lured3nem

Hi, Apologies for the noob question.

I have a claris 8sp drivetrain set, with mecahical postmount discs
What do I need to to upgrade to 8sp 105 set, with hydrualic brakes.
If 8sp 105 is not available, 9sp 105 with hydrualic brakes also preferred.

BTW, i have 9x2 sora crankset.

Thanks!

veganbikes

105 hasn't been 8 speed for a long time. The 8 speed era was late 80s to early 90s in terms of quality. If you want hydraulics and 105 I would look at 11 speed groupsets. You will be replacing the entire drivetrain, brakes, shifters and you may need a wheel at the rear compatible with 11 speed cassettes. However 105 is a good upgrade and a very reliable durable groupset that will get the job done, Depending on what bike you have it may not be a worthwhile upgrade to that bike as it came with pretty cheap parts but bikes are hard to come by so upgrading isn't a terrible option.

if you are looking to save money and get something much better than what you have but not as good as 105, You can find Tiagra and GRX400 with hydraulic brakes and then you can keep the front chainwheel (Shimano doesn't sell "cranksets" but Chainwheels) and potentially your old wheels as this will be 10 speed rather than 11 so may all still work.

If you want to go the cheaper route in terms of brakes, upgrade everything. Get really high quality pads (Kool Stop or SwissStop), nicer Ice-Tech rotors (or similar vented rotors like the Jagwire CR1s or SwissStop Catalysts), good compressionless housing and polished stainless steel cables (I would highly recommend the Jagwire Elite Link but the Pro Polished is also good) and that will be a massive improvement for not a whole ton of money comparatively. Granted the shifting won't get better but you could do something similar there and improve it marginally.

Russ Roth

Your not getting a 105 hydraulic group with less the 11 speeds, they just didn't make them; the first version were rs505 which was a 105 level group though not badged as such, the 405 was equivalent to Tiagra.
If you have a really new bike you can check if there is a spacer behind the cassette, if so its 11 speed compatible and you'll need to buy a groupset; 105 hydraulic levers, brakes, front and rear der, crank, bottom bracket, cassette and chain which won't be all that cheap. Also don't know that 105 comes in a post mount so where ever you buy from you'll need to ask them to change the brakes to an LX version.
If your wheel isn't 11sp compatible you'll have to go to tiagra for a hydraulic setup which will be 10sp, again you'll need to buy mtb brakes instead of road for post mount. Might also be able to find a 10sp partial set of 105 on ebay or after a lot of online searching and just use a cable actuated hydraulic brake. Personally from my use of Tiagra and my experience building 105 bikes and tuning them I'd be just as happy with the newest Tiagra as I would 10sp 105.

lured3nem

If im going to go for tiagra, i only need to change my cassette,(10sp), STI(10sp), chain, FD, and hydrualic calipers?

lured3nem

Is there no available STI for post mount hydrualic calipers?

shelbyfv

I suggest you run this project by your LBS. It's not something you should tackle yourself.

lured3nem

You are right! This sounds complicated. At least i can plan what should i get.

Russ Roth

Any of the hydraulic sti levers will work with 2 piston shimano mtb post mount calipers for your purposes, though more affordable are the cable actuated hydraulic brakes which are nearly as good and with the right housing will be any easier to do thing now if all you're looking for is better stopping power. The other thing to consider before jumping too deep into this project is that the overall quality of the bike isn't going to be that great, 105 will be lots better then claris but if your looking for performance the better gain will be from wheels and tires which yours are probably around the same level as the rest of the parts. You also, as mentioned before, might need new wheels to move to 105 since it is now an 11sp group; you haven't said exactly why you want to move to 105 and that should determine your next step.

fietsbob

8 (or 9) speed Brifters & cable actuated hydraulic disc caliper like TRP Hy Rd is a bit simpler..

Haven't kept up but (perhaps) the Speeds number got to 10 before the road hydro disc thing hit the market..

Elvo

I think 8 speed hydraulic is doable with Gevanelle friction shifters?

https://www.gevenalle.com/product-category/shifters/

lured3nem

I really wanted to retain my 8sp, but i have Zoom Xtech calipers.. do you think ill settle with it then... i think its a cable actuated hydro.. correct me if im wrong.

Russ Roth

Had to look them up and they do seem to be a cable/hydro brake and from the actual user reviews I found they score higher then plain cable discs. I find my cable discs that I have to stop well enough, the only TRP Hy/rd that I have do stop a lot better, mine stop a tandem just fine; if you're not happy at all with the stopping I'd suspect something with the setup of them. Compressionless brake housing is a big plus, making sure the caliper is set just right, and with some there is a need to adjust the pads since they don't self-adjust as the pad wears.
The big issue is that anything hydraulic road means 10-11 speed and even the 10sp isn't fully compatible since Tiagra requires using its own or higher level rear der though you can probably get away with the front der. This means your looking at more expensive shifters 400+ a pair, rear der, cassette, chain, and new brakes for a possibly not huge improvement in stopping though full hydro will still stop better; the quality of the caliper you pick will determine how much and the ones that will be noticeably better will be 70+ each. The deore level brakes I put on my kids' bikes don't really stop much better (kids and bikes combined weight under 90lbs so they can stop fine, I didn't test riding them) then the TRPs on the tandem while my wife's 200 level shimano's stop worse. The Hayes on my MTB are amazing in their stopping power but cost a lot more.
If you're happy with the 8sp check your brake housing, most cables I've seen are running through old fashioned coil housing with a basic liner and cover; if you've got this replace it. Get Jagwire pro housing and have the brakes really set up well, it will make a difference.

lured3nem

Im also considering of getting the trp hy/rd since reviews were better compared to my current and also quality-wise i think. And it would be awesome if paired with jagwire pro.

Thank you so much youve been a great help.

veganbikes

Correct you should really only need to change that. However keep in mind the cranks are 8 speed so you may not have as smooth and crisp shifting.

lured3nem

Hi, You mentioned upgrading my wheels, vision has this team 30 disc wheels for gravel, it is mentioned its compatible drivetrain is 10/11sp. can i run this with my 8 speed cassette with additional spacers or something?

Russ Roth

Your cassette will fit; 8-10sp fit 11sp wheels with a spacer. 8-10 speed cassettes are all the same width, just different cog thicknesses and different spacing between the cogs. Being that you have disc you probably have 135mm rear spacing if quick release and 142mm if thru axle, you will need to make sure the Vision wheels have the same attachment. If your bike is oldold dou check it's 135mm, early road adopters of disc could be 130mm but nothing in the last 10 years.