nimbus hatchet rim

Unicycles and Equipment
45

just taken my hatchet out for its first ride!!

intial shock was the low tyre pressure and feeling the bike squelch around under you (never ridden fat bike either). played with seat height as i had it way too low then had about a half hour ride around in a car park near me that has a nice big slope to it and a speed bump on the entrance,a couple of ruts and is currently littered with tree branches.

i didnt know what to expect really with it,you do have to pedal it hard but its just like a bulldozer and once rolling it just wants to run everything over! first time with a brake for me which i like but can see it could get you in trouble easily.

on the whole its very different to anything i have ridden before but i like it and look forward to next time out on it.

46

Tubeless on the Nimbus Dominator+

So, I finally made the conversion to 4.8 on my Hatchet, and I thought I share my experience in trying tubeless ghetto on the Dominator+ rim, with a Schwalbe Jumbo Jim Snakeskin TL.

The rim does need some padding for the tyre to pre-seat sufficiently to inflate. Rather than playing around with closed cell foam, I went straight for the split tube method. That gave just enough padding to inflate (with a compressor or a SKS RideAir).
I used a 20" tube, nicely stretched over the rim but a 24" would also do.
Now, the proof lies in the pudding which, in my case, is the very muddy (squelch) ground in my local park. I had some problems previously with the 4" Jumbo Jims sinking in or slipping and I found the 4.8 to make a big difference. Speaking of big: I weigh 100kg, so that is fair load for a single tyre.
I initially had the tyre at 15 PSI and I have tried to dial it down to 10 PSI for more float in the mud. That is better on the wet, but obviously worse for self-steer on the access roads albeit manageable (for a beginner like me). However, at 10 PSI the tyre burps easily and sealant seeps out - see photos.
Back at 12-13 PSI and it is holding.

Overall, after about 20km of tubeless riding, I think it was worth a try but not perfect. The rim is probably not ideal for tubeless and with a Schwalbe fat tube weighing ~400g vs a considerable amount of sealant needed in the extra-fat tyre, I doubt that there is much advantage in the conditions that I use it for (tarmac access road, some hard-pack, lots of muddy grass). If I had more hard-pack, thorns or stones the extra puncture protection would probably be worth it. I guess for tubeless it might be better to go 32 hole and use a proper tubeless ready rim as discussed earlier in this thread.

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47

hi tinkerbeau its looks like your getting out enjoying your hatchet more than me sadly.are you going to stick with tubeless then as it sounds and looks like a pain, do you fel any benefit riding it tubeless?

since buliding mine i have only been out twice very briefly it,i have been having back/tailbone trouble recently and find the qu-ax eleven saddle annoys it a lot so i have been trying different saddles on my 20" to try and get to the bottom of it (sorry bad pun!)

48

Hi m00ms, yes, I will keep it for now but have a tube on standby if it should burp itself empty. I am not good enough a rider to feel the difference between tube \ -less but I :angry: punctures. :wink:

Sorry to hear about your backbone pain.
I’d trade you a couple of Qu-ax muni and a (flattened) Nimbus extra padded saddle for an Eleven…
PM me if interested.

49

hi tinkerbeau, tubeless seams to be a love or hate option from my dealings with but im going to stay tubed.

thanks for offer of saddle swaps but i have brought a few qu-ax saddles which im currently swapping around to see which is more suited to me,im going to keep hold of the eleven for the time being but should i decide to get rid of it i will get in touch.

50

So I eventually got my Hatchet complete and ready to roll…

I went with a 36 hole LightBicycle FAT680 carbon rim. It had to be custom ordered from China, which was a complete and utter saga, no fault of LightBicycle, but the original got caught up in the initial Chinese Covid-19 outbreak and eventually got lost in the French strikes on route to the UK around Christmas last year. It was eventually declared lost by the shipper and LightBicycle made and shipped a second one to me (which got caught up in Chinese New Year and their subsequent lockdown), which I received in mid-March this year just days before the UK was locked down… With all that and the Covid situation I completely lost interest in it.

Anyway, enthusiasm eventually came back and the result is pictured below, just before its very first ride… :smile:

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So I went with a 36 hole rim rather than the 32 discussed above since given I was getting the rim made for me anyway I would be as well just go for a 36 hole one, then I could use the relatively difficult to get 32 hole hub I had bought with a more commonly available 32 hole rim in the future.

The wheel is built on a 36 hole Nimbus alloy hub with double butted Sapim Race spokes. The brakes are Hope Tech 3 E4 with a 200mm Hope floating rotor. I thought the 200mm rotor was a bit of overkill but it doesn’t look out of place with the chunky wheel. The tyre is a 4.5" Jumbo Jim Snakeskin.

Cranks are Nimbus VCX+ with Hope F20 pedals. The seat is a Mad4One Leather Muni handle saddle on a Mad4One seatpost with a Nimbus DoubleQuick seat post clamp.

I am currently running this with a tube in, the intent is to run it tubeless but I wanted to at least seat the tyre with a tube in the first instance. I have some rather nice red Nukeproof tubeless valves to go with the red decals on the wheels when that time comes…

My first impressions of the unicycle are very good, I found it really stable and a joy to ride. I really like the saddle. I have only been a few hundred metres on it given the weather this weekend has been terrible, but initial impressions are very good. I haven’t summed the total cost of this build; it will be more than the cost of buying a ‘stock’ hatchet I am sure, however I bought parts when they were on sale where possible, or when I had discount codes etc, so it probably wasn’t all that bad.

I haven’t weighed this, but it feels noticeably lighter than my 32" Oracle.

As a footnote, the original rim turned up a few weeks ago, only nine months late, so after sorting things out with LightBicycle, I now have two :smiley:

3 Likes
51

Nice uni. I don’t usually go for Hatchets but yours looks sharp. Presumably it’s a bit more nimble than a stock wheel.

And I don’t recommend doing so!

1 Like
52

Thanks.

I was quite surprised how light and responsive it felt, I was expecting it to be pretty sluggish with that big tyre. That said I’ve never ridden anything else with carbon rims, no matter how many wheels it has, and I’ve never ridden another Hatchet or fat bike, so I didn’t really know what to expect.

With respect to working out what I spent – you’re absolutely right! Put it like this, if I had to have paid for everything at once I probably wouldn’t have – but I’m pleased with what I have ended up with doing it a bit at a time.

53

Hi DRD,

Thats great to see that you have your hatchet built now and it looks fantastic, have you managed to get some more time in on it yet? im wondering how your finding the brake with it being 4 pot and braided hose ?

My hatchet is the first unicycle i have ridden with a brake so i cant compare but have been finding that i do use the brake more than i thought i would. I have been riding my hatchet a lot and am getting more confident on it and am finding that the harder you push it the more sense and fun it becomes!

There sure are expensive beasts but great and making you smile!!

54

How is that tire working for you? I had one of those for a while when I used to do a lot of riding on sand. I loved how light it was, but I could never find a suitable tire pressure that was low enough to grip in sand but high enough to handle road camber and unlevel trails. It would throw me off balance on turns because of the taller tread on the edges. I’ve always had better luck with tires that have a more rounded profile with even tread.

55

Hi m00ms

I said to you I’d post a photo when it was done, it just took me a while!

I’ve done a bit more on it but nothing significant. I’ve been playing with the tyre pressure a bit and the crank length to see what suits me best, at the moment I’m not sure.

With respect to the brake I’ve only gingerly applied it, little more than a scuff really, I’ve not got much experience with unicycle brakes. I do get the feeling that it will be used more though as going down hill this thing seems to just want to roll! As you say it is probably a lot about confidence.

56

Hi aarons

It is interesting what you say about tyre pressure. I have been playing with that over the last few days. I’ve currently got it pumped up to 2 bar (maximum) but I have been trying to find a compromise that works on the road and on trails.

I initially let quite bit of air out so I could try hopping on it but on some narrow single track at a bit lower pressure I found that it was bouncing off tree roots and stones a bit and throwing me off but the higher pressure seems a bit squirrelly on smoother surfaces.

To be honest I am still at the stage that I blame my own ineptitude rather than the tyre but your comments make me think that perhaps it is not just my incompetence!

57

I’ve found fat tires in general can feel very different depending on pressure. It can take some trial and error to get it right. Usually for me there isn’t a pressure that is good for both trails and roads. I tend to run it kinda low – more like 1 bar – for extra grip, but that makes it handle like a tank on the road. At lower pressures, those wide tires can swallow bumps. You barely notice them.

2 bar is pretty high for muni and extremely high for a plus size tire. If you look at some of the older tire threads, you’ll find people trying ridiculously low pressures – almost flat – in order to roll over big bumps that they can’t get over otherwise. So try a wide range and take your time figuring out what you like.

58

Hey DRD,

It took you a while but you got there which is the main thing.

I remember my first ride on mine at 20 psi and thought omg i have a flat tyre! i weigh in at around 98 kg and find that 18 psi suits my maxxis fbr, it can camber on me but i just put that down to the fat nature but on the whole it behaves fine but it did take a while to get used to.

what crank length options have you on your three drilled arms? im running vcx 165mm which i like as im finding i can get enough speed on downhills and flat with and that there nice and long to help with climbs although i do need more uphill experiance with. i can also idle it with them.

59

Thanks for the advice aarons and m00ms. I read a quite a few posts on fat tyres at one point but figured I was going round in circles and figured I’d just have to suck it and see. The advice people give also makes more sense when you have some context and reference and I suppose it is all part of the learning curve.

I figured 2 bar was pretty high, I’ve always had a thing for pumping bike tyres up to the maximum they are rated to – used to run 700c x 18 at about 150psi back in the day (leads to interesting blowouts…) Anyhow, I had reasonable success on my 32’er in the summer running softer than I had been so I should have learned from that, but that was all on the road.

I put on rim tape so I could run this tubeless at some point, pumping it up hard initially was also to get the tube to apply some pressure to help that adhere as much as possible – that is probably all in my mind though. I didn’t want to run it too soft in case I damaged my nice carbon rim, but that is probably just paranoia. I’ll keep experimenting; to be fair, I now see all the discussions on tyre pressure etc in a new light.

With respect to the cranks, they are the VCX+ with 100/125/150mm drilling. I’m running in the 150mm holes, I briefly switched to the 125mm but found it quite a bit harder to get the thing going, maybe I should have persevered longer. I have the same cranks on my 32’er and ran them at 125mm for a while, after a break from it I put them back to 150mm in the summer, so maybe I had got used to that length.

I haven’t tried idling on it, that said I can’t really idle on my 20" – hopping on it was kind of fun though – if I got the pressure right it would be a pretty expensive space hopper :smile:

60

That’s one of my favorite things about those huge tires. When I was running a 26x4.6, I had a lot of fun hopping on and over things I can’t get with a normal unicycle. The bounce is real.

61

Hello DrD.
Great that you got your Hatchet together.
I have just rediscovered unicyclist.com and got the full update on your progress and rim-journeys. :wink:

Since lockdown my local park is overflowing with people and I have been doing far too little unicycling but I was very interested to read the comments here on the JumboJim big tyre. I am not a very gifted rider but am now happy to believe that it wasn’t all me, as I had problems keeping my balance on the JJ. I have now replaced it for a 4.0 Maxxis FBR and it seems much better; the large JJ is ‘relegated’ to the front of my fat bike, where it makes for a very fine cruising tyre.

62

Is this the small or medium Handle Saddle?

63

It is the medium leather saddle.

64

That’s pretty sweet looking