I got one of these frames from Josh at Culprit about four months ago now but it took me a couple of months to build it up and then another couple of months to finally ride it due to... life. Full disclosure: I paid for the frame though I won't disclose what I paid because I don't know if Josh has set pricing for it yet. I also paid extra for custom paint... which ended up being the wrong color (I was going for Cannondale Green to match my F-Si, the shop matched Cannondale's new "Volt" instead). The parts I bought from independent purveyors (ProBikeKit, Pro's Closet, my LBS, etc).
The build:
Impressions: first, the build was a comedy of errors which were no fault of the bike but rather the components. I won't go into it here. I originally intended to build this bike with 650b wheels and tires. The Specialized Sawtooth tires set up tubeless very easily with some compressed air (I have the MilkIt tubeless kit) and some soapy water applied to the beads. I've fiddled with pressures a bit and settled on 35psi front and rear for now. The tires themselves roll very fast over pavement and, considering that I've always rode 22-25mm (stated) tires on the road the additional compliance was... nice. You know how you have that rough section of road on your regular route? Coarse pavement, potholes, chipseal, etc? To be able to bulldoze your way through that stuff without a care in the world is refreshing. I don't do much riding on the road but, for training, I don't see any reason to ride "race" width tires again.
All that said, these tires suck off-road. Bear in mind I don't have a lot of offroad experience. I have a hard tail with Schwalbe Racing Ralph and Furious Fred tires and, personally, I prefer fast, buff single/double track. I don't have much gravel experience either. I've rented a Salsa something for a week out in Boulder and a Kona Jake the Snake in Aspen and collectively have about twenty hours of prior gravel riding experience. That said, when something sucks, I know it sucks. The tread pattern of the Sawtooth tires fills easily with sand and they just lack traction in general. Cornering with these tires on loose over hard is... dicey.
These tires are getting changed pronto. They both measure ~40c on the Reynolds rims and that leaves ample clearance both front and rear. I'm not sure what the "official" clearances are for this bike but pretty confident I can fit a Schwalbe G-One Speed in 700x50 in the front... though I'm still looking for options.
Groupset: typical Shimano. Brakes are excellent, shifting is excellent (even with the Sunrace cassette which I'll concede was purchased for aesthetics), and I haven't dropped a chain yet. To be honest, I've been lucky in this regard and need to get a chain guide and 1x ring onto the bike pronto.
Bar/Stem/Fit: I'm 6'1 with a 34" inseam and typically ride a 56cm bike. For the RAD, I sized up to the 58cm, ran a short stem, and a rise bar. This is, by far, the most upright I've ever been on a "road" bike. Heck, I don't think I'm this upright on my F-Si. That said, it's refreshing and it also makes the drops very usable. IMO, one should use the drops more frequently when on "gravel". One change I'm going to make is to add some gel under the bar tape of the drops.
About the bike frame itself: there's not a tremendous amount to write here because, in my opinion, a good frame is sort of "invisible" to the rider. The only time a frame is visible is when it does something wrong IMO. I'm not going to BS you and say the frame is "compliant" or anything like that because it's not and, frankly, I don't think any frame is "compliant" in a sense a human can detect. The Cannondale F-Si was engineered rather deliberately to be "compliant" and, tbh, I can't tell the difference between it and an Aluminum hardtail.
If you look at the downtube, you'll notice it's not round or flat but instead has a bit of an "aero" shape to it. Is it aero? I don't know. I'd wager it's more aero than either of the previously mentioned shapes but I can't say much beyond that. I've seen an Exploro in person a few times and I can say the shapes aren't similar. The Culprit's downtube appears to be a larger than normal "conventional" Kamm shape but perhaps a bit wider at the rear than normal. The Exploro's downtube is massive and just... a different shape. More bulbous I'd say. Honestly though, this is just idle speculation. There's no way to know how a shape will perform in a system unless you test it.
If you look inside the frame (literally inside the tubes) you can see the walls are very smooth. I tried to get photos but it was a futile exercise. From my understanding, smooth = quality. Shane Miller (aka GPLama) has some excellent videos on his YouTube channel where he cuts open frames and wheels and discusses them with a composites expert and they touch on this point. They're definitely worth watching.
Where this bike really shines is the mounts. They're everywhere! You can mount bottles on the downtube, seat tube, and under the downtube. The bento box on the top tube (comes with the frame) is really quite cavernous and, honestly, Josh should sell it separately. You could easily hold 10+ gels in there and it's just really well made. The frame has mounts for both fenders and panniers. My one suggestion for Josh is to add an extra set of bosses to the downtube in the XL size. There's certainly enough room inside of the frame.
These are just initial impressions thus far. I've only had it out for a few quick ~10 mile rides (3 road, 4 off-road, 3 road). You can see some pictures below. I'll update this in the coming weeks with some more pics and impressions from a longer ride.
The build:
- Frame: Culprit RAD
- Groupset: Shimano R8000 hydraulic
- Cassette: Sunrace 11-36
- Wheels: Reynolds ATR 700c
- Tires: Specialized Sawtooth 38c set up tubeless
- Crank: Shimano 5700 (placeholder, I have a Rotor/P2Max combo with a proper narrow/wide chainring I need to unbox, assemble, and install)
- Bars and Stem: Specialized 40c drop bars with 10mm rise and flared drops, Zipp Service Course 60mm stem
- Saddle: Selle SMP
- Pedals: muhahaha
Impressions: first, the build was a comedy of errors which were no fault of the bike but rather the components. I won't go into it here. I originally intended to build this bike with 650b wheels and tires. The Specialized Sawtooth tires set up tubeless very easily with some compressed air (I have the MilkIt tubeless kit) and some soapy water applied to the beads. I've fiddled with pressures a bit and settled on 35psi front and rear for now. The tires themselves roll very fast over pavement and, considering that I've always rode 22-25mm (stated) tires on the road the additional compliance was... nice. You know how you have that rough section of road on your regular route? Coarse pavement, potholes, chipseal, etc? To be able to bulldoze your way through that stuff without a care in the world is refreshing. I don't do much riding on the road but, for training, I don't see any reason to ride "race" width tires again.
All that said, these tires suck off-road. Bear in mind I don't have a lot of offroad experience. I have a hard tail with Schwalbe Racing Ralph and Furious Fred tires and, personally, I prefer fast, buff single/double track. I don't have much gravel experience either. I've rented a Salsa something for a week out in Boulder and a Kona Jake the Snake in Aspen and collectively have about twenty hours of prior gravel riding experience. That said, when something sucks, I know it sucks. The tread pattern of the Sawtooth tires fills easily with sand and they just lack traction in general. Cornering with these tires on loose over hard is... dicey.
These tires are getting changed pronto. They both measure ~40c on the Reynolds rims and that leaves ample clearance both front and rear. I'm not sure what the "official" clearances are for this bike but pretty confident I can fit a Schwalbe G-One Speed in 700x50 in the front... though I'm still looking for options.
Groupset: typical Shimano. Brakes are excellent, shifting is excellent (even with the Sunrace cassette which I'll concede was purchased for aesthetics), and I haven't dropped a chain yet. To be honest, I've been lucky in this regard and need to get a chain guide and 1x ring onto the bike pronto.
Bar/Stem/Fit: I'm 6'1 with a 34" inseam and typically ride a 56cm bike. For the RAD, I sized up to the 58cm, ran a short stem, and a rise bar. This is, by far, the most upright I've ever been on a "road" bike. Heck, I don't think I'm this upright on my F-Si. That said, it's refreshing and it also makes the drops very usable. IMO, one should use the drops more frequently when on "gravel". One change I'm going to make is to add some gel under the bar tape of the drops.
About the bike frame itself: there's not a tremendous amount to write here because, in my opinion, a good frame is sort of "invisible" to the rider. The only time a frame is visible is when it does something wrong IMO. I'm not going to BS you and say the frame is "compliant" or anything like that because it's not and, frankly, I don't think any frame is "compliant" in a sense a human can detect. The Cannondale F-Si was engineered rather deliberately to be "compliant" and, tbh, I can't tell the difference between it and an Aluminum hardtail.
If you look at the downtube, you'll notice it's not round or flat but instead has a bit of an "aero" shape to it. Is it aero? I don't know. I'd wager it's more aero than either of the previously mentioned shapes but I can't say much beyond that. I've seen an Exploro in person a few times and I can say the shapes aren't similar. The Culprit's downtube appears to be a larger than normal "conventional" Kamm shape but perhaps a bit wider at the rear than normal. The Exploro's downtube is massive and just... a different shape. More bulbous I'd say. Honestly though, this is just idle speculation. There's no way to know how a shape will perform in a system unless you test it.
If you look inside the frame (literally inside the tubes) you can see the walls are very smooth. I tried to get photos but it was a futile exercise. From my understanding, smooth = quality. Shane Miller (aka GPLama) has some excellent videos on his YouTube channel where he cuts open frames and wheels and discusses them with a composites expert and they touch on this point. They're definitely worth watching.
Where this bike really shines is the mounts. They're everywhere! You can mount bottles on the downtube, seat tube, and under the downtube. The bento box on the top tube (comes with the frame) is really quite cavernous and, honestly, Josh should sell it separately. You could easily hold 10+ gels in there and it's just really well made. The frame has mounts for both fenders and panniers. My one suggestion for Josh is to add an extra set of bosses to the downtube in the XL size. There's certainly enough room inside of the frame.
These are just initial impressions thus far. I've only had it out for a few quick ~10 mile rides (3 road, 4 off-road, 3 road). You can see some pictures below. I'll update this in the coming weeks with some more pics and impressions from a longer ride.