axle upgrade

Anyone know whether the Miyata bearing holders take a 35mm or 40mm OD?

I’m trying to figure out whether I can easily upgrade to a Profile hub. Other
considerations are the frame width.

Has anyone tried replacing a Miyata suzue hub with a profile one? Is this
practical / impossible ?

o o Peter Bier o O o Juggler, unicyclist and mathematician.
o/|\o peter_bier@usa.net


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RE: axle upgrade

> I thought Miyata bearing holders held 40mm bearings - it’s ages since I fitted
> some though. Anyhow looking at their picture at Unicycle Source the bearings
> contained therein appears to be more than twice the width of the (presumably)
> 17mm ID hole.

I also think it’s 40mm. My carbon MUni was built for future use of a carbon axle
with 42mm bearings, if I remember correctly. Right now it has Miyata bearings
and a little bit of shimming. So 40mm sounds right.

John Foss, the Uni-Cyclone http://www.unicycling.com

“I’m one of those people who pray, ‘God, give me patience and do it now!’” –
Carol McLean, Twin Cities Unicycle Club

Re: axle upgrade

Miyata bearing holders are 35mm I think. In any case a uni built for standard
axles won’t fit a Profile hub (40mmOD).

New frames coming soon to unicycle.com, though, specially for Profile hubs!

-Kris. — Peter Bier <peter_bier@usa.net> wrote:
> Anyone know whether the Miyata bearing holders take a 35mm or 40mm OD?
>
> I’m trying to figure out whether I can easily upgrade to a Profile hub. Other
> considerations are the frame width.
>
> Has anyone tried replacing a Miyata suzue hub with a profile one? Is this
> practical / impossible ?
>
> o o Peter Bier o O o Juggler, unicyclist and mathematician.
> o/|\o peter_bier@usa.net
>
> ____________________________________________________________________
> Get free email and a permanent address at http://www.netaddress.com/?N=1


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Re: axle upgrade

Peter Bier wrote:
>
> Anyone know whether the Miyata bearing holders take a 35mm or 40mm OD?
>
> I’m trying to figure out whether I can easily upgrade to a Profile hub. Other
> considerations are the frame width.
>
> Has anyone tried replacing a Miyata suzue hub with a profile one? Is this
> practical / impossible ?

Definitely possible. Hopefully you’ve already got 40mm bearing holders so you
won’t have to swap them. I don’t remember, do you have actual Miyata brand
bearing holders, or just a Miyata axle? As for frame width, the Profile axle
allows for some lateral adjustment of the bearings, just by putting the spacers
either on the inside or the outside of the bearings.

The bearing holders on my Profile are about 0.6 inches farther apart than on our
Suzue equipped 12-incher. With the bearing holders I have (stamped pillow
blocks) I could bring the Profile bearings about 0.2in closer together, just by
moving a couple of spacers to the other side of the bearing. Your bearing
holders may be a little lower profile than mine, so you may get away with moving
them even closer than that. And as long as you don’t have an aluminum or carbon
frame, you can make up the difference just by bending the frame a bit. (Steel
does have its advantages.)

Chris

Re: axle upgrade

Kris and Peter, I thought Miyata bearing holders held 40mm bearings - it’s ages
since I fitted some though. Anyhow looking at their picture at Unicycle Source
the bearings contained therein appears to be more than twice the width of the
(presumably) 17mm ID hole.

The profile hubs can fit : 6203-3/4-2RS (ID 3/4 inch, OD 40-mm, Thickness 7/16
inch) bearings so presumably you could fit them to frames with Miyata bearing
holders (maybe widening the hole for the wider axle).

Leo White

Kris Holm <danger_uni@yahoo.com> wrote in message
news:20010220174651.82634.qmail@web11605.mail.yahoo.com
> Miyata bearing holders are 35mm I think. In any case a uni built for
standard axles won’t fit a
> Profile hub (40mmOD).

Re: axle upgrade

Chris,

So far they’re not coming with disk tabs because Profile is dragging on making
hubs with disk mounts. Without the hub in hand, it’s risky to weld the disk tabs
because they might be in the wrong spot.

Although I’m really keen to try the disk out, I’m a bit concerned that it will
be too vulnerable to damage, and also that the reduced flange to flange width
will reduce rim strength. Hopefully this won’t be too much of a problem.

OK I’ll probably get flak for “personallizing” the frame, but the disc tab will
probably be mounted on the right side of the frame, because I usually pedalgrab
to the left (ie so the disk is out of the way). Anyone who does the opposite can
just ride with the frame backwards (symmetrical except for the seat clamp).

Cheers,

Kris.

— Chris Reeder <reed8990@uidaho.edu> wrote:
> They’re coming with disc tabs, right? Do you have pics or is it top secret?
>
> Chris
>
>
> Kris Holm wrote:
> >
> > Miyata bearing holders are 35mm I think. In any case a uni built for
> > standard axles won’t fit
> a
> > Profile hub (40mmOD).
> >
> > New frames coming soon to unicycle.com, though, specially for Profile hubs!
> >
> > -Kris. — Peter Bier <peter_bier@usa.net> wrote:
> > > Anyone know whether the Miyata bearing holders take a 35mm or 40mm OD?
> > >
> > > I’m trying to figure out whether I can easily upgrade to a Profile hub.
> > > Other considerations are the frame width.
> > >
> > > Has anyone tried replacing a Miyata suzue hub with a profile one? Is this
> > > practical / impossible ?
> > >
> > > o o Peter Bier o O o Juggler, unicyclist and mathematician.
> > > o/|\o peter_bier@usa.net
> > >
> > > ____________________________________________________________________
> > > Get free email and a permanent address at http://www.netaddress.com/?N=1
> >
> > __________________________________________________
> > Do You Yahoo!? Get personalized email addresses from Yahoo! Mail - only $35
> > a year! http://personal.mail.yahoo.com/


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Re: axle upgrade

> So far they’re not coming with disk tabs because Profile is dragging on making
> hubs with disk mounts. Without the hub in hand, it’s risky to weld the disk
> tabs because they might be in the wrong spot.

Theoretically it should work, since disc brakes have gone to an international
“A” standard. But having a hub in hand would be much more comforting before
turning on the production line. I used my disc caliper to make a paper pattern
for tab positioning relative to the axle centerline. The only variable left is
the distance from hub center to the face where the rotor bolts on, which should
also be a standard that we could measure from a bike disc hub. (Somewhere around
39mm) I’m just going to make my caliper stick out as far as possible, leaving
about 2mm of clearance between the Shimano caliper body and the chainring bolt
hole. That way I’ll have as little “dish” as possible in the wheel. Then we just
play with the Profile spacers to shim the hub one way or the other until the
rotor fits in the slot.

>
> Although I’m really keen to try the disk out, I’m a bit concerned that it will
> be too vulnerable to damage, and also that the reduced flange to flange width
> will reduce rim strength. Hopefully this won’t be too much of a problem.

Yeah, slipping off the wrong side of a rail has the potential of bashing the
rotor pretty good. As for improving rim strength, we could start using swaged
spokes on the non-disc side so they all have the same amount of “stretch”.

> OK I’ll probably get flak for “personallizing” the frame, but the disc tab
> will probably be mounted on the right side of the frame, because I usually
> pedalgrab to the left (ie so the disk is out of the way). Anyone who does the
> opposite can just ride with the frame backwards (symmetrical except for the
> seat clamp).

Mine’s going on the right side as well. Should be no big deal for backwards
seat clamps. Of course this also means the brake is being used in reverse, but
trials riders get away with disc brakes for their forward lunges, which is also
reverse braking.

As for brakes, I’m trying the Shimano XT. Does anyone know of a disc caliper
that has a lower profile than this one? The Shimano is also an open system, so
it may or may not work at the funny lever angles we use on unis.

Chris