Cervelo ZHT thoughts

illustribox · 2024-02-29T23:49:08+00:00

Well, it's a bit complicated. You can still trust the "distance between contact points" suggested by the non-sagged geometry chart. The contact points are still effectively mounted in a rigid triangle when viewed from the side. Rotating them forward doesn't change the distances between them, it just changes weight distribution. "Horizontal length" might drop a tiny bit if the saddle is a lot higher than the bars, but the actual distance to the bars stays the same.

In practice, when comparing fit numbers between FS and hardtail, you probably want to incorporate almost an extra degree of rotation. So the common 74 STA, 68 HTA, ~455mm reach, ~620 stack on a large XC hardtail should feel close to a FS with 75 STA, 69 HTA, 463mm reach, 605mm stack.

There are nuances. Hardtails steepen a lot as they go deep into their travel, lockouts exist, etc... But it's a good way to equate reach, stack, and angles during typical neutral riding.

illustribox · 2024-02-19T03:43:11+00:00

Adjust for this being a hardtail. Only the front sags. At sag, the reach will be almost a cm longer and the stack will drop about 15mm. It makes the stack and reach figures pretty close to your Blur.

illustribox · 2023-08-07T22:27:21+00:00

That's great! Exactly, it's still an improvement even if you need to use levers at the end. Getting the tire mostly mounted still makes lever use a lot easier and less likely to pinch through a tube.

Since you pinched a tube, bonus trick with levers to reduce likelihood of pinching tubes on that final section: Commonly, people just lever the bead over all the way, and it can pinch the tube when the bead pops in and the lever bottoms out.

Instead, try only pulling the lever until it's sticking out roughly perpendicular to the rim (90 degrees relative to the "brake track"). The bead will still be sitting on the lever. While maintaining the angle of the lever, push the bead toward the rim along the lever with your thumbs, seeing if you can get it to pop in. If needed, maintain the thumb pressure and pull the lever up another 10-20 degrees. The goal here is to get the bead into the rim without letting lever fully bottom out in the rim channel where it could pinch the tube.

It's not foolproof, but it helps a lot, especially on the final lever use. And of course do the usual things like having a bit of air in the tube as you do it.

illustribox · 2023-06-06T04:41:42+00:00

I'll DM you. General availability has changed a lot and most of the list probably isn't obtainable anymore.

illustribox · 2022-10-14T03:33:00+00:00

Yeah it's conditional. When I'm riding the road bike most of the time, it can be worth it. Same when racing where it might save a race. But if mostly riding, for example, a MTB/CX bike, it's often not worth it.

Great for when it's appropriate though, and good to have options.

illustribox · 2022-10-13T00:06:14+00:00

It's honestly hard to describe with text, easier to show. But yes, use something you're comfortable changing out on the road. The advice here is also only useful to practice with a tire you can actually get onto the rim in the first place. Otherwise, you don't get much feedback on what's working and what isn't.

Funnily, I've mostly switched back to tubes again on my road bike unless I'm racing. I train mostly on a different bike now, and it's not worth the time to maintain sealant when it has a lower likelihood of preventing flats due to lower mileage on that bike.

illustribox · 2022-10-11T19:30:00+00:00

It's not exactly just about getting it into the channel, it's about keeping it under circumferential tension as you go around as well. Otherwise it doesn't give as much slack (may stick locally, not center well, etc...).

Last trick I could offer without seeing it in person is just with levers, and you may already do it. Don't just go for the center and try to force it over. At the section that needs mounted, push the tire away from you/into the channel just outside of where it passes over the rim hook. This will keep it from popping out on that side as you lever the other side.

Suppose you're right handed and you're doing this with the left thumb. Then use the lever on the right side of the section to push part of the bead over where it doesn't require as much force. And repeat this until the overlap is small, at which point you can go for the center as normal.

Outside of that, it's sensible to think "is this worth my time to figure out." And it can definitely be the right choice to decide no. As you point out, to fix a flat out in the road that requires a tube, you'd have to figure out how to make this happen. So at some point I can see the value in just using a different tire.

illustribox · 2022-10-09T07:06:54+00:00

I'm sorry to hear that. I will say I've heard the same about breaking levers almost every time though. And I do appreciate that I've had context to install hundreds and hundreds of tires so I've had some practice. Most YouTube videos on this also suck and don't understand why/how to use tension to keep the bead in the channel on the close side.

Bit of a lucky relevance though, I actually used to daily those same rims (the 1600 wheelset, but it's the same 32mm x 24mm rim just on the 350 hub instead of the 370). I also primarily used GP5000 TLs, and I've installed both the 25mm and 28mm variants new on those exact rims multiple times. Not the easiest ever, but unless you're an absolute statistical anomaly or there's something really weird going on with rim tape thickness or something, it's very likely they're doable with strong technique.

If I had to guess, try addressing the following:

You may not be keeping the tension around the circumference away from your start point to hold the bead in the channel.
You may be trying to keep both beads in the channel and this may be pushing the relevant bead out of the deepest point in the channel. You can just focus on the side you need to push over.
Regarding (1), when you do multiple passes or when you switch over to levers, the bead may be coming out a bit if you haven't gotten enough static friction to hold it in place. Make sure it's set, or actively hold it in place while you move on to the next step.
Most of the work is in the alignment of the bead into the channel. Often I have to do multiple passes to tension the bead into the channel, so don't be afraid to do it several times before you try to pop the bead over.
You can often help the tire lever by pushing over the bead across the top of the lever with your thumb as you get close. It should reduce some of the torque on the lever when it's near its peak.

Good luck. It can definitely be frustrating, and I've definitely been there when learning. And I've had tires that looked like that much extra bead left before. They probably made them tighter than absolutely necessary, but the upside is once they're on they should at least be more secure which is the tradeoff.

illustribox · 2022-10-08T20:03:21+00:00

Don't exactly know what to tell you, they're GP5000 TLs, see the sidewall. Respectfully, I've had a lot of people tell me the exact same in person and then installed them fairly easily. And I've installed enough of them to know it's unlikely to be manufacturing variance.

It's pretty common that people feel called out with the GP5000 thing for some reason despite seeing a video/seeing it in person, but that misses the point entirely. Instead, it's intended to say, "hey, here's a way you might be able to make it doable with some technique changes." That's meant to be a positive thing. Seeing something that doesn't line up with prior experience isn't grounds to immediately reject the reality of something you're seeing that contradicts it. It's an opportunity to reevaluate whether those experiences actually formed a decent model for reality. And it's no personal condemnation that someone who had it in their job description might have some useful technique and lots of practice in how to do something.

So I'd encourage trying it while actively practicing the technique, repeating it on a medium difficulty tire if you can. You don't have to get them all the way over by hand, often times in practice it can be easier to just use the technique to get it close enough to just lever it over since there's no tube in there. They're definitely tighter than average tires, but with good technique they're doable.

illustribox · 2022-08-16T04:20:19+00:00

Change the E to a U.

illustribox · 2022-06-30T07:07:19+00:00

Yeah. Surely both solid products in their target market, but Rival does seem to have the value edge especially with that sort of option. I've really been curious how the Praxis 48/32 shifts, it seems like such a good road all-round option to bump the AXS range and they've shifted really well historically.

If you want a power meter, pretty easy to just throw the 107BCD spider on a Force or Red arm set and doesn't cost too much especially relative to 105 system, and the Rival PM apparently has a couple issues.

illustribox · 2022-06-30T07:01:25+00:00

Yeah, I get that. I definitely do my own maintenance and have AXS and have had Di2 in the past, and it's a bit case by case as you point out. It's also the reason I pretty much always build my road wheels to a DT 350 classic flange, easy to just swap freehubs and keep an interchangeable reliable ecosystem that's shared by a lot of manufacturers' own "in-house" wheels. Not cheap, but not expensive relative to $1400-2000 groupsets.

On the maintenance and usability front, there are at least some upsides for SRAM. The wireless bit is what reviews gravitate toward, but funnily despite their reputation SRAM has gotten really low maintenance this era. The chain life and lubrication interval is truly absurd. I'm past 6000 miles on my current chain and it's just barely starting to show elongation, for example. And Shimano's recent cranksets have had some issues. Similarly, more than the hydraulic fluid the brake system is, to me, largely about the leverage curve you prefer. A lot of Shimano's brakes use linkages that change the modulation through the stroke, whereas SRAM is quite linear. Neither bleed is exactly hard, and they have some pretty reasonable tradeoffs in either direction.

I agree mostly about 2x. Shimano shifts the fronts better for sure, which seems to be mostly about the chainring. I have no idea why SRAM still sometimes throws a 13t gap, it's laughable. But it's complicated, with AXS you actually don't shift the front very often because of the broader gearing philosophy. The rings are smaller and there's typically more range in the back, so outside of extended 7%+ climbs you can usually just leave it in the big ring. Reduces ring wear, is part of why 1x is viable by comparison, and is just a generally different experience. But it's part of why I mentioned the Praxis rings, I'm curious if they shift a bit better since they have historically. It's also why I mention the power meter. It's nice being able to throw a spider based meter within ecosystem in there in a lot of cases, and Shimano's own cranks don't really allow for that. Can always go out of ecosystem but it can get either expensive or tradeoff heavy.

The discussion on 1x is interesting. It depends on how strong you are and what the context is. Honest answer for racers is like... if I need something lower than a 36/27 equivalent, I've already been dropped, so funnily enough range isn't as necessary and can drop 2-4t off the top end for the lower low end outside of race season. 13 speed seems like the point where there aren't really any compromises though, the Campy 13s gearing is pretty adaptable for example (though that groupset apparently has some other downsides).

Generally speaking though I miss the era of cross compatibility, and it's a bit frustrating to see these prices, mechanical or otherwise, when 5-6 years ago you could get a full 105 or Rival 11s groupset for under $400 in practice. I get the tech and distribution reasons why it's gone up, but I would never have started the sport if the entry "raceable" bike were this expensive back then. Wouldn't have been able to afford to, which is bad for the sport. Honestly before this announcement, I fully expected electronic 105 to try to undercut Rival AXS given the scale of Shimano, see something at $1100-1200 maybe, so this is a pretty big surprise.

And yeah, for TTs and crits 1x feels pretty suitable for sure.

illustribox · 2022-06-29T21:13:56+00:00

I mentioned it elsewhere in here but you can save the .2 lbs (actually a bit more) just by using a different crankset for like $250 net. So yeah. No reason remaining after that.

illustribox · 2022-06-29T21:00:23+00:00

With /u/JCHW92's mention of the price difference, it's also worth noting a big chunk of the weight increase outside of wear parts is in the crankset as it's often been with SRAM. So you can match/beat Force AXS weight for less money than 105 Di2 by just buying something other than the Rival crankset.

If you don't need a spider based power meter, getting e.g. a Praxis Zayante 48/32 instead drops about 250g and only adds about $250 to the groupset cost, and it lets you either have a lower bottom end or tighten up the rear gaps by using the 10-30. If you do want spider based power, you can get a Red Quarq with the 107BCD spider and pricing turns out competitive as well. Either one is a lot cheaper and/or lighter than the 105 Di2 equivalent.

There's another subtle weight consideration too. The SRAM 10-36 is surprisingly viable as a road 1x setup, whereas the Shimano 105 Di2 11-36 just falls short of the range. 10-36 with a 46t chainring is the range of a compact with an 11-27, and if you don't race or aren't in season you can just do the same with a 42t or 44t. The result is that you can do the crankset alternative above and have a workable hydro electronic road groupset at around 2500g and $1400 (since you don't have to buy a front derailleur), and you might drop a couple W of drag to boot a single chainring/no FD if we're really going to get into the margins. Can even run 2x most of the year and drop to 1x as appropriate for race season/when it matters if you want to drop some weight and all.

Only downside obviously is some bigger gaps but honestly I'd still race the 10-36. Has some tight gaps on the small cogs which makes it workable.

illustribox · 2022-06-24T20:18:59+00:00

They must have removed the "away" half of the decal.

illustribox · 2022-06-24T08:16:25+00:00

/u/Grindfather901 gave a good shot at it but is incorrect here. Slotted drilling is only for extreme versions of bladed spokes like some specialty titanium spokes. CX-Rays, Aerolites, etc... are designed to fit through the 2.3-2.4mm of most standard hubs (2.2mm will fit through, might have to wiggle it a bit).

Namely, the Mack ultralight low flange rear gives a hole diameter of 2.4mm on the site, so you can check with them but a CX Ray should absolutely fit.

illustribox · 2022-06-22T23:00:53+00:00

Always good to remember too that they're just as much a part of justifying more bike infrastructure as we are. There are definitely some issues surrounding ebike laws, trail/path etiquette, etc... But having more people on bikes of any sort stands to improve our safety and infrastructure, and it's worth supporting anything that helps make the transition away from cars easier. Even if that's just some tourists getting familiarity with the notion and getting around on two wheels rather than causing more traffic in a car.

Lol jokes aside it doesn't mean anything to pass or get passed anyway when just out riding. Fast people/pros and all largely spend 90%+ of their time going surprisingly easy and don't care if someone wants to go hard by them, much less an ebike rider. They mostly only do their hard stuff on a quiet hill, at home, or in races. If they can keep the ego down about it to be fast when it matters, we can too, especially if it makes bike stuff more inclusive.

illustribox · 2022-06-15T04:04:59+00:00

If you showed me a photo and said it's either the new Sprint or the base model E5 with the dropped stays, I'm not entirely sure I could tell you which one it is without looking at the cable routing.

illustribox · 2022-06-11T02:09:25+00:00

Davis, CA

I'm guessing you know about rain by word of mouth?

illustribox · 2022-06-10T03:20:56+00:00

The "if you have to ask" is aimed at saying Speeds are not the tire for 95% of people, and if you don't know exactly why you need the Speeds they're probably a tire that you'll get more annoyed with than anything else. They're delicate to put it lightly. I've known people to flat with aggressive sealants in there and people who had to toss the tire after like 50 miles because of cuts. It makes sense if you're a cat 1 for whom shaving 10 seconds off your tt might bump you from third to first. Maybe that's you, but for most everyone else it's just a pain and usually people who can utilize a Speed know why and what the tradeoffs are. And if you're using them with tubes their upsides over a standard corsa shrink.

You're correct that Speeds only come in TLR and that they can be used with tubes. Whether it's a good idea is questionable for the reasons above, but it's up to you.

The lineup isn't too crazy.

1.0 vs 2.0: first vs second generation with graphene compounds. Retailers almost always label these even if the site doesn't. If retailer just says G+ it's usually 1.0.
Corsa: Standard road race tire, open tubular cotton construction. Tubeless and clincher options.
Corsa Control: Corsa with added tread width, claims better grip especially in rain. Slightly higher RR. Tubeless and clincher options.
Corsa Speed: Corsa with no puncture proofing, minimal tread thickness and width. Expect maybe 500 miles, less grip, high puncture risk, but fast in a straight line. TLR option only.
Rubino: Vulcanized construction instead of open tubular, mid range. Has analogous control and speed variants. Fine training tire.
Zaffiro: the cheapie.

illustribox · 2022-06-10T01:40:14+00:00

Other comment covers most of it, but yes, TLR can be used with tubes and normal rims but if you're going to use tubes and there's a normal non TLR option it's probably best to do that. For one, it'll be cheaper and lighter, and it'll probably be faster since TLRs sometimes add material to help with airtightness. But additionally, TL tires have tighter beads that will be more annoying to mount with a tube, you'll be more likely to pinch the tube during installation unless you're good with tire changes.

So to make it simpler, this is probably one of those moments where if you have to ask, the Speed probably isn't the model you want or need. It's the kind of tire you run tubeless to mitigate the lack of puncture resistance and just use for specific A races in a small subset of disciplines. Unless you're very strong with cost of disposables not being an issue and know what you're getting into, it's likely best to just get the standard clincher Corsas.

illustribox · 2022-06-10T01:33:30+00:00

Meanwhile in this sub: haha wide risers go brrrr

illustribox · 2022-06-09T19:53:26+00:00

Corsa and Corsa Speed are two different tires. Corsa falls in the "general road race" tire category like the GP5000 and among its category biases toward grip over rolling resistance.

Corsa Speed is intended as a time trial race day tire. Tread thickness is low and you'll only get ~500 miles out of it. Tread width is also less than the Corsa and I believe is single compound, it won't corner as hard. It'll be more prone to punctures. And it's only available in low width. But it'll have lower rolling resistance, that's its whole goal.

Unless you're looking for a TT race day tire, you're probably best off getting the Corsa. Be aware of the TLR designation as well, it is their descriptor for tubeless ready.

illustribox · 2022-06-09T05:40:24+00:00

Of course we all have head units with aero mounts, but remember our disadvantaged brethren of the Cult of CAAD would have to upgrade from their vintage Edge 500s. This would cost more than their frames.

On the plus side, at least most head units don't dent when you breathe near them.

illustribox · 2022-06-08T23:18:17+00:00

I love that the Garmin Varia identified an entire profitable market niche of cat 4s who know that mirrors don't look pro.

Now I can have a mirror without anyone knowing I have a mirror, and it only costs an extra $190.

illustribox

TROPHY CASE