Impact of wheelbase on the handling of kids' bikes

My 10 y.o. son has been transitioning from a Marin Hidden Canyon with 20" wheels to a 24" Specialized Hotrock which he is riding until the 24" Cleary bike is available in September. He mentioned that he had a tougher time climbing and cornering on the Hotrock than he did on the Marin. It seems to me that the Hotrock is a little slow to turn into corners. I remember when we got the Marin that it was a lot shorter than the singlespeed 20" Hotrock that he rode for a while. He didn't like that at first since the longer Hotrock felt more stable, but quickly like the shorter Marin better since it was faster & more intuitive feeling on singletrack.

 

I checked out the specs for several bikes and indeed the wheelbase on the 20" Hotrock is about 1.8 inches longer than that of a 20" Marin kids bike and almost 3" longer than that of a 20" Cleary bike.  Out of curiosity, I just did some research on kids' 20" & 24" bike geometry. Specialized does indeed have very long wheelbase frames. It seems like the "enthusiast" brands offer frames with especially short wheelbases which may handle better under kids with some trail riding experience.

Pacific Northwest Summer 2015 XC Tire Comparison Test: X-King, Rocket Ron, Ardent, Neo-moto, Hans Dampf & Nobby Nic REVIEWED

Pacific Northwest Summer 2015 XC Tire Comparison Test

July 19th, 2015

About Dirt Merchant BikeS: 

Dirt Merchant Bike conducts testing to help us determine which products will work best for our customers and their riding style. We are the exclusive Seattle/Tacoma area dealer for Turner Bikes and have the new Turner RFX available to reserve for demo at Duthie Hill Park in Issaquah, WA: http://www.dirtmerchantbikes.com/demos/

Testing Overview: 

Our Winter tire comparison test sessions conducted last November & January established the Schwalbe Hans Dampf and Schwalbe Nobby Nic (2015 version) as our front and rear tire benchmarks for Pacific Nwet winter conditions.  In this latest tire comparison test conducted on June 19th, 2015,, we tested the Hans Dampf/Nobby Nic combo and four additional XC-oriented tires in Seattle area dry, summer conditions.  Product tester included 4 riders recruited from the Seattle area via a Facebook posting and myself.  Each of the test riders rode either a Turner Burner (140mm rear travel) or a Turner Flux (120mm rear travel) for the duration of the comparison test.  Each rider rode the five tires combinations both uphill and downhill.    Tires/wheels were switched to the next rider after an uphill/downhill loop so that test riders rode each of the tire combinations once. 

[New for Summer 2015] In addition to quantitative and subjective ratings, we collected and analyzed uphill, downhill and combined lap times for the first time in this edition of the test.

Research Question: 

Are XC-oriented dry condition tires faster overall in Pacific Northwest loose over hardpack summer trail conditions than the more aggressive Hans Dampf/Nobby Nic established as our winter benchmark combination in our Winter 2015 tire comparison tests?

  • Winter 2015 Comparison Test 1: http://www.dirtmerchantbikes.com/special-events/2014/11/20/tire-comparison-test-report-2015-nobby-nic-high-roller-ii-neo-moto-hans-dampf
  • Winter 2015 Comparison Test 2: http://www.dirtmerchantbikes.com/special-events/2015/1/15/pacific-northwest-winter-tire-comparison-test-session-2-2015-nobby-nic-mountain-king-ii-trail-king-vigilantetrail-boss-magic-mary-hans-dampf

Hypothesis:

The hypothesis before testing was that the more aggressive Hans Dampf/Nobby NIc combination would be faster overall than the XC-oriented tires (X-King, Ardent, Neo-Moto, Rocket Ron,) on an out-and-back course with an climb going out and a descent on the return leg with few flat sections.  Basis for this hypothesis was the prediction that rolling resistance would not be much of a factor on the climb while the more aggressive tires would be faster on the downhill.  Specifically, we had found the Nobby Nic to roll fairly well in our winter testing so this test is comparing a reasonably fast Nobby Nic tires with even faster rolling tires.
[Note: This type of riding situation is pretty typical for Western Washington in which trails usually are either running uphill or downhill.]

Keep reading for the full details.  Or, skip to the end to see if we validated or rejected this hypothesis!

Tire Combinations Tested:

Tire Dimensions based on mounting on a Stans Arch EX rim (21 mm internal width)

 

1.    Continental X-King 27.5” x 2.4 ProTection, Black Chili compound, Front & Rear

  • Claimed Weight: 715g
  • Actual Weight: 685 g (avg of 2 tires weighed with a range of 680-690g)
  • Tire Height: 54 mm
  • Casing Width: 58 mm
  • Knob Width: 54 mm

 

2.    Maxxis Ardent 27.5” x 2.2 Dual Compound, EXO/TR Front & Rear

  • Claimed Weight: 760g
  • Actual Weight: 730 g (avg of 2 tires with with both tires weighing 730g)
  • Tire Height: 52 mm
  • Casing Width: 55 mm
  • Knob Width: 54  mm

 

3.    Panaracer Neo-Moto 27.5” x 2.3, Front & Rear

  • Claimed Weight: 665g
  • Actual Weight: 715 g (2 tires weighed with range of 710-720g)
  • Tire Height: 53 mm
  • Casing Width: 55 mm
  • Knob Width: 59 mm

4.    Schwalbe Hans Dampf: 2.25 Pacestar compound, Snakeskin casing: Front

  • Claimed Weight: 680 g
  • Actual Weight: 700 g (avg of 4 tires weighed with range of 680-730g)
  • Tire Height: 53 mm
  • Casing Width: 57 mm
  • Knob Width: 58 mm

(Though this tire is no longer available in this size in the Pacestar compound, we are using it in this test to establish consistency as this version of the Hans Dampf was used in our winter testing)

Schwalbe Nobby Nic:  2.25 Rear, Pacestar compound, Snakeskin casing: Rear
Claimed Weight: 610 g
Actual Weight: 670 g (avg of 4 tires weighed with range of 660-710g)
Tire Height: 55 mm
Casing Width: 56 mm
Knob Width: 56 mm

5.    Schwalbe Rocket Ron: 27.5” x 2.25 Pacestar compound, Snakeskin casing: Front & Rear

  • Claimed Weight: 550 g
  • Actual Weight: 625 g (avg of 2 tires weighed with range of 610-640g)
  • Tire Height: 52 mm
  • Casing Width: 57 mm
  • Knob Width: 55 mm

Testing Methodology:

Location: Grand Ridge Trail in Issaquah, WA going southbound after the boardwalk. The climb/descent has a 200 foot vertical gain.  Grade on the incline ranges from 6-16 percent.  One-way distance is 0.75 miles (1.5 miles for the round trip).

Trail Conditions: The weather was clear.  Trails had not had significant precipitation for at least a month with slightly loose over hardpack trail conditions.  There had been heavy rain ending two days before the day of the comparison test.  The test riders experienced no problems with rear tire traction overall, but front tire traction was more important with a good number of higher-speed turns as the trail traverses across the fall line.  

Product Testers: Test riders were myself & 4 other riders that had signed on to be product testers with Dirt Merchant Bikes were participants in this comparison test.  All test riders were competent climbers & descenders with some faster on the uphills and some faster on the downhills.  The number of climbs completed during the course of the comparison test were well within the stamina limits of the recruited testers.

Test Bikes: The testers rode either a Turner Flux (120mm travel) or a Turner Burner (140mm travel).   Each rider rode the same bike for all 5 tire combinations tested. (Tires/wheels were switched between bikes)

Wheel setup: Stans Arch rims (21mm internal width) on DT350 hubs.  Tires were run tubeless with 30 psi. 30 psi was the lowest pressure that I was comfortable running with rider weights varying within an 80 lb range.

Testing Procedure:  Each rider rode each of the 5 tire combinations up the course and then back down.  Wheels/Tires were changed after each uphill/downhill round trip.

Evaluation Methodology: The tire combinations were evaluated on the basis of four separate measures:

1. Timed Laps: Tire testing lap times were recorded for:

  • Uphill split
  • Downhill split
  • Total Time (aggregating Uphill & Downhill lap times)

2. Quantitative Rating: Tire combinations were rated on multiple quantitative factors on a 1-5 scale with 5 being the best score, 3 being an average score and 1 being far below expectations. The average quantitative rating was calculated as an average of the 5 individual rider scores on each attribute.

  • 5 stars - Absolutely outstanding
  • 4 stars
  • 3 stars - Solid performance, meets expectations
  • 2 stars
  • 1 star - Misses expectations by a wide margin

3.    Subjective Evaluation: Test riders added subjective comments to the Quantitative Ratings to provide deeper insight into the quant ratings. 

4.    1st & 2nd most Preferred Tires: Each test rider indicated which tire were their 1st and 2nd pick for front and for rear usage.

Note on Interpretation of Results:

I suggest reviewing the subjective comments in conjunction with the quantitative data for a general understanding of each tire’s strength/weaknesses.  Please note the following caveats when interpreting the results from this comparison test.

  1. This is not intended to be a scientific test:  Though this test includes quantitative data, the numerical data is intended only to help interpret rider feedback.
  2. Differences between tires in the quantitative results are not statistically significant: With only small sample of five riders rating each tire, differences in quantitative ratings should be interpreted as directional and not as statistically significant differences.
  3. Projectability of results to other Trail conditions: This comparison test was conducted in typical Seattle area dry summer trail conditions.  These conditions include some loose dirt over hardpack trails.  Perceptions of tire performance generated from this test are generally not projectable to dissimilar trail conditions in other geographic areas.

Lap Times - Uphill, Downhill & Combined:

(based on times recorded for 5 test riders riding each of the tire combinations once)

Notes on Interpretation of Lap Time Averages and Standard Deviations:  

1. Differences between the average lap times recorded for the tires are not statistically significant:  With only one lap time for each of the five riders for each tire, differences in lap times should be interpreted as directional and not as statistically significant differences.

2. Definition of Standard Deviation:  The standard deviation is a measure of how spread out the numbers in a data set are. A smaller standard deviation means the data is more closely clustered around the average of the data set, while a larger standard deviation means the data is more spread out.

3. Interpretation of the Standard Deviation statistic for the lap times recorded for each tire:  My interpretation of the standard deviation of the lap times recorded for each tire is that it is a measure of how forgiving a tire is of less-than-perfect riding.  In this context, tires that are more forgiving will have a lower standard deviation score. I’m defining forgiving as the ability to:

  • Communicate the amount of available traction
  • Quickly regain climbing traction after traction is lost
  • Recover easily and quickly from the front tire sliding
  • Slide the rear tire predictably

The opposite of a forgiving tire will be one that tends to break away quickly and without warning. Forgiving tires will tend to both have reasonably high traction limits and lose traction predictably thus allowing riders to more confidently explore their traction limits.

The reason why I think the standard deviation is a measure of how forgiving  or, put in another way, how accessible a tire’s performance limits are is because I believe a more forgiving tire should result in less variance in lap times.  Tires that break away more unpredictably might be expected to have larger and more variable time differences between “good” runs and “bad” runs.

This is my interpretation of the data, but feel free to post any thought you might have on my blog post on this topic at:  http://www.dirtmerchantbikes.com/special-events/2015/7/16/measuring-tire-cornering-predictability-with-data

Performance Ratings – Front Tire:  

Subjective Comments – Front Tire: 

Continental X-King 27.5” x 2.4 ProTection, Black Chili compound (as a front tire):
Summary:  The X-King had a precise steering feel but tended to break away somewhat abruptly at the limit.  

Strengths: 

  • Steering Feel: “Nimble enough to make up for lower traction limits”, “Steering felt very sharp”

Weaknesses:

  • Lack of communication from the tire at traction limits: “Very sloppy descender with rounded tread. No confidence.” “grip felt on/off close to the limit”
  • Requires more concentration to ride than more forgiving tires: “Similar feeling to the Rocket Ron, but not as sure in the breakaway. “more abrupt breakaway than the Rocket Ron”

Maxxis Ardent 27.5” x 2.2 Dual Compound, EXO/TR (as a front tire):
Summary: The Ardent was a solid tire, but didn’t particularly stand out in this test of strong contenders.

Strengths: 

  • Steering Feel: “Grip felt solid” “Good point and shoot feeling”

Weaknesses:

  • Predictability: “less predictable at the limit than the Hans Dampf” “Darty, tended to bounce off of rocks”

Panaracer Neo-Moto 27.5” x 2.3 (as a front tire):
Summary: The Neo-moto held its own versus the other XC-oriented tires in cornering grip and braking, but didn’t quite match up with some of the newer tread patterns in the areas of steering feel and braking.

Strengths: 

  • Predictable Traction: “Allowed me to take a tighter line. Never surprised me" “Front feels good, not much squirm”

Weaknesses:

  • Not as predictable at cornering limits: “Not as confident at the limit as some of the other tires in the test”

Schwalbe Hans Dampf: 27.5” x 2.25 Pacestar compound, Snakeskin casing (as a front tire):
Summary: Coming into this test, the Hans Dampf was expected to lead its competitors by a wide margin on the downhill section of our test due to its aggressive tread pattern compared to the more XC-oriented tread patterns of the other tires tested.  Overall, the Hans Dampf did not disappoint. Cornering grip, braking and predictability at the limit for the Hans Dampf were best in this test.  Though not a weakness, the steering feel and handling that had been a competitive advantage for the Hans Dampf on the wet trails of our winter testing was not as strong in summer loose over hardpack conditions while the X-King and Rocket Ron had better steering feel that had not expected before the test due to their faster rolling, less aggressive tread patterns

Strengths: 

  • High cornering limits: “Excellent traction, rolls over almost anything.”, “You can just forget about them because they just do their thing”

Weaknesses:

  • Steering Feel/Handing:  Whereas the Hans Dampf had a sharp steering response in wet conditions, the tread pattern tended to skate a bit before gripping In the dry loose over hardpack conditions.  “Tended to skate over loose material before gripping” “Not as surefooted in loose over hardpack conditions as in wet conditions”

Schwalbe Rocket Ron: 27.5” x 2.25 Pacestar compound, Snakeskin casing (as a front tire):
Summary: Despite its fast rolling tread, the Rocket Ron was surprisingly competent both uphill and downhill. On average, it was just slightly slower than the X-king going uphill and faster than all other tires tested going downhill. Its steering response was fairly quick and lots of feedback about available cornering grip allowed riders to easily make the most of its reasonably high traction levels.

Strengths: 

  • Good cornering grip: “Usable grip is very high” “Good, all-around grip”
  • Predictable cornering traction: 
    • “Very surefooted, especially through dry, loose corners” 
    • “Good communication of cornering limits. Very predictable” 
    • “Hooks right back up when they break free”
    • “Breakaway was gradual and predictable unlike the X-king which broke away more abruptly”

Weaknesses:

  • Possible faster tread wear:  We do not have any evidence of this from our recent testing sessions, but will provide an update after longer-term use of the Rocket Rons.  The Schwalbe North America site notes for the Rocket Ron state that “This is an out and out competition tire! Puncture protection and durability are limited!”

 

Performance Ratings – Rear Tire:  

Subjective Comments – Rear Tire: 

Continental X-King: 27.5” x 2.4 ProTection, Black Chili compound (as a rear tire):
Summary: The X-King was perhaps the fastest rolling tire in the test, but was unable to fully exploit this on climbs due to a tendency to break free under power or on less grippy surfaces. The X-King also had a sharp handling feel but tended to have a breakaway point that was less predictable than the Rocket Ron.

Strengths: 

  • Rolling Resistance: “Rolls really well.”, “Fast!“ 
  • Handling: “Feels very sharp and precise in its handling”, “Sure feeling in choosing and following a line.”

Weaknesses:

  • Climbing traction
    • “Not tons of traction, but only gave up climbing traction on rock.”
    • “Tended to break free under power”
    • “Rocket Ron is noticeably more grippy” “Traction not as good as the Rocket Ron”
  • Predictability
    • “Grip at the breakaway point was not as predictable as the Rocket Ron”

  


Maxxis Ardent: 27.5” x 2.2 Dual Compound, EXO/TR (as a rear tire):
Summary: As with its results as a front tire, the Ardent posted solid though not exceptional performance.

Strengths: 

  • Rolling Resistance: “Fast”
  • Handling: “Nice stiff sidewalls, no squirm”

Weaknesses:

  • Braking: “Did not brake well”

Panaracer Neo-Moto: 27.5” x 2.3 (as a rear tire):
Summary: The Neo-moto got a ticket into our summer tire comparison test due to its feeling exceptionally fast among more the more aggressive trail tires that we tested this past winter.  Though the Neo-moto is not as fast or as grippy as newer XC tire designs, it remains a solid choice with one tester seeing it as being “nothing special, but has a nice feel.”

Weaknesses:

  • Cornering Grip: “Lost traction fairly easily” “Soft, flexy. Feels like the tire was coming off of the rim when cornering hard”

Schwalbe Nobby Nic: 27.5” x 2.25 Pacestar compound, Snakeskin casing (as a rear tire):
Summary: While the Nobby Nic was no slouch when it came to rolling resistance, it was slower rolling than the XC-oriented tires that were tested. Coming into this test, the Hans Dampf/Nobby Nic combo was expected to be slower uphill and faster downhill than its faster rolling competitors. Defying both preconceptions, the Hans Dampf/Nobby NIc combo was almost as fast as its fastest XC competitors going uphill, but slower downhill than all other tires tested except the Neo-moto.

Strengths: 

  • Climbing Traction: “Predictable climber. Didn’t need to worry much about losing traction with these tires”
  • Handling: “Super predictable”

Weaknesses: 

  • Rolling Resistance: “Rolled well, just not as well as the X-king and Rocket Ron”


Schwalbe Rocket Ron: 27.5” x 2.25 Pacestar compound, Snakeskin casing (as a rear tire):
Summary: The Rocket Ron had a good balance of skills with no apparent weaknesses.

Strengths: 

  • Rolling Resistance: “Very fast” though “Slower rolling than the X-king”
  • Climbing Traction: 
    • “Climbed best”
    • “Climbing traction is very predictable. Regains lost grip easily”
  • Cornering Grip: 
    • “Great cornering grip” 
    • “Gripped surprisingly well for such a fast rolling tire”
  • Predictability
    • “Breakaway point is very predictable”
    • “The tire breaks away gradually and regains cornering grip easily”

Test Summary:

Front Tire:

Rear Tire:

None of the tires tested are a poor choice for the dry loose over hardpack conditions of our test. Every tire tested received at least one 1st or 2nd place vote.   The Rocket Ron received the most 1st place votes likely due to its balance of st…

None of the tires tested are a poor choice for the dry loose over hardpack conditions of our test. Every tire tested received at least one 1st or 2nd place vote.   The Rocket Ron received the most 1st place votes likely due to its balance of strengths. The fundamental performance attributes common to all of the more preferred tires were good cornering traction and predictable steering/handling for front tires and a balance of rolling resistance with good climbing traction for rear tires.  

Front Tire Summary:

The factors that came out as the key drivers of preference differentiating the most preferred front tires was their steering feel/handling and predictability balanced with adequate cornering grip. Absolute cornering grip did not seem to matter as much as steering feel and good feedback on how much traction is available.

The Rocket Ron was the best at balancing a reasonably high level of cornering grip with predictable traction and responsive steering feel.  The closest front tire competitors to the Rocket Ron were the X-King and the Hans Dampf.  The X-King had perhaps the sharpest steering feel, but tended to break away without much warning.  The Hans Dampf had predictable traction but had a slower steering response due to the tread ‘skating’ a bit before digging into the loose over hardpack conditions of our test. Among the other front tires, the Neo-Moto and Ardent have decent traction, but were more difficult to ride fast due to less predictability at traction limits 

Rear Tire Summary:

For the rear tire, the factor that was most important to testers was “usable” rolling resistance which I will define. “Usable” rolling resistance was a balance of good rolling resistance with sufficient climbing traction. A good example of how this factor came into play was the climbing performance of the X-King.  The X-King was perceived overall as the fastest rolling rear tire, but had a tendency to lose climbing traction on rocks and loose dirt even on the moderate grades of the trails used in this comparison test. The Rocket Ron, in contrast, rolled almost as quickly as the X-King but had unshakeable climbing traction on par with the more aggressive and slower rolling Nobby Nic. Though the X-King was clearly the faster rolling tire, the Rocket Ron’s split times for the uphill segment were only slightly slower than the X-King (and statistically equivalent as the difference was within the statistical margin of error).

Among the rear tires in the test, the Rocket Ron was best at balancing rolling resistance with climbing traction and cornering grip.  The X-King was fastest rolling with sharp handling, but tended to be less predictable in its climbing and cornering traction. The Nobby Nic was best in cornering grip, handling and braking but lost out on rolling resistance to its faster XC-oriented competitors though we found that slightly higher rolling resistance is balanced out by more predictable climbing traction. The Neo-Moto had no outstanding weaknesses, but was just not as fast or as grippy as the newer XC tire designs tested. The Ardent felt solid and rolled decently well, but was unexpectedly weak in braking.

 

Additional Considerations:

Ease of Tubeless Setup by brand:

[Caveat: This is on Stans Arch EX rims so certain brands may happen to match better with the rim diameter and profile of these rims.  In particular, WTB TCS beads are known to be a tighter fit, though my experience has been that I’ve had no issues mounting a WTB Vigilante and a WTB Trail Boss on Arch EX rims. Your experience will likely vary with different rim brands/models.]


Schwalbe: Consistently, Schwalbe tires used in our tests have been the easiest to set up tubeless on the Stans Arch EX rims with 13 of the 15 Schwalbe tires we have mounted in our three comparison tests seating with only a floor pump and no additional manipulation beyond just mounting the tire and airing it up.  About 2/3 of the Schwalbe tires held air even without sealant and all tires held air after doing a shake and distribution of sealant. 
Continental: Of the 6 Continental tires that we have mounted, only 1 of the 6 seated easily with a floor pump, 4 required additional manipulation to seat and I gave up on seating one by hand (and went to the gas station to use their air compressor). All of the Continental tires lost air pressure over time until I did a second shake and distribution of sealant to seal the bead interface.
Maxxis: 3 of the 4 Maxxis tires seated easily with a floor pump and 1 required some additional manipulation to seat with a floor pump. 3 of the 4 tires held air after doing a shake and distribution of sealant and the remaining tire also held air after a second shake and distribution of sealant.

 

Handling Characteristics by brand:

A side benefit to the Schwalbe tire lineup that has been a consistent theme through our three comparison tests was the consistency in handling feel between the four Schwalbe tire models that we’ve tested. The Rocket Ron, Nobby Nic, Hans Dampf and Magic Mary all handle in a predictably similar fashion.  Traction increases as you go from the less aggressive Rocket Ron to the Magic Mary along with rolling resistance, but how the tires respond to steering input remains consistent.  The Schwalbe tires all have a balance between steering response, traction and predictability that gives the tires that we tested a consistent personality. As one tester put it, “The Schwalbes all have the same handling characteristics only with varying degrees of traction and rolling resistance.”  The benefit to you if you have multiple bikes is that switching from the XC-oriented Rocket Ron on your XC/race bike to a heavier duty Magic Mary on your Enduro/All-Mountain bike doesn’t require you to completely change up your riding style to adapt to the change in tires.  The Continental Mountain King II and the X-King also share a similar sharp handling feel, but the Trail King feels less sharp in its steering response

Schwalbe Tread Wear (Long-term report):

There have been online reports of faster tread wear on the Schwalbe tires, but we have not seen faster tread wear or undercutting of tread blocks in the eight months that we’ve had Schwalbe tires on our demo bike fleet.  The more organic nature of our trails compared to more rocky trails elsewhere may be mitigating any tendencies that Schwalbe tires have for faster wear.   For sure, much of the Schwalbe’s performance advantage over the other tires that we tested and their predictable handling do come from the softer rubber compounds and side knobs that extend beyond the casing.  Consider this as similar to high performance tires for sports cars which also wear faster than typical passenger car tire, but offer better traction and response due to their soft rubber compounds.   Schwalbe tires may not be the cost-efficient tire on the market, but we believe after our testing with multiple testers with different riding styles that Schwalbe offer some of the best riding tires available.

Tires that we carry

Based on the results of our two recent tire comparison tests, Dirt Merchant Bikes will be carrying the Schwalbe Rocket Ron tires in addition to the Nobby Nic, Hans Dampf and Magic Mary in all wheel sizes and widths for the summer riding season. We will also carry Maxxis DH-F/DH-R, High Roller II, and Ardent tires as a value priced option.

 

The Schwalbe tires that we carry & our pricing is:

Schwalbe Nobby Nic (new HS 463 version) Evolution Line –26”, 27.5” & 29” tire sizes: Regularly $67.99, 

Schwalbe Rocket Ron Evolution Line –26”, 27.5” & 29” tire sizes: Regularly $67.99, 

Schwalbe Magic Mary Evolution Line –26” & 27.5” tire sizes: Regularly $67.99, 

Schwalbe Hans Dampf Evolution Line – 26”, 27.5” & 29” tire sizes: Regularly $67.99,

Typically, we will have the Pacestar (normal) and Trailstar (soft) compounds with Snakeskin/TL-Easy casing in stock with VertStar (softest compound) available to ship in 2 days.

 

The Maxxis tires that we carry & our pricing is:

Maxxis Minion DH-F 3C MaxxTerra EXO/TR

  • 27.5 x 2.3: $62.99
  • 27.5 x 2.5 Wide Trail: $63.99

Maxxis Minion DH-R 3C MaxxTerra EXO/TR

  • 27.5 x 2.3: $62.99
  • 27.5 x 2.4 Wide Trail: $63.99

If you have any questions/comments about this tire comparison test or questions about tires, please e-mail Dirt Merchant Bikes at jeff@dirtmerchantbikes.com

Ordering Tires:

Tires can be ordered from Dirt Merchant Bikes at: http://www.dirtmerchantbikes.com/tires-wheels/ 

Previous editions of our Tire Testing Reports:

If you're interested in reading the previous editions of our tire testing reports, they are located at:

  • Winter 2015 Comparison Test 1: http://www.dirtmerchantbikes.com/special-events/2014/11/20/tire-comparison-test-report-2015-nobby-nic-high-roller-ii-neo-moto-hans-dampf
  • Winter 2015 Comparison Test 2: http://www.dirtmerchantbikes.com/special-events/2015/1/15/pacific-northwest-winter-tire-comparison-test-session-2-2015-nobby-nic-mountain-king-ii-trail-king-vigilantetrail-boss-magic-mary-hans-dampf


If you have any questions/comments about this tire comparison test or questions about tires, please e-mail Dirt Merchant Bikes at jeff@dirtmerchantbikes.com

Tires planned for testing in Winter 2016:

Our next round of testing will happen again in November 2015 and we will focus again on more aggressive tires for wet trail conditions. We are considering the following tires for testing though any new tires introduced this fall will also be added to the consideration list.


Benchmark: Hans Dampf Trailstar 2.25 (front)/Nobby Nic Pacestar 2.25 (rear) – This combination balances the traction of the Hans Dampf as a front tire with a faster rolling Nobby Nic as the rear tire. We will switch to the Trailstar version of the Hans Dampf as the front tire.

Tires being considered for testing are (In order of testing priority):

  1.  Maxxis Minion DHF 3C EXO TR 2.3 (front)/ Maxxis Minion DHR II 3C EXO TR 2.3 (rear) – As many of you have pointed out, this is been a notable omission in our testing to date. We have the options of testing one or more of the following combinations
    • DHF(front)/DHR II(rear)
    • DHF(front)/DHF(rear)
    • DHR II(front)/DHR II(rear)
  2. Specialized Butcher 2.3 (front)/Purgatory 2.3 (rear) – This is also a popular combination in our area
  3. Michelin Wild Grip’R Gum-X (standard compound) 2.25 on front/rear or Wild Rock’R Magi-X (soft compound) on the front.
  4. Continental Trail King 2.4 Protection(front)/Mountain King Protection 2.4 (rear) – The 2.2 version of the Trail King didn’t so well in our Winter 2015 testing, but some of you noted that the 2.4 version has better traction. The 2.2 Mountain King did well in testing last winter, but was a bit too narrow.
  5. Bontrager XR4 (front)/XR3 (rear)

 

If you have any questions/comments about this tire comparison test or questions about tires, please e-mail us at jeff@dirtmerchantbikes.com.

Measuring Tire Cornering Predictability with Data

In our Summer 2015 XC tire comparison test (to be published tomorrow), we started to record lap times for each tire tested. Though there was a small sample of lap times for each tires (5 test riders riding each of the test tire combos once), I decided to also take the standard deviation of the recorded times to see if I could see any patterns in whether the lap times for each tire were more clustered around an average or were, conversely, more spread out. 

[Definition of Standard Deviation:  The standard deviation is a measure of how spread out the numbers in a data set are. A smaller standard deviation means the data is more closely clustered around the average of the data set, while a larger standard deviation means the data is more spread out.]

What I found was that there indeed was a difference between tires in how spread out their lap times were. Based on a synthesis of the subjective feedback and quantitative performance ratings with the standard deviation of the lap times, my interpretation of the standard deviation of the lap times recorded for each tire is that it is a measure of how forgiving a tire is of less-than-perfect riding.  In this context, tires that are more forgiving will have a lower standard deviation score. I’m defining forgiving as the ability to:

·         Communicate the amount of available traction

·         Quickly regain climbing traction after traction is lost

·         Recover easily and quickly from the front tire sliding

·         Slide the rear tire predictably

The opposite of a forgiving tire will be one that tends to break away quickly and without warning. Forgiving tires will tend to have moderate to high traction limits and tend to lose traction predictably thus allowing riders to more confidently explore their traction limits.

The reason why I think the standard deviation is a measure of how forgiving  or, put in another way, how accessible a tire’s performance limits are is because I believe a more forgiving tire should result in less variance in lap times due to more gradual breakaway characteristics that can be caught and corrected more easily.  Tires that break away more unpredictably might be expected to have a larger time difference between a “good” run and a “bad” run.

 

Your thoughts?

2015 Tire Preferences & Riding Habits Survey Results

Dirt Merchant Bikes conducted a study in February 2015 to understand tire preferences.  As part of that study, we also collected a lot of information on riding habits.  The charts below summarize overall findings on riding habits, tire preferences as well as selected insights by sub-groupings of mountain bikers:

If you have any questions or comments, feel free to e-mail us at jeff@dirtmerchantbikes.com

To start off, the survey results were tested for statistical significance.  Statistically significance indicates that a gap between two data points is likely to reflect that a real difference exist in feedback between two different subgroups of study participants rather than that difference having occurred by chance.  Increasing the sample sizes of participants reduces the amount of variability in survey data and can thus show statistically significantly differences with smaller  gaps between two data points.  The chart shows how to read the results of significance testing as shown in the following charts. 


Riders in WA may be using smaller wheels due to the rough and tight singletrack trails prevalent in Western WA, as compared to the long fireroad climbs more typical in other parts of the country such as in California and Colorado.

Among tire brands outside WA, Specialized and WTB are maintaining share while Schwalbe, Maxxis and Continental  are increasing their share of the market.  Kenda and Panaracer are former market leaders but currently have weaker market share compared to competitors.

In Washington state, Maxxis has been a market leader and continues to hold a strong share of the market.  Part of this is likely due to Maxxis' reputation for making good downhill tires and the propensity of riders in Washington to choose more aggressive tires.  Schwalbe has also made strong gains among riders in Washington.  Kenda, WTB were former market leaders but have since lost ground.