Drivetrain build

[Vasegaard]

Dear community.

I'm on a path to build my first bike and I was thinking of purchasing my drivetrain first as there seems to quite a bit of shimano overstock and perhaps some SRAM as well, even though I haven't seen as much. The bike will most likely be featuring a T47 68 or 86.5 mm BB.

My question is what is your ideal drivetrain build and how would you set it up if you had 1000-1500 eur/usd available? It can be a mix of anything really (looking for inspiration). I have assioma duo power pedals, so no need for a powermeter.

I'm looking for reliability primarily and weight savings second.

Please write up your build and lets inspire eachother

[Ludo]

PES 515 power meter, Spedao or goldix cassette, passquest/stone chainring and ultegra di2 derailleurs and brifters?

That would be my starting point and I would be asking people what they suggest to change on that. I think it fits your budget

[raisinberry777]

Ultegra Di2 and a carbon crank like Bigrock, Leese or ZRace. Comes in around $1100 without a PM, or add another $230 for an XCadey spider PM. Alternatively go a Magene P515 crankset for cheaper but a bit heavier.

[Da11as]

It really depends what you want to achieve, for a road bike 2x is a must unless you live on a krepes frying pan and not planning to use it elsewhere. I will share my budget conscious perfomance oriented build that I made for my Speeder.

- Cranks: Big Rock crankset with Ti axle. If you decided to go for BB86, 24mm axle is your only valid option. Going for Dub or 30mm simply does not worth it. In this case you may pick any of the numerous lightweight copy of Cybrei that are currently available, but only Big Rock has 3-bolt design (at the moment of the purchase) which allows me to install my old but very reliable powermeter. I use my old Rotor NoQ chainrings but when they will worn out I'll probably swap to Pass Quest.
- Shifters and brakes: 105 Di2, minimal weight savings compared to Ultegra and I don't need top buttons, performance and ergonomics are the same.
- Derailleurs: Ultegra Di2. FD has newer design compared to 105 and works faster+better. Both derailleurs are substantially faster.
- Cassette: Lightweight steel monoblock casette. I use more expensive one from ZTTO and they shift very good. Minimal weight difference compared to aluminium or hybrid casette, yet durability is superior.
- Chain: YBN SLA. Top of the line, light and have friction resistance comparable to Dura Ace chains, yet more durable.
- Rotors: I would go for Galfers, as they are reasonably priced, lightweight and perform well. For now I have my Sram Centerline X rotors but swap them to Galfers in the near future.
- Pedals: I use old Look Carbon Blades with titanium axle. They are stupidly light and I got them for very cheap. You may get into the trouble if the spring breaks but I sorted it out.

[Gloopann]

PES 515 power meter, Spedao or goldix cassette, passquest/stone chainring and ultegra di2 derailleurs and brifters?

That would be my starting point and I would be asking people what they suggest to change on that. I think it fits your budget

I feel like getting an ultegra cassette is really nice because you get HG+, so super smooth shifting under load.

[Vasegaard]

Thank you very much for the responses!
I like in one of the flattest countries ever, highest hill is 100 m above sea level, so I have considered a 1x setup.
Anyone have any sram recommendations or ideas?

[POTOOOOOOOO]

I’ve predominantly been using X1 for 15 years on my road bikes. Including a few years living in Geneva and riding the Alps.

It’s very dependent on your location and your ability as a rider. If it’s flat, then worth looking at.
Currently have 6 X1 builds of various descriptions but they’re starting to converge on a style.

Fast road a 10-36 or 10-33 cassette with a 50t chainring
Everything else 10-44 Garbaruk cassette with a 48 or 50t chainring

If you look at the gear ratios, the 10-36 sram cassette has minimal gaps which people like to bleat on about.
If you want to use an ever bigger chainring just go for 13 speed XPLR and the 10-46 has the same ratios as the 10-36 but with the biggest 46t sprocket as a super bail out gear.

Probably not needed if it’s as flat as you say.


SRAM is all mix n match so see what deals are available. Most weight is saved in the crank and cassette so shop around and see what deals you can see on Red parts.
The new force crank arms are 405g and can be found for 150 euro which is a bargain. Mix this with a chainring of your choice.

[Takiyaki]

I have also been running 1x for a while, even with punchy small hill roads. It does suck a little bit when I'm out of shape, but that's just motivation to stay in shape lol.

[wibidi]

40,42 or 44T chainring paired with the 10-33 cassette. If it's really pancake flat you even might get away with the 10-28 cassette which offers a 16T cog which in turn doesn't offer that much benefit.

In no case you'll need a chainring as big as 50. With 28mm tires at a cadence of 100 rpm a 50-10 gear ratio means about 65kph. You'd be multiple ITT world champion and hold the hour record if you could make use of that gear on flat terrain.

[POTOOOOOOOO]

This is the problem with using online calculators and not having real world experience.
It’s not all about the numbers on a spreadsheet.

48 and 50t chainrings are fairly common in X1 road setups. You really don’t need to be anything special to enjoy that level of gearing. And no one consistently spins 100rpm like a CVT.

Flat country usually means windy. Either riding into a headwind or grabbing a tailwind.
Even with a modest tailwind a 44 -10 would be infuriatingly spintastic.

[wibidi]

I think I have enough real world 1x experience to say that there is no need for a 50T chainring in combination with a 10T cog if you aren't a pro or at least a racer and if you don't face long straight downhill sections (but pedalling downhill is wasting energy anyway if this doesn't happen to be exactly where you need to make your move).

Maybe I'm just severely unspecial?

Just take a look at SRAM's general purpose 2x chainsets. They come in 48/35 and 46/33 for mere mortals and they even cater for downhill applications.
Why would you need a bigger gear on a 1x drivetrain you don't even plan to ride downhill?

We aren't  talking about a TT bike build here and Vasegaard didn't hey were after marginal gains like only using gears in the center of the cassette.


Anyway with a 12sp drivetrain I don't see any reason to choose 2x on flat terrain.

[POTOOOOOOOO]

It’s more to do with chain line than gearing.

You choose the chainring so your cruising gear is in the middle of the cassette so you have the most efficient chain line.

50t is an example, 48t is adequate for most people in most situations. The extra 2 teeth make very little difference is real use.


I’m not a pro, and I don’t race, this isn’t Willy waving but from someone who has been riding x1 for over 15 years before it was a “thing”.

[Vasegaard]

Thanks for the replies!

How would you set up a driveline with SRAM with 1x or 2x in terms of components for a budget?

Has anyone done shimano 1x?

[Blueberry]

Thanks for the replies!

How would you set up a driveline with SRAM with 1x or 2x in terms of components for a budget?

Has anyone done shimano 1x?

I've had 3 shimano 1x builds. 2 gravel and and 1 road.

first gravel:
brifters: GRX 810, 11s mechanical shifters.
derailleur: GRX RX812 (1x11s mechanical)
cassette: 46t deore cassette (M8000 I think?)
crankset:38t passquest 1x ring slapped on the GRX 810 crank. Everything worked great even though that RD is only meant for up to 42t.
bike works great  and was pretty cheap to build, definitely kinda heavy.

second gravel:
-just built this one a week ago, it might be the most relevant for a road setup.
-brifter: GRX RX825 shifters (12s di2, you could use road brifters instead of GRX)
-derailleur: new XTR M9250-SGS derailleur
-cassette: 10-51 M9100 for the microspline hub body.
-crankset: Rotor Aldhu Carbon crank with a 3mm offset passquest chainring (although I think it should maybe be 6mm offset).

road 1x di2:
brifters: Dura Ace R9170 (11s, di2, hydraulic)
derailleur: GRX RX815
cassette: deore 11-42 (there is an 11s, 10-42t cassette from spedao for XDR hub if you want a a bigger big gear)
crankset: Rotor Aldhu Carbon crank with Rotor's 42t DM chainring.
worked just fine, top gear was not very high but I'm not super strong and it was never an issue. this build is probably within your budget but maybe use ultegra instead of DA shifters and a cheaper crank like ones others mentioned earlier in this thread. 11s di2 shimano is fully wired together so it can be annoying to build.

I think if I were to do 1x road Shimano again I would probably do:
brifters: 12s shimano, probably 105.
derailleur: XTR M9250-SG
cassette: M9100, 10-45t
crankset: any one of the ones mentioned in this thread with a pass quest 46 or 48t 6mm offset chainring.
Some of these parts a pretty pricey, definitely not a budget build.

I do kinda think Sram is better for 1x because you get the 10t cog and there are more affordable wireless options. That being said, it's totally doable with shimano. The main reason I've gone with shimano in the past is because I don't like dot fluid and it was easier to find used Shimano parts on Ebay. You can probably get a 1x12 rival or force set up for cheaper than my shimano setups. I had a 1x force AXS bike for crit racing a couple years ago and it worked well. Based on my experience, I felt like it was easier figure out which sram parts to put together for 1x. With shimano it seemed like it took way more research to figure out what parts were compatible with each other between road, gravel, and MTB groupsets (bettershifting.com is an excellent resource). If you like doing that sort of thing like I do, it can be a fun challenge but if you don't, sram will be easier to deal with. For Sram I do recommend staying away from any components (chains, chainrings, etc.) that claim to be universally compatible or compatible with both Sram and Shimano 12 speed.

For road bikes I'm actually back on team 2x since it tends to be lighter and have better drivetrain efficiency with wider gear range options.

All of this is just my personal opinion too, I'm sure others will feel differently about some things.