Patent patrol: Campy filed a patent to enable 10t small cogs

[Blue Jays]

Curious how this potentially impacts chain clearance over the chainstay, too?

[weiwentg]

Originally Posted by oldpotatoe

Kinda, sorta..I'll bet 12s are cross compatible like 11s. At least with one manufacturer, a new freehub body wasn't needed for 12s...And no doubt shimano will (finally) get into the 12s road gig.

Remember tho, patent doesn't equal production. Shimano famously patented a 14s cogset and chain, what, 15 years ago?

I changed some lines in the original post to reflect that all of these are filed patents, not granted ones. And you are absolutely correct that even a granted patent might not end up in production. I think it’s safe to say that Campy is probably thinking about 1x drivetrains, though. They might not go into that space, of course.

[Dave]

Originally Posted by R3awak3n

it sucks that at one point we could share cassettes btw all systems and now with 12 speed it is all going to crap

Everything I've read so far says that SRAM and Campy 12 cog spacing is nearly the same - closer than 11 speed.

I've also read of an ESP 12 user testing a SRAM 12 wheel on his bike, with a Campy chain - no problem. I've used the new AXS chain on my Campy 12 bike with no problem. To be safe, I am switching back and forth with Campy chains too, so I don't have a cassette worn-in to just one chain type.

Campy wheels can be converted to use an XDR driver, so SRAM or Campy 12 cassettes can be used.

[Mark McM]

Originally Posted by oldpotatoe

Kinda, sorta..I'll bet 12s are cross compatible like 11s. At least with one manufacturer, a new freehub body wasn't needed for 12s...And no doubt shimano will (finally) get into the 12s road gig.

The new freehub body wasn't required for 12spd, it was required to fit 10 tooth sprockets. To fit 10 tooth sprockets, SRAM developed their XD body for road/gravel/MTB, and Shimano developed their Microspline body for MTB. So far Campagnolo hasn't gone below 11 tooth sprockets, so they can continue to use their 9/10/11spd freehub - but if they want to go to 10 tooth sprockets, they'll have to develop a new freehub as well (such as the one of the patents mentioned).

For those who like to mix-and-match drivetrains, hopefully all 3 will use similar spacing for 12spd. Unless any of them decides to change axle lengths/flange spacing/chain lines, then they'll have to squeeze the 12 sprockets into the same space, so there is little wiggle room to use different sprocket spacing.

[Jaybee]

Captain Obvious here, but 11 speed is "compatible" across brands because there's a limited amount of space to fit 11 cogs. There are differences in spacing, but they're so small as to not matter in practice. I wouldn't expect that to change with 12 cogs in the back.


EDIT: Mark McM said pretty much the same thing - should have read the whole thread.

[oldpotatoe]

Originally Posted by Dave

Everything I've read so far says that SRAM and Campy 12 cog spacing is nearly the same - closer than 11 speed.

I've also read of an ESP 12 user testing a SRAM 12 wheel on his bike, with a Campy chain - no problem. I've used the new AXS chain on my Campy 12 bike with no problem. To be safe, I am switching back and forth with Campy chains too, so I don't have a cassette worn-in to just one chain type.

Campy wheels can be converted to use an XDR driver, so SRAM or Campy 12 cassettes can be used.

Tough to do research on my phone but don’t think Campagnolo makes a Xd driver for their wheels or hubs. Shimano and sram 11s but not 12s sram...AFAIK.

[FlashUNC]

Originally Posted by oldpotatoe

Tough to do research on my phone but don’t think Campagnolo makes a Xd driver for their wheels or hubs. Shimano and sram 11s but not 12s sram...AFAIK.

Fulcrum makes it.

[Mark McM]

Originally Posted by oldpotatoe

Tough to do research on my phone but don’t think Campagnolo makes a Xd driver for their wheels or hubs. Shimano and sram 11s but not 12s sram...AFAIK.

There is an XD driver shown in the Campagnolo 2020 spare parts catalog.

[oldpotatoe]

Originally Posted by FlashUNC

Fulcrum makes it.

Ah..and Fulcrum is Campagnolo, so....

[oldpotatoe]

Originally Posted by Mark McM

There is an XD driver shown in the Campagnolo 2020 spare parts catalog.

Yup, gonna check that next...too hard on phone.

[palincss]

Originally Posted by Mark McM

There's really no way to fit a 10 tooth sprocket onto a Campagnolo freehub without a substantial redesign.

There are a number of Moulton models with Campagnolo drive trains (i.e., that use Campagnolo derailleurs and shifters) that use special Moulton 10-32 cassettes on a Moulton custom rear hubs. (For example: http://www.moultonbicycles.co.uk/mod...UBLEPYLON.html)



Any idea how that's possible?

[Mark McM]

If it's anything like Moulton's other small sprocket cassettes, the freehub is narrower than standard (only 10 of 11 sprockets fit onto the splines) and the smallest sprocket screws onto the 2nd smallest sprocket.

[Dave]

This link to info from SRAM lists a large number of hub brands, compatible with XD and XDR, including Campy and fulcrum. You can also download drawings and their licensing agreement.

https://www.sram.com/en/service/arti...body-explained

https://www.xddriverbody.com/apply.php

[weiwentg]

A tangential thought is that we know that smaller cogs (and chainrings and pulley wheels) mean more drivetrain friction. 10t cogs are pretty small. I wonder why manufacturers aren't sticking with 11t or 12t small cogs and just making bigger chainrings. Is it a frame clearance issue?

[palincss]

Originally Posted by weiwentg

A tangential thought is that we know that smaller cogs (and chainrings and pulley wheels) mean more drivetrain friction. 10t cogs are pretty small. I wonder why manufacturers aren't sticking with 11t or 12t small cogs and just making bigger chainrings. Is it a frame clearance issue?

In the case of Moulton, the issue is small wheels. The AM Moulton, with 17" wheels, originally had a 9-tooth small sprocket. With a 39-53 crank and the Capreo cassette (with its 9-tooth small sprocket) a 17" wheel bike has a top gear of around 100".