Ask the experts

[Roxtar]

But I do love the range of a 12 speed cassette.

And how well they work.
For those of us old guys coming from the bad old days of shifting where you'd better have picked the right gear BEFORE you start the climb...

[Roxtar]

Attachment 429423
Anyone seen this happen before?
Mrs jm2e front flatted today. Zero air would go in, with the mini pump. Nothing to plug, but couldn’t figure out where the air was going using the mini. All DH to the car with Cush Core, so just slow rolled it out.
Back at home, blasted with compressed air and it’s all hemorrhaging out the valve.
Break the bead and when I get to the valve the rubber stopper is missing. A little fishing around with a pick and it seems the rubber but went completely through the valve hole and separated from the stem.
That’s one for the WTF list.


Sent from my iPhone using TGR Forums

When you replace those get a set of these…so slick. Valve core tool, and two spoke wrenches in each cap. https://juicelubes.us/tubeless-valves.html

I put these on mine and Mrs Roxtar's bikes. Great upgrade and no chance of pull-through:
https://www.ethirteen.com/products/q...l-plasma-valve

[simple]

I put these on mine and Mrs Roxtar's bikes. Great upgrade and no chance of pull-through:
https://www.ethirteen.com/products/q...l-plasma-valve

Those don't work with Cush Core. It needs a valve on the side.

[frorider]

Ultimately, the problem is that 12 speed drivetrains are just too damn narrow for mountain bikes. The margin of proper adjustment is tiny, so any little bend in the cage or sloppiness in the pivots results in a non functioning drivetrain. And any derailleur that's been ridden hard is gonna end up with a bit of slop or a tiny bend sooner or later.

But I do love the range of a 12 speed cassette.

Which is why on some of the quiver I run the similarly wide range 11 speed cassettes out there. Best of both worlds.

[skaredshtles]

Which is why on some of the quiver I run the similarly wide range 11 speed cassettes out there. Best of both worlds.

You know what I'd really like? 9sp wide-range cassette. I vaguely recall that some mfg'r might actually make such a thing?

[simple]

You know what I'd really like? 9sp wide-range cassette. I vaguely recall that some mfg'r might actually make such a thing?

I would dispute that the 11 speed shifts nicer than the 9 speed. But I could easily be convinced shift ramp design hasn't improved much. The actual shifters have definitely gotten smoother. I still use 9 speed dura ace but I remember XTR cassettes being smooth until they wore out in a few years.

[toast2266]

Which is why on some of the quiver I run the similarly wide range 11 speed cassettes out there. Best of both worlds.

What's your setup? E13? Does the cassette creak?

The garbaruks look interesting, but the derailleur mods to cover the range seem like a hassle.

[Dantheman]

You know what I'd really like? 9sp wide-range cassette. I vaguely recall that some mfg'r might actually make such a thing?

SRAM makes a wide-range 8 speed drivetrain meant for ebikes (https://www.sram.com/en/sram/mountai...levancy&page=1). But, there's no multishifting and for some reason there's no XD version of the cassette. I almost said that SRAM *used* to make this group, but then I googled to find the name and was honestly shocked to see that they still make it. The cassette is actually kind of rad, 320 g and machined from a single block of steel billet so it should last a long time.

Microshift makes a few wide-range 8/9/10 speed groups. Reviews of their stuff indicate that the shifting is just OK at best, but it's cheap.

[toast2266]

I would dispute that the 11 speed shifts nicer than the 9 speed. But I could easily be convinced shift ramp design hasn't improved much. The actual shifters have definitely gotten smoother. I still use 9 speed dura ace but I remember XTR cassettes being smooth until they wore out in a few years.

I'd argue that anything with a clutch shifts worse than any comparable setup without a clutch. So anything in the pre-clutch era shifted pretty well. Until your chain fell off.

That said, the best functioning drivetrain I currently own is a 12 year old 11 speed xx1 setup. Works beautifully, even with lots of miles on it.

[Dantheman]

That said, the best functioning drivetrain I currently own is a 12 year old 11 speed xx1 setup. Works beautifully, even with lots of miles on it.

I bought a new (used) bike in 2019 with that came with X1/XO1 11 sp and already had a lot of miles on it. I replaced the cassette with a XX1 in 2020, but only because I got a ridiculously good deal on one. I figured I'd wear that out pretty soon then upgrade to 12 sp. 3 seasons and a new frame later and it still shifts dead nuts perfect.

[simple]

I'd argue that anything with a clutch shifts worse than any comparable setup without a clutch. So anything in the pre-clutch era shifted pretty well. Until your chain fell off.

That said, the best functioning drivetrain I currently own is a 12 year old 11 speed xx1 setup. Works beautifully, even with lots of miles on it.

While I agree and my bike has that 11 speed (for life yo!) When I pedal a 12 speed XO Eagle I get envious of how good that shifter feels

[toast2266]

While I agree and my bike has that 11 speed (for life yo!) When I pedal a 12 speed XO Eagle I get envious of how good that shifter feels

Rustle up an 11 speed xx1 shifter. Similar or maybe even better than the x01 12 speed shifters.

[simple]

I've got a XO 11 speed. Now I want to know what the XX shifter looks like inside. SRAM shifters are remarkably simple mechanically

[volklpowdermaniac]

Nukeproof mega 290 alloy
Spire alloy
(Or alloy spindrift/tyee)

Debate.
Anyone ridden both? All? Some? Compare contrast love hate?
Read some issues with the spire and shock alignment and eating shocks? Maybe just in the carbon frame? Some people having to shave something?

thanks

[geomorph]

You know what I'd really like? 9sp wide-range cassette. I vaguely recall that some mfg'r might actually make such a thing?

When I bought my Trail Pistol last year I had the option of having a Box 9 Prime drivetrain on it with an 11-50 cassette. Was tempted by the concept but chickened out and went with the known commodity SRAM drivetrain.

[Tailwind]

Getting caught up on the thread and stoked to see the idea of a aftermarket version. There are a few curves to the cages when they’re new. It’s part of what makes it feel so impossible to straighten a bent one. I’ve seen the Shimano versions bend but I’ve also seen them twist. Doesn’t seem like it needs to be a lot stronger, I’ve been fine with sram cages.

I’d be into the idea of a stronger cage for sure. Shimano clutches being adjustable could help accommodate a little extra weight in the cage.

Yes. I think they are probably stamped. To get the same strength without stamping you'd probably need to go with a thicker material. I don't have a spare 12spd derailleur - just the "modified" (by rocks) XT on my trail bike. Ah ha ha...So...i just remembered that we got a fancy new laser scanner for scanning and measuring complex parts. We are just starting to figure out how to use it and I'm sure the team would be happy to scan a cage for me. I'll try that route first and probably a 3d printed version to see if holes align...

Sent from my SM-S908U using Tapatalk

[Benneke10]

I'm seriously considering buying a used carbon mtb that the current owner re-painted himself. Is that anything to worry about? Is it possible for an amateur to damage the frame in the sanding/painting process? He said that he had painted a few bikes before this, and he sanded it then used a Krylon base with an automotive quality matte topcoat. I like the way it looks, especially since it covers up the Specialized logos and the price is quite good. I'm just worried that a DIY job could have damaged the carbon somehow. There is some paint damage after a few years of use but I don't care about the aesthetic damage to the paint, I can't afford to be picky about that stuff. Should I pull the trigger? Here are some pics of the rougher-looking parts of the frame that the owner sent me

[tgapp]

The bigger concern I would have is the owner hiding a repair or damage under the paint. Sanding and priming shouldn't hurt anything, and there is a very low chance that he is hiding damage under there, but that's the biggest risk IMO.

Sent from my Pixel 6 Pro using Tapatalk

[simple]

IMO it takes balls to sell a repaired carbon frame. I'm confident in my work but not that confident.

[Benneke10]

The owner said in the ad that he just painted to get the color and the frame had no damage but it’s tough to take their word for it when you can’t see anything under the paint

[simple]

Fuck I can't read well in the morning. You didn't say it was broken you asked if the paint might be hiding something.

How cheap are we talking for that Pepto pink frame?

[Benneke10]

They are asking 3k for an ‘18 epic evo with a spec that is pretty much my dream build. Similar bikes are listed at around 4k with spec that I don’t like quite as much

[climberevan]

I've painted (and sold them later) carbon frames. It's not hard to do and doesn't require as much prep as you'd think. The paint itself can't hurt the carbon, so unless the guy went totally nuts with sanding (factory paint is so thick that he'd have to be seriously motivated), I'd say it's fine.

A repair that you can't see under paint is likely to be either very tiny or a pro job. You'll have to trust your gut on this one though--maybe a phone call with the seller to better feel him out would be in order.

Of course, all of that aside: Yer Gunna Die!!

[Dee Hubbs]

I'm seriously considering buying a used carbon mtb that the current owner re-painted himself. Is that anything to worry about? Is it possible for an amateur to damage the frame in the sanding/painting process? He said that he had painted a few bikes before this, and he sanded it then used a Krylon base with an automotive quality matte topcoat. I like the way it looks, especially since it covers up the Specialized logos and the price is quite good. I'm just worried that a DIY job could have damaged the carbon somehow. There is some paint damage after a few years of use but I don't care about the aesthetic damage to the paint, I can't afford to be picky about that stuff. Should I pull the trigger? Here are some pics of the rougher-looking parts of the frame that the owner sent me

Ask him straight out, “has the carbon fiber been repaired somewhere under your paint job? Is that why you painted it?”
Tell him you want this verbiage in the PayPal buyers notes.

Tell him you have a friend of a friend who can x-ray the carbon fiber once you get the frame, and if it’s been repaired you’re going to claim for your money back from PayPal.

That way you know for a fact he’ll tell the truth if it has not been repaired.

[singlesline]

I had a thought about painting something carbon once, but wondered if anyone would buy it down the road.

I figured you could take pictures of the process. Original paint showing no major damage, sanded and prepped showing no repairs, fresh paint. Throw a dated newspaper in the background for some semblance of timeframe.

But then I thought...if someone tried to send me evidence like that, it might make me feel MORE sketched out like they are really trying to cover something up.

Maybe the best bet if you want to paint a bike is to document it on reddit/instagram/forum. Then you can at least casually say "check out this post to see details of the paint job". But unless you used to work in a bodyshop, you're probably devaluing the bike by painting it...