24" wheelbuild w/M41 Ergal Hub!

Just got back from “TBS” (Twins bike shop), and they did a SUPERB wheel build with my new M41 Aluminum hub, alienation “Deviant” rim and Intense micro knobby tire (100psi!)! The WHOLE 24" uni weighs…8.4 pounds! :astonished: :slight_smile:

The only thing that was a bit disconcerting-at least to me-was that the bearings seamed to take a lot more hammer strikes than usual (using deep socket) to get it seated all the way on. Then, the cranks didn’t even come close to going on far enough to contact the spacers (that came with the hub) so I just left them off. But they still went on far enough to be solidly on.

I’m guessing that after some riding they will need to be tightened up and thus go on further. Overall I am very happy with how it turned out and we all are very confident in the strength of the hub and flanges. It is a super solid build. I took it out for a little spin and it is so incredibly light, it felt almost as if I was ridinig on air! Can’t wait to try at Fargo!








If you don’t mind me asking, could you give me a ball park number on cost of something like that? Just curious as I’d be interested in building something similar in the future…

For the whole uni or just the M41 hub? The entire setup would set you back a bit over a grand. The hub alone is $210.

Nice looking wheel, expensive :astonished:

BTW, the spacers are there to prevent the bearing from shifting, so you might want to add some spacers, I had a bearing shift once while riding and it makes for a long walk home.

The M41 hub have a bearing stop molded into the hub, between the flange and bearing, so no separate spacer is used there. The other spacers that fit between the bearings and cranks are useless at this point until the cranks and/or the hub splines break in…a LOT! I test-fit several other cranks, with lithium grease on the splines, including an alloy pair that are fairly enlarged from riding. Even these would not go on more than about 1/2 way down the crank splines! To try forcing them on further would very likely strip the axle bolts! The bearings are also on incredible tight and are not about to move.

Non-Fat uni!

My new 24" climber weighs about the same as a gallon of milk! And like the milk I’m holding, it’s also non-fat! :p:D:) (I’ll be switching frames when my new Impact arrives today!)


I think you misunderstood, I was talking about the spacer between the crank and bearing. What happens is when cranking hard while pulling on the seat, the frame can push the bearing hard enough to make it slip on the spindle.

I had this happen on a big climb while riding muni, the frame “splayed” with the bearing, so the wheel was “cocked” sideways and I couldn’t reset the bearing onto the spindle without a hammer, so I had to walk home with the uni on my shoulder.

Yeah, I understood what you meant. But the bearings are on so tight you cannot believe! And I’ll only be using this uni for very steep climbs that are less than 1/4 mile long, like Fargo. I plan to do many local climbs to break it in, but I want the cranks to work their way onto the axle splines a bit more before I add any spacers that would prevent that.

I have the cromo Mad4one hub and I had to beat the crap out of my seat post cut off bearing presses as well to get mine on.

The spacers that came with the hud were too narrow for my moment cranks, but I have about 3 different sizes as the multitude of crank and hub permutations I have with 5 different cranks and 6 different hubs requires different spacers and at £1 a set it is worth having some of each.

Cranks shouldn’t wear in to the ISIS taper the 2 degree taper is not designed to hold the crank like a cotterless interface so it needs a hard stop in the form of a spacer that the crank is torqued against, if you use loctite you can run without a spacer but things will creep and wear over time

Looks a nice build though, not tempted to build it yourself, I would have thought with your profession you would be fantastic at it, plucking those spokes and tensioning by ear :stuck_out_tongue:

Every crank I’ve installed has come to a “hard stop” at the same point on the axle spline, and absolutely will NOT go any further. I’ve tried different combinations of spacers to fill the space, but it’s either too much or too little. M41 apparently made the fit tolerances on these hubs much less than the usual ISIS hubs I have, like nimbus and KH. With those, the cranks go on with resistance, but have no trouble contacting the spacers when tightened. Same thing for bearings on the kh or nimbus hubs; they tap on dead easy compared to the M41. I’m assuming the reason for the overly tight tolerances is because Aluminum will wear/lose material faster than chromoly.

Maybe they did that for the ALi one but the CroMo one seems to use the same dimensions for the splines as mine is just as tight and needs an 8mm (I think) spacer rather than a 6mm

My Echo cranks are like a wizards sleeve and needs a 4mm on a KH / Nimbus hub but probably a 6mm on the Mad4One.

Doesn’t take much variance in the taper of the axle or crank to make things sit at different points.

Nice build Terry !

+1 :slight_smile:

oooh you getting the Impact Gravity, did notice that :slight_smile:

Mine is holding up to my hamfisted 4+ foot drops so I am sure it more than stand up to hill climbing :stuck_out_tongue:

With the newly arrived Impact gravity frame. Still 8.4 pounds! :sunglasses:


The wheel’s on backwards.

It was just a quick fit for the pic. But thanks for being so observant. Btw, it doesn’t matter which way the tire is mounted in this case.

Turns out I have to send the hub back to M41 (to Marco in Italy!) to have it either re-machined or replaced! No matter which cranks I’ve tried; moments, nimbus and quax, all standard ISIS, NONE will go on more than 1/2 way onto the axle splines! I’ve tried grease and then initial setting with a rubber mallet, but they just will not budge past the 1/2 way point! That leaves close to a 12mm gap between the cranks and the bearings! That’s 4mm more than the 8mm max Marco told me.

Marco warned that attempting to torque the axle bolt beyond the max of 35nm will result in the thread either stripping or the bolt breaking off inside! I used calipers to measure the difference between the outer and inner diameter of the M41 splines, vs the the measurements on my kh and nimbus hubs. Btw, all of my cranks fit those hubs perfectly.

The difference was small, but apparently enough to cause this fit issue. The M41 splines OD and ID are about 1/3mm larger than my kh and nimbus axles. That would probably explain it! They also need to correct the excessively tight bearing fit. :frowning: