Mechanics Quick Question Thread [Ask Questions Here]

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Mechanics Quick Question Thread [Ask Questions Here]
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Posted: Aug 14, 2022 at 19:35 Quote
I wonder if anyone uses the Seal Doctor for cleaning fork seals.

Risk Racing 00-123 Small 35mm - 45mm Seal Doctor, Small (35 millimeters - 45 millimeters)

https://www.amazon.co.uk/dp/B006ZTTY6Q?ref_=pe_780071_41837251_dpLink

Posted: Aug 15, 2022 at 1:00 Quote
char-s wrote:
Doe's any one know if there is any consequences other than more friction from running a standard lower shock bushing rather than a bearing on a 2022 bronson?

None whatsoever. Other than easier shock services, lol

Posted: Aug 15, 2022 at 11:45 Quote
TravellerSeko wrote:
I wonder if anyone uses the Seal Doctor for cleaning fork seals.

Risk Racing 00-123 Small 35mm - 45mm Seal Doctor, Small (35 millimeters - 45 millimeters)

https://www.amazon.co.uk/dp/B006ZTTY6Q?ref_=pe_780071_41837251_dpLink

Seems like a half measure IMO. Just drop the legs and clean the seals and foam rings. Marginally more effort for a proper cleaning.

Posted: Aug 16, 2022 at 12:00 Quote
Looking for some advice on a Rockshox Monach Debonair RC3 fitted to a Canyon Strive.

Symptoms: During compression there is a sudden change in compression stiffness.
As the shock is compressed (even really slowly), the spring stiffness suddenly increases.

This is evident with the shock fully depressurised almost like the sudden change is more to do with the damping system rather than the air spring. I'm thinking that maybe a seal or port has a problem.

We've done a 100 hour service on the main shock and still exhibits the same problem, The only parts we haven't touched are the bound and rebound adjustment systems.

Any suggestions welcomed,
cheers,
Dave

Posted: Aug 16, 2022 at 12:43 Quote
davetvr wrote:
Looking for some advice on a Rockshox Monach Debonair RC3 fitted to a Canyon Strive.

Symptoms: During compression there is a sudden change in compression stiffness.
As the shock is compressed (even really slowly), the spring stiffness suddenly increases.

This is evident with the shock fully depressurised almost like the sudden change is more to do with the damping system rather than the air spring. I'm thinking that maybe a seal or port has a problem.

We've done a 100 hour service on the main shock and still exhibits the same problem, The only parts we haven't touched are the bound and rebound adjustment systems.

Any suggestions welcomed,
cheers,
Dave

Does this happen with the air can removed?

Posted: Aug 16, 2022 at 13:02 Quote
davetvr wrote:
Looking for some advice on a Rockshox Monach Debonair RC3 fitted to a Canyon Strive.

Symptoms: During compression there is a sudden change in compression stiffness.
As the shock is compressed (even really slowly), the spring stiffness suddenly increases.

This is evident with the shock fully depressurised almost like the sudden change is more to do with the damping system rather than the air spring. I'm thinking that maybe a seal or port has a problem.

We've done a 100 hour service on the main shock and still exhibits the same problem, The only parts we haven't touched are the bound and rebound adjustment systems.

Any suggestions welcomed,
cheers,
Dave

Possibilities:

If the shock has recently leaked a load of oil (either out through the rebound adjuster assembly, or into the inside of the air can), then the IFP will have moved up the damper body to compensate. If this happens, the main piston will crash into the IFP somewhere in the stroke, and you will feel a very sudden increase in springrate. This will also likely (depending on the exact layout of the internals, which RS in their wisdom make various wild changes to every now and then) be doing pretty catastrophic damage to the rebound shim stack.

If the nitrogen has leaked from behind the IFP into the damper fluid, this will cause really inconstant damping. At first you will get the symptoms you are describing, with a sudden and significant change to the damping force as the piston hits the surface of the damping fluid. After a few bounces the damper fluid will become aerated and damping will get a bit more consistent, (although way too underdamped) until you leave the shock for long enough that all the air settles out of the fluid again after a few minutes and the symptoms return. If this is your issue, any movement of the suspension will make a horrendous sucking/squelching noise.

Finally, if your particular monarch has a "dish valve" type lockout assembly, it is possible the valving has worked free from the top of the piston, and is randomly activating/deactivating itself at various points in the stroke, whenever the valve plate happens to float close enough to a port to block it temporarily.

It could also be other things, Monarchs are pretty mental on the inside. I'm not sure what drugs Rockshox engineers were on when they designed the monarch platform, but they must have been strong ones... A full service/rebuild on the damper may fix the issue. However, Rockshox being rockshox, it's not unlikely that the £5 part required to fix the thing either isn't something they want to sell, or they will sell you it but you have to wait for 2024 for them to actually get round to manufacturing it.

If you have the cash, I'd strongly suggest upgrading the shock to something more robust. Fox CTD's are incredibly reliable little shocks if you are on a budget. If you aren't on a budget then the world is your oyster. If you aren't inclined to do that, send the monarch off to a good service center, who will be able to have a look inside the damper before advising you further.

Posted: Aug 17, 2022 at 14:46 Quote
Trying to determine which 11 speed GX derailleur to use...
Drivetrain is 1X and has a 46 tooth chainring with a 11-34 cassette.

The 1x11 GX long cage has a chain wrap capacity of 32t.

The 2x11 GX long cage has a chain wrap capacity of 46t.

Please settle a debate.

Much appreciated.

Posted: Aug 17, 2022 at 14:51 Quote
If single chainring (46, really??) of any size, the 1x11 is perfectly fine

The size of the 1x chainring doesn't matter

Posted: Aug 17, 2022 at 14:57 Quote
TibZ wrote:
If single chainring (46, really??) of any size, the 1x11 is perfectly fine

The size of the 1x chainring doesn't matter


This is for a city bike conversion, thus the large 46 tooth chainring.

I was thinking the 2x derailleur would be better because of the larger capacity.

Now I'm confused.

Posted: Aug 17, 2022 at 14:59 Quote
Client9 wrote:
Trying to determine which 11 speed GX derailleur to use...
Drivetrain is 1X and has a 46 tooth chainring with a 11-34 cassette.

The 1x11 GX long cage has a chain wrap capacity of 32t.

The 2x11 GX long cage has a chain wrap capacity of 46t.

Please settle a debate.

Much appreciated.

Either one will work but the 1x should work better with the narrow range cassette because it relies mostly on upper pulley offset to keep the upper pulley the correct distance from the cog which means the distance adjusts directly based on the cog size, whereas the 2x version relies more on parallelogram tilt which means it has a preferred cassette range for the best shifting. For an 11-34 you could use either because they were both intended for 42T large cogs and the 34 just isn't too different, but if you were going to use a super narrow 11-23 road cassette then the 1x derailleur would probably be a requirement.

Posted: Aug 17, 2022 at 15:01 Quote
melanthius ,

Great explanation. I will pass along the data. Thank you!

Posted: Aug 17, 2022 at 15:01 Quote
Client9 wrote:
TibZ wrote:
If single chainring (46, really??) of any size, the 1x11 is perfectly fine

The size of the 1x chainring doesn't matter


This is for a city bike conversion, thus the large 46 tooth chainring.

I was thinking the 2x derailleur would be better because of the larger capacity.

Now I'm confused.
Listen to TibZ.
The rear derailleur size is limited or related to the largest cog of the cassette, not the chainring. So when you see a rear derailleur vs tooth dimension you're considering the rear wheel - not the chainring.

Posted: Aug 17, 2022 at 15:02 Quote
Client9 wrote:
TibZ wrote:
If single chainring (46, really??) of any size, the 1x11 is perfectly fine

The size of the 1x chainring doesn't matter


This is for a city bike conversion, thus the large 46 tooth chainring.

I was thinking the 2x derailleur would be better because of the larger capacity.

Now I'm confused.

The chain wrap capacity measures the chain takeup between the small-small and large-large gear combinations. In a 1x setup the front small and large are the same ring, so you only need as much takeup capacity as the spread in the cassette. In this case 34 - 11 = 23 teeth. Either of those derailleurs is completely overkill in that aspect.

Posted: Aug 17, 2022 at 15:09 Quote
melanthius wrote:
Client9 wrote:
TibZ wrote:
If single chainring (46, really??) of any size, the 1x11 is perfectly fine

The size of the 1x chainring doesn't matter


This is for a city bike conversion, thus the large 46 tooth chainring.

I was thinking the 2x derailleur would be better because of the larger capacity.

Now I'm confused.

The chain wrap capacity measures the chain takeup between the small-small and large-large gear combinations. In a 1x setup the front small and large are the same ring, so you only need as much takeup capacity as the spread in the cassette. In this case 34 - 11 = 23 teeth. Either of those derailleurs is completely overkill in that aspect.

Okay got it. I was overthinking it. Thank you.


 
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