BTLOS wheels

[feynman]

Originally Posted by sevencyclist

Did my ride

That is a beautiful machine.

[54ny77]

i have bitex on 2 wheels (from farsports) with a few k miles on 'em and they roll nicely, pawls on the medium-quiet noise side (waaaaaaay less than dt or chris king though) which i like, but still loud enough so that on paths i can coast for a few seconds and folks ahead of me can hear it if they don't have headphones on. knock on wood they keep truckin' for years to come. where/how do you grease 'em? repack the cartridges?

Originally Posted by GregL

I second this recommendation. I have Bitex hubs on four wheelsets. They have been 100% reliable and preventative maintenance (grease) takes just a few minutes. Since Shimano abandoned the hub market, Bitex has become my “go to” brand.

Greg

[GregL]

Originally Posted by 54ny77

where/how do you grease 'em? repack the cartridges?

Lots of YouTube videos showing how the hubs come apart. Example: https://youtube.com/playlist?list=PL...qvHJSjKMF_Jh4f. I haven’t had to pack any cartridges to date, but any grease similar to the OEM fill should work. Dumonde Tech freehub grease works well on the freehub pawls.

Greg

[sevencyclist]

Originally Posted by DRietz

Which makes less noise, the arrow or the arc?

They are both pretty quiet without any squealing. I have done more miles and descents on the arrow graphene rims and no issues with fade or inner tubes of PTU type. I actually like the sounds of slight whizzing sounds of the arrow brake surface rubbing against brake pads to know how much braking is happening.

The brake pads are the baby blue ones that came with eeBrakes for carbon rims.

[Erikg]

Originally Posted by sevencyclist

I bought a pair of Extralight BTLOS in 30mm height with their carbon hubs and ARC Graphene braking.

2023-08-16 09.27.03 by sevencyclist, on Flickr

I'm building a set of these in 35mm with the graphene 'arc' braking surface. Trying to contemplate the best direction/orientation for the arc rim surface. Has anyone tried both orientations on the front wheel to see which direction is better performing? I've been thinking more about this and have thoughts below:

BTLOS builds their rear wheels with the outside tips pointing rearward from direction of spin, thus creating a centrifugal force that can help shed water and debris faster. I've heard from a number of posts that BTLOS's front wheel builds have the hub logo facing the wrong way. Sevencyclists pic above supports this, and he may have hub logos in the correct orientation with front wheel braking surface having the arc tips pointing forward, opposite of centrifugal force.

I'm guessing there is probably not much difference in brake quality between the two orientation, however the more I'm thinking about it, I postulate the outward tips spinning forward 'opposite of centrifugal force' may create better heat dissipation.

Here's my candor thinking:
Looking to disc brakes on cars to see what the logic is. Figure it Audi posted a similar quandary on YouTube:
https://www.youtube.com/watch?app=desktop&v=gsmtixgpV5A
He ended up rotating his discs with tips rearward in support of easier escape of brake dust and longer pad wear.

Higher end Brembo brakes recommends pointing groove tips forward. The most common reason for the groove is to mitigate cooling of the gases that occur between pad and disc during high heat scenarios.

My thought with tips rearward in support of centrifugal force, it does dissipate water and brake debris faster however also dissipates any cool air that was sitting within that arc groove cavity. With the tips pointing forward, thus not allowing centrifugal force to occur as easily. the arc groove will introduce a bit of cool air/gas between the brake pad. The cool air will be able to remain longer within the cavity, potentially remaining between the surfaces the entire time the groove passes under the brake pad because the air doesn't have an easy escape route. I believe this may be reason for the direction of the groove on high performance auto disc brakes, though not totally sure of the science behind it and haven't found any evidence online.

Between water shedding, brake gunk build-up, and heat dissipation, the heat is the critical factor for carbon rims. Brake pad grooves do a good job of shedding water, and braking surfaces can be cleaned occasionally of brake junk. I'd be really curious to hear others thoughts on this topic, and if you've tried the groove in both directions for the front wheel?

[CAAD]

I did ride my front wheels with the arc pointing the wrong direction for a week. I noticed no difference. Only spotted it visually at a gas station. I'm a fair weather rider so no wet braking experience for me.

[Erikg]

Thanks, good to know there was no difference in dry weather. I just received the rims today and the groove is very shallow and minimal. It looks way more substantial in photos. I'll probably build them with arc sweeping back.

Also just google discovered that Campagnolo has the AC3 brake track that looks very similar to BTLOS. Apparently the groove is a byproduct of the manufacturing process and has no function.

[sevencyclist]

I don't notice any difference in the braking, in sound, modulation, or power, based on the direction of the arc or arrow. So I made both of the front and rear wheels have same Arc direction to have visual conformity between front and rear. (dictated by direction of rear rim laced to the rear drive hub)

Of note, I did consider that BTLOS have not been perfect in making sure the rims are laced to the hubs in the similar direction for front and rear, so I got the house carbon hubs without logos, so there's no wrong direction for the front as long as I fliped it to match the rear. My wheels are either wrong in both front and rear, or both right, but visually they match in the direction.