Hi Kris,
Nice to see you there again !
6mm hole will be drilled on both legs of the frame or only left side ?
20 ! Not 22 ?
No, I meant 12! (edited)
Just wondering, is the word âaluminiumâ required?
I am wondering about compatibility with steel ISIS nimbuses.
Happy to remove it - you can too if you think the change will add clarity etc., no need to seek any approval really on bits that add value or clear up possible confused for this WiKi
I added it in, as a column for Brandsâ Lines/SKU (of frame) felt like it could be excessive and over complicating the table.
However what Roger has highlighted - the frame view here isnât really needed as it comes down to a set of specifications, which when met means a frame has reached compatibility.
Added to all this, while I canât speak for others Iâd not aim on putting a schlumpf (1650g) into a steel frame due to the weight - and presume 99% of riders would opt for aluminium due to that being lighter.
But then again - make a change if you think it needs it
Thanks Felix.
I am contemplating buying a schlumpf hub, I figure it would be good for going fast and far in nice flat areas, at the moment Iâm limited by pedalling speed. The hub is approx AUD$2500 though⌠I donât have any aluminium framed unis, only steel.
Time to buy a new frame then! Such a great hub should not be put into a low-end frame
Hi Didier - the hole is only needed on the the left side.
Low end frames? Steel frames currently on the market are, but itâs not because itâs steel that itâs low-end! I freshly finished a 36er frame made with 4130 steel, and already compatible with all the ISIS schlumpfs generations . Yes there is a little weight penalty over an alloy frame, but it will be a lot stiffer. Plus itâs made with aero tubing, so hey, it should be faster right?
It might be interesting to see old school steel bicycle style steel frames with intricate lugs. Some of those were beautiful and a unicycle made in that style would be really cool.
Nimbus and a bunch of other brands used to make frames like that. Currently I think Miyata might be the only one still making this type of frame: https://unicycle.onlinestores.jp/resources/upload/products/FL2021.jpg
Hey all - update on the comment above, regarding 6 mm vs 8 mm hole for the lock.
It is going to be 8 mm after all - sunwheel production moved faster than expected.
Re KH frame modification (canât comment on others) - suggest avoiding drilling out the upper bearing housing to avoid potential for affecting the weld join.
Yes, the steel 42mm bearing clamps would/do work really with Schlumpf hubs. I used one for my Lands End to John OâGroats ride.
Iâm confused by the 8mm drilling thing - where does the hole need to go and why?
Itâll go into the top section of the bearing mounts. So frame legs side. If frame doesnât have the hole then the jig will line up a spot for you to drill it.
Itâs purpose is to hold that bearing so that it cannot rotate as the hub needs a torque reaction fastener to function.
Previous the solution was a little notch, before that knurling on the bearing for a compression friction fit hold, and way way way before that there was a torque arm that came out of the hubâs body and bolted to the frame.
Hope this helps a bit!
Could we have a poll on Aluminium frame vs Steel frame?
Our just some replyâs to help me decide.
Iâm chatting with Jaco_flans to order a frame for a 125mm schlumpf hub.
I intend to continue commuting 3 days a week with it. It is a hilly commute 15km 150m elevation gain, a couple of biggish hills 25m elev gain at 8-12% grade that I like climbing on current KH36 with 127mm cranks. I am wondering if frame flex and wheel rub would be a problem with aluminium frame and schlumpf hub.
I recently experienced wheel rub on my KH29 127mm crank hill climbing the Access road to Remarkables ski field. Ave 9.5% grade. Tyre press. 42psi.
So, for me would the stiffness of steel be worth the extra weight for hill climbing? I am 74kg. Was 78kg.
Or
Is the weight saving worth the Aluminium frame with a 1.8kg 125mm schlumpf hubâŚ.and frame flex is not an issue or can be managed by other ways, like less tire pressure.
BTW, I only recently became comfortable maintaining 22kph on roads with slight downhill ( in the centre of lane with no traffic behind) using radar on rear light notifying me of any traffic. I wear a 5kg backpack with work computer and lunchâŚ
âŚwill go the full body armour and full face helmet with the schlumpfâŚbut what speeds can I expect in same situation with a schlumpf?
- Steel Frame 36â Schlumpf
- Aluminium Frame 36â Schlumpf
0 voters
Iâd be interested to see the results to this.
My gut says most go with aluminium and it is fine. But I have thought about a Flansberrium frame in steel if I was going to the trouble of having him build me one for a 125mm hub.
Having said that I might also check out if Triton are going to be able to make unicycle frames again (now theyâve moved to Portugal).
Might be a longer wait but I think theyâd be stiffer and also lighter too (if my understanding of metals - titanium v steel - is on the money)
Slight change of subject, I wasnât away of tyre pressure being a cause of frame flex, learn something new everyday. Anyone got any feedback on that? Not that I ever noticed flex on my KH29 or KH36 (with a huge number of kms and many a steep hill as also living in Sydney). On the KH29 I was running the Duro at no more than 22psi on road (18 on trails), 42psi would rattle my old bones apart.
Feels like Iâm writing this comment every time this topic comes up: Material alone does not determine stiffness. Itâs just one variable in stiffness of a frame. Tube choice (diameter, shape and wall thickness) and crown design are equally, if not more important.
Of course, to make it a bit more complex, these properties are not fully independent, because for each material, you have to choose different tubing to achieve the same strength, which is why the common cycling wisdom is:
- Aluminum >titanium>steel in terms of finished frame stiffness,
while the materials youngs modulus (which decides stiffness) is:
- Steel(~210Gpa)>titanium(100Gpa)>aluminum(~70 Gpa)
Reason being that since aluminum is a lot less dense, you can make thicker tubing diameter and wall thickness for the same weight compared to steel, resulting in stiffer frames. On unicycles steel frames tend to be less âoptimizedâ in terms of strength to weight, so they are often as stiff or stiffer than aluminum frames, simply because they are âoverbuiltâ.
Long story short, especially if you are getting one custom you are not faced with a choice of a âflexy aluminum frameâ vs. a âstiff steel frameâ. @jaco_flans (and owners of his frames) can correct me on this if Iâm wrong, but I believe his crown design should make his aluminum frames fairly stiff side to side. I donât think you could do a design like that with steel in a reasonable weight.