Yeah I can picture something like this helping. But I’d want ones from Florian directly to ensure they meet his expectations for fit and load bearing - not that they take too much of that kind of thing.
This is how much space the bolt heads have with 1 washer (1mm) behind the rotor bolts:
My feeling is they’d just clear as they are with the 3x washers as per @Hammer post, but more than that we’d have issues unless using thinner headed bolts.
As for the brake tab on the frame, does anyone know if a small amount of inside face material could be filled off without it losing caliper supporting strength?
We could then pad out the mounting bolts with washers on the outside and this could bring calipers out by a bit/enough?
To be honest, when I ordered my thin screws, I was afraid they would not hold great so I ordered a few “usual” screws… But they definitely hold great. I have had no issue with them in the last 2 months!
BTW, I guess they have to hold as much load as those on the new Schlumpf hubs, so they should be perfect!
I would file the outer part of the IS PM adapter first before filing the brake tab.
Otherwise, in my opinion, there’s no need to worry about the screws, there are 9 screws, it’s huuuuuge. Especially since the disc is stuck on the hub body. I can imagine that it should be held with 3 screws, so with 9 screws with thinner heads, it seems to me more than enough. I didn’t do the math, it’s just intuition.
That makes sense and I think I might try that as I can see there are two small raised areas on the mount that could be flattened and give around 1mm I think.
This all go me thinking if there was an adapter out there that could provide and off set to the mounting plane, which would then allow the use of another brake adapter to install the caliper and have it align to rotor.
But there’s this one from Hope too that has be curious what one could do with it to “hack” a way to in effect move the frame tab outwards without modifying the frame.
One of my go-to shops for obscure bike related parts is SJS cycles, which I think is not far from you? It might be worth a trip over to rummage in their parts bin. Adapters which are intended to go the other way (ie post mount frame to IS caliper) appear to have some offset, although probably too much, as do Rohloff adapters.
Remeasuring the space reserved for the disk, I see that there is just 5mm. So ideally 3mm for spacers and 2mm for the disc. @Hammer your washers are exactly 1mm each? Mine were sold to be 1mm, but in reality they are not exactly 1mm. I wonder how much this can affect the disc.
Given the price of the hub, I would prefer to have spacers that are exactly 3mm
No they are not.
The first 1mm spacers I bought seemed fairly poor made so I went back and bought a box made of some higher grade of steel (A2). The new looks more uniform but when I measured them most are approx 0,96mm but they vary between 0,9 and 1,0mm. They are also not 100% flat which also affects the measurements and as we are talking about very small differences I must admit that I just picked some random washers from the box when I mounted my disc.
Also ended up using some ISO 7380-2 M4x14 (A2) torx screws. I think the stock screws (M4x12) would still be sufficient length but the new also have a head height of only 2.1mm vs stock screws with ~3.0mm so there is a bit more clearance to the frame.
Thanks for those chiming in on this thread. There is little left to offer that has not already been commented on or already figured out, here. First - really appreciate the awesomeness of our riding community to work through these questions. It was really difficult to get geared hub production re-started (years of effort, many starters and non-starters in producing the many components, and finally Florian taking on hand-making more parts than initially he was willing to do.). It’s frustrating that these issues have arisen - really appreciate the kindness expressed on this thread. A few comments:
The assembly instructions will be updated to provide clearer guidance on the items noted in this thread, including the spoke holes and spacers.
Spacers are the preferred option to bring the disc into the proper position and will be included with the hub moving forward. 1x1 mm or 2x1mm will provide the necessary adjustment (will vary slightly with wheel size but unlikely to be more than 3x1mm).
The flange spacing is about 2 mm wider than most existing hubs. There really isn’t a solution to frame clearance constraints except filing the frame slightly if necessary. KH frames should clear without issue.
Re rotor size: this deserves a longer discussion, but I feel you can’t have too much braking power. I prefer a 203 rotor on all of my unicycles. I was thinking about this last Sunday on a ride on the Vancouver North Shore in tough conditions (technical trail and driving sleet and rain and mud) where braking was not optimal. Feathering the brake is also easier when you don’t have to pull so hard. I’ve never personally seen a difference in rotor vulnerability between sizes (and haven’t had a problem with this in over a dozen years of using disc brakes). So - large rotor = more clearance and better performance anyway.
Standard ISIS spec has a spacer fit between the cranks and bearing (no gap). This mattered on the disc-mount cranks because it fixed the rotor position (not relevant here) and it helps reduce crank wear over the long term. This matters much less if you don’t switch out your cranks. From the perspective of a rider, I have to admit that I care less about this than some because I don’t generally switch out cranks, but formally from a design perspective about 2-3 mm of spacer is likely needed at the torque spec and 1 mm spacers are available from Unicycle.com.
Thanks again for the constructive dialogue on this thread, and appreciate your patience as these issues are resolved.
-Kris
Thanks so much for the detailed reply and support here, Kris!
I couldn’t agree more and it’s been a lifeline and a great space to be able to feel positive when these issues arose as we’ve got a collective of people all focused on trying to figure these magical hubs out
This is good to know
Just wondering if longer rotor bolts as demonstrated by @Hammer here are needed or no?
Whenever the time allows it would be great to get the clear spec / brand needed so those of us without these spacers/washers (and if needed longer bolts) can correctly source.
—
I’m also down with the approach to go 203 rotors so it’s good to hear the vote of confidence in them here!
(Perhaps this should be the recommended option on the order page / or the only size for sale?!?)
I don’t think I ever thought I’d see the day when new schlumpf hubs would be made again, let alone with inboard discs and with the 125mm option. But here they are - and in-spite of these initial puzzlements I’d pre-order again in a heartbeat
Anfang der weitergeleiteten Nachricht: Von: Office <[…@schlumpf.ch] Betreff:Unicycle-Hub Datum: 27. März 2023 um 12:46:36 MESZ An:
**Dear ** Around end of April / beginning of May 2023, the next 20 hubs will be ready for delivery.
After reading Kris’ latest post I switched to a 203 rotor. UDC was helpful in finding the correct Shimano adapter for my Hatchet frame.
More good news: From: Florian Schlumpf ...@schlumpf.ch Sent: Monday, April 24, 2023 11:01 AM To: Subject: Re: Uni
Dear ,
thanks for your message.
I have good news: in the past few days, we were able to modify the design of the hub body so that all future deliveries will have 2mm more clearance and should therefore have no problems to fit any size of disk.
In case you would like to stay with your old disk size, please inform us.
Best regards
Florian
Did you get the 1/2/3mm schlumpf spacers? I have not heard anything from Florian about this.
Concerning the blue loctite, in my opinion you do what you want. With the 9 screws you can see the problems coming. I don’t think it’s necessary, but if you do it’s not a problem either.
As for emails getting missed. I’d suggest sending from a new email address / and or emailing Brigitte too. Or if there never any reply, perhaps call?
I haven’t had to call, but if I didn’t get a reply for ages I’d probably do that.
But email again - it’s hardly that much to ask for spacers to bring the hubs that shipped out to us few early receivers, and bring things up to par to the hubs that will be shipping now to other customers.
I guess I’ve been very lucky and have had most of my emails replied to, sometimes with little delay.
Email again, and keep on chasing. Do you have any glimmer of a working wheel yet?
