24, 2022 9:55 am
trailgumby wrote: ↑Thu Jun 23, 2022 1:04 pm
I'd call it production tolerances. While the BB shell is 68mm,is it 68.00mm, 68.05mm or 68.2mm?
When specifying bearing fit, for example, a difference of 0.05mm on the inside diameter of the bearing is the difference between the bearing being a firm fit, an interference fit, or unable to fit. It's why FSA 24mm Mega Exo crank spindles are incompatible with Shimano XT Hollowtech II bottom brackets, and you have to continue to use and frequently replace their overpriced rust magnets (in case you were unclear what I think about FSA drive train products ).
Given the way composites can move and misalign when they cool down, it's my view that some kind of method of compensation so that moving parts can operate at their correct tolerances is essential, and indeed this is why you see it on most reputable drive train manufacturers.
This is what's weird. The lack of anything to take up even a little slack in the system is worrying. While I say its a failure, this is maybe a little tongue in cheek (just a little). I REALLY like it when things bolt together, but maybe this is just a fascination with quality machining coming out. Expecting tolerances to be uniformly tight across a range of manufacturers and systems IS too much. Would be nice if every shell was 68±0.01mm without worrying and you could just bolt up any BB and crank.
nickobec wrote: ↑Fri Jun 24, 2022 9:07 amThe bearing preload is supposed to be handled by the wave washer, as the crank (less the 2mm step down on the non drive side) is the same as SRAM. That is assuming the spline on spindle to non drive side arm interface is a tapered like SRAM, if the spline is straight like Shimano, life gets interesting.trailgumby wrote: ↑Thu Jun 23, 2022 11:54 amAdjusting the cap clearance will have no impact on bearing preload - the room you're aiming to provide is on the wrong side, and will only impact what happens when you loosen the crank axle bolt.
I'd call the lack of end float/preload adjustment a design failure. Obviously it's designed to save cost, but it's quite inappropriate.
The NDS crank and spindle arrived preassembled. Single 8mm hex fitting but it's not going to undo in a hurry unless I get a long bar. I'd say the intent is that you don't need to undo it. The splines on the DS are straight, no taper, so I'm guessing the NDS is the same and it's a reversible spindle.
Anyway, I ripped this all off when I got home last night. Having tightened the crank before leaving work, it was only a little loose when
I got home 15 minutes later. Upon doing this, I discovered some things:
- The binding on the system had been so tight it had loosened the bearing cups in the shell. Both sides were less than finger tight having been installed to a torque I generally use for Shimano or GXP cups without a worry. At least the BSA system worked as intended and simply undid the cups rather than lock up and fail.
- The DS crank has the spider held on by three torx bolts. Having had to be cranked so tight, these bolt heads had contacted the cup and effectively machined off the outer face of the alloy cup and the plastic bearing cover. Evident by the bright line around the cup. And the plastic swarf that fell out when I took the DS crank assembly off. You can see the aluminium swarf around the bolt closest to camera in the photo.
- The cups have a plastic bearing cover which extends into the cup and forms the sleeve that the spindle sits in. So it's really sitting on a plastic sleeve, not the bearing. Almost certainly that will fail/degrade over time and introduce slack. You can see in the photo that the plastic bearing cover extends downwards into the cup forming this sleeve.
I quickly reassembled with more torque on the cups to make sure that wasn't the culprit in all this. Same deal, too tight to spin the cranks except with force by hand or foot. So the movement outwards of the cups was just the effect from a cause. The DS BB cup bearing may even have been compromised by this tightening, so I will rip the plastic off and check it. There are only two other spacers in the box (2mm and 4.5mm) marked for DUB system installation. There is no wavy washer, no other cap, bearing or spacers. Nothing in the crank bag, nothing was left in the original box, nothing in the plastic tub I've had this in for some time.
Now, while I've been known to ham-fist some things in the past, this is looking like a bad system that needs some sorting out to get right. Far from bolt-and-go.
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Re: Sensah Empire
Postby warthog1 » Fri Jun 24, 2022 10:07 am
A scratching for me thanks to your detailed review.
It has been an interesting read.
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Re: Sensah Empire
Postby familyguy » Fri Jun 24, 2022 10:21 am
I'd be fully prepared to go for the rest, slightly troublesome FD and all. It performed acceptably on the road, so I think the fine tuning and cage turning cracked that nut. If you have a 10s or 11s crankset you can sub in, still worth considering.
This was as much a personal exercise in 'is it really saving money?' as anything, so it's been oddly fun, if a little frustrating at times
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Re: Sensah Empire
Postby warthog1 » Fri Jun 24, 2022 10:32 am
Your patience and ability are both higher than mine.familyguy wrote: ↑Fri Jun 24, 2022 10:21 am
I'd be fully prepared to go for the rest, slightly troublesome FD and all. It performed acceptably on the road, so I think the fine tuning and cage turning cracked that nut. If you have a 10s or 11s crankset you can sub in, still worth considering.
This was as much a personal exercise in 'is it really saving money?' as anything, so it's been oddly fun, if a little frustrating at times
I just want stuff that bolts together and works with the minimum amount of frigging around.
105 has done that at my level.
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Re: Sensah Empire
Postby trailgumby » Fri Jun 24, 2022 10:35 am
Soft drink cans are generally about 0.1mm thick, and make great shim material. Why not make an eight-sided star shaped shim to fit in the bottom of the socket in the drive-side crank (use the drive-side end of the spindle as a template) to pack out the drive side? You can use a hobby knife or curved-tipped scissors used for trimming polycarbonate R/C model car bodies to cut the shape.
Keep adding 0.1mm increments to pack out the crank until you get sufficient clearance to solve the problem. Then see if you can acquire some brass or steel shim material from an industrial supply company.
I'm not far from you and have both a digital vernier and micrometer we can use to verify the thickness once you've worked out how many coke can shims are needed.
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Re: Sensah Empire
Postby familyguy » Fri Jun 24, 2022 10:54 am
True, that. I've got an abundance of groupsets that I can just put on and not have to kludge. This is tipping the parts aside from the shifting and braking setup into "nah, not worth it" territory. For the slightly lower quality build appearance of the brakes, they are actually really good on modulation and power.warthog1 wrote: ↑Fri Jun 24, 2022 10:32 amYour patience and ability are both higher than mine.familyguy wrote: ↑Fri Jun 24, 2022 10:21 am
I'd be fully prepared to go for the rest, slightly troublesome FD and all. It performed acceptably on the road, so I think the fine tuning and cage turning cracked that nut. If you have a 10s or 11s crankset you can sub in, still worth considering.
This was as much a personal exercise in 'is it really saving money?' as anything, so it's been oddly fun, if a little frustrating at times
I just want stuff that bolts together and works with the minimum amount of frigging around.
105 has done that at my level.
Correct, no taper evident. I have to dig my calipers out, they're here someplace on the bench, I'm sure! The tin snips and brass 0.2mm plate will be in action, maybe not over the weekend pending the other things required to be accomplished first. Once I get a block of time, I'll space the DS BB out from a 1.5mm start to find the happy place. I can probably machine up to 0.5 off the face of one of the supplied spacers on my hardware without running into issues with the narrowness on the chuck, but making complete ones out of anything but softer materials calls for the big lathe at dads place.trailgumby wrote: ↑Fri Jun 24, 2022 10:35 amHere's a bit of a left-field suggestion. I'm assuming there's no taper on the spindle spline.
Soft drink cans are generally about 0.1mm thick, and make great shim material. Why not make an eight-sided star shaped shim to fit in the bottom of the socket in the drive-side crank (use the drive-side end of the spindle as a template) to pack out the drive side? You can use a hobby knife or curved-tipped scissors used for trimming polycarbonate R/C model car bodies to cut the shape.
Keep adding 0.1mm increments to pack out the crank until you get sufficient clearance to solve the problem. Then see if you can acquire some brass or steel shim material from an industrial supply company.
I'm not far from you and have both a digital vernier and micrometer we can use to verify the thickness once you've worked out how many coke can shims are needed.
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Re: Sensah Empire
Postby foo on patrol » Sat Jun 25, 2022 8:27 am
Interesting to see this, because my mate that has a full groupo has not had any of these problems.
Foo
Goal 6000km
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Re: Sensah Empire
Postby warthog1 » Sat Jun 25, 2022 12:53 pm
Family Guy has given enough detail to put me off.foo on patrol wrote: ↑Sat Jun 25, 2022 8:27 am
Interesting to see this, because my mate that has a full groupo has not had any of these problems.
Foo
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Re: Sensah Empire
Postby trailgumby » Sat Jun 25, 2022 1:48 pm
foo on patrol wrote: ↑Sat Jun 25, 2022 8:27 am
Interesting to see this, because my mate that has a full groupo has not had any of these problems.
Foo
This is why I think manufacturing tolerances are the issue, at least on the crank set. Might not be Sensah, more likely to be the frame manufacturer, but this is why I think some kind of side float/preload adjustment on the crank spindle is not optional for aftermarket gear.
Unless..
I've just noticed that there's no side float adjustment on either set of BB30a Hollowgram cranks on my latest two acquisitions. Given they're all out of the same manufacturer, signoff that tolerances are within spec for crank and BB width in the frame will have the same owner, so you would presume the product would (should) not be allowed out the door unless the frame and cranks match up.
Absent shims being provided to space out the float, I wouldn't be acquiring Cannondale cranks for a non Cannondale bike.
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Re: Sensah Empire
Postby familyguy » Sat Jun 25, 2022 5:04 pm
The crank extraction cap bolt is 16Nm, with no apparent fitment to common tools.
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Re: Sensah Empire
Postby 2wheels_mond » Sun Jun 26, 2022 2:57 pm
https://www.aliexpress.com/item/1005003430944922.html
It's a bit more expensive than some of the other options, but uses a DUB BB and a similar DUB preload adjustment piece.
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Re: Sensah Empire
Postby trailgumby » Sun Jun 26, 2022 8:18 pm
2wheels_mond wrote: ↑Sun Jun 26, 2022 2:57 pmInterestingly, Sensah now has an official crank (or at least these are the ones listed in their catalogue):
https://www.aliexpress.com/item/1005003430944922.html
It's a bit more expensive than some of the other options, but uses a DUB BB and a similar DUB preload adjustment piece.
Very SRAM-like in its design. I wonder if SRAM will take the compliment.
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Re: Sensah Empire
Postby familyguy » Wed Jun 29, 2022 8:55 am
So, I'll put some more km on it via commutes (bike is too small to be comfortable over longer rides) and then see what I do with it. Now that I have it working, swapping it to a nice steel frame might be in order.
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Re: Sensah Empire
Postby familyguy » Thu Jul 07, 2022 10:50 am
Especially if you want to make the jump to 11s or 12s without paying recent upcoming product announcement prices (I'm looking in your direction, newly announced disc-only 105)
While the prices are jumping due to time and various other factors and are sitting around $550-600 for the Empire group with a revised crankset, Australian retailer prices for big makers are around:
Centaur 11s - c.$1200
Shimano 105 R7000 11s - c.$1000
SRAM Rival eTap 11s - c.$1800 (if you can get a rim brake set)
Shimano Sora 9s - c.$450 (if you can get one at all)
If you have rim brake frames and want to keep them alive, this is almost a no-brainer now that the options appear to be getting narrower from the big 3. I removed the crankset and installed it on another frame to check my BB setup wasn't off (narrator: it wasn't, it was just a really odd issue) with the same spacer issue result, but in the absence of a larger sample set, the 1.5 hour of adjusting and checking over the two installations resulted in a usable bike that performed well for a $600 groupset.
I've whipped this stuff off and the frame is going (too small) and look forward to rebuilding it onto something else in the near future.
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Re: Sensah Empire
Postby 2wheels_mond » Thu Jul 07, 2022 10:05 pm
I don't think SRAM sell Rival 11 speed mechanical as a full groupset any longer, though individual components still seem to be available.
Centaur is slightly cheaper from European retailers ($900-ish from the major German retailers), but stock seems to be an issue.
In any case, this stuff is a boatload cheaper now and it'll be interesting to see if it gets much traction in the broader market (particularly if any OEMs decide to start using it). There's more of it starting to appear on Youtube now too which provides another useful resource.
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Re: Sensah Empire
Postby nickobec » Fri Jul 08, 2022 11:59 am
On the OEM front a few years back, a guy I worked with bought a new entry level Cannondale with Microshift, and a quick google says Cannondale still spec Microshift on some bikes.
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Re: Sensah Empire
Postby baabaa » Wed Aug 03, 2022 7:02 pm
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Re: Sensah Empire
Postby familyguy » Mon Jan 29, 2024 1:09 pm
This has seen a couple of bikes and a few more km now.
By way of final judgement relating to some of the points in the previous pages of discussion...
Would I recommend this to someone as an upgrade path without the expense or hassle of Shimano/SRAM/Campagnolo? Absolutely.
It works well. The niggles can be overcome or worked out with a little of the knowledge in the previous pages. I've now bolted it onto 3 frames in total, with none of the FD setup hassles or BB issues given the spacing knowledge. I understand (via another user of the updated crankset) that the spacing quibbles are not really an issue now. Shifts are crisp without being road-race rapid. FD changes up and down fine and trims OK, too. Shifters feel good in the hands. Hoods can be sourced easily enough.
It's hanging on the Merlin as a graveleur/gravelesque build and plays happily with the Avid Shorty Ultimate cantilever brakes, as you'd expect for a road cable-pull group.
The 11s Empire group with crank can still be sourced for c.$420 landed. The 2x12 Empire Pro can be found for as little as $590 landed. If it's the same principles, it's a bargain 12s upgrade path.
Thanks for watching...
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Re: Sensah Empire
Postby warthog1 » Mon Jan 29, 2024 1:46 pm
That sounds far more positive and certainly it is cheap.
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Re: Sensah Empire
Postby familyguy » Mon Jan 29, 2024 3:12 pm
Honestly, aside from the crank issue that seems to have been re-engineered out, it's way beyond any general consumer level group I've used (I'm lumping this as Claris, Sora, Tiagra, Apex), maybe even some of the sport-oriented groups (105, Rival, Veloce). Very line ball with same-era Ultegra and Force for mine. I'm enjoying the additional gear and mid-compact cranks, too.
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