Building a strong MUni

Unicycles and Equipment
1

Talking with DM, I established the following:

I told him I wanted the hardened spindle as on the Hockey Uni, with the
48 hole hub.

I had to convince DM that 48 Hole Rims in sizes 26" and 700c do exist: although
admittedly he said they hadn’t researched it much.

He said if I could provide one of these rims he could build the Uni (in either
ringmaster or ringmaster pro guises)

        - why 48H ?-
  1. I’m not too worried about weight
  2. I’m no light weight myself, and I think strength is required here…

So now the choice: 700c or 26" ?

26": would be strong and I could choose a big variety of tyres, I can get a rim
which takes 1.5" width upwards.

2a: I’m tempted by this option, because It’s a larger (in diameter rim), thus
longer distances = less pedalling ( and also I’ve had the opportunity to
ride Roger Davis’s Carbon Fibre 700c) … BUT tyre choices are certainly
restricted for off-road, I can get a 48H rim which will take 700x35c upwards
(in width) but 35’s are still skinny, I have seen 700x38c’s are they look
skinny too.

So it boils down to the question: What’s the thickest, biggest baddest 700c tyre
I can find - is it likely to be a cyclo-cross one ? any info appreciated.

Thanks

Simon .G

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Simon Greenway | I.O.U o
I.O.U@mindless.com | /#\ Romsey, Hampshire, UK. | Idiots On Unicycles |
| O
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http://members.tripod.com/~derek_b/muni2.HTM
* last updated 29.4.1998 *
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2

Re: Building a strong MUni

(I sent this once before, but apparently it didn’t make it) At 08:36 AM 4/30/98
+0100, you wrote:
>
>Talking with DM, I established the following:
>
>I told him I wanted the hardened spindle as on the Hockey Uni, with the 48
>hole hub.
>
>I had to convince DM that 48 Hole Rims in sizes 26" and 700c do exist: although
>admittedly he said they hadn’t researched it much.

They certainly do. Tandems routinely use 48 hole rims, so there are are several
rims out there that will work. Also, the down hill mountain bikers use 48 hole
rims, which will do quite well for us. The rims I looked at were in the $50
(American dollar) range, which is pretty good.

> - why 48H ?-
>1) I’m not too worried about weight
>2) I’m no light weight myself, and I think strength is required here…

Actually, I think weight is a big concern. The rider weighs something like
10-20 times the unicycle weight, but remember that rider weight is mobile. I’ve
experimented with weights on the uni and it makes a HUGE difference in
unicycle performance. But at the same time, 10 spokes aren’t that heavy. I
break a spoke about every 10 hours of riding, so I think 48 spoke rims would be
worth the weight. How would you spoke those? 3 cross? I would guess that you
could do 4 cross, but I think that the vertical loading advantage of 3 cross
would be best.

>So now the choice: 700c or 26" ?
>
>26": would be strong and I could choose a big variety of tyres, I can get a rim
>which takes 1.5" width upwards.

Good question. Since its an industry standard, there are more choices available
for tires and rims. Remember that we need heavy duty rims which are mostly in
26" sizes. There is certainly an optimum rim size for Muning. A bigger wheel
gives you more momentum to role over bumps and lets you ride farther w/ each
turn. But at the same time, more momentum makes it harder to accelerate, turn
and stop. That means downhill performance is reduced. So we need to figure out
where that optimum size is. Another advantage of 700cc is that you could 170 mm
cranks and still be able to get decent speed (I think 170’s are way too big for
26"). 170’s are available in left and right cranks without spindles for tandems.
Makes getting cranks a lot easier.

What is the frame going to be like? Will it have a lot of clearence for
big tires?

Looking for better Munis, Brett Bymaster bymaster@purdue.edu
http://shay.ecn.purdue.edu/~bymaster

3

Re: Building a strong MUni

Brett Bymaster wrote:

> >So now the choice: 700c or 26" ?
> >
> >26": would be strong and I could choose a big variety of tyres, I can get a
> >rim which takes 1.5" width upwards.
>
> Good question. Since its an industry standard, there are more choices
>
> available for tires and rims. Remember that we need heavy duty rims which are
> mostly in 26" sizes. There is certainly an optimum rim size for Muning.
> …

I disagree here, Muni needs a strong rim, not heavy. If it is heavy then it
reduces manovability. I would definately recommend something like the 26" Mavic
down hill rims that are double eyeletted and don’t have a braking surface (Sorry
I cannot remember there product code, but they are yellow and megga - I want) -
it is very light and also very strong.

> What is the frame going to be like? Will it have a lot of clearence for
> big tires?

DM’s frames have loads of clearance as a rule anyway

> Looking for better Munis,

Arn’t we all!

Cheers

Roger

          ----------------------------------------------------
                       Roger.Davies@Octacon.co.uk
                      Stockton, North East England

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