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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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Bonesbrigade wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


I haven't had a chance to try my compass 650bx48mm yet - Jan Heine actually still has our club's demo wheels. He's supposed to be sending them back soon!

One issue with using an etap FD and wide tires is that the battery doesn't clear (it sits inboard a bit)! So...I've had someone design me a battery harness where the battery is mounted elsewhere - it works well in my limited testing so far. Hopefully SRAM redesigns their etap FD to accommodate really wide tires.

Do you have an estimate on max tire width that works with the eTap FD? Was this only for the 650b wheels? I'm working on a gravel bike build now and was planning on using eTap. The plan was Compass 700c x 35 or 38.

Thanks!
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Re: Tire Width (I don't get it) [SummitAK] [ In reply to ]
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SummitAK wrote:
Bonesbrigade wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


I haven't had a chance to try my compass 650bx48mm yet - Jan Heine actually still has our club's demo wheels. He's supposed to be sending them back soon!

One issue with using an etap FD and wide tires is that the battery doesn't clear (it sits inboard a bit)! So...I've had someone design me a battery harness where the battery is mounted elsewhere - it works well in my limited testing so far. Hopefully SRAM redesigns their etap FD to accommodate really wide tires.


Do you have an estimate on max tire width that works with the eTap FD? Was this only for the 650b wheels? I'm working on a gravel bike build now and was planning on using eTap. The plan was Compass 700c x 35 or 38.

Thanks!

My compass 700x35 and 700x38 both fit - My Schwalbe G-ones did not fit (41mm). My chainstays are 415mm, so that is a factor.

650bx42 should fit, but I haven't tried it.

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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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Great info! Thank you!
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Re: Tire Width (I don't get it) [SummitAK] [ In reply to ]
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SummitAK wrote:
Great info! Thank you!

Here is my hacked etap battery clearance solution if anyone is interested:





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Re: Tire Width (I don't get it) [DarkSpeedWorks] [ In reply to ]
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DarkSpeedWorks wrote:
Hi Josh,
Any idea of what some of the fastest (lowest measured rolling resistance) 25mm (as printed on sidewall, not necessarily actual measured size) tires are? Say, the top 3 to 5 tires?

Of the ones I've rolled, the top 5 are:
1. Continental GP TT (states 23, but measures 24.6mm on a narrow rim)
1. Specialized Turbo Cotton (pick either 24 or 26)
2. Continental Force (states is a 24, but actually measures 25mm on a narrow rim)
3. Zipp Tangente Speed 25C
4. Continental GP4KS2 25C

As you can see, even with this list, asking for "printed on sidewall" sizes isn't very helpful...

http://bikeblather.blogspot.com/
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Re: Tire Width (I don't get it) [joshatsilca] [ In reply to ]
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And really, in the sense of a wheel being "fast" in regards to the "rule of 105", you're really talking about at higher yaw angles, right?

http://bikeblather.blogspot.com/
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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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Bonesbrigade wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


I haven't had a chance to try my compass 650bx48mm yet - Jan Heine actually still has our club's demo wheels. He's supposed to be sending them back soon!

One issue with using an etap FD and wide tires is that the battery doesn't clear (it sits inboard a bit)! So...I've had someone design me a battery harness where the battery is mounted elsewhere - it works well in my limited testing so far. Hopefully SRAM redesigns their etap FD to accommodate really wide tires.

How much do you want to bet that they tell you to just ditch the front derailleur? ;-)

http://bikeblather.blogspot.com/
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Slowman wrote:
nice! 650b x 50! that's a bad boy.


Don't need to go custom or super-expensive to get that...my Fuji Jari can accommodate 650Bx2.0" (~51mm)

http://www.fujibikes.com/usa/bikes/road/adventure-and-touring/jari





http://bikeblather.blogspot.com/
Last edited by: Tom A.: Jun 29, 17 14:37
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Re: Tire Width (I don't get it) [Tom A.] [ In reply to ]
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Tom A. wrote:
Bonesbrigade wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


I haven't had a chance to try my compass 650bx48mm yet - Jan Heine actually still has our club's demo wheels. He's supposed to be sending them back soon!

One issue with using an etap FD and wide tires is that the battery doesn't clear (it sits inboard a bit)! So...I've had someone design me a battery harness where the battery is mounted elsewhere - it works well in my limited testing so far. Hopefully SRAM redesigns their etap FD to accommodate really wide tires.

How much do you want to bet that they tell you to just ditch the front derailleur? ;-)

Ha, true. The shifting on the etap FD is awesome. The Yaw FD on my road is also great. People dog on SRAM for poor FD shifting, but I don't see that.

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Re: Tire Width (I don't get it) [Tom A.] [ In reply to ]
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Tom A. wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


Don't need to go custom or super-expensive to get that...my Fuji Jari can accommodate 650Bx2.0" (~51mm)

http://www.fujibikes.com/usa/bikes/road/adventure-and-touring/jari




This was first attempt a few years ago using 650b racing Ralph's. I had Walt make me a custom fork for the conversion



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Re: Tire Width (I don't get it) [Bonesbrigade] [ In reply to ]
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Bonesbrigade wrote:
Tom A. wrote:
Slowman wrote:
nice! 650b x 50! that's a bad boy.


Don't need to go custom or super-expensive to get that...my Fuji Jari can accommodate 650Bx2.0" (~51mm)

http://www.fujibikes.com/usa/bikes/road/adventure-and-touring/jari





This was first attempt a few years ago using 650b racing Ralph's. I had Walt make me a custom fork for the conversion


Yeah, forks like the 3T Luteus and the Fuji FC440 are real "godsends" for these types of rigs...

http://bikeblather.blogspot.com/
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Re: Tire Width (I don't get it) [Tom A.] [ In reply to ]
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Tom A. wrote:
DarkSpeedWorks wrote:
Hi Josh,
Any idea of what some of the fastest (lowest measured rolling resistance) 25mm (as printed on sidewall, not necessarily actual measured size) tires are? Say, the top 3 to 5 tires?


Of the ones I've rolled, the top 5 are:
1. Continental GP TT (states 23, but measures 24.6mm on a narrow rim)
1. Specialized Turbo Cotton (pick either 24 or 26)
2. Continental Force (states is a 24, but actually measures 25mm on a narrow rim)
3. Zipp Tangente Speed 25C
4. Continental GP4KS2 25C

As you can see, even with this list, asking for "printed on sidewall" sizes isn't very helpful...

I would add to Tom's list:
1. Vittoria CorsaSpeed TLR 23 (measures 24.6mm on 17c rim and is fastest tire we've ever tested..)
2. Michelin Power Competition 23mm which also measures 25mm on 17c Rim.

Also Tom asked:
Quote:
And really, in the sense of a wheel being "fast" in regards to the "rule of 105", you're really talking about at higher yaw angles, right?
And I'd say that this gets really dependent on rim design. For a really well designed rim, the Rule of 105 is mostly about the stall angle..which will be out at the higher yaw angles..but for many non-excellent rim shapes, the Rule of 105 can be the difference between air separating at 2 degrees yaw or 10 degrees yaw. The rule was actually formulated in 2001-2002 when we were doing a bunch of general-science type of tunnel work to figure out the next generation of aero and is what put us on the path to bringing Full Toroidal rims to market. Good example of the genesis of the rule would be my Original Campagnolo Shamals with silver aluminum rims circa 1994. With an 18 mm tire they behave almost like a modern aero rim as we see the drag drop with increasing yaw out to about 5-6 degrees yaw, but with a 21mm tire, the drag climbs from zero.. so you are talking 2-5 watts difference out 2.5 and 10 degrees. The tire narrower than rim isn't making the simple V shape work like a modern rim, but it is at least giving you decent flow over the windward rim faces and helping close up the void off the trailing edge of the tire that much faster.

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
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Re: Tire Width (I don't get it) [Slowman] [ In reply to ]
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Dan, your questions is a good one and it is the root of a big research project we are currently doing. We are in the process of collecting thousands of measurements in an attempt to optimize the entire wheel tire system.

All that said, the reason most people choose 23mm tires and the reason we still primarily recommend them (even though we've proven 25s are faster on our wheels) is because the frame industry has not caught up with the current wheel technology. Wider tires/wheels simply do not fit on a lot of the bikes.


Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling
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Re: Tire Width (I don't get it) [Canadian] [ In reply to ]
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Canadian wrote:
the reason most people choose 23mm tires and the reason we still primarily recommend them (even though we've proven 25s are faster on our wheels) is because the frame industry has not caught up with the current wheel technology. Wider tires/wheels simply do not fit on a lot of the bikes.

go look at the current thread on kiley's test. and the comments about disc brakes. what i said 2 years ago, and before, and since then, is that one real value of disc brakes is the ability to make a wheel, and a frame, that do not contemplate the needs of rim braking.

it's becoming evident now how to make the fastest tri bike. it's clear what will be the fastest tri bike. what's not clear is who is going to finally make the fastest tri bike (wheels and tires inclusive).

everybody likes to rag on the old man! but i've got a bit of a track record when it comes to stuff like this ;-)

Dan Empfield
aka Slowman
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