Ask the experts

[mall walker]

the facebook bike groups I’m in routinely see bikes crappier than my bike but 3+ years old going for $50 off MSRP, Id get up there and take a swing

[snowaddict91]

You guys don’t realize what COVID demand has done to used bike prices for reasonably maintained bikes ...

You aren't wrong. I'm back and forth between adding a hardtail to the stable or just upgrading my fully. Thinking I may put a silly price on my 2017 trance and see what happens.

[schuss]

You guys don’t realize what COVID demand has done to used bike prices for reasonably maintained bikes ... even if the small wheel size depending on kit and condition it could possibly fetch $850 ... but I don’t know if your build has the awesomer stuff or the flexier heavier stuff.

It's a mix, if you remember. Will likely bro deal to a friend for 4-500 before consulting the market. We'll see if it fits him first.

[bagtagley]

Definitely sell cheap to a friend or someone in need.

[schuss]

That's the plan, just wanted to make sure I didn't have an asshole price. Said friend is iffy on it, so if anyone here wants a 26 inch mojo and is willing to grab it from Seacoast NH, let me know. Not allowed to buy a new full squish rig until old one is gone.

[Roxtar]

Spoke conundrum - I broke a spoke in July, having caught a 1" diameter branch in the back wheel on a climb. Got it replaced, and another broke 2-3 rides later with no known cause. Replaced. 4-5 rides later and the first replacement broke at the nipple, no known cause. I'm on a 2016 5010c with WTB 711 sti23 rims and SRAM 746 hub, with stock spokes. I don't ride particularly hard.

It's getting replaced today, but curious if there's some other underlying cause that could lead to the repeated breaks. Or maybe I just hit more crap than I know???

Could be spoke imbalance. Who is truing the wheel after the spoke replacements and do they know anything about wheel building? Could also be over-twisting the replacement spoke (easy to do on a replacement since the new spoke often binds in the older nipple, especially with aluminum rims). Or a bent rim that is being compensated for by over-torquing some of the spokes.

I'd probably do a rebuild (loosen all the spokes, re-tension and true). If the rim is bent when the spokes are loose you should replace it.

This with one addition.
Rebuild with brass nipples. Aluminum is a terrible choice for nipples. Aluminum has a very limited fatigue life and a nipple faces constant stress/relax cycles on every rotation.
Add to the fact that aluminum nipples are very iffy regarding truing after a couple years. They tend to lock onto the spoke and then round off.
In the midst of many, many terrible ideas the bike industry has come up with, this rates way up with the worst.

[Whiteroom_Guardian]

GX Eagle shifting/slipping issues?

New bike came with GX eagle. Not my first choice, but was a good deal on a used bike. It works for the most part. Climbing almost never an issue. Up shifting while pedaling hard on a DH = slippage. Chain not warn, cassette is good. B-screw seems to back itself out daily. But even when its perfect still issues sometimes. Only in the mid range of the cassette.

Is this just the way it is?

[skaredshtles]

This with one addition.
Rebuild with brass nipples. Aluminum is a terrible choice for nipples. Aluminum has a very limited fatigue life and a nipple faces constant stress/relax cycles on every rotation.
Add to the fact that aluminum nipples are very iffy regarding truing after a couple years. They tend to lock onto the spoke and then round off.
In the midst of many, many terrible ideas the bike industry has come up with, this rates way up with the worst.

So much truth in this post.

I'll add in the fun experience of galvanic corrosion with carbon rims and alu nips.

[El Chupacabra]

I didn't see where he said it had aluminum nipples...

[Roxtar]

I didn't see where he said it had aluminum nipples...

Assumption based on the rarity of brass nipple failure

[toast2266]

GX Eagle shifting/slipping issues?

New bike came with GX eagle. Not my first choice, but was a good deal on a used bike. It works for the most part. Climbing almost never an issue. Up shifting while pedaling hard on a DH = slippage. Chain not warn, cassette is good. B-screw seems to back itself out daily. But even when its perfect still issues sometimes. Only in the mid range of the cassette.

Is this just the way it is?

Put loctite on the b screw. And put a little on the hanger bolt while you're at it. I bet your issue is b screw related.

[smmokan]

GX Eagle shifting/slipping issues?

New bike came with GX eagle. Not my first choice, but was a good deal on a used bike. It works for the most part. Climbing almost never an issue. Up shifting while pedaling hard on a DH = slippage. Chain not warn, cassette is good. B-screw seems to back itself out daily. But even when its perfect still issues sometimes. Only in the mid range of the cassette.

Is this just the way it is?

GX is absolute garbage compared to the new Shimano stuff. I had a fleet of GX builds last year and it was non-stop tinkering with shifting, B-screws, and limit screws backing out. Literally every single trip. This year with Shimano XT so far, nothing.

[SchralphMacchio]

Would it be more accurate to say that “GX Eagle is garbage?”

Seems like GX11 speed was pretty reliable and worked well?

After hearing about all these Shimano 12 speed clutch issues and GX Eagle shift issues, I can see why (a very small minority of people) have gone back to X01 11 speed with Garbaruk extra range cassettes ...

(Of course, I ordered my Garbaruk 11 speed cassette a month ago and still haven’t gotten shipping confirmation! Grrrrrr ...)

[Whiteroom_Guardian]

GX is absolute garbage compared to the new Shimano stuff. I had a fleet of GX builds last year and it was non-stop tinkering with shifting, B-screws, and limit screws backing out. Literally every single trip. This year with Shimano XT so far, nothing.

Yeah my old bike I had just upgraded to working man's slx/xt 12 speed which is amazing.

Plan to swap this over to full XT or XTR over the winter. Just need this GX to get me through the end of this season.

Sent from my SM-G973U using Tapatalk

[teledad]

I was assuming "broke at the nipple" meant the spoke broke, not the nipple. I'd assume an OEM wheel with mid-level hubs and rims is going to have brass nipples (since they're both cheaper and easier to build in a machine).

You can build a long lasting wheel with alloy nipples (I have a few built in the 90s and still in active use) but you need to be careful about rounding the nipple as mentioned. A 4-sided spoke wrench (Spokey) helps a lot here, along with lubing the threads with spoke prep or anti seize. And the combination of alloy nips and butted spokes (esp. heavily butted like DT Revolution) can make dealing with spoke windup especially hard.

[toastybroski]

I have been thinking of getting a smaller oval chainring lately. Am I just out of shape? I am currently running a 32t on a 10-50 sram setup. I was thinking of going down to a 30t or 28t. I feel like the hills near me are fucking brutal. Any advice?

[SchralphMacchio]

working man's slx/xt 12 speed which is amazing.

By “working mans” did you have XT on the derailleur or the shifter?

I don’t really understand why OEM spec on mixed builds is SLX shifter and XT derailleur, as if I were building my bike I’d want it the other way around for the precise cable pulling capability and quick feel of the shifter. Am I wrong on that?

[El Chupacabra]

GX Eagle shifting/slipping issues?

New bike came with GX eagle. Not my first choice, but was a good deal on a used bike. It works for the most part. Climbing almost never an issue. Up shifting while pedaling hard on a DH = slippage. Chain not warn, cassette is good. B-screw seems to back itself out daily. But even when its perfect still issues sometimes. Only in the mid range of the cassette.

Is this just the way it is?

If up shifting but *not* during fast DH - shift OK? Is the chain the right length?

I have a bike with GX Eagle and another with XO1 Eagle, both about the same age and usage. The GX cassette shows a lot more wear than the XO1, and the derailleur has more slop. Shifts fine still, just looks like it isn't going to last terribly long. There seems to be a big jump in quality from GX to XO1. I wonder if the revised GX parts are any more durable.

[El Chupacabra]

By “working mans” did you have XT on the derailleur or the shifter?

I don’t really understand why OEM spec on mixed builds is SLX shifter and XT derailleur, as if I were building my bike I’d want it the other way around for the precise cable pulling capability and quick feel of the shifter. Am I wrong on that?

You're not wrong - that's exactly my preference on shifter and derailleur. But people look at the derailleur in the bike shop and that's what sells, I guess.

[Shaaarrrp]

To followup on the broken crank arm....should I be worried enough about this frame damage that I stop riding it or think simplying buying a new arm isn't the best move? Fwiw, the gash by the crank had been there since I bought it 3-4 years ago (open box buy). Hard to tell if the stuff I circled is merely a scratch in the paint/standard wear or something worth worrying about.

It does feel solid and it's possible I am overreacting to a completely unrelated failure. I wouldn't necessarily think too much about my bike falling apart under me until the arm broke but now I'm a bit worried. Every image is of the side in question except for the last. Thanks for any advice/knowledge.



I guess maybe that gash is designed into the frame? Sorry for my complete lack of technical knowledge!

[bagtagley]

Folks that are unhappy with their garbage SRAM drivetrains, please PM me before disposal. I'm happy to take them off your hands. Seriously.

[Dantheman]

But people look at the derailleur in the bike shop and that's what sells, I guess.

Yep.

[SchralphMacchio]

I have been thinking of getting a smaller oval chainring lately. Am I just out of shape? I am currently running a 32t on a 10-50 sram setup. I was thinking of going down to a 30t or 28t. I feel like the hills near me are fucking brutal. Any advice?

Get a pulse oximeter and a COVID test? Or don’t ride in smoke if PM2.5 is above 100?

You could also have mild asthma ... I didn’t get my asthma diagnosis until I was 30, and my pneumatic function test was pretty awful, just laughed and told my doc I’d felt that my entire life and always worked around it/managed it. But yeah having an inhaler in the skin track was much more preferable to going into AMS territory ...

That said, I haven’t done the math, but on an equal length crank I’d guess that the leverage ratio of a 24t bailout ring on a 36t cassette sprocket driving a 26” wheel is probably about the same as a 28t - 50t on a 29” wheel ...

[Whiteroom_Guardian]

Yeah SLX der with XT shifter. Was great.


I checked the chain length on current setup. Using little graphic from 59 second mark of this video.



I mean it shifts decent if riding pretty slow and upshifting, but I don't really do that. I kind of ride everything downhill like it's a race aka hammering on the pedals hard and upshifting.

[El Chupacabra]

To followup on the broken crank arm....should I be worried enough about this frame damage that I stop riding it or think simplying buying a new arm isn't the best move? Fwiw, the gash by the crank had been there since I bought it it 3-4 years ago (open box buy). Hard to tell if the stuff I circled is merely a scratch in the paint/standard wear or something worth worrying about.

Hard to tell from the photos, but the line in the little red circle could be a crack. If you remove the rear wheel and gently squeeze the dropouts together (flexing the stays together - but just a little) - does that line open up and reveal a crack?

Also, your big chainring is pretty much worn out.