Back to Cruzbike - my V20c

[rfneep]

Hi All,

Backstory: After a hiatus of about 2 years, I’ve returned back to the Cruzbike fold. I sold my S30 back then to concentrate on some upright and high racer recumbent riding with a local bike club, with the anticipation of eventually getting an updated Cruzbike in the near future. I was waffling between a V20c or an S40 for months. After talking to Maria and with added input from Robert, I was still indecisive. But then an unused V20c frame kit came up for sale here; I bought it and the seller bought the S40 he preferred. For my riding, I probably should have an S40 but this gives me a chance to try the V20c which I’ve long wanted to do. We’ll see how it works out.

FWIW, I built it with an SRAM 1x12 Force/X01 mullet AXS system. I paid some attention to weight, just as an exercise.

The build is:

Frameset: V20c Gen 2 Race Green
\Wheels: LightBicycle Airia47 700c (1225 gm for wheelset)
Tires: 700c x 32 Continental Gran Prix 5000 S TR
Tubes: RideNow TPU
Drivetrain: SRAM AXS 1x12 speed
Derailleur: SRAM AXS X01
Cassette: SRAM XG-1295 10-52t
Chainring: Stone 38t oval narrow-wide
Crankset: Croder Spirit Carbon crankset 145 mm
Bottom Bracket Wheels Manufacturing T47
Shifter/Brake: SRAM AXS Force 12-speed for mechanical brakes
Brakes: Juin-Tech GT-F Cable-actuated hydraulic disc calipers; Rotors: F/180 mm; R/160 mm
Cable housing Jagwire Pro Brake Housing kevlar compressionless
Handlebar: Salsa Carbon Woodchipper 42 cm
Seat: Thor Seat Easy Carbon
Seat Angle: Adjustable via spacers, roughly 22-28 degrees
Headrest: Cruzbike from adjustable carbon seat

Weight: ≤ 24 lb with no headrest, rear bag, mirrors

Future: Favero MX Power meter pedals; bottle cages; new grip tape; clean up and repaint boom/slider assembly; CB Race Cage (maybe); etc.

I thought I’d want an orange frame but must say that the bright Race Green really pops out, so all is good.

It’s ready for testing in the outdoors. I’ve taken it on a few 10-20 mile runs mostly full of interruptions to tweak the fit, adjust neck rest, etc. The seat angle is presently at 25 degrees, which is close to the 27 degrees I had on my old S30. Similar to what others have reported when comparing the V20c to the V20, the ride feels a little smoother and more refined that what I remember for the S30. I’ve not really opened it up yet since I found, to my surprise, that my MBB skills have atrophied a bit and I’m not as stable as I should be. So, it’s back to some figure-8’s and a bit more acclimation. No big deal.

Two main observations from these initial rides:
1) Using some downhills on my usual conditioning ride path, the bike does not seem (qualitatively) to hold speed in the > 25 mph range as well as my Metabike Mystique high racer does, as indicated by how quickly it slows on the flat bottom path. Assuming weather effects were equal, I suspect that may be due more to the wheels/tires I have on each bike. If so, that would be a bit surprising since I naively expected the new Light Bicycle Airia 47 / Conti Gran Prix 5000 S combo to do as well if not better than the Bontrager Aeolus Pro 49V / Pirelli P Zero Race TRL at 35 mm combo on the Mystique. I’ll try some wheel interchanges to test this out as I get more used to the V20c. It’s useful to note, however, that the Mystique is a fast bike in itself.

2) My V20c exhibits the same loud creaking and squeaking others have discussed. It seems to be localized in the stem, slider clamp area and increases when a heavier load is put on the handlebars. I can easily excite it while stopped by putting a twisting/torsional load on the handlebars. I already tried making sure all bolt torques are up to spec and regreased the slider-to-stem clamp bolt. Still there. This is pretty annoying and has to be addressed. I’ll try some of the fixes suggested on this forum. Any and all suggestions are welcome!

So, it’s all OK for now. I’m eager to resolve the remaining issues and get a feel for the bike’s real potential as my riding skills recover and the weather turns to Spring. Should be interesting…

Ray

 

[Doccus]

Great looking ride! What is the bag you have on it now?

 

[CruzRider]

Welcome back! Nothing like it.
Are you using the longer chainstay on it?

 

[Greg S]

Great looking ride! What is the bag you have on it now?

I believe it’s one of these

 

[rfneep]

Great looking ride! What is the bag you have on it now?

The bag is the Radical Design Solo Aero Seat Bag Narrow.You can make it a little more aero by removing the bottle holder, but I'm keeping it on until I get some cages mounted. It's roomy and has a couple internal pockets.

 

[rfneep]

Welcome back! Nothing like it.
Are you using the longer chainstay on it?

Thanks. No, the chainstay is the standard 19 inch version. I believe the others that are available are longer than this. I wouldn't mind having a shorter one to raise my handlebar a bit, but that apparently isn't in the cards.

 

[IyhelM]

.You can make it a little more aero by removing the bottle holder,

Not sure about that, unless your torso is as narrow as the seat… I’m working on adapting a Universal bag, which is designed for trike mesh seats and is 40 cm wide; without a rider it does not look as smooth and streamlined but aerodynamics should actually be better.

Nice looking setup, once you’ve tweaked it to your liking and you get your MBB balance back, you’ll probably go faster than with the Mystique

 

[rfneep]

Not sure about that, unless your torso is as narrow as the seat… I’m working on adapting a Universal bag, which is designed for trike mesh seats and is 40 cm wide; without a rider it does not look as smooth and streamlined but aerodynamics should actually be better.

Nice looking setup, once you’ve tweaked it to your liking and you get your MBB balance back, you’ll probably go faster than with the Mystique

Yeah, I think I've been a little too casual in my thinking about that bottle holder. As you suggest, it's very possible it has no effect on the aero properties overall. I suspect I am just biased because it looks a bit weird to me. YMMV.

Sometimes I wonder if the V20's largest advantage for speed is mainly its extreme recline angle and hence lower profile. In the past, I could discern little difference on downhills and flats between my S30 and the Mystique when set to the same seat incline angle. Going uphill on the relatively short hills encountered hereabouts, short bursts of extra power on the S30 seemed available. However, this is all subjective and I seldom ride at speeds above 25 mph or so, where the overall profile differences between a CB and the Mystique may become more manifest. In the end, both bikes are more than fast enough for me, and other factors come into play on choosing which to ride when.

As you note, it will be interesting to see how this plays out as I acclimate to the V20c. I suspect I'll migrate to trying the 20-degree design seat angle over time. For now, it's just a bit more extreme than I'm used to.

The important thing now is to just ride...

 

[HeyHealy]

The bag is the Radical Design Solo Aero Seat Bag Narrow.You can make it a little more aero by removing the bottle holder, but I'm keeping it on until I get some cages mounted. It's roomy and has a couple internal pockets.

Was this easy to put on? No extra modifications?

 

[rfneep]

Was this easy to put on? No extra modifications?

This one fits right over the top of the Thor Easy seat. No modifications; just pull it over the seat until tight. Depending on your situation, you may have to temporarily remove your neckrest to get it on. Not an issue with the neckrest that comes with the adjustable carbon seat (which appears similar to the Bacchetta neckrest). The bag fits under the seat pad and attaches directly to the seat. I actually prefer bags that fit on the seat over the seat pad, but this is the best I had laying around. I tried the old Hostel Shoppe aero bags but they sat too low to the rear wheel.

 

[Boreen bimbler]

Have you tried carbon paste on your creaky bits? Certainly worth a try on the handlebar clamp.

 

[rfneep]

Squeaks and creaks eliminated:

The loud creaks and squeaks on my new V20c pretty clearly were coming from the area of the Slider/Stem clamps area. Using guidance from various forum discussions, I addressed it with a couple fixes.

I disassembled the stem and slider clamp assembly and followed Robert's advice: thoroughly clean all parts; reassemble while strongly greasing all parts (stem clamp bolt mount, slider clamp bolt attachment area; both inner and outer bolts; and pack grease into all relevant areas. I used considerably more grease than usual. I also put a thin layer of grease on the slider itself under the clamp area. Basically grease freely everywhere in the compound clamp area. Just as importantly, I followed Chicorider's recipe of adding a small gasket made of tubeless tape between the stem and slider clamps. Again, grease freely. The reassembly went very smoothly.

There has been no hint of the creaking and squeaking heard earlier. I did some static twisting and weighting tests on the handlebar. I also took it out on a short 5 mile ride with some aggressive riding and stress applied to the handlebars. No noises at all under the conditions that earlier gave rise to loud noises.

So it looks like this problem is readily resolved.

BTW, I had earlier lubed the handlebar clamp area and the boom bottom bracket area with Park Tool carbon joint lubricant, so those were tight and did not contribute to the original problem.

 

[bromclist]

Thor easy seat - was it mounted without any modifications? Thor guys are unresponsive - they were supposed to make the seat compatible with S40/V20.

 

[rfneep]

Lat's see, if you mean did it mount directly to the V20c frame with no modifications, the answer is no. You need to drill holes in the seat no matter what. They are delivered with reinforced areas indicated for where you should drill holes for your particular bike setup. This is common for Thor seats for any bike since bike designs vary.

First, I note that the Cruzbike seats - the standard and the adjustable carbon one - are both excellent seats and work fine if they provide your desired recline angle and shoulder return. They are the only seats I am aware of that are plug-and-play for the Cruzbikes. If you want to mount a third party seat, you will have to devise a modified mount structure. The main reason to mount a third party seat seems to be the desire for different recline angle or a different seat curvature (although extra padding can help there).

I actually have found the Thor seat guys to be very helpful and responsive. Over the years, I've bought maybe 3-5 seats from them and all went smoothly. I recently had him make me a seat with more reinforcement in an area along the rib in back where I had experienced an earlier failure.

It is no small effort to make a seat directly compatible with a Cruzbike. They would have to change the rib layout and presumably some of the carbon fiber layout to provide strength where the CB mount holes are. The rear area may require some modifications also. Overall this could mean essentially designing and making the molds for a new seat. I am not sure that is worth the effort when someone instead could standardize a simple mount bracket system to attach a generic Thor seat to the Cruzbike frame. That would be sweet for those of us who don't want to build our own!

Many people have offered solutions to mounting a Thor (or other) seat, and you can find them throughout this Forum. My approach has been to make a simple AL conversion plate that attaches to the front holes on the V20c and provides two mount holes an inch or two backwards that are closer together to both avoid the seat ribs and allow mounting bolts through the reinforced carbon area. My attachment in back is more complicated since I am requiring the ability to vary the seat angle a bit to help me acclimate to the extreme seat recline natural to the V20c. I use some bolts and spacers attached to a plate that is secured to the frame. When I get time, I'll try to get some photos and show things in detail if anyone cares.

Good luck on finding a solution that works for you.

Ray

 

[LarryOz]

Thor easy seat - was it mounted without any modifications? Thor guys are unresponsive - they were supposed to make the seat compatible with S40/V20.

I send them a V20 frame over a year ago - They halted progress on it because of the tarrif stuff. I will have to ping them again.