Como Tire - what options for a tire narrower than the stock tire?

rj cedar

New Member
Region
Canada
Como Tire - what options for a tire narrower than the stock tire?

Has anyone gone a narrower width 650B tire for the Como? What did you get? How do you like it? Is it quiet on pavement? Is it hard to remove?

The stock Como tires are the Nimbus II Sport Reflect, 60 TPI, 650b x 2.3" tire.
https://www.specialized.com/us/en/nimbus-2-sport-reflect/p/157608?color=236370-157608
In the 650b size, the Nimbus II Sport Reflect is not made in any other widths, only the 2.3” width.

I am looking for a not so wide tire, something around x 2.0 “with good flat protection, 70% use is on asphalt and 30% use is on good gravel trails.

One option seems to be the Specialized Pathfinder Pro. See this for description
https://www.specialized.com/us/en/p...870?color=237517-157870&searchText=00019-4411
Note the casing TPI with the Specialized Pathfinder Pro is twice that of the stock Como tire (120 vs 60). Pathfinder weight is 555g; Sport Reflect weight is not given.

Side by side comparison – info for sizes other than 650B was deleted.




NIMBUS 2 SPORT REFLECT

$40
The Nimbus 2 Sport Reflect tire features an updated tread and compound that rolls even faster and has more grip than ever before. It comes in many widths to accommodate different bikes, riding styles, and comfort levels, so it's the perfect choice for riding on any road or bike path. And with BlackBelt flat protection and reflective accents that increase your visibility to motorists in low-light conditions, you get an added dose of that good ol' peace of mind.

  • Casing: 60 TPI
  • Bead: Wire
  • Compound: 60a
  • Flat Protection: BlackBelt
  • 26 x 1.5", psi 35-65
  • 650b x 2.3", psi 25-50

PATHFINDER PRO 2BLISS READY

$50
Born in the American Midwest, gravel riding is one of the fastest–growing styles of cycling. The sense of adventure, conquering new challenges, and simply experiencing a new style of riding are some of its big selling points, but doing so without the proper tires makes the difference between having fun and cursing and hollering on the side of the road. The Pathfinder delivers the versatility that these adventure-laden rides deserve—fast rolling, lots of grip, and a whole lot of fun.
  • Casing: 120 TPI
  • Bead: Foldable
  • Butyl wrapped bead = 2Bliss Ready
  • Compound: GRIPTON®
  • Flat Protection: Endurant Casing and BlackBelt
  • 650b x 47mm [1.75"], psi 35-65, approximate weight 555g




Can you identify some good, narrower alternatives to the Como stock? Thank you.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
@rj cedar: I'm genuinely surprised with your need of going with a narrower tyre. Your voluminous tyres offer something extremely important in case of e-bike missing the suspension (that your Como is): the capability to absorb shock, and especially rapid vibration common in gravel riding. Many of us would be happy to use wider tyres in our, say, Vado or SL e-bikes but we are missing proper fork/fender clearances.

Why do you want to swap your tyres for anything else, in the first place?!

Are you also aware changing the tyre size will affect your speedometer and trip distance meter?
 

Deacon Blues

Well-Known Member
I have Pathfinder Pro 2Bliss (47mm on q 650b wheel) on my e-gravel bike and I'm very happy with their performance. I'd highly recommend this tire, but I have to agree with Stefan's comments-If you're not happy with the tires on your biked look for another brand/style of tire, but don't change your tire size.
 

rj cedar

New Member
Region
Canada
Thanks Stephan,

This is my wife's bike, looking for better flat protection. I agree with you re shock absorption importance. We are exploring alternatives, and pros and cons....... no decision made yet.

Re tire size difference, what is the difference in circumference between these 2? I thought the difference would be in width only, given each is 27.5/650 for the circumference measure. So wouldn't the difference be that the stock tire width is 2.3" and pathfinder tire width, at 47mm, would be 1.85" wide? Still would like a wider tire than 1.85, something around 2".

If there is a circumference difference, can the Mission Control App not be use to account for that?

They use different rubber in these 2 tires, stock tire uses Compound 60a and Pathfinder uses GRIPTON, I would like to find out more on the slip difference between these 2 on wet asphalt.

I did have a concern to be sure to stick to the same bead seat diameter (BSD) to avoid problems but manufacturers don't seem to give this important metric, and their use of NOMINAL measures instead of actual tire measurements adds to the confusion. This video
discusses BSD issues. How can one get the BSD on specific tires?

Thank you.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
@rj cedar: I'm distracted a little bit at the moment. Let me only tell you Gripton compound makes the tyre grip the pavement extremely well, also in sub 0 C temperature conditions.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
More answers.
How can one get the BSD on specific tires?
It is super-easy to understand. The ERTRO BSD of 584 (mm) means exactly 27.5" (inch system) or 650B (French system). These things have been completely standardized (that's why nobody discusses it!), and don't worry about it. There is, however, another matter (also discussed in the video), which is the rim width. If the rim is narrow, you cannot put too wide tyre on it. Or, if the rim is too wide, you cannot put too skinny tyre on it. In either way, the wrongly chosen tyre would deflect unfavourably. Small tyre width changes are acceptable. For instance, if you go from 2.3 down to 2.1", nothing wrong would happen. Go down to 1.75", and I would start wondering...

Now: Specialized love to make tyres in a little bit non-standard width (but the BSD of 584 mm remains, as it has to). Therefore your tyres are 2.3". More popular size is 2.25", which is virtually the same. I have gone to the
Tire Search of Schwalbe North America

The ERTRO size is 57-584 (27.5x2.25"). Several candidates:
  • Hurricane with Race Guard - a good all-rounder, great puncture protection, @Alaskan favourite
  • Marathon Plus MTB - easy rolling tyre with maximum puncture protection (Level 7) - I cannot promise that would be noiseless, though.
  • Smart Sam Plus - my favourite. A tyre that is silent on pavement and aggressive off-road. Great puncture protection.
My advice is: go for 57-584 (27.5x2.25") as all the benefits of the properly sized tyre will remain, and only the style and protection will change.

P.S. Look at the marking on the existing tyre sidewall. I can bet it will be 58-584 :)
 
Last edited:

Ebiker53

Member
Como Tire - what options for a tire narrower than the stock tire?

Has anyone gone a narrower width 650B tire for the Como? What did you get? How do you like it? Is it quiet on pavement? Is it hard to remove?

The stock Como tires are the Nimbus II Sport Reflect, 60 TPI, 650b x 2.3" tire.
https://www.specialized.com/us/en/nimbus-2-sport-reflect/p/157608?color=236370-157608
In the 650b size, the Nimbus II Sport Reflect is not made in any other widths, only the 2.3” width.

I am looking for a not so wide tire, something around x 2.0 “with good flat protection, 70% use is on asphalt and 30% use is on good gravel trails.

If you are simply looking for better flat protection, Specialized makes the Armadillo version of the stock Como tire for approximately $10 more. I've used these for over 1500 miles without and problems.
 

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Elkman

Active Member
Specialized puts the Pathfinder Pro 2Bliss Ready on their gravel EVO bikes and these 38mm wide tires have been successfully used in racing and customers reviews have been universally positive. The Pathfinder Pro provides less resistance when riding on pavement if that is important.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
Specialized puts the Pathfinder Pro 2Bliss Ready on their gravel EVO bikes and these 38mm wide tires have been successfully used in racing and customers reviews have been universally positive. The Pathfinder Pro provides less resistance when riding on pavement if that is important.
With the full power Como the rolling resistance is less important than the big tyre cushioning effect. 38 mm tyres are used in Specialized Vado SL ebikes for their light weight and low rolling resistance, as the SL bikes are intentionally underpowered.
 

Elkman

Active Member
Specialized put 24mm wide tires on its triathlon bikes and 30mm on its gravel bikes, so a 28mm wide tire on the Creo is on the wide side for a road bike. The Creo SL bikes do require a more fit rider but they are still very heavy at 28 to 30 lbs for road bikes, and 15 lbs heavier than a comparable carbon frame bike like their Tamrac.

Profiles and fill pressures vary widely and this has a big effect on rolling resistance. Specialized puts 28mm 110 PSI tires on its standard Creo SL and 38mm 80 PSI tires on its EVO version of the bike. The EVO tires will provide a softer ride and more traction but also have a lot more rolling resistance to overcome.
 

rj cedar

New Member
Region
Canada
Thanks for all your comments. Now I am trying to summarize measurements to use and a method to select a tire to match a rim. As you will see below, the method I have used below raises some questions. Compared below are the fit of 2 tires to the SPECIALIZED TURBO COMO stock rim. The tires are the Specialized NIMBUS 2 SPORT REFLECT, with comes stock with the Turbo Como bike, and a possible alternate tire, the SPECIALIZED PATHFINDER PRO tire.

Specialized Website Product Information on these 2 tires.


NIMBUS 2 SPORT REFLECT​

$40
The Nimbus 2 Sport Reflect tire features an updated tread and compound that rolls even faster and has more grip than ever before. It comes in many widths to accommodate different bikes, riding styles, and comfort levels, so it's the perfect choice for riding on any road or bike path. And with BlackBelt flat protection and reflective accents that increase your visibility to motorists in low-light conditions, you get an added dose of that good ol' peace of mind.

  • Casing: 60 TPI
  • Bead: Wire
  • Compound: 60a
  • Flat Protection: BlackBelt
  • 26 x 1.5", psi 35-65
  • 650b x 2.3", psi 25-50

PATHFINDER PRO 2BLISS READY​

$50
Born in the American Midwest, gravel riding is one of the fastest–growing styles of cycling. The sense of adventure, conquering new challenges, and simply experiencing a new style of riding are some of its big selling points, but doing so without the proper tires makes the difference between having fun and cursing and hollering on the side of the road. The Pathfinder delivers the versatility that these adventure-laden rides deserve—fast rolling, lots of grip, and a whole lot of fun.
  • Casing: 120 TPI
  • Bead: Foldable
  • Butyl wrapped bead = 2Bliss Ready
  • Compound: GRIPTON®
  • Flat Protection: Endurant Casing and BlackBelt
  • 650b x 47mm [1.75"], psi 35-65, approximate weight 555g
Source

https://www.specialized.com/us/en/n...608?color=236370-157608&searchText=00319-5132

https://www.specialized.com/us/en/p...870?color=237517-157870&searchText=00019-4411

FIT COMPARISSION

First, the rim:

  • Diameter. The stock turbo como rim is set up for a 27.5/650b diameter tire. The key number be concerned with is 584 mm, the bead seat diameter (BSD).
  • Inner rim width. SPECIALIZED does NOT give this specification, yet this metric is key to a fit assessment. This is discussed later. I measure the Turbo Como rim outer rim width as 30.65 mm so the inner rim width, will be less than that, I will GUESS 26mm as the inner rim width and use that number for this discussion.


Second, the tire, what measurements to use.

E.T.R.T.O. ( European Tyre and Rim Technical Organisation.) first developed a system that uses real, exact measurements. The system is now called the ISO (International Standards Organization) system. Use the ISO number, which, on a tire sidewall will look like this: 58 x 584. 58mm is the tires largest width, and 584 is the BSD. The ISO numbers on the sidewall for these 2 tires are:

  • Specialized NIMBUS 2 SPORT REFLECT: 58 x 584.
  • Specialized PATHFINDER PRO: 47 x 584.
Third, does the tire fit the rim?

  • For DIAMETER, tires both need to be 584mm BSD, they are. BSD is ok.
  • For INNER RIM WIDTH one has to use a GENERAL GUIDELINE, since the tire width at the bead is never given. https://sheldonbrown.com/tire-sizing.html says the general guideline is that the tire width should be between 1.45/2.0 x the inner rim width. Using an INNER RIM WIDTH OF 26mm and the 1.45 to 2.0 range for tire width acceptability, the acceptable width range is 1.45 x 25 = 37.7mm to 2X 26mm= 52mm. 38 – 52mm.
Applying the fit assessment result to these 2 tires:

  • Specialized NIMBUS 2 SPORT REFLECT: 58 x 584. At 58mm tire width, this tire width is over the width acceptability range of 38 to 52mm.
  • Specialized PATHFINDER PRO: 47 x 584. At 47mm tire width, this tire is within the width acceptability range of 38 to 52mm. The middle of the range is 38 + 7 = 45, this tire is only 2 mm off the middle of the acceptability range.
It seems wrong to conclude that the since the Nimbus 2 is the stock tire on the Turbo Como is not right for a technical fit. What am I missing using this approach? As I understand it, a rim to tire fit assessment is carried out to ensure there are no safety issues with the tire becoming unstable on the rim under various conditions, and the assessment has nothing to do with ride comfort.
 

kahn

Well-Known Member
Region
USA
City
northWET washington
I am actually missing the old days. I had a 700cc rim and just bought tires!
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
rjcedar, you seem to overthink it. After all the recommendations you got, you are back at the post #1 :)
 

Kless

New Member
Thanks for all your comments. Now I am trying to summarize measurements to use and a method to select a tire to match a rim. As you will see below, the method I have used below raises some questions. Compared below are the fit of 2 tires to the SPECIALIZED TURBO COMO stock rim. The tires are the Specialized NIMBUS 2 SPORT REFLECT, with comes stock with the Turbo Como bike, and a possible alternate tire, the SPECIALIZED PATHFINDER PRO tire.

Specialized Website Product Information on these 2 tires.


NIMBUS 2 SPORT REFLECT​

$40
The Nimbus 2 Sport Reflect tire features an updated tread and compound that rolls even faster and has more grip than ever before. It comes in many widths to accommodate different bikes, riding styles, and comfort levels, so it's the perfect choice for riding on any road or bike path. And with BlackBelt flat protection and reflective accents that increase your visibility to motorists in low-light conditions, you get an added dose of that good ol' peace of mind.

  • Casing: 60 TPI
  • Bead: Wire
  • Compound: 60a
  • Flat Protection: BlackBelt
  • 26 x 1.5", psi 35-65
  • 650b x 2.3", psi 25-50

PATHFINDER PRO 2BLISS READY​

$50
Born in the American Midwest, gravel riding is one of the fastest–growing styles of cycling. The sense of adventure, conquering new challenges, and simply experiencing a new style of riding are some of its big selling points, but doing so without the proper tires makes the difference between having fun and cursing and hollering on the side of the road. The Pathfinder delivers the versatility that these adventure-laden rides deserve—fast rolling, lots of grip, and a whole lot of fun.
  • Casing: 120 TPI
  • Bead: Foldable
  • Butyl wrapped bead = 2Bliss Ready
  • Compound: GRIPTON®
  • Flat Protection: Endurant Casing and BlackBelt
  • 650b x 47mm [1.75"], psi 35-65, approximate weight 555g
Source

https://www.specialized.com/us/en/n...608?color=236370-157608&searchText=00319-5132

https://www.specialized.com/us/en/p...870?color=237517-157870&searchText=00019-4411

FIT COMPARISSION

First, the rim:

  • Diameter. The stock turbo como rim is set up for a 27.5/650b diameter tire. The key number be concerned with is 584 mm, the bead seat diameter (BSD).
  • Inner rim width. SPECIALIZED does NOT give this specification, yet this metric is key to a fit assessment. This is discussed later. I measure the Turbo Como rim outer rim width as 30.65 mm so the inner rim width, will be less than that, I will GUESS 26mm as the inner rim width and use that number for this discussion.


Second, the tire, what measurements to use.

E.T.R.T.O. ( European Tyre and Rim Technical Organisation.) first developed a system that uses real, exact measurements. The system is now called the ISO (International Standards Organization) system. Use the ISO number, which, on a tire sidewall will look like this: 58 x 584. 58mm is the tires largest width, and 584 is the BSD. The ISO numbers on the sidewall for these 2 tires are:

  • Specialized NIMBUS 2 SPORT REFLECT: 58 x 584.
  • Specialized PATHFINDER PRO: 47 x 584.
Third, does the tire fit the rim?

  • For DIAMETER, tires both need to be 584mm BSD, they are. BSD is ok.
  • For INNER RIM WIDTH one has to use a GENERAL GUIDELINE, since the tire width at the bead is never given. https://sheldonbrown.com/tire-sizing.html says the general guideline is that the tire width should be between 1.45/2.0 x the inner rim width. Using an INNER RIM WIDTH OF 26mm and the 1.45 to 2.0 range for tire width acceptability, the acceptable width range is 1.45 x 25 = 37.7mm to 2X 26mm= 52mm. 38 – 52mm.
Applying the fit assessment result to these 2 tires:

  • Specialized NIMBUS 2 SPORT REFLECT: 58 x 584. At 58mm tire width, this tire width is over the width acceptability range of 38 to 52mm.
  • Specialized PATHFINDER PRO: 47 x 584. At 47mm tire width, this tire is within the width acceptability range of 38 to 52mm. The middle of the range is 38 + 7 = 45, this tire is only 2 mm off the middle of the acceptability range.
It seems wrong to conclude that the since the Nimbus 2 is the stock tire on the Turbo Como is not right for a technical fit. What am I missing using this approach? As I understand it, a rim to tire fit assessment is carried out to ensure there are no safety issues with the tire becoming unstable on the rim under various conditions, and the assessment has nothing to do with ride comfort.
Interesting write-up, however, the inner rim width on the Como (at least on mine) is 30mm (not 26mm). Applying the general guideline of 1.45 to 2.00 x width of 30mm, seems the 47mm (1.75") tire would still be in acceptable range, but much closer to the narrow end of acceptability.
 

rj cedar

New Member
Region
Canada
Interesting write-up, however, the inner rim width on the Como (at least on mine) is 30mm (not 26mm). Applying the general guideline of 1.45 to 2.00 x width of 30mm, seems the 47mm (1.75") tire would still be in acceptable range, but much closer to the narrow end of acceptability.
Thanks Stephen! Yes, I realized after posting that I had made a mistake …I had written the Como rim exterior width number down wrong, so my calculations were out. The measurements I have now are 35.1 mm for external rim width and, the important one, 30.2 mm for internal rim width. 30.2 corresponds with your 30 so that is a good check. I will use 30mm.

Applying the inner rim width of 30mm to the “total tire width” acceptability range of 1.45 to 2.0 x rim inner width (very general guideline source: https://sheldonbrown.com/tire-sizing.html ), the result is a tire that has a width ranging from 43.5 to 60mm is acceptable.

Comparison: At a width of 58mm, the Nimbus 2 sport reflect is 2mm from the top of acceptability range, while the Pathfinder pro is up 3.5mm from the bottom of the acceptability range. Both tires are acceptable but each is at different ends of the acceptability range.

I was worried about safety…the tire coming off. Subsequent technical information I have received is that this very general guideline is way out of date, there really is no standard, safety concerns come in at the extreme ends of the range, but people have been putting fat tires on skinny rims for a long time, and a more relevant consideration than safety is comfort and handling.

Going through this has helped me understand better tire measurements and suitability, but a few things stand out:

  • The consumer is left to navigate through confusing terms and outdated information.
  • Nimbus 2 sport reflect should be a very comfortable tire
  • I am not comfortable going to the Pathfinder Pro, now more for comfort reasons than safety.
Thanks for your perspectives.