(Just for fun…) 48 spokes on a 20" wheel might be unnecessary but do look pretty cool IMHO. That’s what’s on my “unbike” mostly because I spotted a Primo Balance 7005 rim in ugly brown (though less ugly in person than in pictures, it turned out) as an eBay closeout for something like $15 and dug up a hub to match. It got a bit fiddly lacing it up though, having to work the spokes into some tight spaces.
OK so does anybody suggest 36 hole hub/rims over 32 for my application? A 20" flatland uni. No major drops, mostly freestyle/flatland tricks. Looks like the high-end freestyle like Equinox have 36 hole, double wall rims.
Maybe something like this would be good: http://www.danscomp.com/products-PARTS/422034/Demolition_Zero_Rim.html
On a 20" wheel there is no real strength difference. I would pick the rim you want and match it with the appropriate hub. Since it’s your first build I would keep it simple. Use a hub without a disc mount and you will have a single spoke length to deal with. That demolition rim with the triple box section is probably more than capable for a flatland uni. The real strength in any wheel comes from having the spokes and nipples seated well, and even tension.
How essential is a fat tire for hopping? I mean, would a 2.0 tire be OK?
The here, but the Odyssey Chase Hawk appears not to have been reviewed yet on this forum. It does look like a good one, though, and can also be pumped up to 100psi if you get tired of hopping and just want responsiveness.
The reason I asked whether 2.0 is OK for hopping is that it’s all my LBS has for sale- a Hookworm (1.95) and some other, similar tire.
The three inch road hog is too narrow for a 100mm rim. The link you posted is or the 4 1/4" road hog.
You can hop on any size tire, but wider tires allow you to run lower psi without rim hits. Also, bigger riders may need wider tires even with higher psi. Whether or not you need wide tires has a lot to do with your size, style and technique.
Just spoke to Josh at UDC. Nimbus is coming out with a 20" flatland rim at the end of June. I might wait for that. This echo rim is 40mm wide though, and is cheap. Do you think it’s wide enough to round out the Grifter 2.10 tire?
http://webcyclery.com/product/echo-urban-20-front-rim-1827.htm
Man, when I was talking to UDC about a getting a freestyle (20") rim they said there was no market for them so they had no plans to carry such a thing… That was only a month ago.
What do you mean when you say “round out” the tire? Do you mean make it more flat, and less balloon like?
Yeah, that’s what he said. It’s going to be much like the rim used on the KHFL.
Guess there is a market for it.
That’s what I meant, sorry. To make the tire more flat. Will a 40mm rim be wide enough for the Grifter 2.10 tire?
I don’t ride flatland but like the wider rim on my basketball unicycle so I can ride with less pressure in the tire and hop. I’ve also ridden with a Grifter on my freestyle rim (32mm) and liked that set up over narrower tires. I personally think the Grifter is a little narrow for a 47mm rim and am going to try something wider. Your 40mm rim should be fine with it. Here are some width ratio calculations for reference:
Trials
1.35 (2.5"/47mm) KH
1.5 (2.5"/42mm) Nimbus
Freestyle
1.55 (1.95"/32mm) Nimbus
1.67 (2.1"/32mm) Nimbus
Flatland
1.13 (2.1"/47mm) KH
1.33 (2.1"/40mm) Demolition Zero
To a few percent, it’s the same width ratio as a 2.4" tire on the KH 20" flatland rim, which is 47mm wide. I don’t recall any complaints about that combo and have none myself.
And yeah, I still think that’s a screaming deal, especially in black. There can be peace of mind in not having sunk too much money in the parts you’re using while learning a new skill.
OTOH you could just go with the KH if you want max width and if Goudurix really still have them:
http://www.goudurix.com/us/rim-20-kris-holm-flatland.html
I hadn’t thought to check if there were still any out there. Benoit is the man to ask at Goudurix.
Edit: Waalrus did the same math and posted his numbers too. And I respect his judgement that the Grifter might be narrow for the KH rim.
How much tire pressure can drilled-out rims handle before the innertube blows out through one of the holes? Somewhere I think there was a thread mentioning something about maybe reinforcing with a second rim strip…
I pulled the trigger on the echo rim. Can’t go wrong at that price for $25 with shipping. Wish me luck in my new hobby of wheel building!
I’m sure I’ll be back on here with more questions…
I had a blow out at 80psi on my KH Flatland Rim. I generally ride 40-45 and wouldn’t recommend going above 60.
Just to be sure this is the hub I want with that echo rim right?
There’s a warning:
“Note: this hub will not fit in frames with machined bearing housings designed for 40mm bearings. It requires either pressed bearing housings or frames machined to take these larger bearings.”
Again my frame is an Impact Regent long neck frame.
Yes. Both 32h. It’s gonna be a nice wheel for sure!
OK, now spokes. Bear with me. What kind, size etc. The only thing I know is I need 32! Links are appreciated. White spokes might look good with a black rim and white frame…
I don’t order the spokes until I have the rim and hub in hand. I like to measure the ERD, and the hub dimensions. I have found that most of the time the data in the various spoke calculators is pretty good, but occasionally it is off enough that the spokes suggested are wrong. Measuring your own guarantees the correct length.
I measure the circumference of the outside of the rim, divide by Pi, then subtract the relief (x2) from the edge of the rim to the bottom of the slot in a nipple placed in a rim hole. This method automatically averages the rim at all points around, and so I prefer it.
The ERD, and the hub flange diameter are the most critical to get right, the width dimensions matter, but they have less effect on the final length.
Once you know what length you need you can look around for different options. BMX spokes come in many colors, and in full sets to build wheels. The problem is that they are usually only available in a few sizes, and may not be the size you need. You could get lucky though.
Here’s a link to the spoke length calculator that I’ve been using for the last couple of years. It has been good to me.
My spokes just came in today for a geared hub wheel I’m building. It looks like that bike will be back in one piece tomorrow!
Good luck with the build, and let me know if you have any other questions.
OK. Maybe I should read Sheldon Brown’s article on wheel building first before asking more questions. I don’t have any spoke nipples. Should I get some first before the spokes?
Depending on how you measure the ERD you will want either a nipple, or two spokes with two nipples. The length of the spokes is somewhat irrelevant since you will be using them as a tool. Ideally the nipple used in either method will be the same type/length as the ones you will use for your wheel. That may be getting more picky than necessary.
Definitely read the Sheldon Brown article. He may have advice on measuring the ERD that’s easier. To be honest I’ve skimmed the page once to see if it was any good before I recommended it, but otherwise I don’t have much recollection of what’s in it. I do remember that my lacing method is very different from what he directs. Still both get you to the same result, so it’s all good.