Williams Racing Products Centre Hub

I thought I'd put this in a separate thread as it may be of interest to some people who'd have no interest in my Yalla.

Originally I built my downhill bike with a complete SRAM group - which I took to Queenstown in NZ and got to know a little. I had originally intended on building it with the Centre Hub, but timelines didn't workout.

Here's where we started:

Things came apart easily, this workbox top is handy:

Mounting the ring with the printed text facing outward meant that the chainring bolts bottomed out before clamping, as there is a relief milled into the face of the chainring around each chainring bolt hole:

I reversed the ring, which as there was no relief around hole on this face resolved the issue:

My centre hub shipped with three spacers, the purpose of which being to space the ring correctly - non-boost, boost, super boost etc are all catered for by dint of the ring floating on the splines of the hub and being able to be secured in place by two bolts that tighten it down when in the correct position.

Sadly all three of my spacers had been mangled in shipping, so I made my own, in a rather jaunty green PLA as that was what was in the printer:

This wasn't the correct spacing, but my cat had taken the correct one and hidden it, so I used this whilst I printed another 6mm offset spacer so I could get on with things.

Stock SRAM was hex-head, WRP was PH2:

Not going to work:

Better:

The SRAM ring has this surface that butts up against the spacer on the axle:

Whereas when equipped with the Centre Hub it's resting on the heads of the three mounting screws, which I'm not entirely happy about but it's probably fine:

Snugged up the Centre Hub immediately jammed against my MRP chain/bash guide:

Printer pinged:

This was from a file that Mic (owner of WRP) had sent me, rather than the green spacer which I'd drawn up:

All torqued up, I need an upper chain guide (mandated by WRP) that has a stack height when installed of 4mm or less:

With the cassette zip-tied to test function:

https://www.youtube.com/watch?v=8j8XeZNpIrU

Impressive fixing

This is all very cool. Can’t wait to hear what you think of its performance/whatever it’s supposed to do?

With the chain device stack height…

edit - I just seen you other post that explains it’s at the iscg mounting points. I have a cascade chain guide that I haven’t installed yet, I’ll check the dimensions.

It’s the width of the back plate that is the issue as it occupies the same space that the edge of the WRP spider does- and therefore jams it solid.

Which does mean you can spin the cranks backwards, but whilst fun that’s not very useful ultimately

Cascade components chain guide; 4.98mm

Shimano SMCD-50: 4.04mm

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Any idea what chain guide the chap from WRP is using?

I briefly ran my dh bike single speed without a chain guide and just relied on the narrow wide ring taking care of it. I felt like it was working surprisingly well right up until the chain came off twice on the same day that both got me close to a brown underpants moment. Wouldn’t run my dh bike without now.

The chap at Cascade Components is very sound and replied to my questions on Instagram very quickly. It’s probably an extreme way to go but you could maybe ask him to machine a sub 4mm backplate for you.
Edit - just realised the cascade one is 32t max

Obvs the shimano guide could be worth a try but they are a bit ugly.

WRP guy (Mic) has mentioned that he knows someone (but could not recall their name) who could machine a back plate out of 2mm steel, he said he’d get back to me.

Thanks for the measurements!

A note on the use of the spacers to get the spider in the correct position- I did use one, but such is the friction even when you have the pinch bolts backed off that it’s hard to get the spider parallel to the bearing it sits upon.

I was pretty careful but ended up with runout, so with it mounted on the bike I used the depth gauge end of my verniers and a small plastic faced hammer to gently check and tap the spider with the pinch bolts loosened until the vernier gave me 1mm all round.

I think next time I’d eyeball the chain line with everything on the bike then tap it into alignment- but I have files for the spacers if anyone wants them to print their own.

I popped downstairs to measure my One Up Components chain guide/bash- 4mm but the bolts protrude which means I’d need to face them. Possible route forward though.

I would love to use the (well, two) MRP units I have- as they are not cheap, but even if I found a place that would machine the rear of the plate to 4mm, due to the way it’s designed to be spaced that may still lead to issues with the upper and lower guide. With this unit you use spacers behind the plate to handle gross alignment and then thin shims between the plate and the guide for fine alignment- I’d not be able to do any gross alignment due to the clearance issue.

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Cascade won’t do any customisation of their guide.

I'm wondering whether we could (pending discovery of what's available here in Singapore) machine ~1.5mm of material from the face of the plate in the area within the circle.

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Does this have a similar effect to the cranks some trials riders use with the freewheel on the front and a fixed cog on the back?

Aside from the suspension benefits it seems (in my non engineer head) to be a good way to have a potentially lighter back wheel with the freewheel parts removed - could you machine a one piece cassette and hub?

If I had the skills, yes I imagine so. The hub doesn't need (in fact, you have to disable if it does) any sort of freewheel, so if such a thing existed as a 12 speed track hub, with a 157mm axle and a disc rotor mount then it would be perfect.

The WRP Centre Hub comes with a 3D printed titanium lock-out ring that you put into a DT Swiss hub (which is what I have). The advantage is that you can convert back to having a freewheel by removing that.

The whole idea of this Centre Hub is to remove, or largely mitigate, the effects of the suspension pulling on the chain when active, therefore removing deleterious effects on the suspension and also detectable to the rider as the pedals kicking back.

https://www.pinkbike.com/news/does-pedal-kickback-actually-happen-i-use-data-acquisition-to-find-out3.html

Pedal kickback and kick forward explained
.

Although I admit that there doesn't seem to be a consensus online as to whether the centre hub works or not, but I thought that it was cool.

They seem to do some cool stuff, but I found dealing with that guy to be a shambles to deal with, doesnt answer communications and just wasn't that aren't in actually selling the product when I wanted to buy something from him and eventually gave up.

Yeah this does seem to be a common theme. Before the price of the trinity frame was made public, I’d emailed twice asking about price and availability. No reply at all.

Machining down a back plate that you have is almost certainly a possibility eh. There’s got to be a small engineering firm in SG that could help out.

Edit to add: even if you get the back plate machined down, would it still leave problems getting the upper and lower guides spaced correctly without rub?

that there doesn't seem to be a consensus online as to whether the centre hub works or not

This is what I really want to know.

On a different note, I ran my dh bike single speed for a few months one summer and also rand my nomad with the small 7 speed dh cassette on for a while.
I am 100% convinced that the rear suspension on both felt way better compared to when they went back to having cassettes. Especially on the nomad when it when back to a 52t cassette.

It makes me want one of these gear box bikes.
@konastab01 give me a shout if you ever still ride at Inners much these days. Would love to see that bike in the flesh.

I’ve noticed that there are no photos online of any bikes with the centrehub installed and running a full top and bottom chain guide.
The only one I see is that Commencal frame with the stfu rubber loop thing on the chain stay.
The WRP site says that the centrehub must be installed with a top guide.
Has Mic made any suggestions as to what they have tried that actually fits together without fouling anything?

No, not yet.

I think the new one that rotates freely in both directions unless you are pedalling would genuinely solve the issues people talk about- I did think that’s what I had ordered, but got the first one.

Now that I have it I want to see if I can make it work- but the promise of the thing is the (IIRC) Centre Hub Zero, which will enable the suspension to work/isolate the pedals whilst braking.

I might buy the STFU thing, but to my mind that’s not doing the same thing as a chain guide.