Holy 14T - Sweet Spot!

[MattB]

I just finished riding with the 14T and it is exactly what I was looking for!

I ran the 12T for about 5 hours then switched to the 13T. The 13T was better but I still found myself wanting a little less grunt and slightly more top speed.

The first few laps with the 14T I found myself over jumping by a little bit. The rear tire also didn't break loose as easily.

This was all in mode 4 on a fairly fast MX Track.

If you are a track rider give the 14T a try!!

 

[snydes]

From what everyone is saying it sounds like this is the way to go. Paul at Highland Park also has his MX geared way up, I think he even dropped a bunch in the back.

 

[Philip]

I was initially considering going the other way, but I am glad it is all making sense to me now. If you install a 14/45 gearing, it will feel like Map 2 at low speeds and like Map 4 at high speeds. And you will have even more power at 50mph and above.

Anyone wants to see what a 14/45 gearing will look like on this plot?
https://altaownersforum.com/threads...-riding-maps-demystified.158/page-2#post-1490

 

[Josh402]

So it really doesn’t feel any bit slower than stock gearing? When I’m on long dirt roads I would like to see another 10mph at the top.

 

[rayivers]

Just FWIW... if I gear up my Alta to 3.78:1 (14/53), I'll try 13/49 or 12/45 sprockets instead. After trying to live with huge (65 - 71T) rear sprockets on my direct-drive Zero, I found the anti-squat effect from large-diameter sprockets to be very real, and (IMO) NG for most dirt riding / racing.

I'm sure everyone here is familiar with this, but anyway... when the swingarm is angled down under hard acceleration, the anti-squat effect from sprocket leverage pushes the rear axle down. This fights the shock rebound damping, and also makes the front end feel heavier. When the swingarm is angled up - like when accelerating in a G-out or flat-to-hill transition - the opposite occurs; the wheel is pulled up, and the front feels lighter (though that probably wouldn't be noticed with the suspension loaded down).

Mainly because of this, I've never been able to get a good rebound setting for both acceleration and braking. It's so cool to have the option of trying smaller rear sprockets on the Alta.

 

[Philip]

So it really doesn’t feel any bit slower than stock gearing? When I’m on long dirt roads I would like to see another 10mph at the top.

It will feel slower only at speeds below 35mph. Which is not a big deal because most of us seem to prefer slower maps at low speeds anyway. After that it will feel faster. And you will gain some top speed, in case you need it.

You will be able to use more of the bike's power if you ride in Map 4 with a taller gearing, compared to riding in Maps 3 or 2, where the max power is limited.

 

[Philip]

Just FWIW... if I gear up my Alta to 3.78:1 (14/53), I'll try 13/49 or 12/45 sprockets instead. After trying to live with huge (65 - 71T) rear sprockets on my direct-drive Zero, I found the anti-squat effect from large-diameter sprockets to be very real, and (IMO) NG for most dirt riding / racing.

Maybe this is why the Alta feels so teeter-tottery in the whoops compared to other bikes?

I rode a 2016 Factory Edition KTM 450SXF yesterday, and while it felt very top-heavy, slow (for my skill level), and not as exciting as the Alta, it stayed dead level through all the whoops and bumps.

 

[rayivers]

Maybe this is why the Alta feels so teeter-tottery in the whoops compared to other bikes?

Yes, could be - the Alta has so much torque available all the time, it might be happening more strongly & more often. Under acceleration my Zero does the teeter-totter thing to extremes, and if I set the shock rebound to compensate for what I call 'wheel hammer', the rear tire's spending most of the time in the air everywhere else. The effect is exaggerated with giant sprockets, but I imagine it's always present to some degree.

 

[MattB]

The 14t should give us some more life on the chain guides. It might be my imagination but I swear the 14/53 gearing sounds smoother overall.

 

[MattB]

I was initially considering going the other way, but I am glad it is all making sense to me now. If you install a 14/45 gearing, it will feel like Map 2 at low speeds and like Map 4 at high speeds. And you will have even more power at 50mph and above.

Anyone wants to see what a 14/45 gearing will look like on this plot?
https://altaownersforum.com/threads...-riding-maps-demystified.158/page-2#post-1490

I would definitely like to see it! I have 45T, 48T, and 50T in my sprocket inventory.

 

[Philip]

I would definitely like to see it! I have 45T, 48T, and 50T in my sprocket inventory.

Here you go:
https://altaownersforum.com/threads...-riding-maps-demystified.158/page-2#post-1658

 

[Philip]

I am testing my MX today with a 12/45 gearing. Very nice, I like it a lot! In Map 4 the pull begins slightly better than my old (stock) favorite Map 2 but continues pulling harder and much-much longer!

 

[Philip]

The battery drains about the same as in Map 2.

The most favorite part for me is that I no longer have to twist the throtte goon-style on straightaways or on jump faces when Maps 2 or 3 run out of steam.

 

[Fod]

The battery drains about the same as in Map 2.

The most favorite part for me is that I no longer have to twist the throtte goon-style on straightaways or on jump faces when Maps 2 or 3 run out of steam.

Ha ha, I wish I could do just one thing not goon style!

 

[gprix1]

I'm trying to wrap my head around this. I will be using the MXR as my race bike in sprint enduros this upcoming season. Typical distance is 60 miles and 80% technical single-track. I want to make sure to complete the event so I had planned to use map 1 for most of the race and switch to 2 or 3 for faster sections.
However, is it possible to just gear up, use map 4 and have endurance and mild power at slower speeds like using map 1 while being able to wind it out in faster sections? That would be much better than switching the maps back and forth.
I have 13/50 gears I'm going to try which puts the ratio at 3.85 which is similar to 14/53 (3.79).

 

[Mark911]

Power is power. If takes so much work to move your bike at a specific rate and gearing can't directly change that. What gearing can do, however, is move the bike (motor) into a operating condition where it is more efficient most of the time. Without extensive dyno time where efficiency as well as power/speed/throttle position is measured we're just guessing. Alta has done all this work and incorporated it into their maps and they say map 1 is most efficient. Unless you are planning to operate the bike at speeds significantly above/below stock gearing for extended periods I'd say just stick with map 1 and stock gearing.

 

[Philip]

Assuming we have no idea where this motor has its sweet, most economical RPM range, the only sure way to increase the range is to avoid any wheelspin, use the brakes as little as possible, and carry momentum.

A different gearing would help the range only if it allows you to ride more smoothly and with less wheelspin. If you twist the throttle and go faster than before, it will cost you. There is no free lunch.

 

[Duncan]

gprix1: I don't see how you will be able to do 60 miles of 80% single track unless you are swapping bikes, swapping battery or charging in between sprints.
I get about 35 miles on tight single track with some dirt road connectors mixed in.
I have gotten as little as 22 miles in severely technical terrain.

Hey MXR's, how do you like your foot pegs?
The EX foot pegs are no good and am considering swapping with aftermarket (YZF 250 fit) but based on threads herein the aftermarket pegs will angle forward a bit and I would rather get MXR pegs if they are good in wet mud conditions.

 

[rayivers]

where this motor has its sweet, most economical RPM range

Judaslefourbe posted this at the EMF Alta forum a while back:

"One thing you need to consider with EVs is the motor efficiency also. The Redshift sweet spot is between 6,000 and 8,000 RPM."

 

[Philip]

gprix1: I don't see how you will be able to do 60 miles of 80% single track unless you are swapping bikes, swapping battery or charging in between sprints.

Agreed. Even on a smooth paved road 60 miles is not likely, unless you are descending from a high elevation or have a strong tail wind.

Hey MXR's, how do you like your foot pegs?

The MXR peds are nothing special, similar to the stock pegs on other MX bikes. They are not as slippery at the MX and EX pegs. We have a couple of some footpeg threads with recommendations.
https://altaownersforum.com/threads/brake-mod-and-foot-pegs.36/