[Closed] Gravel groupsets - help!

That rear mech won't work with the 9 speed Sora shifters. You'd need an MTB 9 speed mech (or 8, or 7 speed).

It's difficult to overstate how much better gravel rising is with hydraulic brakes than cable though.

It’s difficult to overstate how much better gravel rising is with hydraulic brakes than cable though

This x100. Hydraulic brakes are the 'key' to good off-road performance on a Gravel bike. I'd not even consider anything else.

I'd try go with 10 or 11 speed one-by.

Use a tanpan to unlock the use of various MTB cltuch derrailuers.

https://www.wolftoothcomponents.com/products/tanpan

Yeah, I wanted hydraulics, because it's what I'm used to, but I'd end up pretty much having to buy a complete 105 group, by the looks of it.

I've probably got an old 9 speed MTB mech somewhere deep in the spares box, which presumably would need a goatlink for capacity.

It's a whole new world of incompatible standards. 🙂

Sora 9 speed shifters with some kind of mechanical disc caliper (had hoped to use hydraulics but compatible levers means 11 speed and £££)

10sp Tiagra levers or GRX400 levers. (they're basically the same thing).
Allows hydraulic braking.

Or I can sell you my Hope V-Twin which allows you to run any cable shifters you want, the cable goes to a little box under the stem and pulls a piston, the braking is then converted to hydro at that point and runs down hoses to the brake calipers (Hope although it can be persuaded to work with others).

They don't make the V-Twin anymore - it was a "stopgap" solution to the early days of disc brakes in CX which was bastardising road and MTB components. Back then the only hydro road levers on offer were the very top end ones so people were looking for options to run hydro discs.

Ok, so if I got this:

https://www.sigmasports.com/item/Shimano/GRX-400-Hydraulic-Mechanical-STI-Levers-2-x-10-Speed/SXMR

Is the tanpan so I can use a mtb mech with a road cassette, or so I can use mtb mech and wider range mtb cassette? I currently have an 11-36 10spd mtb cassette and XT non-clutch mech.

Or I can sell you my Hope V-Twin

If you went down that route, I have a set of 2x10 Tiagra non hydraulic brifters buried in the classifieds somewhere..

Thanks for the offer CrazyLegs - but I might be a bit too much of a tart to accept the aesthetics 🙂 (plus it might make attaching a bag off the bars a bit awkward). Plus dot4 would mean new calipers as well!

Re the mechanical vs hydraulic issue - my gravel bike has TRP mechanical brakes and I was fully expecting them to be rubbish. And they were for the first couple of rides but once they bedded in I was quite surprised how well they worked. I cannot abide cack brakes and have 205mm rotors front and back on my hard tail MTB.
The only thing I changed from standard was put 180mm rotors front and back on my gravel bike - they are decent Shimano rotors - instead of the 160mm it came with as standard.

It does seem opting for hydraulic brakes on a drop bar bike is ruinously expensive if building from scratch, and that’s if you can get the parts at all.

jtek shiftmate might be the answer to the problem?

Thanks for the offer CrazyLegs – but I might be a bit too much of a tart to accept the aesthetics 🙂 (plus it might make attaching a bag off the bars a bit awkward). Plus dot4 would mean new calipers as well!

I've got the Hope X2 calipers with it but they're post-mount, just in case that adds any other compatibility issues!

It's becoming such a pain with the evolution of gravel bikes tending towards 1x and bigger tyres / more clearance plus things like thru-axles, it can mean you end up with 3/4s of a perfectly good bike and then very few non-bodge options to finish it off.

Yeah, it's a bit of an irritating mess of standards.

Is the tanpan so I can use a mtb mech with a road cassette, or so I can use mtb mech and wider range mtb cassette? I currently have an 11-36 10spd mtb cassette and XT non-clutch mech.

It's so you can use an MTB mech with road shifters. Which, in turn, allows you to use a bigger cassette and / or spread of gears. So yes, it would allow you to use that mech and cassette with Shimano 10spd road shifters.

You'd need a GoatLink as well if you wanted to use a modern big cassette (bigger than 36t) on a 10spd mech. But if you're going 2x then you shouldn't need more than a 36t sprocket anyway, I'd have thought.

The other option is just to sack off brifters and use separate brakes and shifters:

From CtB

Chinese seller and much cheaper, purportedly identical, I think?:
AliExpress

This x100. Hydraulic brakes are the ‘key’ to good off-road performance on a Gravel bike. I’d not even consider anything else.

Agree. I love my GRX 810 setup.

OK, next question

Will my XT785 10 speed 2x crankset (currently 36/26, I think) be OK transplanted onto a 68mm BB width gravel bike, or will the chainline be no good? In theory I should be able to get aftermarket larger rings onto it, no?

My brain is hurting!

I think I'm right in saying that up to 9 speed Shimano road and MTB have the same pull ratio so you can use a 9 speed MTB rear derailleur with road shifters. As for brakes there's the halfway house of hybrid (cable actuated hydraulic such as TRP hy/rd or Juintech).

I think I’m right in saying that up to 9 speed Shimano road and MTB have the same pull ratio so you can use a 9 speed MTB rear derailleur with road shifters.

You can use a 9sp MTB rear mech with 10sp shifters.
I've got an old M972 XTR rear mech doing shifting duties across a 10sp XT cassette pulled by 10sp Ultegra levers.

It's the old (1.7:1) cable pull ratio on the rear mech that mainly limits your choices
(shimano MTB groups used this up to 9 speed, Road used it up to 10 speed, with the exception of 4700 Tiagra).

I've been using an old SLX 9 speed mech on my gravel bike for the last few years, initially with a tiagra 4500- 9 speed shifter, then with a bodged thumbie and most recently with a pukka Gevenalle (microshift) 10 speed, that works well enough for me 1x with an 11-34 or 11-36 cassette.

The Best looking candidate cheapy 9 speed MTB mech (available today) I reckon is the Alivio M4000, essentially it's a 1st gen' shadow mech (no clutch) with that older cable pull ratio, pretty much Deore from about 12 years ago.

I'd echo the comment that hydraulic discs are the preferable option, but there are "halfway" solutions. Personally I quite like the look of the Giant 'Conduct' system which can be had for ~£100 and minimises the cabled run to just the bars. Thereby allowing you to keep your conventional levers with a master cylinder mounted at the stem. I know one chap with a set of them and they seem to work pretty much as well as my fully hydraulic TRPs for less than half the price.

There are options available.

I am using Aliexpress cable hydros on one bike. Fine and 26 quid a pair.

Cable hydros are dogshit and if you think they're good enough youd probably be fine with rim brakes for your riding.

The cheapest not crap way to get into gravel 1x is SRAM 10sp rival or apex hydro matched with a 10 speed type 2.1 rear mech, which will do 42 at the rear with some coaxing.

“ Cable hydros are dogshit and if you think they’re good enough youd probably be fine with rim brakes for your riding.”

Crikey. 🙄

Cable hydros are dogshit and if you think they’re good enough youd probably be fine with rim brakes for your riding.

Speaking as a man who has put in some fairly long and grubbly miles through the Highlands on his rim braked gravel bike and latterly with cabke disc brakes, l can confirm both are plenty good enough for gravel riding. Of course, one man's gravel riding is another man's 'let's ride gnarly singletrack on a gravel bike'...

Personally I quite like the look of the Giant ‘Conduct’ system which can be had for ~£100 and minimises the cabled run to just the bars. Thereby allowing you to keep your conventional levers with a master cylinder mounted at the stem.

Basically the same as the Hope V-Twin although it's a neater mount in front of the bars rather than under the stem. Or actually, is it part of the whole stem? As in proprietary stem?

Cable braked gravel bike atop the Glen Tilt singletrack, complete with overnight gear. At no point did I think I needed hydraulic brakes despite some fairly high consequences for getting it wrong on that trail. My TRP cable discs are marginally stronger again, albeit much much noisier.

Basically the same as the Hope V-Twin although it’s a neater mount in front of the bars rather than under the stem. Or actually, is it part of the whole stem? As in proprietary stem?

Yep it's basically the V-twin concept for substantially less spend.

It uses a replacement stem faceplate, obviously it will fit at least some giant OEM stems (apparently it's made for giant by TRP?). I can't say conclusively, but a quick Googling yielded anecdotes of the conduct stem faceplate fitting other brand/models of stem, it's a bit of a gamble as bolt spacings aren't standardized.

Its potentially a better solution than some of the others out there, and certainly cheaper than "The cheapest not crap way to get into gravel" by throwing money at SRAM, YMMV and so on...

You can use a 9sp MTB rear mech with 10sp shifters.

You can't use the GRX400 levers though, they and latest Tiagra have the same pull ratio as 11-speed I think. Your best bet is probably the GRX400 mech, which is a 10-speed clutch mech for about 50 quid. Will work with the shifters and an 11-36 10-speed cassette. I've just been through this and it seems like the easiest way of getting hydros without going through the whole 11-speed rigmarole. Apparently the CX70 front mech works with the shifters too, which is just as well as that's what's on my cross bike already. I may of course be wrong, but I hope not given that I have all those bits waiting to go on the bike. Watch this space.

Didn't see this pop up again.

My brain eventually gave up trying to recycle bits of my MTB drivetrain, so GRX 400 crankset, levers and mech are incoming. Now just need a front mech, and braze on/band on adapter, by the looks of it. The aim is to run 46-30 up front with 11-36 or 11-40 on the back.

Now then, wheels...just realised the mtb front wheel I'd earmarked can't be converted down from 15mm to 12mm, despite being DT Swiss. 🙂

or you could go SRAM.... 10spd road and MTB SRAM runs the same ratio - I've got Apex levers pushing a GX mech (long cage) around a 42T cassette on the commuter. It's also got cable discs - Avid BB7 Road, which are 'fine', but definitely not as good as the hydros on either the CX or gravel bikes.

I think the S700 hydrolevers are 10spd if you want hydro brakes.

Now then, wheels…just realised the mtb front wheel I’d earmarked can’t be converted down from 15mm to 12mm, despite being DT Swiss

You can get generic 15 to 12 mm inserts for the axle to solve that

Ref 15 to 12mm - just be aware that just becuase you can shim the axle down, doesnt mean it'll fit. I built some very nice XTR hubbed wheels for my gravel bike with the plan to use said shim, however the end caps would not fit into the fork ends regardless of axle size.

Ended up having to rebuilt the wheel onto a GRX hub - almost identical dimensions but different end caps.

(I even tried re-assembling the XTR shell around some ultegra internals but it just wouldnt match up).

You can get generic 15 to 12 mm inserts for the axle to solve that

It's 240OS with a screw-in rather than push in endcap. I managed to get it down from 20 to 15, but I don't think a 12mm end cap exists for this hub.

Also, as above, there's a strong possibility that it wouldn't fit in the dropout anyhow (I don't have the frame in front of me yet to measure it).

The aim is to run 46-30 up front with 11-36 or 11-40 on the back

Let me know if you can find an 11-36 cassette! I think 46-30 and 11-36 (or 11-38) would be ideal for me. I have a hunch that shorter rear mechs and smaller cassettes make for more reliable rear shifting so will be going 2x again for my next 'summer' gravel bike. I think you can build custom Miche cassettes in which case I might even go 11-38.

All I know is that a 31-34 ratio is not low enough for some of the gravel around here once you strap some overnight gear on the bike 🙄

Let me know if you can find an 11-36 cassette!

I got an XT one from BikeShak in Altrincham. Quite by chance actually, I'd been looking all over online for it with no luck. Was just passing by for something else and then I spotted it on the workshop shelf so I bought it quick!