Tu be or not tu be.

[ME 109]

I've finally managed to get a Mac 50 rear fitted tubeless to a snowflake but the valve stem does leak.
The valve stem is not very rigid at all.
There have been posts about filing? the inside of the wheel at the valve hole to get a flat spot for a better valve seal.
Is there a specific size/pattern valve out there for this application?

Two reasons for going tubeless are ease of puncture repair on a fully loaded bike on a dirt road out the back of shit creek, and because I reckon I got much better mileage from a tubeless Mac.

[Garnet]

I have no idea, but that has never stopped me from giving advice.


I would try to drill or machine the stem hole so that the recess matches the profile of the valve stem.

Or clean the wheel up really well and silicone the stem in place and let cure completly before applying air presure. There is a pic on Team Incomplete's website showing him useing silicone to seal the spoke nipples on a wire wheel so that he can run tubless.

[Kurt in S.A.]

I suspect a few people will weigh in with thoughts...mine is that the snowflake rim isn't designed to properly secure a tubeless tire bead. That's why the tube is needed.

Kurt in S.A.

[Scot]

There is a pic on Team Incomplete's website showing him useing silicone to seal the spoke nipples on a wire wheel so that he can run tubless.

Thanks for the trip down memory lane, Garnet! You took me back to May of 2004, and some very special memories. Many of them bring a broad smile to this ol' man's face.

James . . . I hope you're well . . .

[vanzen]

I have found that typically it will be the outside of the rim that needs attention.
The place where the valve stem protrudes on the flake is somewhat "crowned",
and a few licks with a file flattens the area nicely to solve this.
No other machining is necessary.

I don't remember the specific brand name of valve stem,
but it will be the type that has a washer and a rubber seal inside and outside
with a threaded stem and nut – the pieces are sandwiched to the rim and held tight by the nut.

Use a valve stem that looks like this:


Not like this:


Disclaimer:

Definite real-world road advantages exist with the use of a tubeless tire / wheel.
Those advantages can be realized using the tubeless / flake combo,
but not without RISK.
To do so disregards the LAW as mandated by the D.O.T. (USA)
which requires a certain profile rim (having safety beads) to be marketed with tubeless-tire operation.
and the official WORD of BMWcorp. –
which cannot recommend an activity contrary to the D.O.T. mandate
without the consequences of litigation and liability.
To do so also involves RISK on behalf of the operator
should a situation (such as sufficient impact) where the tire is forced from the rim be encountered.

My conclusion is that this potential RISK is minimal
and that the every-day, every-time-you-ride advantages are worthwhile.
In consideration of my well-being, the law AND the word will be secondary
to my studied and experiential determination of which is the safer mode.

I do not presume to tell you what to think or how to proceed.
Ultimately, you will be "playing at your own risk".
In the absence of "empirical evidence" or "definitive case study"
(no such evidence or study exists relative to the tubeless use of the BMW snowflake cast wheel),
controversy is likely to continue due to an inability to objectively quantify that "risk".

[vanzen]

... There is a pic on Team Incomplete's website showing him useing silicone to seal the spoke nipples on a wire wheel so that he can run tubless.

There are a number of "products" on the market that are better suited to accomplish this task.
None, including the "Silicone James Smear", are D.O.T. approved for road use ...

[ME 109]

Thanks Vanzen for that pic. I'll see if the tyre fitter can source one or one like it.
I thought I would attempt a tyre change myself with the last change. I've done it once or twice before on the RS but years ago.
This time with a pirelli fitted I couldn't even break the bead. one of those vice type bead breakers would be needed..... for me.
As far as pumping up the tyre and reseating the bead using those little bottles, fat chance. That was the case recently when fixing a flat on my brothers RS.
A mini compressor is the go for remote tyre fixing.
Having seen guys fix tubeless punctures in 10 minutes using those little bottles is most appealing.

Risk.... That starts as soon as the bike is put into 1st gear.

[Hunsta]

Very interesting thread. I had often thought about this, but on advice Ive had from others the snowflake is just not safely capable of holding a tubeless tyre properly. In my opinion the Snowflake is a far better designed wheel for dirt road use than later models, as it seems to be a better braced pattern. Its just a pity they didnt evolve into a tubeless wheel.

[Duane Ausherman]

Very interesting thread. I had often thought about this, but on advice Ive had from others the snowflake is just not safely capable of holding a tubeless tyre properly. In my opinion the Snowflake is a far better designed wheel for dirt road use than later models, as it seems to be a better braced pattern. Its just a pity they didnt evolve into a tubeless wheel.

Snowflake......... off road? Just look at one and it has a dent in the rim. I would keep it on smooth pavement.

We straightened so many of them where the owner had no clue as to what he hit.

[ME 109]

Off road.......flakes are excellent. Just don't hit massive pot holes at high speed. Much.