Gearing for ST (Single Track)

[thsm007]

What are guys running for gearing that run mostly ST? My 250 2t is 14/51 and it works pretty good for me, bike tractors. But as of now I’m still running stock on the Alta. I don’t need the top speed bc I’m close to trails. I want that rear wheel torque to be manageable and good traction for loose climbing and obstacles. I know for erzb they made gearing changes.

 

[OneLapper]

Alta realized they geared the bikes too tall for Erzberg on the prologue, they both overheated. One of the interviews mentioned they corrected it for the race, but they didn't mention if they used stock gearing.

I'm riding mostly ST with some sprint enduro races. The stock setup on my MX seems perfect. I can manage wheel spin with map changes and throttle. Speed is never an issue. It's certainly quick enough off the line for the starts.

 

[thsm007]

Alta realized they geared the bikes too tall for Erzberg on the prologue, they both overheated. One of the interviews mentioned they corrected it with for the race, but they don't mention if they used stock gearing.

I'm riding mostly ST with some sprint enduro races. The stock setup on my MX seems perfect. I can manage wheel spin with map changes and throttle. Speed is never an issue. It's certainly quick enough off the line for the starts.

Thanks for that. Where are you doing the sprints? I’d love to race this bike I know it won’t make a long course enduro (obvi) and am not sure on h/s as im a B racer so on the long course. At least 2 hrs cld be 2hrs plus a lap.. so that leaves sprints.

 

[WoodsWeapon]

Sprint enduros seem to be getting more popular the last couple years, for Altas theyre the perfect format. Our local series are GPs, which consist of 2-20 minute motos and laid out half MX track, half woods. Its a real eyeopener for guys that have only ridden one discipline. As you would expect woods guys dont jump doubles, and MX guys tiptoe through the woods.

 

[thsm007]

One thing I notice is that I don’t get nearly as tired on the Alta as my gas bike. Not sure what that’s all about yet. Maybe just power delivery. I also really like the turn radius - I guess no radiator to get in the way gives another inch or two both ways helps.

 

[Philip]

One thing I notice is that I don’t get nearly as tired on the Alta as my gas bike. Not sure what that’s all about yet. Maybe just power delivery.

Yep, this is a common experience. I think it has to do with not having to pause your breath, dance on footpegs, switch your pace, or brace for a power hit when you would shift on a gas bike. Add a LHRB and riding will become even more relaxing.

 

[thsm007]

I actually just ordered the lhrb from rekluse. Looking forward to it!!

 

[OneLapper]

Thanks for that. Where are you doing the sprints? I’d love to race this bike I know it won’t make a long course enduro (obvi) and am not sure on h/s as im a B racer so on the long course. At least 2 hrs cld be 2hrs plus a lap.. so that leaves sprints.

The sprint enduros are J Day Offroad events that are run in the New England / Tri State area. They usually combine the SEs with a GP, one each day. It's ideally suited to the Alta. The GP events have enough time to charge up between motos. The SEs are more challenging, 9 tests in total, three different courses ranging in time from 5 to 15 minutes each. You have 2:45 to finish all 9 tests.

 

[thsm007]

The sprint enduros are J Day Offroad events that are run in the New England / Tri State area. They usually combine the SEs with a GP, one each day. It's ideally suited to the Alta. The GP events have enough time to charge up between motos. The SEs are more challenging, 9 tests in total, three different courses ranging in time from 5 to 15 minutes each. You have 2:45 to finish all 9 tests.

Do you use a rapid charger for the GP
And SE? Are you able to finish w the Alta? If so how much generator time do you need?

 

[OneLapper]

Do you use a rapid charger for the GP
And SE? Are you able to finish w the Alta? If so how much generator time do you need?

The GP has two motos that are 30 minutes long and usually a couple of hours between them. I have a standard charger that I run at 240vac off a generator.

The sprint enduros are more challenging because you have 2:30 to finish the tests. I haven't figured out the most efficient way of doing them. I usually do the longest first (woods test), then the extreme test, then go to the trailer to charge up and have a drink for doing the MX test.

I've been able to finish them with the exception of breaking the foot brake bracket in a tip over. I skipped the last test bc I ran out of time trying to figure out a fix. I thought it was too risky doing the test without a rear brake given the slick conditions and steep hills.

BTW, I'm no MXer. Been riding single track stuff my whole life. I've been going to a local practice track and it's obvious the battery gets drained much more quickly there than in the woods.

 

[Rix]

Alta realized they geared the bikes too tall for Erzberg on the prologue, they both overheated. One of the interviews mentioned they corrected it for the race, but they didn't mention if they used stock gearing.

I'm riding mostly ST with some sprint enduro races. The stock setup on my MX seems perfect. I can manage wheel spin with map changes and throttle. Speed is never an issue. It's certainly quick enough off the line for the starts.

I went from a 13/53 combo to a 12/52 combo. Picked up about 6% mechanical advantage. I have been running this ratio for a while now, I really like it.

 

[Tuner]

FDR depends on the conditions, map selection, and ones objective. If traction is a concern, then a taller ratio (lower numeric ratio) will often be of advantage. If you have plenty of grip, and looking for maximum acceleration at lower speeds, then a shorter ratio (higher numeric ratio) will often be of some advantage. Erzberg was an extreme case as one must climb out of the mine with speeds often exceeding 85 mph. Even with sustained wide open throttle the Alta would not carry a sustained top speed of 85 mph under such conditions without thermal limiting the motor. The compromise was to shorten the FDR to provide a greater mechanical advantage with the compromise being that of top speed. All in all, the FDR is relatively insensitive regarding the Alta in most situations, and therefore often becomes more about feel, than calculated optimum. For what it may be worth, 14 / 53 was our go to gearing regarding most applications. All that said, and as with the MXR suspension, these values were established using top level athletes most of the time. In hindsight, we likely should have tested more with B and C riders as our test pilots seldom missed their mark (not much over jumping or coming up short) placing our MXR settings on the light side for some. Average, fully dressed weight was between 180 and 200 pounds, and ability, was top level athlete, with Kris Keefer being our primary test pilot. Glen Helen, Pala and Milestone being the predominant test facilities. Rider feedback, data acquisition (lap times, split times, average speed, minimum speed and top speed) along with close observation being the markers used.

 

[Redwolf]

I love hearing about all the development behind the scenes stuff

 

[Rix]

FDR depends on the conditions, map selection, and ones objective. If traction is a concern, then a taller ratio (lower numeric ratio) will often be of advantage. If you have plenty of grip, and looking for maximum acceleration at lower speeds, then a shorter ratio (higher numeric ratio) will often be of some advantage. Erzberg was an extreme case as one must climb out of the mine with speeds often exceeding 85 mph. Even with sustained wide open throttle the Alta would not carry a sustained top speed of 85 mph under such conditions without thermal limiting the motor. The compromise was to shorten the FDR to provide a greater mechanical advantage with the compromise being that of top speed. All in all, the FDR is relatively insensitive regarding the Alta in most situations, and therefore often becomes more about feel, than calculated optimum. For what it may be worth, 14 / 53 was our go to gearing regarding most applications. All that said, and as with the MXR suspension, these values were established using top level athletes most of the time. In hindsight, we likely should have tested more with B and C riders as our test pilots seldom missed their mark (not much over jumping or coming up short) placing our MXR settings on the light side for some. Average, fully dressed weight was between 180 and 200 pounds, and ability, was top level athlete, with Kris Keefer being our primary test pilot. Glen Helen, Pala and Milestone being the predominant test facilities. Rider feedback, data acquisition (lap times, split times, average speed, minimum speed and top speed) along with close observation being the markers used.

Just throwing this out there, I personally know of a 285 pound guy (gear, camelback full of water and tools) that has A rider skill in off road conditions with C rider speed that would gladly assist with rider R&D should Alta every come back.

 

[Redwolf]

Just throwing this out there, I personally know of a 285 pound guy (gear, camelback full of water and tools) that has A rider skill in off road conditions with C rider speed that would gladly assist with rider R&D should Alta every come back.

I think they would be able to find half a forum full of us who would volunteer for this duty!

 

[Rix]

I think they would be able to find half a forum full of us who would volunteer for this duty!

That is a no shitter for sure.