Neutron Ultra freehub the same as old school Chorus freehub?

Everything about building wheels, glueing tubs, etc.
Post Reply
User avatar
Sjoerd
Posts: 262
Joined: Fri Jan 15, 2010 7:22 pm
Location: Les Pays Bas

by Sjoerd

Hi all,

I am leaving for the Mont Ventoux on Wednesday and I just learned that the tiny spring in my Campagnolo Neutron Ultra freehub is broken. I have an "old school" cup and cone Campagnolo Chorus rear hub lying around with a perfect freehub body on it. Optically it looks just the same as the Neutron Ultra one and it seems to fit too, but I don't want to take any big risks.

The end cap -if you could call it that- is a little bit different. With my Neutron Ultra hub there's a two-piece end cap on the drive side: a spacer and a nut (part number FH-RE126, taken from https://www.campagnolo.com/media/files/ ... part_C.pdf). On the Chorus hub this is one piece. Apart from that, I cannot find any differences, but I can imagine tolerances are tight.

Can anybody help me out? Should the Chorus freehub body fit the Neutron Ultra wheel? Any help is much appreciated!

uraqt
Posts: 898
Joined: Mon Apr 03, 2006 8:53 am

by uraqt

I'm not an expert, but it's my understanding that you should be good as long as they are from the same generation..... I think the Ghibli is the only wheel with "non-standard hubs"

C

by Weenie


User avatar
Sjoerd
Posts: 262
Joined: Fri Jan 15, 2010 7:22 pm
Location: Les Pays Bas

by Sjoerd

Thanks for the input! To clarify a little further, my Chorus hub is this type:

http://www.bikerecyclery.com/campagnolo ... silver-nm/

User avatar
Calnago
Posts: 8549
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

I think as long as it’s 9, 10, 11, and now 12sp compatible the freehub will work with any of the cassettes. What I can’t remember is when they changed from the 3 pawls, each with their own tiny spring, to the system of 3 pawls, but with a circular single spring that fit the entire circumference of the freehub. Even that spring was altered slightly (more spring) somewhere along the way.
In any case, I think that’s the main thing you have to look out for, and perhaps the axle size (diameter). Think they went from 15mm to 17mm at some point but I’m just going from vague memory now, which gets vaguer by the day. But at least it will give you a couple areas that you should verify are compatible.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

User avatar
Sjoerd
Posts: 262
Joined: Fri Jan 15, 2010 7:22 pm
Location: Les Pays Bas

by Sjoerd

Thanks very much Calnago, I'll look into it tomorrow morning with the vernier calipers in hand. And a keen eye also :)

[edited for typo]

graeme_f_k
Shop Owner / Manufacturer
Posts: 387
Joined: Mon May 26, 2008 12:21 pm
Location: UK
Contact:

by graeme_f_k

Sjoerd wrote:
Mon May 27, 2019 7:37 pm
Thanks for the input! To clarify a little further, my Chorus hub is this type:

http://www.bikerecyclery.com/campagnolo ... silver-nm/
The body will swap straight across.

Just be careful when fitting into the Neutron Ultras, the best way to do it is to bring the pawls into gentle contact with the bub body, then just put a few grammes of pressure (lierally) on the cassette body towards the hub & depress the pawls one at a time - when you do the third one, the cassette body should just drop in. It should go in with an absolute minimum coating of grease - oil is better in the older ones.

Avoid just turning the body anticlockwise as you push in - that tends to cause the pawls to twist on their seats slightly and can kink or nick the spring, causing premature failure.

Calnago is right - the spring was stiffened up in 2012, by being made from square rather than round section wire. This was done to allow grease rather than oil to be used to lubricate and, importantly, control corrosion.

In 2017, the individual springs and packs of pawls were discontinued for the single-spring version of the cassette hub as a spare part (still available for the old 3-spring type) with a pawl-and-spring kit is now offered for the alloy cassette bodies (FH-BUU014) and a different kit offered for the steel ones (FH-BUU014X). This allows a matching of pawls to spring and it was considered prudent to go this route as experience showed that users utilising the newer, square section pawl springs, if they had one on the "large" end of the sizing tolerance, when matched to pawls at the "low" end of the sizing tolerance, in terms of the slot size (where the spring sits,) tends to push the spring out and into contact with the drive ring, causing early spring failure and damage to the drive ring.

Alloy and steel cassette bodies use pawls of slightly different length, hence two kits.

Pre 2006 bodies will fit on all oversize (17mm) alloy axles but post 2006 bodies will not fit onto pre-2006 axles, due to a change in axle design. Post 2006 axles, will however fit pre-2006 hubs (axles from post 2015 hubs may need a replacement pre-load ring as well as the thread pitch changed in 2015) so almost whatever your conumdrum, you can save the hub ...
A Tech-Reps work is never done ...
Head Tech, Campagnolo main UK ASC

User avatar
Sjoerd
Posts: 262
Joined: Fri Jan 15, 2010 7:22 pm
Location: Les Pays Bas

by Sjoerd

Dear Graeme, thanks for taking the time to reply in such a detailed way. It's good to know it would've fit, but with the trip just around the corner I chickened out and ordered a FH-BUU015 kit late last evening and thankfully it was delivered in time. If it would not have been here on time I would have taken the jump and used the Chorus one. It looked pretty much identical and all the measurements came out the same way. It's nice to see you confirm that it would work.

When I get back home I will order a pack of pawl springs for the broken body and do some repairs. Together with the Chorus-freehub that makes two spares :)

I'm off to the Ventoux, thanks again everyone.

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post