Constant Hope Pro 4 freehub failures – anything to be done?

TLDR: Hope Pro 4 free hubs (pawls and/or inner free hub bearing) keep failing in a ride ending fashion. Will a DT Swiss, or another (guidance appreciated) solve the issue?

Longer read. As some may know, I’ve a chi-ti fat bike frame (197mm rear). I use it mostly in 29+ guise, and it is absolutely glorious fun. But, drivetrain and especially rear hub failures have been a nightmare. This was also the case with the Ice Cream Truck before with the same 29+ wheels.

2 scenarios: It is always the inner free hub bearing that fails, which then cascades to pawls snapping and generally FUBAR nature. Or, its just the pawls that go BANG. I would estimate there are issues approx every 100km or so. Maybe 200km at a push. Always ride ending, but the worst bit is that you just can’t trust it. So you always have that nagging feeling, when about to crank up a steep hill, that there wi.. BANG! shit, there goes my knee into my shifter and no more forward drive. FFS.

Hope replaced the last hub under warranty as the failure fubared the whole hub. New hub, relatively little use (again, maybe 200km), with new steel free hub body – this morning I got the BANG! then another BANG a bit later and that was that. Another set of pawls gone.

I am big and heavy (195cm and 115kg), so putting a lot of strain through the drivetrain and I am beginning to wonder if a 197mm width hub just cannot handle the power I’m putting through it, esp with wider hub/axle and chainline being not ideal.

Would a non ideal chainlike be a contributing factor? Is it just I’m too heavy for a super wide hub with possible flex? Would a DT Swiss or AN other help overcome?

Note, no issues with other hubs on normal boost 29er.

I just want to go ride without the worry of will it g… BANG! and bloody fail again.

What size hub are you using?

How does it attach? QR?

I would suggest it’s flex in the axle but could be talking rubbish

That was my first thought, what kinda axle Dia is it?

It’s a 197mm hub, 12mm through axle

Not sure what I can suggest that you’ve not covered. Trying to fix the chainline might help if you think it’s far out. If the problem occurs when you are grinding a low gear then consider shifting the chainline in towards the wheel a bit?

If you are looking at alternative hubs and considering DT Swiss then look for one with a low ratchet count (or be prepared to convert it). You’ll lose a bit of pick-up speed but it should be more robust.

It might also be worth getting the frame checked to make sure the drop-outs are correctly aligned.

You didn’t say if you’ve had the same problem running it full-fat, but what hubs do you use for that?

I will shift the chainline in a bit, I’ve got I think 4mm of BB spacers on the DS, will see if things work putting them on the NDS. Wonder if there is such a thing as a boost cinch chainring with spacing that mens I could flip it to get it closer as well… (race face cinch cranks)

Frame check, would be worth doing, will ask if my fab LBS could have a look at that. But, TBF, the same thing happened on the Ice Cream Truck.

Full-Fat hub is also a Pro4, similar issues. On Original salsa/formula rear hub it did the same thing, on both ICT and chi-ti.

Sounds bizarre as ive been running Pro4’s for a long time with no issues

Previously used a 177mm hope hub on my old fatbike since 2014 with no freewheel issues – always with a 10 speed cassette – 10K+ miles

Running a 197mm hub with 11 speed on my new fatbike since Jan20. 4K miles with no freewheel issues

I’m 94kg and properly grind up hills in a big gear

I have heard of Pro4 hub issues when running 12 speed – not fatbike specific though

I am beginning to wonder if a 197mm width hub just cannot handle the power I’m putting through it

It’s all relative, there will certianly be more powerful riders putting more torque through the Hope rear hubs than you irrespective of body mass.

It’d say there’s some kind of misalignment going on there causing the forces to be acting at angles not within the tolerances of the hub, so get your drop outs checked for alignment.

I’ve recently changed the bearings on a pro4. the visual difference between correctly seated and in wonky and not able to spin is basically imperceptible to the naked eye.
Perhaps you’ve got one that is so nearly right so it sort of works for a bit?

I’m ignorant of the exact internals of these things, but would a star ratchet design be any more resilient?

Clutching at straws a bit here but………

Are you making sure the green seal is seated properly?

I’ve seen people use a screw driver to press it in! And even some people thinking it will push into place when they tighten up the cassette.

The seal seating tool is really useful.

https://www.sjscycles.co.uk/tools/hope-pro-4-seal-tool-htt100306s-silver/

The only thing I can think of is that maybe the frame’s axle isn’t supporting the hub as much as it needs? The old Pro 2/12mm was exactly like this- the hub’s axle wasn’t strong enough (because it was designed for 9mm and they adapted it for 12mm by drilling a bloody big hole through it) and ended up totally dependent on the bike’s axle to stop it from snapping, which meant there were frames that were basically incompatible with Hope until they fixed the axle with the Pro 2 Evo.

Fat axles are sort of hard to replace but if you can find an alternative that fits it might be worth a try?

THe centre bearing’s a pretty weird place for a failure to start, all in all.

I have a DT Swiss Big Ride (basically a 197mm DT350) and it’s been flawless as you’d expect, DT make the best hubs… but then I weigh 10 stone so it’s not that comparable.

soundninjauk
Full Member

I’m ignorant of the exact internals of these things, but would a star ratchet design be any more resilient?

Star ratchet up to 36T is pretty much indestructible tbh, it’s kind of like a gripper clutch- the more pressure it’s under the harder it holds together. Even the 54T’s reliable, as long as you get a genuine one. Though, the failure here’s starting in the bearing which is, well, weird.

im thinking bent or broken axle.

Are you filling the freehub / pawls with grease – that can cause issues

I had a Hope hub fail on exactly the same hill last Friday!

I assume you have done nothing to the relatively new hub since it’s been replaced – which rules out the suggestions about seal seating etc.
I am tempted to suggest that this is another hub failure worthy of replacement by Hope.

Most of my friends swear by Hope but others claim DT Swiss are far better.

Is it an alloy axle? Replace with steel if they do it.

How much tension do you put on your through axle? It might not be holding the hub rigidly enough.

Sounds like the axle is flexing/bending, sideloading the bearing and killing it.

Is there any markings on the driver body?

Have you got any pics of what the pawls look like after failure? May be helpful to those of us trying to visualise how it is going wrong.

Hmm.

I stopped using pro4s about 2 years ago.

Inner freehub bearings (nearest the pawls) didn’t last long and I suspect the hub axle was flexing under load.

Yeah, does sound like a 115kg rider putting power into a hub/axles that’s been adapted to two inches wider than it was iriginally designed for – same amount of bearings but two inches further apart.

What ind of rear axle is it? Any hope of a stiffer one? Would guess that very pretty Ti frame has some nice flex in it too, which is a good thing except when it isn’t

Big unit on super wide hub, skinnyish stays isn’t an ideal combo and probably asking a lot from any hub on the market, solid thru axles are out there and could help, think there’s one called thunderbolt.

Many thanks all, really appreciate your engagement.

Will go out this evening and take pictures of the damage, which may be blurry due to the tears and spittle of frustration pouring from my face. real ugly crying 🙂

I have a pal who is the same size as me, a bit shorter (L rather than XXL), he has also 197mm frame with Hope Pro 4, and has no issues at all. I must be doing something wrong/different.

Interesting questions about thru-axle and stiffness. I have a rockshox 12mm QR thru-axle at the moment, but it is a little bit cheese based. I have a spare Bolt Thru – could try that for a while as it feels a lot heavier. may not = stiffness, but worth a try.

@SirHC – yeah, I did a little digging into bearing failures, you may be correct

@StirlingCrispin – TBF, Dumyat shot was just to show the bike, it was actually riding back up the path to the Wally Mony that did it this morning.

The old pro2 axles used to snap with the necked down rockshox bolt throughs.

I had stans freehubs chewing themselves to bits, as the ali axle was too flexy, the fix was a steel one.

I’d definitely give the solid axle a go, with such a wide hub and a compliant frame, the bending loads on the axle might be a bit too much.

Wonder if there is such a thing as a boost cinch chainring with spacing that mens I could flip it to get it closer as well… (race face cinch cranks

There are. Several people make boost spaced rings and the oneup switch system has a boost spaced spider.

Hmm. I’ve been using Hope hubs for 20+ years because they were so reliable and easy to work on, never had any issues. In the past year I’ve had the inner freehub bearing collapse on my old skool 26er. This has happened twice

if the middle bearings going then i would be looking at misalignment between the freehub and body.

If the pawls have gone without the bearing going thats even more strange. is there any axle damage? pawl tooth damage?

I have a customer that breaks them, Hope have never seen it happen (Ha Ha)

I think its a long thin wall alloy axle flexing (pro 2s used to snap axles if you did not use a non waisted through axle, they made a steel axle that sorted it)

Hope wont make a steel Fatsno axle, I have asked.

If it were me I would look for a beast of a through axle that will hopefully reinforce the hub axle.

Could maybe even try threading a bit of 12mm steel tube and weld a nut or cap head on?

Worth checking the current through axle can clamp the wheel, and that the threads dont bottom out just as the wheel is clamped?

A “proper” freehub design,like Shimano’s, feeds pretty much all of the wheel’s load into the axle through the outer hub bearings, where they’re supported by the dropouts. They were originally designed to solve the issue of freewheel hubs, with their unsupported central bearing, loading and flexing the axle in the middle, and regularly breaking.Sound like a similar thing to what’s happening to your’s (It’s pretty much what happened to mine on a 2007 Five, Hope XC’s snapped axles for fun, Royce shattered pawls continuously, Shimano 525 are still running problem free 14yrs on, though not sure if proper freehubs are available for your use)?

On this free hub, turns out the famous inner free hub bearing is absolutely fine.

No axle damage.

@Scienceofficer Here is the free hub body (steel) which looks very like yours, and the pawls. Three are buggered, one is OK. Hub teeth seem OK, but really it’s quite hard to tell. Maybe they really not in great nick if they are gouging the free hub body like that?

I’ve fitted another free hub for now, again. (I have got very used to multiple levels of redundancy). And also gone back to the bolt through. @big_n_daft Interesting video, nipped up the bolts to 12nm, which is considerably more than I ever used ot put through them, and of course a lot more than the cheese based maxle.

It does seem to be heading towards an issue of axle flex, I have a feeling one last roll of the dice with a DT Swiss hub would be worth it. Certainly far less than a whole new bike.

That video above is very interesting. I had never given any thought to the importance of the clamping force before. I had been wondering why Hope specified the axle torque on the HB130 as high as 30-35 Nm. Maybe that is what is required to keep the Pro 4 working reliably. My little Norbar wrench only goes up to 20 and I had been thinking that felt plenty tight enough. Better think again.

Two comments

I used to get similar scoring on hope xc hubs, definitely flex in the axle

The scoring I had was over more of the freewheel, suggests it’s not seated fully

You do get 15mm front through axles that have a cam that compresses the hub, might be worth looking for a 12mm rear one?

Thanks all for the input, but: Shit ****

Last night I shuffled the chainline, by swapping bb spacers, fitted a brand new freehub to replace the almost new one that had just failed, and used the old bolt through axle clamped up to a wee bit beyond 12nm.

Ride this morning, first steep up and BANG. Oh FFS.

I guess the hub shell, axle or teeth are indeed borked.

It would seem unlikely to be a not seated fully freehub – this has happened to both brand new from Hope hubs, 3 times, and also by me fitting many alternative/replacement freehubs. I have the tools (I’ve done a lot fo work on hope hubs!), am a very average mechanic, but i don’t believe me and Hope consistently make the same mistake.

So I guess we are down to 3 issues/resolutions:

1) Find someone who can mill me a steel 197mm hope hub axle (from that video it seems that the thru axle plays no part in stiffness of the set up, so i guess we can discount that)
2) roll the dice with DT swiss
3) accept that huge me + 197mm hubs + a bit of flex or alignment issue with frame means I retire chi-ti, get a Taival or BFe Max with a standard rear wheel (i get on very well with Hunt hubs/wheels), and use my mastodon and 29+ on the front. Super Mullet baby!

Bollocks.

Hunt? Now they really are cheese!

No issues over years (including some rowdy alpine stuff) with my Hope 197 w/alu freehub, but that is on a carbon frame where I have to crank the rear axle (cam-type) up proper tight to avoid creaking.

Hunt wheels are quite soft, I’d steer clear.

I’d communicate all this to hope and see if they can help you, machining an axle is not the job of a moment, but not that hard either, hour on a lathe for a good machinist. Boring the length of the axle will be the trickiest part, stopping the bit wandering (see point about good machinist), something like EN16 would be ideal

You’ve got the steel washer between the freehub and hub bearing fitted havent you ?

Given that the pawls are failing on an edge, I’d be looking at the axle bending and then loading the pawl edges, which is also shown with the freehub body catching on the ratchet ring.

Are the hub bearings rough at all? With the spacing between them being larger, the axle will deflect more, which in theory will also side load the hub bearings too. The axle then comes out of the driveside hub bearing at an angle. I should probably draw it out, hope it makes sense?

Given that the pawls are failing on an edge, I’d be looking at the axle bending and then loading the pawl edges, which is also shown with the freehub body catching on the ratchet ring.

this imo

Are the dropouts on your frame aligned properly?
Ask Hope what the weight limit is for that hub?
As others have suggested I suspect the problem is the axle not being stiff or strong enough ( freehub bearings are too big therefore axle diameter is too small) to support the load you are putting on it without bending and borking the bearings and putting the pawls out of alignment.

What you need is a Shimano fat bike hub, but they don’t make one.

Machine the freehub to accept a larger bearing? Video

Just a thought

Many years ago a mate had a ti mtb. Rigid 26 inch wheels, rim brakes. One night we put it on a old school turbo trainer. Front fork clamped reer wheel on fan.

We were all amazed by how much the frame flexed at the bottom bracket. I would say several centimetres. More than enough to really change alignment. Hugely more movement in chain than say moving a chain ring 3mm. Much more than my steel frame

Not all ti frames are the same but just a thought

If it were mine I’d be machining a steel axle and using short M10 cap head bolts at each end (with top hat inserts to make them fit the dropouts). Bit like the Hope singlespeed hubs. You can buy that type of solid bolted (aluminum) axle for regular Hope hubs but probably not the fat version. If going the custom route you probably want stainless or it is going to end up a rusty corroded mess….

There are also the Onyx hubs but they are even more ££ than DT. Reassuringly heavy and there looks to be a a lot of overlap / insertion where the non-pawl freehub joins the shell. Maybe worth dropping them a message and explaining your current problems?

The point that video makes that I hadn’t thought of is how much more torque is required to a M12 thread (vs the old qr) to generate sufficient clamping force. His recommended torque is roughly as per spec on the one I have with a 6mm Allen key head, but on my other bike I have a M12 QR one. Presumably I’m getting nowhere near the required clamping force on that.

Perhaps we should all be replacing our quick release thru bolts with good old Allen key ones?

(Accepted this is no use to the OP!)