I’m interested in purchasing a mad4one hub, but I’m not sure which one to purchase. My biggest reason for purchasing one is for the weight savings, so ideally id buy the aluminum one, but am skeptical of the strength in comparison to the cromo. All of the hubs I have seen people use have been the cromo hub, but I don’t know where to look for the reviews of the aluminum one. This will be strictly for my flat unicycle (rolls obviously but Also flips and spins =P) so curious of all input, preferably of the well informed 
The reinforced ergal hub kit that Mad4one has to offer is very strong. I use it for street right now and have no issues with it. If you are going to ride strictly flatland I highly suggest purchasing it. The kit is extremely light and feels amazing to ride with.
My question is whether the M41 ergal (aluminum) hub will withstand heavy pedaling downforces during steep hill climbing on smooth paved streets? This will be my primary use for this hub, and there will be no impact forces such as drops or riding over rough terrain.
The later pinned version that Jacob is running looks pretty awesome and if it stands up to his abuse it will be fine for the majority of people but I think that we are talking about the standard ISIS axles in that case I would suggest the CroMo small flange one as it is very light (and not really in a place you will notice it anyway, and that’s coming from a weight weenie) and the slight increase in weight saving at the risk f twisting/ breaking and axle isn’t worth it, a sharp sheared axle stub and soft flesh are two things you don’t want to meet . If you have the cash get a Titanium eXceed hub as it is the same design and 80g lighter (and over twice the price).
I run the 32 hole version on my trials and it is rather lovely and lets me run trials bike rims, if I get some more cash my 32 hole 24" Muni/big street build might get one as an upgrade from the heavy 32h nimbus (but like I say it is a poor place to lose weight and it would just be me being a tart) 
ISIS “few years old” I wouldn’t give a try as I’ve read that it is not strong enough for uni-basket player weighting more than 80kg (180+ lbs)
the new M41 reinforced with pin definitely.
Look at Jacob vid’s…
And I’m close to 220lbs with equipment and enjoying Alpine-muni with one reinforced m41 hub.
MAD4ONE reinforced ergal hub kit+flat =>look at these 
:
Can I buy the reinforcement kit separately and retro-fit? I bought the hub from UDC but they don’t have the kit. And do you know how much weight it adds? Btw, how does this reinforcement kit work, and do you have to use M41 cranks, or will any isis crank be compatible with the system?
I’m pretty sure “kit” just means that everything you need to run the parts is included: the pins, spacers, bolts, bearings, etc. Which hub do you have? 6 pin or 10 pin (ISIS)? If it is the 6 pin hub you will need to use mad4one 6 pin cranks. I believe there are two sets of ergal parts, the freestyle one that is NOT suitable for heavy duty riding and the reinforced one which is suitable for anything you can throw at it, as shown by the abuse it’s taken from Jacob and Adrien, to name a few. 
In cromo you can only get 10 pin so it will be compatible with any ISIS cranks.
I’m getting the M41 “Ergal” Aluminum 100mm isis hub. It will be used ONLY for steep hill climbing on smooth paved streets, so there will be no impact forces. The only force applied will be that from pedaling up hills. So I’m thinking maybe I won’t need the reinforcement kit.
There is no reinforcement kit. There is the freestyle kit, and the reinforced kit. Kit meaning hub/crank set. As Marco said on facebook, the freestyle hub is designed for short freestyle cranks that generate much less torque, so it is not recommended to use it for anything else. It may hold up, it may not, but it is typically used with 90 mm cranks in level gyms. The reinforced hub uses the 6 pin interface rather than ISIS so that it can withstand more torque and that ergal hub is suitable for street/trials/muni etc. I hope the freestyle hub works out for you though!
Also to clear up some more questions about the 6pin ergal hub kit. Its an entirely different hub as in design. You can only fit th mad4one 6pin cranks to it. The difference on it vs the ISIS hub is that the 6pin hub has a larger diameter than the standard ISIS hubs and also less pins. This is so there is more hub axel which makes it stronger.
Good luck with the project, saw one of your uphill videos and you were spinning!
Thanks Jacob. Josh explained that the the M41 aluminum hub does have a thicker axle due to the smaller bolt holes. He thinks it should be more than strong enough for spinning up hills. I get that it’s not made for any extreme type riding like doing drops, trials, etc. But I would find it very surprising if it twisted like licorice while simply riding it up hills. Apparently, Ergal aluminum is very strong, and the hubs are warrantied for 3 years against defects, so I should be covered. With the rim and tire I’ll be using, the 24" wheel set will weigh only 2.3 pounds!
I almost forgot that the Ergal ISIS hubs run M8 bolts(correct me if Im wrong)! Ergal is amazing! It is the same Aluminum that the new KH cranks are made out of, super hard it is. I once fixed a stripped pair of M41 cranks and tapping out the cranks were a pain in the ass! Even with a drill press we had issues with the bit seizing up. I even brought a pair to a machine shop and the guy that did the cranks said the aluminum was not soft one bit. Im sure you will be blown away once you get your hub, the craftsmenship in mad4one products are outstanding I think. All parts are made in a small machine shop in Italy one at a time (thats also why they cost so much :p)
I cannot say much about the hub since I have never ridden one but hopefully it works well for you, I think it will be just fine if you are riding it just for road use.
Yeah, the bolts take the same 8mm allen key size, but the thread diameter is smaller than the standard 8mm ISIS bolt, or so I was told, so the smaller hole makes the axle thicker at the splines. The bolts sure look like a smaller thread diameter. In fact, they look a lot like these.
Yes there is a big difference! I saw a few of these before and the holes are TINY!! My only biggest concern would be stripping out the hub threads. Be sure to put grease on everything, Ive had some bolts be a complete pain in the ass to take off when there wasnt enough grease. The tolerances are small on the hubs so everything fits very SNUG.
Thanks for that info, I’ll make sure to thread the bolts in very carefully, Luckily, once the cranks are on, they won’t be coming off for a while, if at all.
I’m sure using a smaller bolt, and hence having a smaller hole through the middle of the axle does make them stronger - the trouble is that adding extra metal to the centre of an axle is a very poor way of adding strength, so the difference isn’t going to be huge.
All Mad4One parts, aside from the AISI tempered hub, are made of 7075-T6 Certified Aluminium (Ergal). Same for the std ISIS (10 pins) freestyle hubs and for the oversized reinforced ergal kit (hubs+cranks, 6 pins).
That’s the best aluminium you can find, everything is CNC-machined, and you can bet the material is 7075-T6 (ergal), unlike most parts coming from china (believe it or not, punched cranks ARE NOT made of ergal).
Freestyle hubs have been developed keeping in mind typical freestyle (gym) usage and short cranks, mostly 60-110mm. The spindle is 100% ISIS and the internal holes are M8x1.
That kind of usage doesn’t brings much forces to the freestyle hub’s spindle, however I’ve seen people’s (70-80kg) using those hubs for MUni with 140mm cranks without breaking them (mostly XC and light MUni).
I only seen the ergal freestyle hub break after one 1.30mt-plus drop, or consecutive drops over 60-80cmm, both using 140mm cranks.
I think that for your purposes the hub should hold with no problem, but keep in mind that using it in conditions different than freestyle with short crank, will void its warranty. 
Even though it was on facebook, I not entirely agree about the forces.
I still disagree about the forces.
Check out this video of a (reinforced?) normal (non-freestyle) 100mm 36h Ergal hub + 125 mm cranks:
Now that last sentence I do agree on!
However, 6 pin 125mm Mad4One cranks already failed on us, we simply do squeeze the pins, and get play!
So I replaced them for 0 pin cranks of Nimbus, I feel more confident with that.
Which proves nothing at all about the forces on the hub’s spindle, or indeed the durability of such a hub if it was laced correctly.