Mechanics Quick Question Thread [Ask Questions Here]

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Mechanics Quick Question Thread [Ask Questions Here]
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Posted: Aug 24, 2019 at 22:01 Quote
my nipples get hard when i sneeze

Posted: Aug 24, 2019 at 22:10 Quote
seraph wrote:
Brass nipples only come in black and silver. Colored are alloy.

Ah shit well that sucks

Posted: Aug 25, 2019 at 11:03 Quote
Is it possible to convert vintage MTB rims to tubeless?

I have this old (early 2000’s) Giant Boulder that I use as a project bike and some XC riding. I had the idea to do a tubeless conversion, so I bought the Stan’s Standard Tubeless System that includes all the rim tape, rim strip and sealant I need.

Problem 1 is that the inner rim surface is not flat, as the screws from the spokes stand proud of the aluminium. As a test I applied the tape anyway and found that it is too narrow, but mainly it doesn’t look like it can make an airtight seal because of the bumps in the surface.

Problem 2 is that the rim is not very deep. When I add the rim strip, the tire only has a tiny amount of space to sit properly in the rim.

Did anyone encounter similar issues or found a workaround for this?



Posted: Aug 25, 2019 at 11:17 Quote
I'd suggest gorilla tape, or 3m 3939 tape.

That said, that is never going to hold a bead well enough to be safely tubeless.

Posted: Aug 25, 2019 at 11:41 Quote
I wouldn't try it. The old rim bead shapes don't work well with modern tubeless tire beads.

Posted: Aug 25, 2019 at 12:02 Quote
dhmtbr777 wrote:
my nipples get hard when i sneeze

When my nipples get hard I sneeze.

Posted: Aug 25, 2019 at 12:47 Quote
Hi! İ'm building a wheel for my enduro and im 100 kg
Which spoke you guys recommend dt swiss champion , competition or different ?

Posted: Aug 25, 2019 at 13:07 Quote
Noeserd wrote:
Hi! İ'm building a wheel for my enduro and im 100 kg
Which spoke you guys recommend dt swiss champion , competition or different ?

Use different spokes on either side to compensate for the asymmetry of the dish. Depends on the hub and rim dimensions. Try to use rims with an offset spoke bed.

For a big guy, I recommend 36 spokes on the rear and 32 on the front. You can probably use Revolutions on the stronger sides of the wheels with Competition on the weaker side of the front and Champion on the weaker side of the rear. Again, it depends on the specific geometry of your components.

Posted: Aug 25, 2019 at 13:26 Quote
R-M-R wrote:
Noeserd wrote:
Hi! İ'm building a wheel for my enduro and im 100 kg
Which spoke you guys recommend dt swiss champion , competition or different ?

Use different spokes on either side to compensate for the asymmetry of the dish. Depends on the hub and rim dimensions. Try to use rims with an offset spoke bed.

For a big guy, I recommend 36 spokes on the rear and 32 on the front. You can probably use Revolutions on the stronger sides of the wheels with Competition on the weaker side of the front and Champion on the weaker side of the rear. Again, it depends on the specific geometry of your components.
mixing spokes seems uneccesary and sounds like it would be a pain in the ass if you ever needed to fix the wheel on a road trip and had to buy spokes from a shop.

I would just do a tougher rim with 32 spokes, 2.0/1.8 double butted all around and call it a day.

Posted: Aug 25, 2019 at 17:40 Quote
For sure with the same spokes all around. I build a lot of wheels and I've never once had to recommend different spoke models for different sides. I just choose one spoke based on rider requirements. For someone heavier I would do 32/32 3x lacing with a 3-5mm offset rim. DT Swiss Competition 2.0/1.8 spokes should be sufficient in that combination. Brass nipples too of course, with a good spoke prep.

Posted: Aug 25, 2019 at 18:25 Quote
Nobble wrote:
mixing spokes seems uneccesary and sounds like it would be a pain in the ass if you ever needed to fix the wheel on a road trip and had to buy spokes from a shop.

I would just do a tougher rim with 32 spokes, 2.0/1.8 double butted all around and call it a day.

Nothing is "necessary". Some things are just better. It's not complicated. Make a note of your specs on your phone or even write it in Sharpie on the rim. If you need a spoke on a road trip, just use whatever you can get, even if it's not the same as its neighbours.

seraph wrote:
For sure with the same spokes all around. I build a lot of wheels and I've never once had to recommend different spoke models for different sides. I just choose one spoke based on rider requirements. For someone heavier I would do 32/32 3x lacing with a 3-5mm offset rim. DT Swiss Competition 2.0/1.8 spokes should be sufficient in that combination. Brass nipples too of course, with a good spoke prep.

You'll never "have" to recommend optimized spokes. Some people are just satisfied with less optimal equipment.

A hub with highly asymmetric flange geometry combined with a non-offset rim can produce double the stress on one side, compared to the other. If you're willing to spec an offset rim to help equalize stress, why not also match the spoke cross-sections to the stresses? Same logic. To not do so is either ignorant or lazy - and there's nothing wrong with being too lazy to bother, but let's not pretend equal spokes on unequally stressed wheels are equally good as stress-matched spokes.

Posted: Aug 25, 2019 at 18:33 Quote
mvdeplas wrote:
Is it possible to convert vintage MTB rims to tubeless?

The solution is what we used to call "ghetto tubeless".

Tape over the spokes with some sort of tough tape. Thicker is better, as long as it doesn't prevent you from mounting a tire. Old Velox cotton tape is great, but super thick.

Take a tube and cut it down the middle on the surface opposite the valve - the surface that would normally be nearest the tire's tread. Open it up and mount the tire inside it, with the "wings" of the tube hanging out beyond the tire bead. This will be a huge hassle, but that's how it is.

You now have a functional, and probably not too sketchy, tubeless system. Cut the excess tube material. Not too close to the bead, though, or else you won't be able to reuse it and the tube could tuck inside the bead if you ever burp the tire.

Posted: Aug 26, 2019 at 2:40 Quote
R-M-R wrote:
Nobble wrote:
mixing spokes seems uneccesary and sounds like it would be a pain in the ass if you ever needed to fix the wheel on a road trip and had to buy spokes from a shop.

I would just do a tougher rim with 32 spokes, 2.0/1.8 double butted all around and call it a day.

Nothing is "necessary". Some things are just better. It's not complicated. Make a note of your specs on your phone or even write it in Sharpie on the rim. If you need a spoke on a road trip, just use whatever you can get, even if it's not the same as its neighbours.

seraph wrote:
For sure with the same spokes all around. I build a lot of wheels and I've never once had to recommend different spoke models for different sides. I just choose one spoke based on rider requirements. For someone heavier I would do 32/32 3x lacing with a 3-5mm offset rim. DT Swiss Competition 2.0/1.8 spokes should be sufficient in that combination. Brass nipples too of course, with a good spoke prep.

You'll never "have" to recommend optimized spokes. Some people are just satisfied with less optimal equipment.

A hub with highly asymmetric flange geometry combined with a non-offset rim can produce double the stress on one side, compared to the other. If you're willing to spec an offset rim to help equalize stress, why not also match the spoke cross-sections to the stresses? Same logic. To not do so is either ignorant or lazy - and there's nothing wrong with being too lazy to bother, but let's not pretend equal spokes on unequally stressed wheels are equally good as stress-matched spokes.

You remind me of the customers who used to take the tubes out of the boxes and weigh them to see which one is 2g lighter than the others.

Posted: Aug 26, 2019 at 6:10 Quote
seraph wrote:
R-M-R wrote:
Nobble wrote:
mixing spokes seems uneccesary and sounds like it would be a pain in the ass if you ever needed to fix the wheel on a road trip and had to buy spokes from a shop.

I would just do a tougher rim with 32 spokes, 2.0/1.8 double butted all around and call it a day.

Nothing is "necessary". Some things are just better. It's not complicated. Make a note of your specs on your phone or even write it in Sharpie on the rim. If you need a spoke on a road trip, just use whatever you can get, even if it's not the same as its neighbours.

seraph wrote:
For sure with the same spokes all around. I build a lot of wheels and I've never once had to recommend different spoke models for different sides. I just choose one spoke based on rider requirements. For someone heavier I would do 32/32 3x lacing with a 3-5mm offset rim. DT Swiss Competition 2.0/1.8 spokes should be sufficient in that combination. Brass nipples too of course, with a good spoke prep.

You'll never "have" to recommend optimized spokes. Some people are just satisfied with less optimal equipment.

A hub with highly asymmetric flange geometry combined with a non-offset rim can produce double the stress on one side, compared to the other. If you're willing to spec an offset rim to help equalize stress, why not also match the spoke cross-sections to the stresses? Same logic. To not do so is either ignorant or lazy - and there's nothing wrong with being too lazy to bother, but let's not pretend equal spokes on unequally stressed wheels are equally good as stress-matched spokes.

You remind me of the customers who used to take the tubes out of the boxes and weigh them to see which one is 2g lighter than the others.

Posted: Aug 26, 2019 at 7:48 Quote
@ajax-ripper, I've seen you do this a bunch of times now where you just quote something without adding a comment. Is this on accident or is this your way or like, giving the comment a prop?


 
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