Help an idiot pick a groupset and understand drive trains

[Corex]

Disclaimer: I'm an idiot that's building his first bike learning everything from scratch

So basically I'm building a gravel/road bike using a Cwind GT30 frame. I've been researching which groupset to get and so far have decided that a 2x11 setup seems best for me, and looking at my options I'm currently torn between something like an LTWOO R9 for $260 NZD or Shimano 105 (R7020+R7070 & R7000) for $470 NZD. To my uneducated brain based on my research the Shimano is well worth that price gap? Are there any other options I should be considering?



LTWOO R9 - $260
https://vi.aliexpress.com/item/1005006449025000.html

Shimano 105 (R7020+R7070 & R7000) - $470
https://vi.aliexpress.com/item/1005005412227135.html


Also basically anything to do with the drivetrain confuses the hell out of me - people talking about all these different configurations and compatibility considerations. I understand that I need to make sure my cassette and crank are for 11 speed and that my crankset works with my bottom bracket but what's with everything else?

[coffeebreak]

IMO, If it's your first time building, get the Shimano 105. It's worth every extra penny you will spend over LTwoo or Sensah.

As enticing as low prices of Chiner groupsets are, those are for more experienced tinkerers as you often have to struggle with setup and quality issues.

Don't think much or experiment with components in the beginning - get everything in spec as in 11 speed chain, 11s cassette, 11s crankset to go with 2x11 shifters.

Keep reading threads here and elsewhere, build experience with bike maintenance and you'll have questions come up which you can then ask or search for existing data.

[Corex]

For the most part I've been trying to consider all of my options to try and land the best deal paired with my ideal setup but I think you're right - keeping things simple for my first build has value as well.

I think I'll order a Shimano 105 groupset + drivetrain combo to keep things simple for myself, after crunching numbers this looks like a good deal over buying everything separate https://vi.aliexpress.com/item/1005006653718580.html

I'll just need to wrap my head around what the difference between the RDGS 34T Set and the RDGS 32T Set are

[BeR]

For the most part I've been trying to consider all of my options to try and land the best deal paired with my ideal setup but I think you're right - keeping things simple for my first build has value as well.

I think I'll order a Shimano 105 groupset + drivetrain combo to keep things simple for myself, after crunching numbers this looks like a good deal over buying everything separate https://vi.aliexpress.com/item/1005006653718580.html

I'll just need to wrap my head around what the difference between the RDGS 34T Set and the RDGS 32T Set are

It is the teeth of the biggest gear on the cassette.

[Corex]

Am I right in thinking that simply more teeth = bigger gaps between gears but less range? Does the HG700 have any other differences than the R7000 besides teeth? I'm assuming that I also want to be getting the RDGS and not RGSS

[OralMaster]

will you be joining a cycling group that is slightly more affluent? I'd recommend the Shimano 105 di2, it would keep you off the bay of wanting to upgrade to a electronic groupset due to peer pressure. In 1 more month, the prices of OBM 105 di2 will be dropping significantly, at one point the entire 105 di2 groupset was 4800 rmb in June 2024.

[bremerradkurier]

105 Di2  will also be easier to install for internal routed frames, gives you the option of a 34x36 low gear, and far easier derailleur adjustments compared to mechanical.

[kbernstein]

will you be joining a cycling group that is slightly more affluent? I'd recommend the Shimano 105 di2, it would keep you off the bay of wanting to upgrade to a electronic groupset due to peer pressure. In 1 more month, the prices of OBM 105 di2 will be dropping significantly, at one point the entire 105 di2 groupset was 4800 rmb in June 2024.

Can you explain what OBM means and how you are predicting european prices?
4800rmb is ~610 euros, I've seen full 105 di2 for 780ish

[jonathanf2]

will you be joining a cycling group that is slightly more affluent? I'd recommend the Shimano 105 di2, it would keep you off the bay of wanting to upgrade to a electronic groupset due to peer pressure. In 1 more month, the prices of OBM 105 di2 will be dropping significantly, at one point the entire 105 di2 groupset was 4800 rmb in June 2024.

If he's on an affluent cycling group, I'd bet most those riders wouldn't even know how to service their own bike. OP is attempting to build his first bike and I think it's best to have a grasp of mechanical before jumping into electronic. He can upgrade down the road, keep his brake calipers in place and just upgrade the shifters and derailleurs to 105 Di2. Pulling shift cables out is easier than installing them.

Oh yeah, buy 105 and don't bother with any of the LTwoo or Sensah components. That stuff is for DIY tinkerers who can deal with the slight oddities of Chinese drivetrain components. Also I highly recommend removing the stock shift cables from 105 and use Dura Ace polymer coated shift cables. Those cables are WAY better for anything mechanical shift related. They don't fray, don't crush and can easily be straightened out to be reused.

[OralMaster]

Can you explain what OBM means and how you are predicting european prices?
4800rmb is ~610 euros, I've seen full 105 di2 for 780ish

It will come as a set that is not in retail packagings, most likely groupsets sold in bulk to bike manufacturers or shops. They get it from Shimano on the cheap and still make a margin by selling at such low prices.

I have been wandering around taobao to see what's in supply and what's not. e.g you still get get such groupsets from aliexpress but it will be a little more expensive compared to buying from taobao and using your own forward shipper.

https://www.aliexpress.com/item/1005005399017410.html?spm=a2g0o.productlist.main.5.23b9M4sBM4sB9M&algo_pvid=9833f71c-8bcb-4c04-8a90-85305c1a20ac&algo_exp_id=9833f71c-8bcb-4c04-8a90-85305c1a20ac-2&pdp_npi=4%40dis%21SGD%211360.88%211320.05%21%21%217189.00%216973.33%21%4021015c7617253793585417534ec266%2112000034587750441%21sea%21SG%21176727628%21X&curPageLogUid=CXTlyBfeGruy&utparam-url=scene%3Asearch%7Cquery_from%3A

the current prices are not as good comparably, but still attractive, I implore OP to go for 105 di2.

[Sakizashi]

 It might be worth checking max chainring sizes with the road crank to ensure the combination you want will fit this frame. It appears to be a gravel frame, so there could be limits to the chainring to keep in mind.

The other thing is that if you plan on using it like a gravel group, you want a clutch. It will really help with chain retention, keep the bike quite a bit quieter over rough stuff, and prevent your chain from messing up the chainstay.

[Nkearb]

I have a 2x11 drivetrain on my gravel bike, a winspace g2.

Just my opinion but with a semi internal cable routing gravel build, mechanical-hydraulic hybrid brakes make more sense. Your not going the bombing hills at speeds that make full hydrulic breaking forces useful and usually you will not be able to take advantage of high breaking forces due to lack of traction. Id recommend r7000 shifters and zrace br-005 calipers. Save you about $100 on the groupie

Another thing is the frame will have a certain chainring size limitation for a 2x system. If you are getting a r7000 crankset you can only go as low as 50-34 which likely won't fit. You can use 2-3mm of spacers on the driveside to make it fit but that will impact chainline, but not signifigantly. You would need to go with aftermarket chainrings or just go with a different crankset. I ended getting a senix pr3 w/ 48-32 chainring it even comes in 46-30 if your really worried about it fitting.

Final thing a clutch style derailleur would be nice. I got a rx810 and 11-34 105 cassette. Maxing out the b-limit screw it supposedly can take a 11-40 cassette. I plan on eventually buying a 10 speed goat link and running a 11-42 cassette.

[rtuk]

I plan on eventually buying a 10 speed goat link and running a 11-42 cassette.

Are goat links speed specific?

I'd assumed that broadly they were all the same - but like many things current on road / gravel / mtb - I'm finding my knowledge needs updating.

[coffeebreak]

Are goat links speed specific?

I'd assumed that broadly they were all the same - but like many things current on road / gravel / mtb - I'm finding my knowledge needs updating.

No, they are not speed specific. In fact there are pretty cheap Goat Link alternatives on Aliexpress and they work all the same. Lets face it, its a piece of metal that lowers the derailleur.

[rtuk]

No, they are not speed specific. In fact there are pretty cheap Goat Link alternatives on Aliexpress and they work all the same. Lets face it, its a piece of metal that lowers the derailleur.

Thanks for confirming