Dynamo hubs

The SP thru axle hub. Will this not last as long as a QR version? I would guess (but I’m often wrong) that it would have smaller bearings to accommodate the axle

Previous discussions have been about this hub having less robust bearings due to, as you say, the larger ID required to accommodate the TA.

This has been theoretical however. I don't think there has been reports of higher / faster failure rates on one vs the other.

So they increase the ID but not the OD? Seems odd. Why not just increase the OD the same amount?

Can’t confirm they did not increase OD, but from recollection comments were about smaller ball bearing size within the bearing itself

I see. I mean in a larger race each ball would take a smaller load so smaller bearings sort of makes sense*. It may also be a difference as the previous size would not fit in the new race (in terms of there being one ball too many or one less but no happy medium).

*but then the OD couldn't have been increased by the same proportion as the inner.

I'm not very familiar with thru axles. Is it possible to over tighten one and squash the hub bearings? As seems to happen with Hollowtech II BBs.

Some people did report of SP thru axle hubs failing, when they first introduced it. But it seems the current version is good.

This is what the SP 8x product page used to say in 2016 (text was copied to another discussion)

The QR15 thru axle specification for suspension forks imposes a design
constraint requiring compatible hubs to employ thinner bearings than
standard hubs. This is due to the fact that the 15mm inner diameter of
its hollow axle together with the 6 bolt disc brake specification
simultaneously constrain both the inner and outer diameters of
bearings that can be used in 8X hubs. This thickness is necessarily
smaller than that for standard 9mm hub axles. The resulting thinner
bearing races as well as smaller individual ball bearings together
that the 8X is, by design, incapable of matching the durability of our
8 Series dynamo hubs. Additionally, unlike standard QR15 hubs, QR15
hub dynamos require electrical output to be transmitted via wires from
the internal dynamo to an external connector. Though physically small,
this design requirement nevertheless enlarges the inner bearing
diameter and thus requiring bearing thicknesses narrower than standard
QR15 hubs. Consequently, bearing thickness for QR15 dynamo hub is
smaller than standard QR15 hubs. In theory, 15mm suspensions forks
together with the QR15 thru axle should be stronger than standard.
However, the mechanical design limitations outlined above mean that
the 8X Series dynamo hub will be less durable in practice than the 8
Series hubs. In short, where durability is more important than
performance, we recommend 8 Series dynamo hubs.

And this is what the page says now:

New 8X Is Released In 2017

Our QR12 and QR15 thru axle hubs are required to employ narrower
bearings than standard hubs (9mm QR). This is due to the 15mm diameter
hollow axle and 6 bolt disc brake specification which simultaneously
constrain both the inner and outer diameters of the hub’s bearings.

In theory, 15mm suspension folks with QR15 thru-axle hubs should be
stronger than standard. In practice, mechanical design limitations
have reduced bearing size and thus durability.

SP engineers have devoted considerable time and resources to creating
a mechanical design strategy for overcoming this technical challenge.
These efforts have culminated in an innovative mechanical design
relying on superior quality bearings and precision assembly processes.
Our computer aided modeling simulations indicate that we have
perfected the interplay between bearing and limited internal space,
making the new 8X bearing assembly as durable as the time tested – and
proven – 8 Series hubs. Formally released in 2017, we stand behind the
newest version of our 8X dynamo hubs.

http://www.sp-dynamo.com/8Xseriesdynamo hub.html

That's not true. I just haven't bought one yet because my SP hubs have worked.

Sorry I was busy having an awesome time in another country. You slipped under the radar.

So, I'm now going TA.

Does anyone have an unused 28 or 32h 15mm TA SP hub before I buy new for £122

gag

*£119

https://www.spacycles.co.uk/m2b0s133p3776/SP-DYNAMO-PD-8X-Thu-Axle-6-Bolt

Wanted centrelock though

So I left my fixed gear alone for some weeks and now the (shutter precision pv-8) dyno hub is almost seized, has much much more resistance than the normal notches when spinning by hand, and does a sort of metal-on-metal rubbing noise. Looks like I'll have to go down the route of the servicing then. Eugh. The hub was bought 2.5 years ago, I'll try to see how many km it has done since.

I’ve had an XT 1.5w on my beater for more than two years now. Year round, snow, salt, rain. Works like the day I built the wheel, no service needed yet.

Have you ridden any distance on it? I have headsets do that and they free up after another ride and I go back to forgetting about it.

I see what you mean. I may have done 15 km in two rides. I'll persevere a bit more and treat it as extra training I guess.

Was it stored outside or in an unheated area?

Always in my flat or in the underground shed at work.

I wondered if the recent cold temperatures had congealed the grease.

I actually used it once or twice in that snowy weather; much preferred the full length mudguards and wider tyres of the rando bike. I'm wondering if some of the salt or whatever they put on the roads could have gotten inside and killed it somehow.

What's the current forum suggestion for a not madly expensive hub/front and rear light/USB charger?

Can someone please do me a favour and help me to check something?

So my bespoke frame will have 15mm bolt thru axle for the front (we could make it 12mm but 15mm seems to be the the norm here? Will ask on the Any question thread about axle sizes etc)

Anyway, it would seem SON doesn't do a front hub that is both for disc center lock and 15mm thru axle.

I have found SON 28 15, but it's 6 bolt only.

I have found SON delux 12, which is center lock , but it's 12mm.

SP does both center lock and 15mm thru axle, but my heart still perfers a SON hub, am I missing something from the SON range?

Might be useful...

edit - don't know why the FB embed shows in preview but then disappears but Igaro D1 posted about the differences to their FB pages recently. Delux is optimized for smaller wheels (i.e folders)

Do peeps on here use their dynamo wheels all the time like training/commuting/audaxing or do you swap out for a non-dyno wheel when lighting is not needed?

SP does both center lock and 15mm thru axle, but my heart still perfers a SON hub, am I missing something from the SON range?

I couldn't find one when I was looking so went with the SP. My criteria were exactly the same.

All the time. That's the beauty of them. I just leave my lights on day and night with no thought about charging batteries. Increased visibility, safer and convenient.