Mechanics and Fixing Any Questions Answered

I would start with the finest grade you have to hand and see what the finish is like, then go coarser if needed. That way you go carefully and won't make big scratches that take forever to sand out (have done this in haste before!)

I’m just replacing the FUBAR drivetrain on my cross bike.

Is it ok to fit superstar components raptor 1x chainrings “backwards”?

The rings clearly have a front (machined) side and a back ( smooth) side. However, chainline, and my frame’s integrated chain catcher mean that it would be better to fit the chainring on the spider’s inner position, and the countersunk bolt holes mean that they need to be “flipped” so the smooth side faces out. I can’t see any reason why this would be an issue, but it’s a few years since I last worked on a bike so just wanted to check.

but presumably the shape of the teeth are symmetrical side on, if they are, which is what i would expect them to be, it’ll be fine

Yes - have fit a narrow wide backwards and makes no difference

Running 11 speed grx and just switched to the 3rd (possibly 4th new chain). I was expecting to change cassette as well but the new chain is happy on existing cassette and chain rings.

Change the cassette anyway or leave as is ? Thanks.

If it isn’t broke don’t fix it?

Going to convert my singlespeed to geared. I’m currently running a 39t alfine chainring and have a 46t inner ta chainring lying around, neither have pins.

Is my front derailleur going to hate me if I try running a 39/46 combo using STIs?

46T inner? Blimey, that must have come from some hefty gearing setup.

What's your concern with 39/46 on the front? I'm currently running a 34/46 and it's fine. A smaller difference between chainrings should give fewer issues in terms of shifting as far as I can work out.

Yeah i ordered it as an outer ago a while back. My concern is mainly that they’re both unramped unpinned chainrings - would shifting be functional if not pretty?

M615 disc brake caliper. Should both pistons move or just one? If both then how do I free a piston that is stuck on not moving? Thanks

both.

check out sticky pistons / releasing stuck pistons on youtube. hard / long winded to explain via text so the YT videos do a good job of presenting solutions to try!

Fixed it! Thanks

Front derailleur sitting about 2 mm too high I think. It is already set as low as it can go on the braze on, and the tube is not round. Is there something that can fix this? thanks.

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You can get extenders apparently- https://www.lfgss.com/conversations/385142

Alternatively, is there much material you could remove from the mounting hole in the hanger to enable the FD to go lower? Or could you drill 2 new holes in the braze-on hanger?

SRAM gxp bottom bracket. I fitted it (with preload washer) some Praxis 1x cranks in a 68mm bottom bracket shell. The cranks had some knocking type movement so I refitted the bb with one spacer (thinking the cranks might be some MTB size.
The cranks don’t spin completely freely.
What’s right?

The cranks came without instructions either , so don’t know the torque for them

If the cranks were mtb size they’d be wider not narrower so should spin more freely

What’s the crank model? I’m not sure gxp bbs work with all praxis cranks

It’s these, they came with a bb but it was push fit

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The bb spacer is too wide? Is it your 2.5mm ht2 type? Maybe try and get a thinner, metal shim washer?

As for torque, horse it up, the bolt on gxp style cranks isn't preloading the bearing, it's just holding the arm on so don't be shy.

Should be no spacers and just the wave washer on the drive side I believe

i think torque on gxp is alotNm

I assume that's wiggle selling off the 24mm axle OEM cranks in which case the support manual is here https://praxiscycles.com/wp-content/uploads/M24-ROAD-CRANK-DM-DIGITAL-REVE.pdf

Photo?

I assembled it with no spacers then held the pedal end of the crank and gave it a bit of a wobble inwards towards the chainstay. I felt a slight knock.
Thinking this might be because the axle is meant for a wider MTB bottom bracket i added one of the supplied spacers and the cranks don’t spin freely.
I’ll have another go tomorrow, I’ve just rushed a lacquer coat over the decals and ballsed that up so can’t touch anything for a while.

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Look likes the spider is pretty close to the BB cups with the spacer?

AFAIK you don't use a spacer as they use a wavy washer to take up the slack.

Maybe double check the assembly order based on the manual +fredtc supplied?