Quick question about seat tube length

It might just be the photo but those cranks look really long.

They do 127/135/140 mm cranks, I guess those are 140s.

Yeah, it does sound like Mad4one probably gave you the best and most honest advice. That Chinese thing you ordered really doesn’t seem too bad, and it might be a long time before you feel the need to upgrade. If I were the one buying that uni, I would hope they put the 125mm cranks on it, as those are more versatile, but if you really end up being as focused on trials as you think you will be, then 137 or 140 would be better. In any case, for the next few months, or possibly longer, it won’t matter!

Chris Huriwai uses 125mm cranks. Being a street unicyclist, he doesn’t do quite as much high jumping as a real trials unicyclist, but the jumping he does do, as well as the other stuff, is pretty impressive!

I read your reply just in time and asked the seller to supply the 127 mm cranks, which are only available in black, so with the all-black look it’s going to be a stealthy look! Once I can do basic riding I will get a pair of longer KH cranks from UDC as these cranks have generally got very good reviews round here. Cheers!

This looks like one of the best ripoffs of an old impact gravity that I have seen and may end up being fairly strong framewise.

OK the uni arrived today, first impressions are fairly good especially the wheelbuild feels solid with the beefy 13g spokes. Frame is hydro-formed which is nice.

  1. “Fork” flex: I can pull the fork tips together by about 1cm using one hand. Is this considered normal? Using my Echo 20" trails bike fork as a reference, the same unscientific test results in about 2mm deflection (if that)—in a word: stiff. The frame with no seat post clamp, no bearing clamp and no bearing clamp bolts—so basically just the bare frame—weighs exactly 563g on my digital kitches scales.

Tealiang: 563g (presumed 6061-T6)
KH20: 605g, 7005-T6
Impact Gravity: 572g, 6061-T6
‘Knight’: Don’t know but definitely heavier and stiffer than Teliang
Echo ‘Urban’ 20" trials fork: 740g, 6061-T6

I suppose trials bike forks endure greater stresses than a unicycle frames, hence the added weight, however the Teliang frame does seem a bit too feathery. When I tap with my nails on the metal it rings hollow, whereas my trials fork rings in a way that you couldn’t tell if it was hollow or not without holding it in your hand. If that makes sense.

  1. The seat post goes deep into the neck, I could easily hack off 4-6 inches and the end would still be a couple of inches below the clamp. If I was to shorten it, what’s the recommendation i.e. how long below the top of the neck?

  2. How tight do I tighten the seat spost clamp bolts? The goal is to prevent the saddle from turning while riding the uni.

  3. No crank stops: The bearings are press-fit, and there is no spacer between the inner race of the bearings and the cranks a.k.a. ‘crank stop’. All trials bikes with ISIS bottom bracket have crank stops. Just read this thread: A small space where the axle is visible, should I worry about this?

On a side note, I can’t understand why anyone would want press-fit bearings. Am I crazy or something? A snug fit is sufficient if crank spacers are used.


All three tubes are hydroformed

The above quoted thread is illustrative of the confusion surrounding the ISIS standard. I think you should worry about the small space. Your new unicycle could last for a very long time, but not if parts get loose. If I were you, I’d order a crank puller, more/different spacers and a new set of ISIS hub bolts. I added the last item because it’s possible the hub bolts that came with your unicycle are not of the highest quality and might deform under serious tightening.

If I detach everything from my 20" frame, grab the top of it and tap the fork against my knee, it resonates nicely, like a tuning fork, though it gives an A flat instead of an A. I don’t think I could bend it a whole centimeter, though, unless I were trying to destroy it!

They say 2 inches minimum, but I wouldn’t mess with that too much just yet if I were you. The more seat post you have in the frame, the less likely it is to swivel, and the less likely the seat tube is to break. Also, in your first year of riding, you are going to want to experiment with a lot of different seat heights, so right now, you can’t be sure how much you should saw off. You can always saw off more later, but if you saw off too much, you can’t put it back!

Is it possible the company forgot to send you spacers? My concern would be that dust and crud might get into the bearings or something.

Yeah, I think press-fit bearings are the cheap kind. I forget what the better kind is called, You seem to know more about a lot of this stuff than I do, though, maybe because of your trials bike background, and maybe because you do lots of research, but in any case, hopefully at least some of what I have said is helpful.

But now it is time for you to take action. This instructional video was posted recently by another user on this forum. If you do what it shows 50 times or so, you will most likely find yourself going on longer and longer rides. Note that the fall shown in the instructional video is a worst-case scenario. Most of the time you will just end up on your feet.


Kind of like the New Coke thing from 1985, for those that are old enough. Except Coca-Cola managed to (after a while) turn that into a triumph.

Yup, back in 1999 we thought John Drummond was insane to spend $5000 US on the unicycle.com domain (before that they were unicyclesource.com). They were pioneering the idea of selling unicycles online, and it was a very much unproven thing at the time. But he got it oh so right! Someday I will offer unicycling.com to the highest bidder… if there are any…

Pretty amazing for them to recommend someone else’s product over theirs. Probably said “China” based on your location, or just on knowing that if you’re serious about unicycling you’d be back pretty soon. :slight_smile:

I would expect KH to recommend his own products; he probably assumed you wanted info about them specifically (and they’re good stuff). I love the Mad4One unis; beautiful colors and great builds, but a little expensive, especially when adding shipping to the US.

Stealthy is a relative term; you’ll only be stealthy at night. :slight_smile: But it should make a nice, sinister Bat-Uni!

That sounds pretty flexy, but the true test will be riding. I’m pretty sure my handmade Wilder 6160 frame wouldn’t flex that much. The unknown with “off brand” unicycles will tend to be in the hub and cranks. They’re either good or they’re not, but even if they’re not great, they will probably last you through a lot of learning, and be a really good starter uni.

To be fair, Trials forks are purpose-built for Trials bikes, so are probably extra burly for that reason. I think the biggest stress on a Bike Trials fork would be from being bashed from the front, either from riding up against things or hopping on the front wheel (if that’s a thing; I’m not a Bike Trials guy). Unicycle forks get their share of abuse, because they carry 100% of the rider’s weight 100% of the time; no “sharing” with a large frame and another wheel at the other end.

I recommend zero shortening. The only reason to do that would be if you couldn’t get the seat low enough. Extra seat tube is extra structure, which is especially a good thing on a cheapish uni.

Uh, enough to do what you just said. Unless the tube is a non-standard size, you can always replace the clamp. Double-bolt clamps tend to be the strongest, but are a bit more hassle every time you change seat height.

I agree with the advice on having spacers in there, especially if the frame likes to flex.

Thanks John and Song for the thorough replies, all points noted. BTW that gif looks scary but indeed probably the quickest way to learn.

Regarding fork flex, it’s literally 1cm (just measured it), but that’s both ‘prongs’ combined, i.e. I can reduce the spacing between them by 1cm. The mad4one frame is even lighter than this one (alghouth it’s 7005-T6 aluminium), and the Impact Gravity is only a tad heavier so it seems they are all in the same ballpark.

Regarding the crank spacers, I need to ask the seller if he forgot to include them, but I don’t think so because the axle looks like it’s not designed to hold a spacer there, see pic below:

The blue stuff you see on the spindle is Loctite ‘threadlock’. I know what you are thinking: of all places, why would anyone would that stuff there? I have no idea either, that’s how the uni was supplied. I’ll bring it to the attention of the seller though. They also applied copious amounts of threadlock to the crank bolts; here one could argue there’s a valid reason to do so, but when you remove the bolts and see small metal shavings coming off you know that thread should have been greased, not locked.

Anyway, back to the spacers, a 9mm spacer is needed for this particular axle+crank combination. The widest one available from UDC, the KH one, is 8mm but I can buy some very thin 22mm stainless steel shim washers to fill the gap, which might turn out to be better than a single spacer that’s the right size should the gap narrow over time.

For me the spacer serves three purposes:

  1. To ensure both cranks are symmetrically spaced
  2. To increase crank stability by acting as a shoulder
  3. To prevent overloading the ISIS interface if bolt over-tightened

Sounds like this spacer is a good thing to have in place!

I’m also putting some M6 shim washers between the frame and the bearing clamp. I realise the clamp doesn’t need to be crazy tight especially with the ‘nyloc’ nuts, but with the shims in place I can tighten a little more to help stiffen the assembly without fear of deforming the bearings.

Yes, Loctite on the splines is definitely weird. When I first saw that photo, I assumed the blue stuff was some sort of exotic bicycle grease that I hadn’t seen before. A bit of bicycle grease on the splines (and crank bolt threads) is a good idea.

The only place I ever used Loctite was on the bolts on the underside of my seat. All my hopping was loosening them. Some people’s crank bolts come loose chronically, so they use Loctite or they have some sort of enhanced hex wrench to twist them until they scream, but I have never needed to resort to these measures.

There’s clearly a market for bolt-locking technology, say a grove across the threads with a strip of nylon to create friction whilst the the thread can be greased.

It’s the only way to learn! Some people postpone it by clinging to a fence and pedaling slowly along, and insist that it helps, but I don’t think it does, and sooner or later, everyone who rides a unicycle does what is shown in that gif. As long as you always fall forward, rather than back, the worst injury you are likely to get is a pedal bite or two. Enjoy!

BTW my uni frame rings out an A flat :smiley:

Thanks for the mention Song, that was my gif.

Here’s a link to all the other videos from the day. Most of them aren’t very dramatic as you can see.

I haven’t shared Google Photos using a link like that before so let me know if it works. Also if I thought anyone would be watching them 13 years later I might have kept my shirt on!

Yeah, the link works. Recording your learning process was a wise move. Whatever anyone thinks of unicycles, learning to ride one is something you only do once. Last year I saw an old guy learn to unicycle for the second time, but it wasn’t the same, even though he had gone more than 40 years without riding.

You’re grabbing at the air for balance in one of those videos- I did that for a little while too! I had thought it was because of my prior experience on a slackline, where hand and arm movements are more important, but maybe it wasn’t. The thing I did learn from the slackline that was applicable to unicycling, though, was that you could only learn it by pretending you already knew how and falling off again and again. The people who tried the slackline with a parent or friend holding their hand never got anywhere at all!

Very true. I still get surprised when people try and learn something by doing things that don’t really resemble what it is that they are trying to learn, but then I suppose I was once that way too.

I’m in a very specific part of the Navy and we do lots of learning, all day every day, even (especially) the very experienced guys. The only way to really know a system, routine or operation is by touching it, operating it, practicing how to use reversionary modes or drilling the procedures. This cannot be learned from a book alone, even though trainees often think that it will work for them. It’s easy to tell if someone knows the book answer or whether they actually understand something simply by asking questions which expose their level of understanding of how multiple complex systems interact.

Let go of the fear, allow yourself to be wrong in the training environment for as long as it takes but make sure the training environment has been designed appropriately. Would anyone who persisted long enough to be successful regret letting go of the wall too early during their learning? Clearly not. So the logical inference is to let go of the wall immediately!

The knowledge that people can learn at different rates is neither uncommon nor contentious.
The knowledge that many people enfeeble themselves by overestimating and avoiding risk is less common, more controversial but true nonetheless!

Hi again guys! Just thought I’d give an update. I finally managed to get my unicycle built up, got some KH 8mm crank spacers from UDC China (thanks Alex :)) and added a 0.3+0.5 mm stack of M22 shim washers to achieve the total spacing needed. Also got some 7075 alu crank bolts and transparent pedals. Looks pretty sick.

My learning experience started on Friday. Did two 30 minute sessions in my building’s corridor, managing a couple of 3 full crank turns towards the end (my best for the day). Despite the advice of “just going for it” given in rich’s gif above, I found having walls within close reach was an incredible time-saver. Constant dismount-mount cycles consume a lot of time and waste energy if what I’m trying to do is get a feel for balance. However the corridor was too narrow at 120 cm and that was preventing me from progressing. I gave up for the day. That night my legs felt as though they wanted to keep pedalling, it’s as though my legs were still on the unicycle. I could feel the unicycle under me even thought I was just lying in bed. Groin area slightly sore.

Yesterday (Saturday afternoon) I found an alleyway about 20cm wider than my stretched arms can reach. I found this to be perfect for learning. It allowed me to launch off whilst still having the option of a friendly wall to either side to prevent UPDs. Any time I was definitely going to fall, I would just lean onto the nearest wall, straighten up and try again. Within about 15 minutes I was able to ride half the length of the alleyway without walls—about 10 metres. Once that happened my courage went up quite a bit, especially because I realised bailing was relatively easy, landing on my feet 100% of the time. I know that’s what everyone told me, but you have to experience it for yourself before the brain buys it.

With the fear of falling gone, I then went to a nearby road, and holding onto a wall, launched off into the open, no side walls. After a few attempts, I managed about 50 metres. Felt friggin’ awesome :sunglasses: The ride was only 30 minutes, and it kicked my ass. My whole body ached by the end of the day.

This morning (Sunday) I went out again, for about one hour this time. Towards the end I was able to ride for about 100m with not much arm waving and managed to turned a 90 degree bend in a more or less controlled way. I was also able to free-mount once.

Hopping was trivial, maybe coming from a bike trials background helped.

Overall I’m pretty happy with my progress so far, and I’m finding unicycling to be very addictive.

I encountered a few setbacks though, advice needed:

  1. Groin discomfort: This is the second biggest roadblock I’ve encountered thus far. According to various threads here on this forum, it’s caused by a combination of poor moisture control, inadequate padding, pants material, whether underpants are being worn or not, saddle geometry (width, etc), saddle orientation and saddle height. That’s a lot of variables with one common denominator—a sore groin. Just few minutes into my first attempt, my inner thigh area was already hinting at the problem, and the end of the ride was clearly marked by my groin’s ability to endure the burning. One thing that helped make the situation better was to adjust saddle height correctly. As it turned out, my saddle was initially about 5 cm too low. Will padded cycling pants eliminate the chafing?

  2. Diamonds: We’ve all seen the picture. I have to literally grab and pull my diamonds up before every mount. Doesn’t look particularly classy and the extra step is a bit of a chore. Will tight-fitting cycling pants make this better or is it an issue with the saddle?

  3. Sitting on perineum: Biggest roadblock for at the moment. I want my sit bone to be directly above the seat post. That requires the widest part of the saddle—the rear of the saddle—to be positioned also directly above the wheel axle. Unfortunately, my saddle is already is adjusted as far forward as it can go and it’s still inadequate. Currently the only way round this is for me to lean further forward, which brings the back of the saddle to where it should be (good) but the back of the saddle ends up sloping downwards and forward. As a result, I tend to slide forward into the saddle, further sliding prevented by my perineum hitting the upslope of the saddle. Sitting on the perineum is incorrect and very uncomfortable. Eventually I just end up semi-sitting and semi-standing, which is very inefficient. I am convinced this is a seat ergonomics problem. I know KH does a flatter saddle, that seems like it might do the trick. I would love some advice on this as it’s preventing me from enjoying my rides.

I’ll post some pics of my machine later :slight_smile:

Unlike many people on this forum, I don’t even wear cycling shorts, just gym shorts, (preferably of thin, stretchy material), and I have gone 50 km in one day with no significant discomfort in my crotch. Every 20 minutes or so, I do have to rest, either by standing up on the pedals for a minute while riding, or by dismounting, but the various kinds of extreme discomfort you describe from such short rides sound more like the result of a poorly-designed seat. You might adapt to it somewhat, but replacing it may be easier. I once rode someone’s Avenir (cheap) unicycle that had a seat that seemed to have been precision designed to keep your bodyweight directly on top of your nuts at all times, no matter what.

The seats on both my unis are some sort of KH/Nimbus joint project, and not flat. I have tried one of the KH flat seats. They are easy on the crotch, but painful on the ass! It feels like you are sitting on a board. People do get used to those seats, though, and really like them, but as far as I know, they are usually for distance riding rather than trials.

Sounds like you are making good progress. Riding without sitting on the seat (SIF we call it here) is also possible, and allows for some very big hops, but you might not be ready for it just yet, and in any case, sometimes you have to sit down.

Flat you own saddle

I had a spare saddle from an old style uni. Reading on the forum I flattened it: removed the cover and the foam, used an heat pistol and pressed the base. Than, I decided to use a thinner foam… found an old foam I used when younger to build miniatures buildings: firm and light weight. Cut the form, cut a deep hole for diamonds and glued it to the base… I was luck: it’s my choice for every kind of riding! Without handlebars the flat seat implies front leaning and more speed to keep balalncing. With handlebars it’s really great (I prefer it to the KH fusion which however is also good too).

The most important thing is to create a deep, long, big cutout to securely store family jewels (as we say in Italy referring to diamonds) https://imgur.com/a/9EsawZP