Upgrade

I have considered replacing my KH 07 model trials for a while because of the Onza hub and cranks. They seem indestructible but the Q factor is more than I enjoy and the sharp edges on the axle end of the cranks aren’t good for my boots.

I considered a new hub and cranks. I thought about a new wheel too but it just didn’t seem worth investing that much time and money in an old uni. I am only a dabbler in trials and I don’t think I will ever be serious enough to warrant a KH Spirit hub. For me trials is about trying to ride backwards, dropping off gutters and a two inch high jump.:o

I have seen a couple of decent old KH trials come up on gumtree and eBay. They were either too expensive or never made it through to bidding day.

This weekend I saw a second hand Impact Athemos in as-new condition on Gumtree. The Athemos is described as a beginner trials so I figured it was at my level. It wasn’t far away and were asking $75 (Aussie) when a new one at UDC-AU costs $345 plus post. Seemed like a low risk way to go ISIS.

Looking at the specs they have a Cr-Mo ISIS hub, double wall 42 mm rim and stainless spokes. Quite a nice looking wheel with the white powder coated hub and rim. The aluminium cranks look pretty solid but I wouldn’t assume they are high grade alloy.

Well it looks like Impact spent all the money for that model on the wheel. The steel frame, steel post and pedals are very basic. The tyre is a Cyko-lite. The saddle looks and feels awful with literally square edges. It is described as a Naomi without the removable cover.

But perfect for me that thye put all the quality into the wheel. I fitted the Athemos wheel with my OBR Gekok tyre (the original Creepy-Crawler on my KH07 has been worn right down in places when I bought it and had lost some resilience with age.). The wheel fitted straight in to the KH frame.

I’m really happy with my new wheel. It is four millimetres wider than the KH rim. But I think I am going to have to refinish the frame now. (It came with a dreadful red respray.) Considering polished raw or maybe even anodising it.

I built the leftovers into another trainer for unicycle parties. Learners don’t sit on the saddle long enough for the Impact saddle to matter and the big Q-factor seems to work for first-timers.

But I have a dilemma. Did I upgrade my KH with a new wheel or did I upgrade the Athemos with a KH frame and saddle? ;)My seat post was already a Nimbus.

I just bought my cousin an Athmos for Christmas. It weighed the same as my Nimbus Street frame with Dominator 2 rim & KH cranks (10.6lbs). I thought it was a really decent uni minus the bearing holders and the only difference between the higher end Impact wheels is the non-eyeletted rim and lower-end tire.

I’ve never used Onza cranks/hub but they sound heavy. I think they would be more durable than the Athmos cranks, though, like you said.

So in terms of upgrading, you probably lightened your KH with the new Impact components, but it might not be as strong as the Onza set-up. The Athmos is now probably stronger, but more of a side-step since it’s most likely heavier, and older technology but totally fully functional.

I think it’s a win-win; you can always change it back or swap parts around, but for $75 for a while uni vs building a new wheel for 3x the price, I think it was a great find!

I just bought my cousin an Athmos for Christmas. It weighed the same as my Nimbus Street frame with Dominator 2 rim & KH cranks (10.6lbs). I thought it was a really decent uni minus the bearing holders and the only difference between the higher end Impact wheels is the non-eyeletted rim and lower-end tire.

I’ve never used Onza cranks/hub but they sound heavy. I think they would be more durable than the Athmos cranks, though, like you said.

So in terms of upgrading, you probably lightened your KH with the new Impact components, but it might not be as strong as the Onza set-up. The Athmos is now probably stronger, but more of a side-step since it’s most likely heavier, and older technology but totally fully functional.

I think it’s a win-win; you can always change it back or swap parts around, but for $75 for a whole uni vs building a new wheel for 3x the price, I think it was a great find!

The wheel on the uni I bought has eyelets. UDC-US specifies the Athmos as having eyelets. I really can’t fault the wheel at all. All the high end Impacts now use their new bearing system so it is hard to compare the hubs.

The specs at UDC-UK say the the Athmos cranks are machined from 7075 grade aluminium. Although this is the same alloy as a Nimbus Venture, it doesn’t mention the T6 tempering used on the Nimbus cranks so I expect they are untempered giving them only about 60% of the strength. There are no pedal thread inserts.

This thread seems to concur with use of a lower spec alloy.

The Impact site doesn’t even mention Athmos cranks as spare parts. UDC-US points to the Eiffel Tower as a replacement. This would suggest they are obsolete.

Anyway I can always upgrade. If I do manage to break them I expect I will be more than happy to pay for replacements because I will have reached a whole new level of riding. Either that or I will be broken too. :astonished:

BTW The rim is 47 mm not 42 as I said in the original post.

The hybrid uni came in at 4.9 kg (10.8 lbs) with a 400 mm Nimbus seat post (4 mm wall) and the 07 KH Fusion saddle. Now to clean that paint off to further reduce the weight. :wink: