Riding all day in Cadillac area got us talking after a long day on the trails, as to what causes perfectly fine trails to turn into complete crap by the end of the day and cause the dreaded stutter bumps? I realize that trails get lots of traffic, but how does that cause the bumps?
Stutter bumps
- Thread starter biggdave
- Start date
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lenny
Guest
when you get into the throttle the suspension applies track pressure to the snow. You know how when you hit the flipper some sleds want to wheelie depending on how sus is set up thus pushing the track into the snow. If the sus is soft the sus goes up and down more and that pushes snow out or softens (loosens) the snow. The next sled does the same and sus absorbs the loose with the front of the skid and than in turn the rear of the skid rides over the loose pushing sled up. Sus comes back down and this happens over and over till sleds push up bigger and bigger. Has little to do with underlying unevenness but it only takes a bump to get the sus going up and down. Ever notice that the bumps get started most noticeable going up a hill when sled is under constant throttle. Sled has increased track pressure on snow because more resistance on incline. Sleds also push lots of snow out of corners when you hit the flipper and moguls get started. Straights hold up best because speeds are more consistent and acceleration starts from the corners. Enough traffic will create moguls in miles of straights on flat grades. Anything that causes the sus to move up and down starts the stutter but more so the natural dynamics of a sled under acceleration allows the sus to do the same.
Bottom line, sled pushes itself forward pushing snow backwards loosing the snow. Loose snow is displaced by next sled track pressure that pushes machine forward. Snow continues to be displaced over and over. Suspension accentuates the problem with up and down movement.
Bottom line, sled pushes itself forward pushing snow backwards loosing the snow. Loose snow is displaced by next sled track pressure that pushes machine forward. Snow continues to be displaced over and over. Suspension accentuates the problem with up and down movement.
shoelessjoe
New member
Yup, what lenny said. 
Basically one bump turns into two bumps and two into three and so on until it's just a bunch of bumps. Depending on the traffic levels and the snow conditions it can happen very quickly and despite the best efforts of the groomers there is only so much you can do.
Basically one bump turns into two bumps and two into three and so on until it's just a bunch of bumps. Depending on the traffic levels and the snow conditions it can happen very quickly and despite the best efforts of the groomers there is only so much you can do.
GOT to understand rebound in your rear suspension the bad ride is due to kick need to slow rebound down & getting front & rear to work together. My old outdated, heavy, Yamaha Apex Attak GT with the mono rear suspension cuts that stuff like butter. A little fine tuning on the fly with ohlin EC button & I fly thru that stuff always a sweet spot that is best. I like it just not a problem for me but others complain about manboob punishment & trail grooming SUCKS. To me you have to exspect it & just hit the hammer & ride & be able to tune rebound & everything AOK. So many just don't know how to ride studders or what to do about it a real shame.
So many just don't know how to ride studders or what to do about it a real shame.mjkaliszak
New member
Well another contributing factor is the sledders whom ride all night long, the groomers go out, the nightriders pound the un-set ribbon into smithereens all night long, They wake up at noon or 1:00 and go home.
I was at Caddy yesterday morning, we went that direction for our 1/2 day ride, figuring trails should be OK since around Cabrefea they do a pretty good job grooming, we were wrong things were hammered by 9:30 AM ???
Just saying.
I was at Caddy yesterday morning, we went that direction for our 1/2 day ride, figuring trails should be OK since around Cabrefea they do a pretty good job grooming, we were wrong things were hammered by 9:30 AM ???
Just saying.
shoelessjoe
New member
GOT to understand rebound in your rear suspension the bad ride is due to kick need to slow rebound down & getting front & rear to work together. My old outdated, heavy, Yamaha Apex Attak GT with the mono rear suspension cuts that stuff like butter. A little fine tuning on the fly with ohlin EC button & I fly thru that stuff always a sweet spot that is best. I like it just not a problem for me but others complain about manboob punishment & trail grooming SUCKS. To me you have to exspect it & just hit the hammer & ride & be able to tune rebound & everything AOK.
I guess if you can adjust on the fly that's a big advantage but in general I would set up your suspension as good as possible for the way you ride (trails, off trail, etc) and then adjust your speed to match conditions.
It's somewhat counter-intuitive and can take some people a while to realize it but often times the best way to ride the stutters is to increase your speed a bit. A lot of people get into the chop and want to slow down, that is usually the worst thing to do and you will end up hitting and feeling every single stutter. Speed up a bit and you will find a spot where you are just hitting the tops and it will smooth out a bit.
Been trying to convince my sister inlaw of that for years now and she just won't do it. Sucks cause her husband (who leads our group) will speed up and I (I ride in the back behind my sister inlaw) get to watch him cruise along smooth and pulling away while I bounce around. I usually fall way back and then blast back up so I can find the right speed and at least smooth out some of the run.
Well said Lenny!!!!! Two years ago in January we left Trout lake to go to new berry.. The normal crappy places aka the swamp was great and the places you could normally just let we rip were terrible not sure why it was weird you come out of the woods and trail runs along side the road before you go through some trees then cross the road the gas station that has the huge log there well litteraly 40 yards from turn i was doing 35 40 boom huge bumps and dips threw me from my sled and broke my ankle it was the �� day ever
thanks for the replies. I have to say that your answers make sense i could see how through the course of the day the constant track movement could affect the top layer of snow, and I know that going faster does help, but the area we were in wouldn't have allowed for that, tight twisting trails through the woods. All i know is that after riding those types of trails, I am sure beat up. Overall the trails were fantastic, it is nice to see snow again
polarisrider1
New member
I remember a girl in Jr. High (that's middle school for you youngin's) nicknamed "Stutter Bumps", we were so mean back then.
Here's a good read about trail grooming that covers how certain conditions form.
http://atfiles.org/files/pdf/Snow-Groomer-Training.pdf
http://atfiles.org/files/pdf/Snow-Groomer-Training.pdf
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lenny
Guest
that's a really good resource, thanks for posting it
First let me apologize for any spelling or grammar errors as I was always a "C" student in school. I do as much riding as possible in the northern lower Michigan, say from houghton lake to a little north of Gaylord. The bumps tend to get out of control during the day. I have read the link above and understand that the trail needs time to "set up"....but there has to be a better way! The groomer needs to be out 24/7 on the weekends. I know that the operators are volunteers and are doing the best they can with what they got. How can we make it possible for more grooming? Double, triple the price of trail permits to buy more equipment,supplies and maybe pay the nice guy driving the groomer? I know snowmobiling is already to expensive and if you have a family to buy trail permits for it can be really expensive. Maybe have a Jr rate trail permit for the kids and teens? I am open to ideas and look forward to hearing some. My final thought is after investing in the cottage, snowmobile, gas, time ect. It seems like we are going cheap on the grooming. Makes no sense. Also is there a way to find out what the groomers route and time schedule will be for an area?
You just don't get it. All the grooming in the world can not keep up with heavy traffic I have seen trails go to junk in 10-20 minutes with heavy traffic. It's not bucks & constant grooming that produces smooth trails. It is the type of snow you are grooming set time & of course the riders that ride the trails on a fresh groom. PM Lenny & he can give you tons of info but it is pretty dry stuff but at least you will have better understanding of why trails turn to junk & all part of the weather & sport.
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lenny
Guest
whitedust is correct, grooming 24/7 is just PR and a total waste of fuel, time, and effort as it yields no results. Trust me bud, I totally understand your perspective, I was there once. Trails need a good 2-3 hrs to set up for optimum durability depending on temps.
Are the trails you are referring to being groomed daily? Are they being groomed late after traffic has slowed? Are the groomers experienced and doing quality work? Trust me, grooming can be taken lightly with poor results if the individual doesn't understand how to work the machine and snow.
You mention you have a cottage, can you adjust your rides times better.
There are things that riders can do but just thinking about it is a real joke. Riders can slow down. If they cannot slow down they can lighten up on the hole shots and keep steady speeds up hill instead of accelerating. Ride the corners a bit slower. Think about it like this, Groomers usually leave a smooth trail but the sledders often abuse the trail so why not see the rider make the adjustments. It is more common than not for me to see with my very own eyes guys just rip onto a fresh groom right behind me. The worst time to let it rip is right behind the groomer but that is typical.
I am not making excuses just giving you facts and there is no more a groomer can do other than grooming daily, grooming late and doing a quality job, the rest is up to the riders to lookout for each other,,, and that my friend is the joke I was referring to earlier,,will never happen.
Are the trails you are referring to being groomed daily? Are they being groomed late after traffic has slowed? Are the groomers experienced and doing quality work? Trust me, grooming can be taken lightly with poor results if the individual doesn't understand how to work the machine and snow.
You mention you have a cottage, can you adjust your rides times better.
There are things that riders can do but just thinking about it is a real joke. Riders can slow down. If they cannot slow down they can lighten up on the hole shots and keep steady speeds up hill instead of accelerating. Ride the corners a bit slower. Think about it like this, Groomers usually leave a smooth trail but the sledders often abuse the trail so why not see the rider make the adjustments. It is more common than not for me to see with my very own eyes guys just rip onto a fresh groom right behind me. The worst time to let it rip is right behind the groomer but that is typical.
I am not making excuses just giving you facts and there is no more a groomer can do other than grooming daily, grooming late and doing a quality job, the rest is up to the riders to lookout for each other,,, and that my friend is the joke I was referring to earlier,,will never happen.
mezz
Well-known member
Here is the answer to all the trail woe's. This would have actually been nice to have put into use in the dry snows that we were getting consistantly to start. www.mtukrc.org/ksp.htm -Mezz
-MezzI remember one that some nicknamed thumb tacks, but wow did things change in high school. Can't be too much more ignorant than being a boy in jr high!
alwaysright
New member
The other thing to do (tough if you have a cottage your going to) is to find trails that aren't used as much. I used to go to the UP fairly regularly (3-4 times a winter) but have stopped. There are alot of trails all over the midwest that see alot less traffic. One of my new favorite spots is the north shore of MN, you can ride all day and maybe, on a busy day, see 30-40 sleds, in the UP, you can see 30-40 sleds at a single bar or gas station. I also like riding around hawyard wi, but that see's alot of traffic, but if you head to the east around Glidden and ride up to (not quite to hurley) and back it can be a fun day where you just don't see as many riders and therefore the trails are "generally" in better shape.
back to the trails and bumps, ever driven down a dirt road that is stutter bumps the whole way? it's due to the suspension in the car and is very similar to what's happening on our trails, good luck, hope you find better trails the rest of the year.
back to the trails and bumps, ever driven down a dirt road that is stutter bumps the whole way? it's due to the suspension in the car and is very similar to what's happening on our trails, good luck, hope you find better trails the rest of the year.
Snojoe what kind of sleds do you ride? Rider forward sleds take bumps much better than old sit down sleds. Newer sleds really do take bumps very well & I prefer 136 or 144 tipped as bridges those stutters & smooths the ride. Better to spend money on new sleds to help yourself than think you can buy better trails via increased grooming. I understand your problem but you have to approach the opportunity by what you can do for yourself vs thinking grooming 24/7 will help & infact would damage trails & reduce snow cover.