I broke my Ti hub ysterday. Anyone else have this happen?

It’s the original KH Ti. I completely seperated the splines from the hub body, cracking the welds so that the rim spins seperate from the hub, so completely wasted.

I bought it during the April fools sale at UDC the year before last, so it’s about 18 mo old. Stored indoors, never abused, no drops over two feet, built up as a 26er.

I think it has a lifetime warranty, but I have not heard back from UDC yet. At $400 it should be warranteed. I worry about my other KH Ti hub which is built into a 36er, but then that uni doesn’t get nearly the use and the spokes are so long that I’d be suprised if they overstressed the flanges like a muni.

I’ve seen the splines get weak on the old style KH and Nimbus hubs, and I’ve heard of them cracking, but I couldn’t find any threads on brokenm flanges for the KH Ti hub.

Anyone?

I know Joe Dyson done the same the same thing to his first KH Ti hub, he got it replaced through UDC.

I’ve seen the flanges separate on 2 hubs locally. They were both about 2 years old and had significantly more abuse than it sounds like your hub saw. Good luck!

Bugger! This really sucks. I have recently aquired a KH TI Hub to build it into a 26’’ muni setup, I had heard of them breaking from a abusive riders… but not from doing 2 foot drops max :frowning:

should make a video… show us the damage

I have seen one of the hubs that Max mentioned. It looked like it cracked all the way around on the weld between the spindle and the flanges.

i know two french people that had exactly the same problem as yours…

It’s a shame to see $400 go down the drain like that. Personally I’d try and see if I can get it replaced with other KH components that make up $400 like a new chromo hub, frame, and other bits. A new Ti hub will just run into problems again, yep even the new alu flanged one.

Upon seeing the Ti welded hub at first I instantly had suspicions of the quality of workmanship and materials behind it. Ti is hard to weld, and even harder to weld well. Considering the amout of force a unicycle wheel goes through, welded flanges are sketchy. Which is why the new MAD4ONE hub is very appealing as it’s the only true one-piece ISIS hub currently. Now if Exceed or KH revised their Ti hubs to be totally one-piece machined that’d be worth a look but I reckon costs would be far far too high for a realistic number of sales.

Do you have a picture of the broken hub right now by chance? and were you using normal plain gauge spokes or double butted? DB spokes are much friendlier towards the hub, rim, and overall wheelbuild strength whilst being lighter. I’d never risk running an expensive hub with standard spoke for just those reasons.

Hope you get it warrantied smoothly! Kris is normally good with these things.

:slight_smile:

you should get it replaced by KH with one of the new Ti hubs or something else

Well, I spoke to Josh at UDC and since I have been riding it for 18 months, I am outside of the 12 month warranty period :frowning:

I sent Kris an email asking if he’d help me out, esp since it’s known that this hub had breakage issues due to its design, hence the redesign.

I agree on the Ti weakness issues, the metal does seem to be a little on the brittle side esp considering how flexible it is compared to Al.

I was running straight gauge spokes, not excessive tension, also a 26" wheel, so not a bunch of side loading. I actually do very few drops, I’m mostly a roller kind of guy, minimal hopping, so if anything, it was under abused.

Yeah, $400 for a hub that lasts 18mo is not good.

I’ll post a picture when I get a chance, but for those who know the first generation KH Ti hub, I cracked the welds that attach the spline to the hub body, all the way around on both sides. So my unicycle freewheels now.

It’s bad enough that I have to mess with rebuilding a wheel, but to take a big $$$ hit, that’s a drag.

Josh did offer me a crash replacement, but it was still going to make a replacement T hub very expensive.

Hey,

I chatted with Josh at UDC and Ben (via email) - it’s true that it’s past warranty but we’ll work on something that’s reasonable to everyone.

On a separate note, here’s a comment about flanges I passed on to Ben:

Regarding the new version of the Ti Hub (and the CrMo hub) for that matter, with the polished aluminum flanges. I like the combination of high strength aluminum flanges, with a Ti (or CrMo) spindle, because it takes advantage of the properties of both materials - max strength on the spindle, and a lighter material that can be optimized on the flange in terms of its shape. For production reasons (and for weight reasons in the case of a CrMo) hub, a fully one-piece hub is likely to have small spoke flanges. While this is one way to reduce weight, unfortunately it’s not possible to get around the mechanics that flange size is directly proportional to the stress placed on the spokes at the hub. Plus, a small flange reduces the spoke angle, and high spoke angle is better for wheel strength. A flange is heavier than spokes, so the challenge is use a spindle size that’s optimized to be just large enough to avoid spoke breakage, to maximize spoke angles to the rim, and to be angled correctly to reduce stress on the spokes as they come off the edge of the flange. That is the goal of the size and shape of the flanges on the new gen Moment Hubs.

Kris

Hey,

I chatted with Josh at UDC and Ben (via email) - it’s true that it’s past warranty but we’ll work on something that’s reasonable to everyone.

On a separate note, here’s a comment about flanges I passed on to Ben:

Regarding the new version of the Ti Hub (and the CrMo hub) for that matter, with the polished aluminum flanges. I like the combination of high strength aluminum flanges, with a Ti (or CrMo) spindle, because it takes advantage of the properties of both materials - max strength on the spindle, and a lighter material that can be optimized on the flange in terms of its shape. For production reasons (and for weight reasons in the case of a CrMo) hub, a fully one-piece hub is likely to have small spoke flanges. While this is one way to reduce weight, unfortunately it’s not possible to get around the mechanics that flange size is directly proportional to the stress placed on the spokes at the hub (e.g. larger flange = less stress on spokes). Plus, a small flange reduces the spoke angle, and high spoke angle is better for wheel strength. A flange is heavier than spokes, so the challenge is use a spindle size that’s optimized to be just large enough to avoid spoke breakage, to maximize spoke angles to the rim, and to be angled correctly to reduce stress on the spokes as they come off the edge of the flange. That is the goal of the size and shape of the flanges on the new gen Moment Hubs.

Kris

Thanks Kris!

You know, it’s really something that you stay involved with the forum, even if sometimes things don’t go always go smoothly. Lots of new riders on here, so seeing you’re ongoing positive participation is really golden.

I realize that gear breaks and that someone has to carry the cost, of course I don’t wanna be that guy, but to a degree I am the one who broke the hub :o

I’ll be working with Josh and Amy to get a replacement.

Nice team, UDC and Kris Holm :slight_smile:

Always good to see companies treating their customers with decent service. :slight_smile:

As a general point not directed to any individual however, I have to say that whilst optimising wheel strength is important, I believe that protecting the individual parts is more important. Considering how much bashing a trials/street unicycle goes through, in my experience and seeing others’: a larger flange is more likely to break or deform as well as being more vulnerable to sideways damage from mis-timed sidehops or overshot grinds etc. It’s never nice to mangle up a flange when spokes are far cheaper and are more of a disposable item than a hub which should be a component that can be used for years. What I like about the new MAD4ONE hub is that it’s totally one-piece machined and the flanges are small and low profile so the spokes can take the scrapes and bumps rather than a hub flange. I think a spoke or two snapping or all the spokes loosening off ever so slightly more often is a really worthwhile tradeoff compared to a hub failure because of flanges.

To Kris, if you read this thread again!: Will future KH models be specced with double butted spokes of a decent brand like Sapim or DT Swiss? I know you’re very keen on wheels being as strong as they can but isn’t releasing your wheels and full unis with heavy plain gauge spokes acting negatively towards your goal? I realise it’s to cut costs but from somewhere like say: Tartybikes in the UK, plain gauge Mutiny BMX spokes are £10 whereas Sapim double-butted custom spokes are £12.50. It’s not too much a difference in price, but a huge difference in quality, weight, and massively helping the strength of a wheelbuild. Are there any plans to release info on new KH prodcuts? I’m always interested to see! Thanks :slight_smile:

Thanks for the feedback - well taken.

Re flanges - individual issues like bashing from mistakes on grinds are valid concerns, and it’s very cool to see new products like one piece hubs out there as options. However, it’s also important to keep in mind what the majority of people need for most kinds of riding, most of the time: 100% of riders want a wheel that maximizes wheel strength for reasonable weight. It’s not just about spoke snapping; it’s also about longterm wheel durability, and flange size has a major effect on that. That is especially the case for the larger wheel sizes.

Kris

Fair points there!- I wasn’t taking larger wheel sizes into account so much as I’m a trials rider. I can see a tiny flanged hub maybe being a bit bizarre on a 29 or 36er.

It is true that 100% of riders want to maximise wheel strength, but I think there are a lot of important factors that a brand like KH can’t always control like: quality of wheelbuild (by those doing it at home or at a shop), brand or type of spoke used, and very importantly yet often neglected is knowing how to retension+true the wheel.

I believe the main reason why people trash their wheels so much especially in trials/street is because most people aren’t aware of what to do with a wheel as far as maintenance goes which is crucial yet surprisingly simple. It’s something that is quite often pointed out in the biketrials community that an average/midcard rim built with average spokes onto an average hub can outlast a super strong highend rim, the best double butted spokes, and a really intricately thought out hub.-> depending on wheelbuild quality. So I never allow anyone but the absolute best wheelbuilding shops to build my wheels for me. A really worthwhile investment! :slight_smile:

That being said, having good parts to start with is even better. I’d say quality DB spokes from a reputed brand like Sapim or DT Swiss is somewhat a hidden gem within the unicycle community as there are so many benefits to every discipline and size. They are less prone to snappage too! (So long as people don’t bash them on grinds repeatedly).

If anyone is reading this and is getting a new wheel soon, make sure to let it have its ‘break in’ period (around a week depending on how much/hard you ride). Then comes the retensioning (which is different to truing, and is a monkey job of only 5 minutes!). It’s so important and will make a huge difference to the longevity of your wheel.

I’m still holding back on buying some parts for my uni I’m rebuilding up as I’m curious to see what KH is offering for the new year! I’m a bit surprised why there’s no “KH 2011 lineup and products” topic by you yet Kris!

Ha Ha. A KH “2011” announcement is coming very soon, maybe Thursday…

I couldn’t agree more about wheel maintenance. Most catastrophic wheel failures and especially wheels that prematurely wear out are preventable by regular wheel truing. A good re-tensioning soon after riding a new wheel is particularly important for any production unicycles including KH unis, followed by regular minor truings. That also keeps wheel truing mostly in the range of minor lateral adjustments, as opposed to dealing with flat spots, which are much harder and often impossible to completely fix.

Kris

Though I’d like to have DB spokes, I don’t see the need for my riding style and the style of most riders I know.

For example, I build all my own wheels, been building wheels for twenty years, though I’m far from an expert, I do build a decent wheel. I haven’t broken a uni spoke in the 2+ years I’ve been riding, likely because I’m easy on my gear, though I do regular maintenance which helps. For the most part my wheels stay straight and require little truing, maybe once ever couple months.

I’d take lighter spokes, but straight gauge works fine and they’r eless expensive.

even so I broke one, I love the old KH Ti hub.
the design is very clear and everything is well but the welding is suboptimal and that causes the problems…

I used to think that same way but when I really gave DB spokes a chance for some research and real testing I’ve found they are one of if not the only true all-benefit no-loss product out there. Even for someone not riding trials or street bashing, I’d say just for the simple fact that uni wheels all undergo so much strain and force no matter the riding style (anything from freestyle to distance) that DB spokes add the midas touch that no other weight saving component can. I’m certain your Ti hub would have lasted a lot longer with DB spokes, probably still be totally fine to this day and this topic would never have been created. :slight_smile:

It’s not so much about spoke snappage, it’s more about the benefit they bring to the overall wheelbuild. I used to just think they were lighter and a weight weenie upgrade but I did some reading and found since they flex more in the centre due to being being butted thinner there along the length they actually benefit the overall wheelbuild strength, meaning instead of transferring shock and strain on the hub flanges (really important), the rim, and the overall tightness of the wheel they dissipate it well through the minor unnoticable flexing they do.

So all hubs have been proven time and time again to last longer, rims crack less, and wheels stay tighter and truer longer than using stressful plain gauge spokes. Especially for a welded uni hub, I think DB spokes are such an important match that can undisputedly prolong the life of its connecting components. If I ever ran something like a welded hub that were super expensive and known to be fragile I’d never pair it up with plain guage spokes for the reason that I want my parts to last as long as possible.

I’d say that DB spokes are the only weight-loss upgrade that carries tremendous benefit without any negatives (except for spending maybe a few pennies more than nasty plain guage). Still, if people are so willing to splash out on parts like Ti hubs, Ti axles, magensium pedals, carbon bits and light tyres/tubes then DB spokes sit right above all of them.