Pace RC429 - An unfortunate short term review

It's because SRAM

The Hope E4 I tested would disagree.

Touche

That mount looks like it is on the wonk - under heavy braking the frame & the brace looks to give no support. I wonder if the demo might've been a pre-production model or something?

Not the case - full production model and set-up as other shown in online photos.

Does look little under supported, but hard today from a photo.

Did you try a different (smaller diameter) rotor at all? Resonance is due to vibration matching the natural frequency of an object. If you change the object dimensions, then the natural frequency would change also, which may cure it.

Is there a maximum rotor size for that?

Bitd with IS mounts, I would have got my facing tool out and got it faced to perfection to stop unwanted noise. Could it be that this was also slightly out so not totally perpendicular to the rotor?

I've had a few bikes do similar. Not that it will happen with every different setup but that kind of brake mount design with minimal support is basically asking for vibration. I was sort of interested in a 429, just seeing that mount puts me off somewhat.

Other factors are involved, for example resonance vibration is more likely with metallic pads, or bigger rotors because they need taller mounts. I've got a bike now that does it occasionally. Never happened with the stock aluminum wheels, but does now with carbon wheels, nothing else changed. So something about the original wheels was obviously damping out vibration or changed the resonance frequency. I've seen riders sticking/strapping small weights to the caliper to stop vibration. I tried this with old Avid Juicy brakes, stopped it completely.

Rotor size on the T-Spec model is 180mm - which is what I had fitted.

I tested with both organic and metallic/sintered pads.

I make my own steel frames from scratch (including the dropouts and disc mount). I also work in a structural durability test lab so do have some experience of stiffness / resonance issues in non-bike applications - they can be a complex combination of variables, so not surprising that some builds are presumably ok for other people . Pace have lots of experience, but I personally wouldn't make a disc mount like that (caveat - I never use post mount anyway as the unfashionable ISO mount is easier to make and more flexible for hub gears and single speed)

We've once had a different dropout issue with a major bike manufacturer. They "had never encountered it before" but agreed to replace the frame. The replacement frame (next model year) used mostly the same dropout, but they'd changed the forging to put extra material and surface area in the exact place we had the problem - what an amazing coincidence......

The video I sent to Pace with my testing

https://youtube.com/shorts/p6_aPxesp7Y?feature=shared

They “had never encountered it before”

Ha, I had that from one brand. This was after telling me they were replacing stays for affected customers. Bizarrely their store had the bike for several weeks and couldn't do much about it because they claimed the issue couldn't be replicated, despite it happening straight away for me and being on video.

IANAE

That central welded on brake mount does appear to be a recipe for flex or resonance under braking. Surely the load path is down(ish) a the front of the mount, so any resonance or on/off at the pad/rotor meeting is just going to be amplified?

A quick look at other steel frames and brake mounts, it seems even some with adaptors have a 'forward projection' - but they all are IS to PM via an adaptor. But all have a wider base than the Pace...
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Interesting. That flex looks pretty bad in the vid. Thankfully my 529 uses IS mount. Though I did have a similar issue with my signal ti, basically changed everything part by part to get the rear brake to stop reverberating horrendously through the frame. New everything solved it I think.

Is the mount square to everything else? We had horrendous vibrations/noise from a trek fuel a decade ago, mount was massively out. That was an IS mount that worked ok with a post mount adapter and brake but not a IS caliper.

Apparently so. Pace checked it over and said it was spot on.

Did you try a different brake mount? It might have made a difference.

Yep. Hope and SRAM.

Pace are expert engineers and bike designers and never get it wrong. If something fails it's the riders fault. Ask anyone who had a 303.

This thread isn’t exactly filling me with confidence when I’ve got an RC429 frame on pre-order!

I’m not here to slag off Pace

You clearly are. ( Which is fine TBH, everyone is entitled to an opinion)

And calling it s review is a bit of a stretch.  Fair enough if you think the bike is shit then say so. If you think Pace is shit then say so, but don't try to dress it up as something else.

A review is judgement or discussion of the quality of something. Review also means to go over a subject again as part of study or to look at something another time. Review has many other senses as both a noun and a verb. A review is a critique of something—a look at something's good and bad points.

Likewise - entitled to your opinion.

If the brake mount design changes...I'd have zero hesitation ordering another one. As I said, the rest of the bike is absolutely nailed. So much so, I'd love to be in a financial position to go to someone like Curtis, Dawley etc and have a custom frame made with the exact same numbers and geo.

OnzadogFree Member
Pace are expert engineers and bike designers and never get it wrong. If something fails it’s the riders fault. Ask anyone who had a 303.

Or a 405

A review is judgement or discussion of the quality of something

Ok, so change the thread title to

Pace RC429 Rear Brake Mount– An unfortunate short term review

That's the only bit of the bike you actually dedicate any time to whining about...

I thought the original post sounded fair and reasonable without being rude, we could argue about the title but if I was lucky enough to be considering a Pace RC429 then the title would catch my attention better than “howling Pace brake”. I think @someareset is quite right to make us aware of his problems, as for the “whining” comment above? Very rude.

The video I sent to Pace with my testing

The movement you are applying to the caliper isn't what's causing the juddering,vibration. Your comparison pics of the brake mount show where the issue is - the thin forward support of the mount will be flexing and allowing the caliper to rotate slightly with the disc when applied until the load 'pulls' the caliper back into its original position *(chest infection/mega man flu definitions) resulting in vibration. There also doesn't appear to be a lot of weld when the mount is attached like Pace have done. The other frame builders approach looks better.

thegeneralist sounds like a Pace child fanboi..it's a very fair observation, my riding buddy has the same issue but lives with it. Definitely a frame design issue, but Pace are never wrong obvs

I thought the original post Pace's response sounded fair and reasonable

Fixed that for you 😉

Now the OP is very publically whining about this on a large UK MTB forum, under a thinly-veiled guise of a 'review' which seems deliberately constructed to somewhat cynically get maximum forum views and responses.

I'll bet Pace absolutely love the OP.

But each to their own, I suppose. Carry on..

The thing about the design that strikes me is the bracing for the rear triangle isn't connected with the "top" bolt but I'd have thought that's the location of peak load.  I guess there's a reason they've adopted that approach.

I also appreciate I'm an accountant not an engineer 🙂 .

I can see Pace changing that mount for the next version, to me its obviously spindly at the front, so much so it would put me off the frame, I've had frames with post mount issues so it's now something I look more closely at, I personally think that's a terrible design and needs to be as thick as the rear section if it's gonna be unsupported like that, why make it that weak at the front when most of the braking force is going to it. It would probably be better if they flipped it. Look how the adapter is made then look at the post mount and where the material is.

You'd think the thicker arm of the mount would point forwards so that when the brake is used the thicker but would move / twist less than the narrower/longer section?

What size discs are you using and what does the frame claim to support?

Hang on.

In wet conditions and on steep terrain where the rear brake is under high load, I kept getting the most horrendous resonance through the frame into the pedals.

So not all the time? Very much not an engineer, but if it was such a problem, it would do it all the time, no? And there would be lots of reports from others with the same issue?

Given how much you say you like every other aspect of the bike, I’m not sure why you are SO focused on this and unwilling to even try a replacement frame, but each to their own.

That's a very fair observation Tom...one of which Pace also expressed when I told them how happy I was with it otherwise.

But wet conditions and steep terrain is pretty much half the year of my riding then. So not quite as limited as it might seem. And the issue I was facing certainly wasn't something I could just live with or ignore, it was far to noticeable.

If it had been found my frame had a manufacturing issue, I'd have of course taken the replacement and tried that. But once it was confirmed to be within tolerance and exactly as designed I felt it would just be wasting my time and money rebuilding it again and just as importantly wasting Paces. They'd end up with another used frame.

I've no issue with what the OP says or how he presents it.

I looks to my non-engineer brain a poor design of mount which will be more susceptible to flex and resonance.

One of the things I like about forums is you get the long term testing of products from other users that professional reviews don't always give you.

I've never read a review of the previous gen RaceFace carbon cranks failing. It's only after reading forums that you find out 75% of them ended up with wobbly pedal threads

Isn't that what's happening here whether the title or delivery is ideal is semantics.

From this thread I've learned that the rear brake vibrates under certain conditions and does so for more than one rider. It happens with a 180 rotor on steep stuff which is how I'd possibly use it. I'm a heavier rider so would apply more force which seems to be part of the problem.

I've also learned that Pace might be improving their attitude towards customers since I was last bitten by them as OP managed to get a resolution.

All useful stuff, I'd say.

Now the OP is very publically whining

I thought the OP refrained from whining and kept it factual. And as a former owner of Pace forks they have my sympathy.

It's a little odd that Pace presumably did a bunch of pre-production testing without, presumably, encountering the same issue, but that aside, I always enjoy the 'I am not an engineer but...' genre of commenting.

In proper STW victim-blaming tradition, can I be the first to suggest that the OP must be using their rear brake incorrectly 🙂

Finally, it's not a 'review' in the sense of being a balanced picture of a product. It's an entirely one-sided account of a problem.

The comment above states "and does so for more than one rider"

Unless you've seen otherwise outside of this topic - I'm not aware of that being the case. Apologies if you picked that up anywhere in what I said, I certainly didn't mean to imply that.

Testing has only been undertaken by myself - although my local mechanic did check everything over and came to the same conclusion and thoughts.

At the time of purchase - the only notable review of this frame online was by GuyKesTV. While I trust his views and thoughts, he clearly isn't capable of testing every bike in every condition.

I've tested in different conditions and posted my own thoughts - both positive and negative.

After confirming everything I had tested, Pace agreed to collected the frame and undertake their own review.

Upon receipt, Pace checked everything over and confirmed everything was good and that the issue was with my brake set up and not the frame. I didn’t agree.

Pace kindly agreed to send me out a replacement frame, but I declined this as I truly believe the rear mount is flawed. After plenty of back and forth between myself and Pace it was agreed best for all parties that my money be refunded.

Flippancy aside, if Pace can't reproduce the issue you're having, then essentially it's your word against their's. Are you particularly heavy OP? I wonder if you're simply needing/able to apply greater braking forces than the likes of Adrian Carter or Guy K, both of whom are relatively light to medium riders.

Beanieripper has a riding buddy with the same issue.

Are we still still calling Guy Kesteven a reviewer? I was somewhat surprised to hear him say negative things about a 50mm WTB gravel tyre recently because his still seems to thinly veiled promo rather than reviews these days.

@BadlyWiredDog - 5ft10 and 75kg

Flippancy aside, if Pace can’t reproduce the issue you’re having, then essentially it is your word against theirs.

I think there are a few on here who would suggest Pace's 'word' in the past has been less than ideal.

OP seems to have been fair and measured in detailing the experience here.

I wonder if Pace took the bike out for their test ride on some steep trails in the wet, or just had a quick pedal around the car park?

Yes, that's potentially unfair speculation - but y'know.

I’ll bet Pace absolutely love the OP

Sounds like they're doing the R&D for Pace, after spending good money on a product that appears to be not quite up to scratch, according to the OP. Are there still weight limits on their frames/forks, incidentally?

As for living with an issue you don't like on a bike - plenty on here would swap a frame or parts just for being the wrong colour, or not being the latest/blingiest. An actual issue that ruins the ride, that's another level.

Just to play devil's advocate, just imagine Pace had found the problem described by the OP on that frame.

What would you expect them to say? Anything different from what they did say?

It's not just Pace who do that. Different manufacturer says to me, how odd, we've never had that happen before. My reply, really? It's the second one I've sent back.

Similar with matching frames for me and the wife that had problems.

Must be a one off says bike company. What? On two frames of different sizes?

Looks like an assembly error to me.

I've had flutter induced by the pads overlapping the rotor spokes when not spacing the calliper correctly. or using a 203mm rotor on a 200mm mount.  Easily remedied by adding washers/spacers under the calliper.

Being as you've got the cup washers on the wrong side of the calliper (they don't do anything to help align the calliper if fitted above it) I'd say the the pads are probably not sitting in the right place on the face of the rotor and are catching on the rotor spokes.  That's be what's causing your vibrations though who knows why it's more noticeable in the wet - it's probably the steep bit that's the main factor.

I’m grateful to the OP. I think they pointed out the issue in as level-handed way as they could.

OP seems entirely reasonable to me.

Looks like a poor design for a brake mount.

I ride where Pace live and I can confirm its usually wet and very steep. Just adding that in case anyone thinks Pace develop their stuff in year round 30 degree heat and sunshine.

Being as you’ve got the cup washers on the wrong side of the calliper (they don’t do anything to help align the calliper if fitted above it) 

You say this but I've never seen a calliper fitted with the washers below it.

Eeesh, OP is getting a hard time for a what on the face of it at least, seems to me it was sorted to his satisfaction, he's just raising his issue to a bunch of folk who might be interested to hear about it and be a factor in decided to buy this frame or not,  and sounds like pretty good customer service from Pace.

Tough crowd.

@Speeder

Suggest you check your own setup if you are running the cup and cone washers below.

crossed

You say this but I’ve never seen a calliper fitted with the washers below it.

It's a bit of a red herring as it may or may not need them. The SRAM Manual say the that set up is correct but it depends what level the mount it welded at as to whether it sits in exactly the right place and it's up to the installer to get the pads in the centre of the rotor.  This may take any number of washers.  It's well worth some careful set up at build stage.

Manual

Imo, cup and cone above is usual now and ensures the bolt sits flat. The mounts still need to be perpendicular to the rotor. Cup and cone below was the old avid set up and was used take up any variance.

Just to play devil’s advocate, just imagine Pace had found the problem described by the OP on that frame.What would you expect them to say? Anything different from what they did say?

Well, we had a frame from a small UK manufacturer. There was an issue with disk rotor clearance to the chainstay with some, but not all hubs. Had a chat, sent it back. Manufacturer agreed and made some modifications to the frame to ensure clearance regardless of the hub and sent it back. Frame now happily in it's 10th year or so and still going strong. Happy outcome.

Some brakes use cup and cone washers below the caliper, the BB7 comes to mind. I think most hydraulic brakes aren't set up like this though.

OP seems reasonable enough to me. The way that post mount is welded to the frame doesn't inspire confidence in me, the only disadvantage I can see to welding it on as per OPs other photo is that it may require more manipulation of the seat stay or the mount itself to make it sit correctly.

@someareset - what makes you think that either of those are correctly set up?  They're just tests done by mags not SRAM installations. I do accept they're probably correct as they are fork fitted which is a mass produced item and very likely to be to the exact standards. A frame may not. be.

Was it even considered that something could be set up wrong?

Very much not an engineer, but if it was such a problem, it would do it all the time, no?

No. Can't test every scenario. And outliers get missed. Or it only happened "once or twice in testing" so it was rejected as an issue.

You also find some issues that are particular to a duty cycle and installation, even if the installation is correct and the duty cycle is within range.

Eye is an injeneer.

Also, from a stress/bending load perspective. First look at that makes me think "That's awful". Attaching a brake mount on a tube like that, the whole thing will move around unless the tube is at least a couple of mm thick, probably more. I'd start by doubling (or tripling) the surface area between mount and tube. Would be interesting to see how long they last before the weld starts to crack the tube.

Being as you’ve got the cup washers on the wrong side of the calliper (they don’t do anything to help align the calliper if fitted above it)

AFAIK in that installation they are there to make sure you've got no bending load in the bolt, so go between bolt face and caliper.

Tough crowd

I think it's partly that one person's anecdotal experience - with an additional 'friend of a friend' one - is doing a lot of heavy lifting in a 'I had this issue which I think is down to the brake mount' is extrapolated to 'there is a general issue with the brake mounts on this frame' way.

That might be true. It might not. But it's not unreasonable for people to be skeptical rather than just accepting everything they read on here.

No offence to anyone, not saying the OP is lying or that they're wrong, just that it's basically impossible to tell from anecdotes and people's 'I'm not an engineer, but that mount looks funny' / 'I'm not a fan of Pace' posts.

@Speeder - Absolutely it was considered. I'm no XCO World Cup Mechanic, but I've been doing this long enough to know what to check.

It was fine on my Squatch, not to the RC429 and then fine on my Squatch again. There was only one variable there.

@BadlyWiredDog Of course - I can't disagree with anything you've said there. I wasn't expecting to post this without getting flamed by some users. And I certainly hope people are able to form their own opinions without taking everything on the internet a gospel.

As I said - this is all my experience and what I've found riding the frame. That may well differ 99% of the other buyers.

My only thought was whether a non straight through +20mm caliper mount might have made a difference. You can get a +20mm mount that bolts to the frame and then the caliper bolts separately to the mount

@someareset furry muff - I still think there's more than one variable in the 2 builds but being as it's now gone back, there's not way to tell. If you'd posted a "What's wrong with . . . ?" post we could have possibly trouble shot it but now that's impossible so we're just conjecting.

Best for all concerned to chalk it up to experience and carry on.

@dc1988 - Tried the Hope L mount along with an E4 caliper.

In my case, it made no difference. That mount also pushed the caliper up even higher, which I believe puts more stress on the frame mounting locations.

I want to clarify something. The OP's brake caliper, mount, and washers, are fitted correctly.

I'm reposting their picture on this page for clarity:

And an extract from Srams document "disc-brake-caliper-mounting-specifications-for-road-and-mtb.pdf"available here; https://www.sram.com/en/service/models/db-mthw-a1

The cup and cone washers go outside the bracket.

These brackets use long bolts, that pass through ovalized holes in the bracket. The caliper moves outwards, but also at an angle, relative to where it would be fitted directly to the frame with a 160mm rotor. The post mount brake standard is not radial mount.

You can see clearly from the silhouetted shape in that diagram, the mounting plane of the frame for 160mm rotor is NOT parrallel to the final mounting plane of the caliper for 180mm rotor. Ovalized holes, with cup and cone washers allow this to occur. Otherwise we would have a bent bolt.

I have, quite literally, got a set of these on the desk in front of me as I type.

For what its worth, I also agree that this has been an entirely fair review or sharing of informtation from the OP - it does look exactly like poor design. WhilstI havent done any testing for many years, I'm am quite sure that if this were modelled up and tested you would find that the method PACE have chosen to assemble this brake mount, is indeed going to lead (in some circumstances) to flex - which of course leads to flutter, resonanance, noise etc.

My Trek Superfly (aluminium frame, post mount, but both posts were sturdy square aluminium posts rising up from dropout/seatstay) generated exactly the same horrible, physical resonance that the OP is experiencing, so right off the bat I would suggest that Pace's frame design might not be at fault.

I fought with it for a while, strapped lead wheel-balancing weights to the stay (which helped actually) changed from SRAM Level to Shimano Deore brakes, multiple different pads and rotors, etc. etc. Eventually what cured it (and the horrible squeal the brakes produced whenever wet or cold) was absolutely cooking the brakes on a long ride in the Cairngorms.

This convinced me that all bets are off until a brake is PROPERLY (i.e. not just twenty hard stops on the pavement) bedded in. There are articles out there explaining it in more depth but specifically there is a difference between bedding a brake in, and burnishing the rotor. The latter takes potentially much longer and explains my issues on the road and gravel bikes where I just don't brake hard or often enough to achieve proper burnishing (or gave up and went back to rim brakes before I eventually achieved it). I don't know if it's a heat thing, or an accumulation of pad material thing.

Flippancy aside, if Pace can’t reproduce the issue you’re having, then essentially it’s your word against theirs. Are you particularly heavy OP? I wonder if you’re simply needing/able to apply greater braking forces than the likes of Adrian Carter or Guy K, both of whom are relatively light to medium riders.

Also this. I'm 90kg, ride large frames. It doesn't surprise me that e.g. a pal who weighs 65kg and rides small or medium frames maybe doesn't get the same squeal, less force going through brakes, less resonance through frame etc. I don't think it's fair to say a problem doesn't exist if a different rider can't reproduce it.

My Trek Superfly (aluminium frame, post mount, but both posts were sturdy square aluminium posts rising up from dropout/seatstay) generated exactly the same horrible, physical resonance that the OP is experiencing, so right off the bat I would suggest that Pace’s frame design might not be at fault

You've had a few different bikes though, haven't you?  And ride a fair bit?  But thought of one specific frame with this issue?  Is it not fair to suggest that some frames might be more susceptible to it than others?

And if absolutely cooking the brakes in  proper mountains is the only way to have properly set up brakes, it's got to be accepted that 95% of riders won't be doing that. If a bike feels/sounds horrible to ride, it's a bit victim-blamey to say it's the rider's fault for not having driven to Scotland every time they replace their brake pads, when the issue doesn't show up on other frames. 😀

You’ve had a few different bikes though, haven’t you?

Yes, Trek was the only one with the resonance issue, rest have just squealed when wet. My logic though is that the resonance/squeal all come from the same source, i.e. pads stick/slipping over a non-fully-burnished rotor. My thoughts were that this effect for the OP was enough to cause the resonance on the Pace frame, even if it didn't cause squealing on other frames.

And ride a fair bit?

No, I'm actually embarrassed that you're the second person to assume that, I must spend WAAAAAY to much time posting on here 😆 I average just over 5000km a year (although, pertinent to disc brake discussion and bedding in, I spread that over 4 bikes, so 1500km/bike/year, which might explain why I never REALLY got brakes bedded in properly, as a lot of that mileage was gentle road miles or flattish gravel miles, very little death gripping or prolonged braking).

If a bike feels/sounds horrible to ride, it’s a bit victim-blamey to say it’s the rider’s fault for not having driven to Scotland every time they replace their brake pads

100% agreed, and my frustration with disc brakes is that there still seems to be some voodoo about getting them bedded in and set up right. I am the poster boy of people who should really be riding disc brakes (heavy-ish, 'enthusiastic', ride in all weather) but won't because they don't work for me. My idea is that manufacturers should be selling rotor and pad sets, pre-burnished and bedded in, or someone (e.g. Hope) should have a rig for doing so (at a cost, obvs).

The point of all this is that burning my pads in properly cured the exact issue OP is suffering on my Trek, so regardless of the brake mount design of the Pace, it might just be that run-of-the-mill disc brake black magic would eventually have sorted it for him.

someone (e.g. Hope) should have a rig for doing so (at a cost, obvs).

Your dreams answered

https://sinter.si/pages/smart-bedding-machine

Summary of this thread

One owner had a problem with the rear brake on a ex-demo Pace frame.  He believes this to be a fault of the frame through what he reports as a thorough process of replication and elimination against other frames / brakes.

Pace quickly engaged with their customer to find a suitable resolution.  Despite reporting they were unable to replicate the issue, offered the owner a frame replacement (new for ex-demo?  Not clear) or a refund.

Due to lack of confidence in the mount design, the owner took the refund.

My takeaways are that there is potentially a so far unproven issue on the frame model … buyer beware and do your investigations if planning to buy.  Balance your purchase with Pace being  a customer focussed manufacturer who will seek to support one to one even when they disagree with the complaint.

So by all means buy a Pace, be a little cautious around the RC427.  Have thick skin if you post on STW.

@dave_h

Exactly that.

Lack of confidence in the design - based on my findings.

I think it’s hilarious that some people now seem to get their knickers in a twist over other people expressing their opinion/describing their experiences of owning and riding mountain bikes on a mountain bike forum.

Could the bolts be flexing ?

Seems like a fair and informative post to me. That brake mount does look crap and I bet they change it for the next batch.

All that load on a base which narrows on its way to the frame looks like the opposite of what you want. I am obviously not an engineer.

And for those who have never experienced it, "Oh that's strange, we've never seen this problem before and no matter what we try we can't possibly recreate it here in the office." is the standard reply every time you have a problem with anything from any manufacturer. I heard it at least once a month when the Fox X2 came out.

I think it’s hilarious that some people now seem to get their knickers in a twist over other people expressing their opinion/describing their experiences of owning and riding mountain bikes on a mountain bike forum.

Are you new here?

my magura discs and mount came with some foam inserts , i guess they are anti vibration mounts

no idea how if they do anything though!

Fair play to the OP for keeping calm and a measured first post.

I note at least 2 engineers querying the design

Absolutely nothing wrong with the OPs post, some members just have issues, one in particular just cannot admit when they're blatantly wrong.

 some members just have issues, one in particular just cannot admit when they’re blatantly wrong.

Just one? You're being generous.