Advice needed on single speed gravel bike setup

Hi All,

Turning my SS Karate Monkey into a SS gravel/road bike (mostly road).

I have 30mm rims so I believe 42mm tires are the smallest I can go. I am getting some conti contact speed tires. Anyone else have experience riding this sort of tire? Sluggish? Ok?

Also I'm thinking about hearing, I currently run 30x16 off road. What road gear would you choose? 36 is the biggest chain ring I can find for cinch. I figure I'll start 36x16 but will probably want something smaller in the back. Thoughts on what you would run?

Lastly, bottle cages. Any thoughts on what cages you think look good on an old fashioned steel bike? I hate plastic cages on a steel bike.

Thanks for your insights.

Posted by: RAHrider

Hi All,

Turning my SS Karate Monkey into a SS gravel/road bike (mostly road).

I have 30mm rims so I believe 42mm tires are the smallest I can go. I am getting some conti contact speed tires. Anyone else have experience riding this sort of tire? Sluggish? Ok?

Also I'm thinking about hearing, I currently run 30x16 off road. What road gear would you choose? 36 is the biggest chain ring I can find for cinch. I figure I'll start 36x16 but will probably want something smaller in the back. Thoughts on what you would run?

Lastly, bottle cages. Any thoughts on what cages you think look good on an old fashioned steel bike? I hate plastic cages on a steel bike.

Thanks for your insights.

I run a fixed gear on gravel, with a 700x25c tyre in the rear. Gearing is 50x17. My buddy runs 36x15 or 36x16 on a 26x2.15 tyre. Both gears work nicely for our terrain on gravel*. The latter leaves some possibilities for singletrack diversions open as well, my 26er singlespeed runs 34x16, which is a bit too low for road and flat gravel sections, but way nicer offroad.

* = medium sized and smaller gravel for the most part, think 100km distance and 1400m of elevation as a frame of reference.

Obviously, your terrain and personal preferences will be different from mine, but your starting point with a 36 sounds reasonable.

As for cages, I mostly run either cheapo alloy cages with that classic wireframe design, or these modern springloaded ones (but that's probably what you meant by "plastic cages", as few are made of metal).

That tyre you mention should roll pretty fast, if my experience with a 30mm Ritchey Alpine JB is anything to go by.

My OG Surly Krampus is my SS gravel bike. I run a 34 x 20T gear with 29 x 3.0" tires. That feels pretty good as an all around gear ratio. I can crush roadie dreams on the climbs and still pedal fast enough on the flats to get places. I'm coasting on any reasonable downhills. I'm not sure what my max RPM is, but I can spin pretty darn fast when I need to hustle. I like not having to walk any climbs.

I have a Wolftooth Morse cage on my hardtail. Looks good and it's quite adjustable if you need/want to fine tune bottle placement. Bottle stays secure despite a lot of smashing on rough terrain.

I was running 40mm Mavic Ksyrion XL tires that came with my wheelset. They've been pretty good considering they're an inverted tread with almost no side knobs. My bike is more like a road bike that can do a little extra rather than a full-on gravel bike.

I ran it SS initially with 40x17 and it was good on the roads and gravel south of the bridges but I ran out of steam easily on the Shore.

Thanks for the feedback. Not sure about TWK running 50x17, that's ridiculous! Unless he lives in the prairies and only rides with a tailwind.

Ordered the parts I need today. I'll start with the 36x16 and drop the cog as needed. I'm pretty stoked to have a simple bike I can do an after work workout all year round no matter the weather.

Don't have the bottle cages picked out yet. I reckon the mighty riders or bicicletta might have some good options. I'll see what I can find.

Thanks again

King Ti cages or Lezyne alloy

Posted by: RAHrider

Thanks for the feedback. Not sure about TWK running 50x17, that's ridiculous! Unless he lives in the prairies and only rides with a tailwind.

There's multiple key components to that: being a featherweight with a t-rex like build, and being enough of a masochist to ride an old track bike on gravel (and light singletrack when necessary). Finally, my local riding is more of an up-down-up-down kind of deal, but 20% grade on a road has been barely climbable, and 16% has been the steepest I got up on gravel, the climb being upwards of 120m of elevation gain. My calculations put your gear at 4.96m of development, mine at 6.21m. With a lighter bike, and less rolling resistance, the gear becomes less ridiculous than one might think :). Still, when faced with the choice, I take that bike on flatter terrain than anything else I ride.

I also can't conjure up winds, even tho I'd like that...

Posted by: Endur-Bro

King Ti cages or Lezyne alloy

I'm a fan of King stainless. Little less spendy than Ti and all the same function.

I'm in awe of your 50x17. That would be a grind up many of the hills in my area. I thought it must have been a typo. Good on you.

King cage stainless steel ended up being my choice. Their ti cages have been amazing for me and I like the simple styling.

Posted by: RAHrider

I'm in awe of your 50x17. That would be a grind up many of the hills in my area. I thought it must have been a typo. Good on you.

King cage stainless steel ended up being my choice. Their ti cages have been amazing for me and I like the simple styling.

Agree, that's nuts. I rode 46/16 as an all round FG ratio. OP, on my gravel bike I'm at 40 up front and most often find that i'm around 15 or 17 for general use - down towards the 11/13 when I'm hustling though. I live out towards PoCo so rides are flattish gravel.

(40x28)/15 = 74.66

(40x28)/17 = 65.88

(36x28)/16 = 63 - unless you're into big climbs or rolling along slowly, IMO this is too low.

(36x28)/15 = 67.2 < more reasonable, but probably still too low for where I live as an only gear, I find I'm regularly bumping off the limits of 40x11. Yes, if I span at 110rpm i wouldn't be, but I don't.

Perhaps take your average speed and work backwards from there if you're still on the fence. What gearing and RPM will it take to be able to do your average speed comfortably.

Edit - i see you decided already. Good luck and have fun!

That's helpful. I got a gear setup that was readily available. I think I will have to order a bigger ring from wolftooth if i want cinch bigger than 36. I got a cheap ring for $40 that will be a good starting spot. I have an old shimano cassette that may have some smaller cogs I can try for different gear ratios as well. I suspect I may end up closer to your 40 tooth. I looked up what salsa specs with their single speed gravel bike - 38x17or18. Turns out my 36x16 is exactly half way between these.

Posted by: nouseforaname

Posted by: RAHrider

I'm in awe of your 50x17. That would be a grind up many of the hills in my area. I thought it must have been a typo. Good on you.

King cage stainless steel ended up being my choice. Their ti cages have been amazing for me and I like the simple styling.

Agree, that's nuts. I rode 46/16 as an all round FG ratio. OP, on my gravel bike I'm at 40 up front and most often find that i'm around 15 or 17 for general use - down towards the 11/13 when I'm hustling though. I live out towards PoCo so rides are flattish gravel.

(40x28)/15 = 74.66

(40x28)/17 = 65.88

(36x28)/16 = 63 - unless you're into big climbs or rolling along slowly, IMO this is too low.

(36x28)/15 = 67.2 < more reasonable, but probably still too low for where I live as an only gear, I find I'm regularly bumping off the limits of 40x11. Yes, if I span at 110rpm i wouldn't be, but I don't.

Perhaps take your average speed and work backwards from there if you're still on the fence. What gearing and RPM will it take to be able to do your average speed comfortably.

Edit - i see you decided already. Good luck and have fun!

I ride (38x26)/16 = 61.75 on my city commuter. Its definitely a bit too low for the flats, but I like it for the hills. Ive never attempted to ride it on a gravel ride, but id imagine it would be pretty good.  Unfortunately my frame wont allow for a bigger front ring and 16T is the smallest freewheel I can find. Id love to bump it up to a 40T or even 42T to help speed things along on level ground.

Posted by: nouseforaname

Perhaps take your average speed and work backwards from there if you're still on the fence. What gearing and RPM will it take to be able to do your average speed comfortably.

Edit - i see you decided already. Good luck and have fun!

I found a calculator that works backwards from speed. I regularly spin around 90 and 100 is not at all uncomfortable for me. I did an experiment on a big step climb and found my sweet spot was 90 and higher. If I drop my cadence and push a bigger gear it doesn't actually make me go faster. 

On a rolling road ride I usually average around 32-34km/h. Not sure what kind of average speed to expect with 42c tires, 26-30? A 36x16 at 90rpm puts me at 27km/h and at 100rpm 30km/h. I haven't done much gravel riding so I really don't know what to expect for speeds. The 36x16 might be an ok starting spot. I have a hope ss hub so I have a pretty big range of small cogs I can use. I think I can go as low as 13 tooth. Using the 36 chainring also keeps me in the land of cheap drivetrain parts. I can usually find chainrings for around 45$ rather than the 120 wolf wants for their 40t ring.

Anyone know if there is a downside to using single speed chains on 11 speed chainrings in terms of wear or other problems. The SS chains are wider but much stronger and will resist stretch better I believe.

Anyone know if there is a downside to using single speed chains on 11 speed chainrings in terms of wear or other problems. The SS chains are wider but much stronger and will resist stretch better I believe.

You might get a bit more noise because the chain has some lateral play on the chainring, but if it's a narrow-wide, I wouldn't worry. That said, a lot of 7/8 speed chains are cheap as dirt and plenty strong after years of optimization by the manufacturers, too.

I personally ran/run 10spd, 8spd, and dedicated singlespeed chains on 3/32" drivetrains with very similar results.