8t Extrovert Drivers

[s1d3w1nd3r1480]

I need some quick opinions here. I have a chance to grab some me Wahls 8th extros for my XTX for just over $100. I had no intention of dropping a tooth but sometimes you just gotta go with the deal. I will work on my gearing accordingly and won't need to trim my rails. Am I gunna hate the loss of efficiency and the hit to the approach angle that much with 8t or will it not be bad and worth the deal. It will also let me go bigger lugged later on if I wanted.

 

[sorenson1610]

Go for it! Can always re sell them later on

 

[s1d3w1nd3r1480]

That's exactly what I was thinking.

 

[revster]

If you're a trail rider I'd stick with the 9ts.

 

[Supa Dexta]

Why? 8t is a gear down, and makes for a quicker point and shoot. Depends on your trails.

 

[s1d3w1nd3r1480]

I ride trails but not much anymore. Usually only because the majority of the group does on the trip. You usually catch me off the trail somewhere messing around. That's usually only the big trips too. Most weekend trips are completely backcountry. That's why I have made so many changes to my sled

 

[revster]

Why? 8t is a gear down, and makes for a quicker point and shoot. Depends on your trails.

I wouldn't say it's "gear down" you are changing your final drive. So it's not like changing the rear sprocket on a motorbike, it's like changing the size of the rear tire. It is a less efficient drive set-up which does not benefit trail riders that spend a lot of time at higher speeds. If you are an off trail rider and you are doing it to clear big lugs and push snow thru the tunnel that is another story. So that is why I asked. Not a lot of trail riders want to loose 10 mph off their top end.

Back when ski-doo was running 2.52 pitch tracks on the revs they were actually running 10t drivers on trail sleds. I had a set of 10t extros and 9t extros and switched them back and forth and played with my gearing to see what worked best.

 

[s1d3w1nd3r1480]

Ya I lost top end with the BC track and am not a lake racer. Most I do in trails is 70. Definitely not worried about losing speed.

 

[revster]

Ya I lost top end with the BC track and am not a lake racer. Most I do in trails is 70. Definitely not worried about losing speed.

Yeah 8ts will work for ya then, although not needed for 1.75." But you'll have room if you ever want to goto a larger lug.

 

[s1d3w1nd3r1480]

Well I picked them up today and will be installing tomorrow. I ran the stock drivers all last season with the BC and got by ok except in situations climbing or catwalking out where it would ratchet and stop me. I was just sick of the occasional ratchet to come at the worst times. I had all intentions of going 9t but the price was right and will leave me track options down the road. First trip is looking to be dec 28 so I'll report back on my opinions of the change

 

[Supa Dexta]

Why? 8t is a gear down, and makes for a quicker point and shoot. Depends on your trails.

I wouldn't say it's "gear down" you are changing your final drive. So it's not like changing the rear sprocket on a motorbike, it's like changing the size of the rear tire.

Not quite. You don't lose that much speed from a tire change. But a - front sprocket change will (gear down the front and/or gear up the rear sprocket on a bike) Which makes for quicker accel and easier wheelies, but also the loss in top speed as mentioned. Ive got the 8t with a 2" track, it pulls harrrd, and still goes plenty fast for the riding I do. Ill get some real world numbers for you guys on the top speed, but its still up there.

One tooth on drivers is equal to 2 in the chain case is what the general idea is. Taken from another site:

'Say you gear lower by 2 top teeth – that will reduce your peak mph by 6~8mph however for the upside of accelerating harder by 6%~7% to get to that peak mph.'

Some good reading here actually - http://www.ibackshift.com/article/gearing-150.asp

Ive also got an R1 and play with its sprockets -and tire size actually -

 

[revster]

Why? 8t is a gear down, and makes for a quicker point and shoot. Depends on your trails.

I wouldn't say it's "gear down" you are changing your final drive. So it's not like changing the rear sprocket on a motorbike, it's like changing the size of the rear tire.

Not quite. You don't lose that much speed from a tire change. But a - front sprocket change will (gear down the front and/or gear up the rear sprocket on a bike) Which makes for quicker accel and easier wheelies, but also the loss in top speed as mentioned. Ive got the 8t with a 2" track, it pulls harrrd, and still goes plenty fast for the riding I do. Ill get some real world numbers for you guys on the top speed, but its still up there.

One tooth on drivers is equal to 2 in the chain case is what the general idea is. Taken from another site:

'Say you gear lower by 2 top teeth – that will reduce your peak mph by 6~8mph however for the upside of accelerating harder by 6%~7% to get to that peak mph.'

Some good reading here actually - http://www.ibackshift.com/article/gearing-150.asp

Ive also got an R1 and play with its sprockets -and tire size actually -

Well if you don't believe me you should mount the rear wheel from a grom on your R1 and see what that does. (Other then look really awesome.) I may have mislead you by saying tire when wheel is the word I should have used. I am talking about if you took 20" rims off a bike and put 17" rims with the same profile tire.

I have a bike as well and have re-geared my bikes. I am also aware of Joe's site I use to sell clutch kits for him back in the Rev days.

I never said that your sled won't pull hard or it won't work well, cause of course it will. You have a 2" lug track, 8t is a good play for you. However I was suggesting that a trail rider who does not have large lugs to clear should not reduce their driver size.

You seem to be under the impression that as long as the final math adds up all things are equal, However this is not the case. On a bike if the front sprocket gets too small the chain has to make a tight turn around it which makes it less efficient. Your gearing selection can also effect the way the bike handles with the angle of the chain in relation to the angle of the suspension. It's a balance between the two sprockets. The same thing is true with sled drive systems. The smaller diameter drivers are less efficient and change the approach angle of the track where as going to a smaller sprocket does not do either. Plus it's waaaay cheaper. So the dropping 2 teeth on the top sprocket is NOT equal to 8t drivers.

I think we have to be careful giving guys advice before know what their particular application is. What works well for one guy may not be the best choice for another.