# Adding a 11-42 to my gravel bike



## Frankuota

Good day to you all. I just bought an inexpensive gravel bike with the purpose of riding on pavement as well as fire roads, grass and whatever I find on my way, and also do some light bike touring, bike packing.
The bike has good specs and a 42 mm tire clearance even though it does come with 28 mm slicks which will be replaced soon.
Where I have to make a mayor modification to suit my skills and power is in the drive train. I talked to a mechanic at the LBS and he said he could change the cassette to a sunrase 11-42 and a wolf tooth adapter, which would be more than sufficient for the climbing I need to do in the local mountain fire roads.

This is the bike BUILD:

Frame-set 6061 Hydro-Form Aluminum Double-Guage
Wheels Aerus Quantum AL-24 700c x 28c Rim: 24mm
Tires Hutchinson Nitto 2
Shifters Shimano 105 5800, 11 Speed
Front Derailleur Shimano 105 5800, 11 Speed
Rear Derailleur Shimano 105 5800, 11 Speed
Crankset Shimano RS-500 46-36 (XS-SM: 170mm, MD-LG: 172.5mm, XL: 175mm)
Cassette Shimano 5800 11-28, 11 Speed
Brakes Hayes CX Comp
Chain KMC X11, 11 Speed
Seat-post Aerus SP-619
Handlebar Aerus DR-AL-199BT
Stem Aerus TDS-507B

This is project I would like to attempt on my own with my very limited mechanic skills, learn as you go project.
Given a 105 short cage 105 RD and an 11-28 11 speed cassette and a 46-36 crankset.
- Is this modification possible?
- Do I need to change the SS rd to a GS mid cage 105? could it be Ultegra?
- Do I need to replace the chain? to what?
- Do I need to stick to a sunrase cassette, or could I use a MTB cassette in combination with what I already have?

Thank you and I will appreciate all your imput.


----------



## cxwrench

Frankuota said:


> Good day to you all. I just bought an inexpensive gravel bike with the purpose of riding on pavement as well as fire roads, grass and whatever I find on my way, and also do some light bike touring, bike packing.
> The bike has good specs and a 42 mm tire clearance even though it does come with 38 mm slicks which will be replaced soon.
> Where I have to make a mayor modification to suit my skills and power is in the drive train. I talked to a mechanic at the LBS and he said he could change the cassette to a sunrase 11-42 and a wolf tooth adapter, which would be more than sufficient for the climbing I need to do in the local mountain fire roads.
> 
> This is the bike BUILD:
> 
> Frame-set 6061 Hydro-Form Aluminum Double-Guage
> Wheels Aerus Quantum AL-24 700c x 28c Rim: 24mm
> Tires Hutchinson Nitto 2
> Shifters Shimano 105 5800, 11 Speed
> Front Derailleur Shimano 105 5800, 11 Speed
> Rear Derailleur Shimano 105 5800, 11 Speed
> Crankset Shimano RS-500 46-36 (XS-SM: 170mm, MD-LG: 172.5mm, XL: 175mm)
> Cassette Shimano 5800 11-28, 11 Speed
> Brakes Hayes CX Comp
> Chain KMC X11, 11 Speed
> Seat-post Aerus SP-619
> Handlebar Aerus DR-AL-199BT
> Stem Aerus TDS-507B
> 
> This is project I would like to attempt on my own with my very limited mechanic skills, learn as you go project.
> Given a 105 short cage 105 RD and an 11-28 11 speed cassette and a 46-36 crankset.
> *- Is this modification possible?*
> - Do I need to change the SS rd to a GS mid cage 105? could it be Ultegra?
> - Do I need to replace the chain? to what?
> - Do I need to stick to a sunrase cassette, or could I use a MTB cassette in combination with what I already have?
> 
> Thank you and I will appreciate all your imput.


Short answer: Yes. But...

Why? No road derailleur no matter how long the cage (which isn't what allows a 'longer' cage derailleur to work w/ big cogs anyway) will work. No mtb derailleur will work w/ those road shifters, compatibility went out the window w/ 11 speed. The Wolf Tooth adapter _works_ but you will never have shifting performance as good as what you have now. It moves the upper derailleur pulley away from the small cogs to create clearance for the bigger cogs. I've installed one and seen a bunch...they work ok at best. With a GS cage road derailleur you'd be 5 teeth over the capacity. If you try to use a mtb derailleur it won't work because of cable pull ratio differences so you'd have to add one of those stupid pulley things to change the ratio...the Tan Pan? 
While it's possible to do this I certainly don't recommend it.


----------



## Frankuota

Thanks for your input.
What about adding a 11-32 cassette, and replacing one of the middle cogs with a bail out monster dinner plate 42 to be used only in extreme situations?


----------



## tlg

Frankuota said:


> Thanks for your input.
> What about adding a 11-32 cassette, and replacing one of the middle cogs with a bail out monster dinner plate 42 to be used only in extreme situations?


Huh? You want to go 11-12-13-14-16-18-20-*42*-25-28-32


----------



## Frankuota

Obviously not. 42 would take the last position.


----------



## tlg

Frankuota said:


> Obviously not. 42 would take the last position.


Not obvious... you said replace "one of the middle cogs", not the last one.
You can't simply replace the largest cog since it's part of the cluster. And even if you could, that would change absolutely nothing from the post from cxwrench. Still the same capacity.


----------



## Frankuota

tlg said:


> Not obvious... you said replace "one of the middle cogs", not the last one.
> You can't simply replace the largest cog since it's part of the cluster. And even if you could, that would change absolutely nothing from the post from cxwrench. Still the same capacity.


You actually can. remove the 16 or 18 and its spacer. Add the spacer to the end and the large ring after that. 
Are you up to just making fun of what I say or not? or do you have something positive to contribute to my needs?


----------



## jeff400650

Go to a 32 or 34 in back and smaller rings or a triple up front.


----------



## tlg

Frankuota said:


> Are you up to just making fun of what I say or not? or do you have something positive to contribute to my needs?


I am contributing. By pointing out what you're talking about is no different than using an 11-42 cassette. Still the same capacity.


----------



## Frankuota

tlg said:


> I am contributing. By pointing out what you're talking about is no different than using an 11-42 cassette. Still the same capacity.


Is capacity the limitations of the RD ?


----------



## Frankuota

jeff400650 said:


> Go to a 32 or 34 in back and smaller rings or a triple up front.


That was my first though. But this bike will also be used for group road rides, which sometimes I do on my hard tail triple 44-32-22 and 34 cog cassette but it is getting to hard to keep up given that it is a MTB with 2.2 knobby tires. 
Is a road triple comparable with a GS RD and 34 tooth Cassette?


----------



## tlg

Frankuota said:


> Is capacity the limitations of the RD ?


RD-5800-GS-L
Model Number RD-5800 
Series 105 
Cassette Compatibility 11 
Maximum Sprocket Low sprocket 32T/ Top sprocket 12T 
Minimum Sprocket Low sprocket 28T / Top sprocket 11T 
Maximum Front Difference 16T 
Total Capacity 37T


----------



## Lombard

Frankuota said:


> I talked to a mechanic at the LBS and he said he could change the cassette to a sunrase 11-42 and a wolf tooth adapter, which would be more than sufficient for the climbing I need to do in the local mountain fire roads.
> 
> This is project I would like to attempt on my own with my very limited mechanic skills, learn as you go project.
> Given a 105 short cage 105 RD and an 11-28 11 speed cassette and a 46-36 crankset.
> - Is this modification possible?


As CXWrench said, yes, but.......



Frankuota said:


> - Do I need to change the SS rd to a GS mid cage 105? could it be Ultegra?


Change to a GS. Rear derailleurs are cheap. Doesn't matter if it's 105 or Ultegra.



Frankuota said:


> - Do I need to replace the chain? to what?


Absolutely. But only because your current chain will be too short to wrap around the larger cogs.



Frankuota said:


> - Do I need to stick to a sunrase cassette, or could I use a MTB cassette in combination with what I already have?


It is advisable to have your chain and cassette be the same brand. It is not absolutely necessary, but they are designed to work together. Your shifting will be best that way.

Some more thoughts.

I think an 11-42T is way overkill and as CXWrench said, your shifting will work, but it will be clunky. I would try an 11-36T cassette adapter and a new GS rear derailleur with the Wolf Tooth. The 11-36T should be sufficient with the 46/36 crankset If you go with an 11-32T, you won't need to Wolf Tooth, but you will have less hill climbing improvement.

I'm also wondering if you could change the small chainring to a 34. That with the 11-32T cassette would work best.


----------



## tlg

Lombard said:


> I'm also wondering if you could change the small chainring to a 34. That with the 11-32T cassette would work best.


That's the best option. Nothing you shouldn't be able to climb in a 34x32


----------



## Frankuota

Lombard said:


> As CXWrench said, yes, but.......
> 
> 
> 
> Change to a GS. Rear derailleurs are cheap. Doesn't matter if it's 105 or Ultegra.
> 
> 
> 
> Absolutely. But only because your current chain will be too short to wrap around the larger cogs.
> 
> 
> 
> It is advisable to have your chain and cassette be the same brand. It is not absolutely necessary, but they are designed to work together. Your shifting will be best that way.
> 
> Some more thoughts.
> 
> I think an 11-42T is way overkill and as CXWrench said, your shifting will work, but it will be clunky. I would try an 11-36T cassette adapter and a new GS rear derailleur with the Wolf Tooth. The 11-36T should be sufficient with the 46/36 crankset If you go with an 11-32T, you won't need to Wolf Tooth, but you will have less hill climbing improvement.
> 
> I'm also wondering if you could change the small chainring to a 34. That with the 11-32T cassette would work best.


Thanks, I appreciate. Would a 105 triple 30-39-50 work with the GS RD and wolf tooth to a 36 tooth 11 speed cog?


----------



## Lombard

tlg said:


> That's the best option. Nothing you shouldn't be able to climb in a 34x32




Except those hills steep enough to spin your rear wheel on gravel or do an accidental wheelie. In either case, gearing would be irrelevant.


----------



## Blue CheeseHead

Frankuota said:


> You actually can. remove the 16 or 18 and its spacer. Add the spacer to the end and the large ring after that.
> Are you up to just making fun of what I say or not? or do you have something positive to contribute to my needs?


The reason the larger cogs are clustered is to distribute the load on the freehub body. Good luck finding a 42T cog that fits a freehub as a single unit. (by the way, it still will not work for all the reasons others have stated)


----------



## Frankuota

You don't know me ! Ha ha ha. I am not very strong, plus my hills are up to 16 -20% dirt mixed with gravel.


----------



## Blue CheeseHead

Frankuota said:


> You don't know me ! Ha ha ha. I am not very strong, plus my hills are up to 16 -20% dirt mixed with gravel.


Traction will be your issue.


----------



## Lombard

Frankuota said:


> Thanks, I appreciate. Would a 105 triple 30-39-50 work with the GS RD and wolf tooth to a 36 tooth 11 speed cog?



Yes, probably. Would it work well? Probably not. And also keep in mind if you change to a triple front, you will need to change your front shifter too. This would get expensive.



Frankuota said:


> You don't know me ! Ha ha ha. I am not very strong, plus my hills are up to 16 -20% dirt mixed with gravel.


If your hills are indeed 15% or more and on gravel/dirt, unless you have a knobby mountain bike tire on the rear, you won't be staying on the bike regardless of your gearing or strength.


----------



## Frankuota

You are right. I thought about a tubless setup, low pressure, knobby tires. The % i mentioned are ocational here and there. Mostly 6 %


----------



## Frankuota

Lombard said:


> Yes, probably. Would it work well? Probably not. And also keep in mind if you change to a triple front, you will need to change your front shifter too. This would get expensive.
> 
> 
> 
> If your hills are indeed 15% or more and on gravel/dirt, unless you have a knobby mountain bike tire on the rear, you won't be staying on the bike regardless of your gearing or strength.


Totally right about the triple added cost ( x-out choice)

I was planning on installing CX knobby tubeless tires.

Would a MTB xt rd and 11-40 or 42 cassette work with the 11 speed 5800 shifters?

Shimano XT RD-M8000 11SP Rear Derailleur > Components > Drivetrain > Mountain Rear Derailleurs | Jenson USA
Shimano XT CS-M8000 11 Speed Cassette > Components > Drivetrain > Cassettes | Jenson USA


----------



## cxwrench

'Knobby tubeless CX tires' don't fit in road brakes.


----------



## jason124

Frankuota said:


> Totally right about the triple added cost ( x-out choice)
> 
> I was planning on installing CX knobby tubeless tires.
> 
> *Would a MTB xt rd and 11-40 or 42 cassette work with the 11 speed 5800 shifters?*
> 
> Shimano XT RD-M8000 11SP Rear Derailleur > Components > Drivetrain > Mountain Rear Derailleurs | Jenson USA
> Shimano XT CS-M8000 11 Speed Cassette > Components > Drivetrain > Cassettes | Jenson USA





cxwrench said:


> No mtb derailleur will work w/ those road shifters, compatibility went out the window w/ 11 speed.


If you had a 9 or 10 speed drivetrain, you can certainly do this. For example, I currently have a XT 11-34 cassette and RD on my bike using my Ultegra shifter. In the front, I have a 38/50 crankset. If you revert the shifter to a 10 speed, then it will open up the possibility of a MTB cassette + RD, but it will be costly.

As others have mentioned, I think your best bet would be a 11-32 in the rear and a compact 34/50 in the front. As you ride, you will get stronger. I used to want a compact in the front so that I had a 34:34 for climbing, but then realizing I can tackle a 13% grade with my current setup, I stopped worrying about it.


----------



## rcb78

Actually you CAN shift an 11sp shimano Mtn rear derailleur with an 11sp road rear shifter. Like CX said the Wolf tooth Road Link isn't ideal because it just moves the derailleur down. What you want is the Wolf Tooth/Lindarets TanPan adapter that changes pull ratio of to make the two play nice. I've got one, I have put nearly 1k miles on it now, and it works and shifts perfectly.
That said it is NOT ideal, it was done for a specific event, and now that it's over I'm going back to 11-28 and 11-32 on my two wheelsets (road and trail).

Tanpan ? Lindarets

Tanpan ? wolftoothcomponents.com

I promise you that set up correctly it shifts like a dream. It's also not for everyone and has it's drawbacks.


----------



## Lombard

Lombard said:


> I'm also wondering if you could change the small chainring to a 34.


Looking into this a little further, it doesn't appear that a smaller chainring is made for this particular crankset. Too bad, as if you could change only the small chainring, that would be inexpensive.



cxwrench said:


> 'Knobby tubeless CX tires' don't fit in road brakes.


I believe he said he has a gravel bike with 42mm tire clearance. Am I missing something?


----------



## cxwrench

Lombard said:


> Looking into this a little further, it doesn't appear that a smaller chainring is made for this particular crankset. Too bad, as if you could change only the small chainring, that would be inexpensive.
> 
> 
> I believe he said he has a gravel bike with 42mm tire clearance. Am I missing something?


I missed the part about it being a disc brake bike, my bad.


----------



## Frankuota

It is a disc brake bike as you see in the bike specs Orig. Post.


----------



## Frankuota

I appreciate all your help guys. I Still haven made a decision, but I will let yu know what I did and how it went.


----------

