Schlumpf 2022 Build Questions

mindbalance · April 3, 2023, 6:01pm

I can already feel the postal service becoming weighed down by customers returned 180 and below sized rotors…

Begs the question why those were an option if this kind of thing was a likely result.

Does anyone know if these a clear way to measure calipers?

Be nice to know which are the slimmest and which are the widest in terms of spoke-ward protrusion.

Totally agree. It is adding to the manufacturing complexity for what would seem like minimal purpose / gain, and in fact likely issues.

I have 203 and 180 rotors. Will test when I get my wheels with Hope Tech3 E4 brakes

Hammer · April 3, 2023, 6:13pm

I just build my Schlumpf uni yesterday and I did build with the spokes “the right way” (opposite of yours) - and with a 180mm disc it did rub the disc brake caliper. I tried both with Magura and some different (cheap) Shimano calipers. With a 1mm M4 spacer behind the disc (between disc and hub) a Shimano BR-MT420 could just barely clear the spoke. But with the slightest sideways force it would hit the spokes so I ended up using 2mm spacers between disc and hub. I think it will be just fine as the brake discs still slots into the hub so there is not really much force on the spacers/screws.

Btw I also filed a bit of the corner of the disc caliper just for some extra clearance.

I guess I should order a 203mm disc… or does anyone know of any really slim brake calipers?

Hammer · April 3, 2023, 7:25pm

I’ll share a few pictures / notes from my build as it may be of help for others.

Hub is 100mm 36h

Frame is a M4O size M.

EN933 light bicycle rim (29", 3mm offset)

I’m using Sapim Race (2.0-1.8-2.0) spokes on the disc side.

Disc is 180mm with 2x1mm M4 spacer between disc and hub (my caliper measured them at 0,8mm each so it’s probably closer to 1,5mm than 2mm spacers)
Caliper is a Shimano BR-MT420 (with the corner filed off for a bit more clearance).

Picture shows the very tight clearance between spoke and caliper. Likely ~1mm.
Spacers between disc and hub is also clearly visible.

In the picture its visible how the brake disc was made to slot into the hub. Seems like a very clever trick to make the force of the braking be transferred to the hub body, and not the screws (even with spacers).

As @Joris pointed out the cranks does not seem to go against the crank-stop/spacer on the hub. I experienced the same. I did a few quick measurements and it seems the interface is missing approximately 2mm of spacers to be similar to my other hubs.
I mounted 2,5mm spacers on mine and after using 42nm torque it still did not fully close the gap / using Nimbus Venture cranks as seen in below picture. I assume a bit more would close the gap but with no manual available yet I played it safe and stopped.

I’m using Sapim D-Light (2.0-1.65-2.0) spokes on the non-disc side.
The clearance between spokes and frame is almost non-existent. It’s less than 1mm.
If I have to rebuild the wheel someday I will add some spoke head washers to bring spoke closer to the flange (it shortens the j-bend).

Be aware that the flanges on the disc and non-disc side are very different thickness. One or two spoke head washers could probably be added without issues for the non-disc side but the disc sides has no room (or need) for those as the j-bend closely follows the flænge.

Edit: I added one spoke head washer on the non-disc side flange. Now there is ~1mm clearance to the frame and the spokes follows the flanges with no visual gap

holyroller · April 4, 2023, 1:24pm

Replying to my own thread hijack when I looked (briefly) at my hub and swa I had the spoke heads wrongly in the countersunk side of the flange hole…

… I now looked closer and see that there are countersinks on both sides of the holes on my hub (400 series). In fact looking it up on the Schlumpf hub history thread I see it was a feature introduced in that series:

KH/Schlumpf Generation 3
adding protection rings (external dust/water guards)
reinforced rim to avoid broken spoke holes
spoke holes countersunk on both sides

So that means definitely no hub rebuild needed - phew!
I wonder why Florian went back to only single side countersinks on this latest series, especially when some of the flanges are really wide.

mindbalance · April 4, 2023, 2:23pm

Yes this is the odd and contradictory part about the whole business.

As previously shared here:

The manual snippet says that heads go into the bigger diameter countersink. But I am totally convinced that when it is alternating countersinking, then the spoke heads have to go on the flat side as the primary aim for the countersink is for the J-bend. And given the current likely fixable “disaster” regarding how close everything thing is for clearance - I also think spoking the wheel this way round (heads on the flat) helps give a wee bit extra space. And every 0.1mm counts!

As to why Florian went back to not countersinking every hole. This is firmly in the land of conjecture.

I know I’ve written my thinkings as to why this is the case somewhere in one of my rambling posts - but I can’t for the life of me find it. So I’ll summarise:

Having the spoke heads go into countersunk holes makes little to no difference for strength of build - so then going on a flat surface as with hubs of yesteryear is a moot point
On an asymmetrical build of this ilk countersinking the holes for the heads could lead to weaknesses in that area - so best not to do it
It’s an oversight and complete mistake
If they had been countersunk there would have been even worse non-clearance of spokes and caliper than we’re seeing currently - so Florian needed to skip this for them

My gut says it is in fact a mixture of 1 + 4. I think the heads going into a flat hole makes their attachment strong and secure and actually allows for the use of washers more easily. And I do wonder if Florian has been hunting for every millimetre of space probably both internally and within the constraints of the hub body… so perhaps there’s awareness that doing things this way helps set things up for as snug and close spoke lines as humanly possible.

Incidentally I’ve looked at my 200 series and I can see it was built the bad way round - so I’ve another Schlumpf project to fix one day with that beast.

My brain is basically reeling, wheeling and down right befuddled by all of this - but I’m still in the zone trying to enjoy the pain of problem solving and fishing for insight into the mysterious world of Schlumpf’s innovations

Hammer · April 6, 2023, 10:19am

I was doing a bit of calculations. I wanted to figure out if upgrading from a 180mm to a 203mm would make it possible for me to remove the spacers I added.

I’m using the initial drawing from Florian as reference (I did not verify if the final hub is any different)

From middle of left bearing to left flange
E:16+D:17mm = 33mm

Left flange to middle of rim
100mm/2-33mm = 17mm

Note the measurements D+E is to the outside of the left flange.
So let’s add 1mm (even a thin/blade spoke has 2mm thickness at the flange) because we are measuring from middle of the spoke at left flange to middle of spoke at rim

17m + 1mm = 18mm “left-right distance" for the length of the spoke

Using 270mm spokes (likely typical for a 29" wheel build).
Going from 180mm to 203mm disc adds (203-180)/2=11,5mm to the radius.

18mm/270mm*11,5 = 0,77mm added clearance from using a 203mm disc compared to a 180mm
(18mm+3mm)/270mm*11,5 = 0,89mm added clearance from using a 203mm disc and a 3mm offset rim

Personally I’m using a 3mm offset rim but the 0,9mm will only make it possible for me to skip one of the spacers. Maybe grinding a bit more off the corner of the brake caliper would then do the trick. But it seems to me that even a 203mm disc does not make it an easy build without spacers. Or at least the brake caliper choice will be limited (assuming slimmer brake calipers even exists…)

Did I miss anything or are my calculations wrong?

Maxence · April 6, 2023, 11:37am

Not sure about all your calculations, but it seems you missed a /270mm there.

gocup · April 6, 2023, 12:12pm

I think your calculations would be pretty much correct IF the spoking was radial.
BUT I think you gain a bit more clearance with 3-cross spoking because a spoke which crosses the caliper “touch point” actually comes from a flange hole which is a bit lower and is coming across at an angle (when wheel is viewed from the side, i.e. axially), so it has a bit more distance to move proportionally inwards (away from the caliper) more.

By the way, I think a TEKTRO caliper is a bit smaller than the Shimano caliper, and so will have slightly more clearance - I noticed this because my standard Nimbus 26 with D’Brake has such a caliper.

To change from 180 to 203 rotor, the caliper needs to be moved outwards by using a suitable “Post to Post” adaptor, which are common and inexpensive, although ideally the existing adaptor should be removed and a suitable single “IS to Post” adaptor should be used (but I find them a bit confusing to figure out which ones are appropriate, and they are not as common).

So that is merely my opinion, I could be wrong, I’m not an expert.

By the way, if the rim spoke holes are staggered (as well as asymmetrical), you could get a teensy bit more clearance by using the “more distant” rim holes for the spokes.

Good luck, and keep us all in the loop!

[EDIT: hmm, I just did the trigonometry and (if I did it right), the difference is minimal: my calculations, taking into account the 3-cross spoke angle, give 1.0mm of extra caliper clearance gained by using the 203 rotor instead of the 180 rotor, compared with your 0.89mm, which although 12% more, is still not much!]

mindbalance · April 7, 2023, 1:35pm

Spokes clear the caliper of a Hope Tech3 E4 by about 1.5mm I’d judge when on a B 203 mount. Feels amazingly on point.

Will be attempted to mount rotor next - suspect I’ll neee washers/spacer to get that sorted.

But the biggest issue with these hubs is at least resolved.

Will post wheel build specifications soon too.

I am so relieved

mindbalance · April 7, 2023, 3:48pm

So the 24” fit my Flansberrium frame without any filing needed - @jaco_flans

This is the clearance I got with no washers or spacers. Yes it is very close but it does freely clear.

I will think about adding one washer to this for a bit extra - and that’s what I’ll opt for on my 29”

The 29 Flans frame needs about 0.3 mm of frame taken off just by the non disc fork. It’s marginal and will be easily lower that the engraving indents.

Yes this one needs cranks.

mindbalance · April 7, 2023, 7:06pm

Here are the specs that allowed for this to clear with minimal washer addition -

While on that point, the more I look at the way the rotor locks into the hub, the more I’m convinced that this space is there so that the rotor can be spacer’d out from the hub to help with alignment. Of course we’d need a manual and assurances on this for sure, but when you place the disc on it clearly and precisely offers up movement inwards and outwards. As @Hammer said this is very clever!

So the recipe:

203 Rotor
Hope Tech3 E4 brake on B type mount from Hope
29” LightBicycle AM935 which has a 2mm off set
24” KH Freeride - off set spoke holes
CX Rays spokes
1 x spoke head washer on inside spoke hole on non-disc flange
2 x spoke head washers on outboard spoke hole on non-disc flange
Sapim DoubleSquare nipples - not that I picture this helping with clearance issues
29” Flansberrium frame - non disc side needs 0.3-5 of metal filing to allow for spoke heads to clear freely. Expected. Not an issue.
24” Flansberrium frame fits like a glove no filing needed. I think this is due to the more acute spoke angles from flanges in such a small wheel.

I am personally a huge fan of the washers on the spoke heads and love the attention to detail Ryan from RyanBuildsWheels has done here.

Also it took a while to work it out, but he realised he could mount the axle splines in his truing stand and clamp them there, if the hub was in high gear, and it will turn. Never occurred to me!

It really shouldn’t go unnoticed that the CX Rays being bladed spokes, this does make their profile noticeable slimmer. When I mounted the rotor to my 24” with no washers at all the clearance was there, it cleared by what looked like 0.4mm so a bit to slim. I’d want 1mm to feel relaxed.
With round spokes this would have been more like 0.1mm (guess!)

I also wonder if bladed spokes have a better angle shape due to how they cross, it’s like they’re not forcing spokes out so much when they cross.

I had worried my going with CX Rays was purely vanity / wanting “the best” but it seems to have paid dividends.

Tomorrow I will carefully fit my cranks with some spacers and then hope this all aligns with what Florian advises in the manual that must surely be arriving next week

jaco_flans · April 7, 2023, 9:52pm

Thanks @mindbalance for the detailed info. As for Flansberrium frames, the current frames out there might need to be filed on the non-disk from what I’ve been seeing right now. I am waiting on exact info from Florian to correct this on the futur frames.

Felix did message me before filing down the fork leg. If you own a frame and need this done, message me first

mindbalance · April 8, 2023, 7:14am

Thanks for the chime in Jakob

Yes I should have been clearer that I got the OK from you for my filing needs.

This point was in no way my casting aspersions or maligning Jakob’s stellar work - I was in the mode of trying to get the hubs to work, so clearance issue where small amounts of filing was needed felt like valid comment, but this is more a critique of the hubs being such a tight fit than any frame creator’s work. My guess is we could easily see KH and Nimbus frames landing with the need for some filing.

Flansberrium4Life

mindbalance · April 8, 2023, 3:11pm

Be careful folks when mounting cranks. I was using a short L shaped hex tool to tighten cranks after grease and rubber mallet - applying what I’d term moderate force and got this happening to the bolt:

It still works and will no doubt back out but it is surprising how weak it is give that we have no harden pre-torque bolt.

And this was with 2mm spacers to shorten the gap on KH Spirits.

Has Florian dropped the ball here?

When tightening be warned even with the shifting rod pushed through the other side - it feels very close to the end of your Allen key head and it seems like it is spring loaded and under some pressure as you try and tighten cranks.

I’ve got it to spacer I think but will stop and check with a torque wrench from my LBS soon

We so need a manual for this point!!!

holyroller · April 8, 2023, 4:16pm

Did the new hubs come with the more beefy bolt which is purely for positioning the crank in place (to the required torque), after which you remove it and screw in the weaker bolt? I mangled a crank bolt worse than yours before realising the stronger tightening bolt existed.

mindbalance · April 8, 2023, 4:23pm

Sadly no such bolt and I heard more recent hubs - as in the previous version no longer needed that bolt.

But again it would seem like it would have been a nice to have

Think my bolt is OK to leave and can be serviceable in terms of taking it back out.

How did you get your totally stuck one out? Just out of interest…

holyroller · April 8, 2023, 5:08pm

Yes, I used a next size up torx socket and tapped it in - I could send it over if you get stuck

holyroller · April 8, 2023, 6:32pm

Just found I posted about it on fb
https://www.facebook.com/groups/268679360444983/permalink/621980088448240/
But if its an 8mm hex bolt you won’t be using a T40

mindbalance · April 8, 2023, 8:21pm

Crank install update!

(Do hope people find this useful my constant posting of my build stages/report backs! )

I found the second crank to go on far easier and I also made sure to only use the supplied hex bit in a ratchet driver, about palm length so pretty low power.

I did however find the rubber mallet whacking easier with the second crank as this time I had the first crank as something solid to hammer down on to.

All this you need to follow at your own risk of course, but personally I feel however violent it feels whacking a crank onto your expensive hub’s axle, it is far far safer than using the clearly soft axle bolt to do the forcing on.

I’m thinking I probably should have used 3mm spacers all round - but I didn’t have them and 2mm looked right. Plus I didn’t want the cranks so far off the axle proper that the shifting buttons didn’t have some spongey play when fully depressed (as they should/need).

But 3mm would be optimal I feel.

I only of course realised all this when doing the second 24” cranks. The first one was very very difficult to get in with just the provided hex bit and ratchet driver, but I decided to do it little my little, and changed the position of the hex bit’s engagement into the bolt. Be sure the bit is place fully inside also as that helps avoid rounding out I think.

So now they’re all installed, and second crank was much easier than the first on the 24”. Basically if I were doing this again, I’d partially seat and tighten each crank (making sure shifting rod is clear when working on each side) and then - I’d use the rubber mallet again when the axle is resting in something hard pressing against both cranks.

Think of this as a crank sandwich, with the Swiss hub as the filling

And I would say give it several decent whacks!

It really helped make the distance for the second cranks on both these wheels easier and I think for the first cranks to go on as easily - you’d need to find a way to sandwich them on together so that you can have at it with the mallet and it not lose power on the task in hand.

Again. This isn’t the official manual - following my views could be wrong, but you really don’t want to go in with a full on torque wrench and round that bolt out, as this is sadly clearly easy to do. I didn’t do it, but came close as I was just using a short L wrench.

Rubber mallets to the rescue is what I say, until we find out that a pre tightening bolt should have shipped after all. I know I wouldn’t mind one.

Maxence · April 8, 2023, 9:59pm

That’s what my local uni builder advises to do for ISIS cranks, especially for Schlumpf hubs.