kvz

Looking to upgrade my road bike. I am 6'7" and currently ride a 64cm Specialized Roubaix Expert. No 64 Roubaix's anywhere except for AUS. right now. Dealer talking to me about the Cannnondale Synapse HI MOD GRX DI2. The geometry seems to work but do not know much about the GRX part of it. What I know so far, the GRX replaces the Ultra and will do well on gravel. My bike will most likely never see gravel. Question: Is this new Shimano groupset good for road only or is it more gravel specific? Anybody have any insight?

blakcloud

If you can live with the 50/34 chainrings up front and a crankset that has an increased 2.5 mm chainline and that you are married to this group in terms of replacement components then it might work. If this bike was never going to see gravel, I would pass and wait until you can get what you really want. It is a big chunk of change to have something that is a compromise.

Cyclist0108

You should hold out for the bike that fits you best and suits the riding you want to do.

(I misunderstood and thought they had a GRX sub-compact crank.) The only other remaining major difference is that the brake levers are supposedly more ergonomic.

noodle soup

Incorrect.

here's a link to the specifications.

https://www.cannondale.com/en/bikes/...ku=c12101m1048

Cyclist0108

Oh, they use their own crankset, not the GRX options.

Rides4Beer

It'll have no issues on the road, in fact, I like using the clutched derailleur on the road, I just leave the clutch on all the time. No chain slap when bunny hopping potholes or going over rough sections. I'm waiting on my GRX di2 parts so I can upgrade, but from all the reviews I've seen, the shifters are supposed to be fantastic, several reviewers said they were going to put them on their road bikes.

kvz

Thanks for the input. I think I'm going to keep looking. Looks like a great bike if you want to start doing some gravel biking.

PoorInRichfield

Interesting... I didn't realize GRX had Di2 until now.

That bike confuses me a bit... I'm not quite sure why it has GRX. I thought one of the selling points of GRX was a wider crank axle which would allow for wider tires... and since Cannodale didn't even use the GRX crankset, I'm wondering if that bike can handle wider tires? That bike looks pretty much like a road bike with a gravel groupset.

Regardless, I'm pretty sure that bike would make a fine road bike. As Rides4Beer stated, having a clutch on the RD would be nice, even on a road bike. I get quite a bit of chain slap on Ultegra Di2 equipped bike.

Rides4Beer

Def an odd choice for a road bike that only has clearance for 32mm tires, don't know why they didn't just use Ultegra di2. They do have a clutched Ultegra di2 RD, RX805, I will def be using that on any future road bike setups.

Cyclist0108

It looks like it would be a better road bike than a gravel bike, fwiw. The main differences are a gravel bike can handle wider tires (say 40mm or more) and typically has lower gearing (which the GRX crankset would have allowed, but they preferred to use their own, more road-oriented crankset). The GRX group commands a premium vs. Ultegra, so they presumably didn't put the other GRX stuff on there to save money.

mstateglfr 

I guess. The 32mm max tire kinda makes it a terrible bike for my gravel riding.

I just rode a dozen miles of gravel on my road bike as part of my route today, but that was hardpack dirt gravel so its basically bumpy pavement.
Any of the other gravel I ride would quickly become brutal on 32s. 4 hours of that?...no thanks

msu2001la

The Cannondale Hollowgram crank is a really nice and light crankset. Seems like a step up from the GRX (or any other Shimano crankset).
The only difference here between GRX800 Di2 and Ultegra Di2 is slightly different hood shape/texture and pivot point on the levers, and a clutched rear derailleur that can be switched on/off.

Does the GRX rear derailleur allow a larger rear cassette than Ultegra? This bike is specified with an 11-34, giving an ultra-spinny climbing 34/34 gear option. Is Ultegra Di2 limited to 32t?

EDIT:
GRX DI2: RD-RX815 max size is listed as 30T-34T https://bike.shimano.com/en-EU/produ.../RD-RX815.html
Ultegra RX Long Cage: RD-RX805-GS max size is listed as 28T to 34T https://bike.shimano.com/en-EU/produ...-RX805-GS.html
​​​​​​Ultegra Medium Cage DI2: RD-R8050-GS max size is listed as 28T to 34T https://bike.shimano.com/en-EU/produ...-R8050-GS.html

So I have no idea why Cannondale is using GRX on this bike. There is a GRX derailluer that goes up to 42T rear cog, but that would be insanely low when paired with a 34T front ring. I"m also not sure why they have minimum large cog sizes. Why would it matter?

faulker479

It's a road bike. I have heard of Cannondale reps hosting demo gravel rides with the Synapse. I don't understand this thought process when you have a real gravel bike in the Topstone. Yes, 32mm technically can handle it, but like you said it won't be much fun for long.

The gearing on that bike is the same as other synapse 2x11 offerings.

Steve B.

If you want a carbon gravel and do not want suspension, your SOL with Cannondale. Sounds like they are trying to make the Synapse fill a gap in the product lineup. The Topstone aluminum will handle a 45mm tire, the carbon Topstone maybe a 43mm, I'd doubt the Synapse willl go that mg, 37mm maybe.

msu2001la

You can fit 42mm tires on the SuperX. I've heard of people running up to 45mm in 650b size on that bike. It was the winning bike at Dirty Kanza just a few years ago, so definitely gravel approved.

The synapse is limited to 32mm on paper. You could maybe squeeze 33mm in there, but I don't think anyone is pretending that this bike would be useful for anything other than very light-duty gravel riding.

noodle soup

It's a strange component spec for sure. It will work fine, and probably be a good endurance road bike, but it's probably a little more expensive than it needs to be.