GLC43 jerking when accelerating after near stop
#26
The only time I use S+ is when I'm already doing freeway speed and I want to make moves or if I intend to floor it from a stop. This mode isn't intended to be used for slow speed driving. In stop and go traffic if I want to be aggressive then I use S.
I think the problem here is that you guys are using the mode in the wrong situations. Once I forgot it was in S+ and I started from a stop with partial throttle, it did the jerking thing. I let off the gas, put it in C and I was good to go.
Now, with that said, there shouldn't be any jerking while braking. Mine doesn't do that. While coming to a hard stop in S+, it will aggressively downshift and keep the revs high to aid braking. I've never tried it while gracefully slowing down; because if I was doing that I would switch to S or C.
I think the problem here is that you guys are using the mode in the wrong situations. Once I forgot it was in S+ and I started from a stop with partial throttle, it did the jerking thing. I let off the gas, put it in C and I was good to go.
Now, with that said, there shouldn't be any jerking while braking. Mine doesn't do that. While coming to a hard stop in S+, it will aggressively downshift and keep the revs high to aid braking. I've never tried it while gracefully slowing down; because if I was doing that I would switch to S or C.
#28
It's a throttle issue and you are crazy if you take it to a dealer and have them tear down the trans to find the "cause"...IMO. This isn't a Lexus LS. I believe in the manual it even states that you shouldn't be in Sport+ or driving like a bat out of hell until your trans warms up. The software is VERY aggressive in S+ and shifts aren't real smooth, even when warm, but they are quick and responsive. I agree the first time you experience it, you are like WTF, but it's all in probably millimeters of movement of the gas pedal on whether it happens or not and some can make it happen (or not) at will. If it's not to your liking, its probably not the vehicle for you...and that's ok. Some have been able to get a software update that helps fix it, but also neuters the vehicle from my understanding. Good luck.
the jerking issue is obviously related to being in bat**** mode before the car even knows you have turned it on. not even worth an hour visit to a dealer or me.
#29
The only time I use S+ is when I'm already doing freeway speed and I want to make moves or if I intend to floor it from a stop. This mode isn't intended to be used for slow speed driving. In stop and go traffic if I want to be aggressive then I use S.
I think the problem here is that you guys are using the mode in the wrong situations. Once I forgot it was in S+ and I started from a stop with partial throttle, it did the jerking thing. I let off the gas, put it in C and I was good to go.
Now, with that said, there shouldn't be any jerking while braking. Mine doesn't do that. While coming to a hard stop in S+, it will aggressively downshift and keep the revs high to aid braking. I've never tried it while gracefully slowing down; because if I was doing that I would switch to S or C.
I think the problem here is that you guys are using the mode in the wrong situations. Once I forgot it was in S+ and I started from a stop with partial throttle, it did the jerking thing. I let off the gas, put it in C and I was good to go.
Now, with that said, there shouldn't be any jerking while braking. Mine doesn't do that. While coming to a hard stop in S+, it will aggressively downshift and keep the revs high to aid braking. I've never tried it while gracefully slowing down; because if I was doing that I would switch to S or C.
"This mode isn't intended to be used for slow speed driving" - you obviously have not listened to the music iof the AMG exhaust in slow speed after a nice run. slow and sensuual. ok, i'll stop. cracking myself up.
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Mr. J (04-27-2019)
#30
i wouldn't say it is a power issue.
#31
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Mercedes-AMG GLC 63 4Matic+ Coupé 2017
Same thing here ... brand new 2019 GLC 63 Coupé (C253) demonstrated a jerkiness (almost like misfiring) when pulling away from standstill or slow speed.
Problem occurred from day one but doesn't happen all the time but very noticeable when it does and makes for apprehensive lack of confidence when pulling out into traffic.
I doubt very much that the problem is related to the transmission and is definitely not caused by poor foot management on the accelerator (FFS).
First revisit to dealership last week resulted in problem being attributed to "dirty" fuel when car originally collected, but two or three complete refills of 98RON petrol haven't cured the problem, so back it goes to the dealership this week.
Will post any update as and when we have one.
Problem occurred from day one but doesn't happen all the time but very noticeable when it does and makes for apprehensive lack of confidence when pulling out into traffic.
I doubt very much that the problem is related to the transmission and is definitely not caused by poor foot management on the accelerator (FFS).
First revisit to dealership last week resulted in problem being attributed to "dirty" fuel when car originally collected, but two or three complete refills of 98RON petrol haven't cured the problem, so back it goes to the dealership this week.
Will post any update as and when we have one.
#32
Member
Article from June 2017. Why were they even referencing it? Known annoyance? Yes!
"I also have to applaud Mercedes for not making throttle response overly sharp in Sport+ mode. That keeps smaller throttle applications from being abrupt, head jerking moments"
They will "look" at every issue you drag your ride back in for, even if they know there is no "real fix" just to make you think they are doing something about it. They will tear your gearbox apart and spread it all over the shop as many times as you ask them to, possibly creating other future issues in the process.
#33
Junior Member
so which is it? the thread seems to have started on this issue
"This thread is intended for GLC43 / GLC63 owners whose vehicles exhibit a jerking / bucking behavior when applying partial throttle from a low speed"
but some of you are describing an issue while braking. different problems I assume.
On the original issue, I experience it in my 19 GLC63 but only after first cold start of the day and immediately starting to drive in Sport+ or Individual mde which is mostly Sport+ for my setting.
Did that specific issue get any resolution whatsoever?
"This thread is intended for GLC43 / GLC63 owners whose vehicles exhibit a jerking / bucking behavior when applying partial throttle from a low speed"
but some of you are describing an issue while braking. different problems I assume.
On the original issue, I experience it in my 19 GLC63 but only after first cold start of the day and immediately starting to drive in Sport+ or Individual mde which is mostly Sport+ for my setting.
Did that specific issue get any resolution whatsoever?
1) Thread title: Jerking when accelerating after near stop
2) My problem: Jerking while braking to a full stop
Maybe I should try accelerating instead of coming to a full stop and see what happens. The car in front of me may not be happy about my little experiment
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viper3ez (04-23-2019)
#34
lol. I drive in sport+ 90% of the time, and have only driven in comfort for a few minutes by mistake. I know the 43 and 63 are both 9spd but they aren't the same transmission are they? Interesting that they exhibit the same issues.
on "using the mode in the wrong situations", speak for yourself "BRO". if there was a wrong mode for sport plus, i would have bought a GLC300.
"This mode isn't intended to be used for slow speed driving" - you obviously have not listened to the music iof the AMG exhaust in slow speed after a nice run. slow and sensuual. ok, i'll stop. cracking myself up.
"This mode isn't intended to be used for slow speed driving" - you obviously have not listened to the music iof the AMG exhaust in slow speed after a nice run. slow and sensuual. ok, i'll stop. cracking myself up.
#35
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Mercedes-AMG GLC 63 4Matic+ Coupé 2017
Car goes back to the dealer next week. Will advise any outcome but for the avoidance of doubt:-
The problem happens in Comfort mode.
Any suggestion of operator malfunction or driver incompetence is, frankly, rude and ignorant. We have driven cars with higher power-to-weight ratios than the GLC 63 - with and without slush-boxes - and not had this problem before.
It definitely seems like a fuelling problem and who are we to disagree if the dealer's initial suspicion (guess) is that dirty petrol might be the cause? Doesn't mean to say we believed them then and they don't believe it now either.
The problem happens in Comfort mode.
Any suggestion of operator malfunction or driver incompetence is, frankly, rude and ignorant. We have driven cars with higher power-to-weight ratios than the GLC 63 - with and without slush-boxes - and not had this problem before.
It definitely seems like a fuelling problem and who are we to disagree if the dealer's initial suspicion (guess) is that dirty petrol might be the cause? Doesn't mean to say we believed them then and they don't believe it now either.
#36
MBWorld Fanatic!
My 2017 GLC43 exhibited both the described conditions in this thread.
1. Bucking/jerking/lurching on acceleration:
A. It would sometimes "buck" in S+ especially after an incident of moderate-hard braking and after the transmission had downshifted. This was easily repeatable on winding steep roads with "switchback" turns.
B. Throttle tip in for S+ was unnecessarily aggressive. Yes, S+ should be more aggressive but I was consistently getting WOT with very little depression of the pedal. It was drastically different than C or S. So much so that it was very difficult to transition smoothly since muscle memory would have you press much more than required and now you're at 90% of WOT with barely any pedal travel. It was manic, and not in a fun way. I basically just stopped using S+ and reprogrammed my Individual mode for S drive, and S+ for steering and suspension.
C. In comfort mode, my vehicle would hold 2nd on aggressive acceleration. "Pretty cool", you're thinking right? Well it would do it all the way up to redline even with the oil temp below 60 deg F. Not cool. I learned to be careful accelerating onto high speed roads when cold and I manually shifted to avoid over-revving a cold motor.
2. Jerking/Lurching while coming to a stop:
Mine did this on occasion. It was most noticeable when fully warmed up and driving in S. Basically slowing in 1st gear made the issue noticeable to passengers. In second gear it's only noticeable to an attentive driver. I initially thought it was a problem with the gearbox. Upon further observation I noticed that the when the charging meter modulated my braking force did as well. This was only noticeable at slow deceleration with minimal braking force, think creeping up to a stoplight. Just before stopping the car would lurch to a halt if linear braking was applied. It felt like you would expect if the driver was increasing the braking pressure while coming to a stop. I adapted to this by reducing my braking force while decelerating then increasing again just as prior to full stop, or I just drove in C if I had passengers on board. This is not the normal way to brake any vehicle in fact it was a PITA since it runs contrary to all my driver training and decades of muscle memory that I've ingrained.
So I just brought the car in for B service. I had complained about issues 1. A, 1.B, and 2 at another dealership and they just told me: "normal characteristic of the car blah...blah....". Well I mentioned issue 1. C to the service department that I'm currently using and they took that one seriously and updated software for engine and transmission control. This update appears to have fixed all of my issues. I'm still testing now, but so far so good.
And yes, some of us do own faster more aggressive cars than the GLC and some of us actually do know how to drive a motor vehicle well. Suggesting that this is all driver induced is BS.
The solution appears to be: document your issues, clearly and concisely explain them to your SA, politely insist they check for software updates, change SA's and/or service centers if they gaslight you.
1. Bucking/jerking/lurching on acceleration:
A. It would sometimes "buck" in S+ especially after an incident of moderate-hard braking and after the transmission had downshifted. This was easily repeatable on winding steep roads with "switchback" turns.
B. Throttle tip in for S+ was unnecessarily aggressive. Yes, S+ should be more aggressive but I was consistently getting WOT with very little depression of the pedal. It was drastically different than C or S. So much so that it was very difficult to transition smoothly since muscle memory would have you press much more than required and now you're at 90% of WOT with barely any pedal travel. It was manic, and not in a fun way. I basically just stopped using S+ and reprogrammed my Individual mode for S drive, and S+ for steering and suspension.
C. In comfort mode, my vehicle would hold 2nd on aggressive acceleration. "Pretty cool", you're thinking right? Well it would do it all the way up to redline even with the oil temp below 60 deg F. Not cool. I learned to be careful accelerating onto high speed roads when cold and I manually shifted to avoid over-revving a cold motor.
2. Jerking/Lurching while coming to a stop:
Mine did this on occasion. It was most noticeable when fully warmed up and driving in S. Basically slowing in 1st gear made the issue noticeable to passengers. In second gear it's only noticeable to an attentive driver. I initially thought it was a problem with the gearbox. Upon further observation I noticed that the when the charging meter modulated my braking force did as well. This was only noticeable at slow deceleration with minimal braking force, think creeping up to a stoplight. Just before stopping the car would lurch to a halt if linear braking was applied. It felt like you would expect if the driver was increasing the braking pressure while coming to a stop. I adapted to this by reducing my braking force while decelerating then increasing again just as prior to full stop, or I just drove in C if I had passengers on board. This is not the normal way to brake any vehicle in fact it was a PITA since it runs contrary to all my driver training and decades of muscle memory that I've ingrained.
So I just brought the car in for B service. I had complained about issues 1. A, 1.B, and 2 at another dealership and they just told me: "normal characteristic of the car blah...blah....". Well I mentioned issue 1. C to the service department that I'm currently using and they took that one seriously and updated software for engine and transmission control. This update appears to have fixed all of my issues. I'm still testing now, but so far so good.
And yes, some of us do own faster more aggressive cars than the GLC and some of us actually do know how to drive a motor vehicle well. Suggesting that this is all driver induced is BS.
The solution appears to be: document your issues, clearly and concisely explain them to your SA, politely insist they check for software updates, change SA's and/or service centers if they gaslight you.
Last edited by Mr. J; 04-27-2019 at 11:59 AM.
#37
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2014 - W212 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
GLC43 and GLC63 do not share the same transmission.
GLC43 has torque converter aka normal automatic gear, but with more aggressive shifting profile.
For some reason unknown it is called AMG Speedshift TCT, Torque Clutch Transmission...what a weird name for a common torque converter type automatic transmission.
GLC63 uses AMG Speedshift MCT , multiclutch and has no torque converter.
Those with TCT ( GLC43 ) best ask a senior MB workshop engineer, what makes a this gearbox any "faster" than the so called normal 9 speed Gtronic ?
If it is only software based and no mechanical improvement for actual faster shifting .....hhhmmmm ... make your own guess.
.
GLC43 has torque converter aka normal automatic gear, but with more aggressive shifting profile.
For some reason unknown it is called AMG Speedshift TCT, Torque Clutch Transmission...what a weird name for a common torque converter type automatic transmission.
GLC63 uses AMG Speedshift MCT , multiclutch and has no torque converter.
Those with TCT ( GLC43 ) best ask a senior MB workshop engineer, what makes a this gearbox any "faster" than the so called normal 9 speed Gtronic ?
If it is only software based and no mechanical improvement for actual faster shifting .....hhhmmmm ... make your own guess.
.
#39
Senior Member
Lol. GLC AMGs have this problem also? I have a 2016 E63 with the prev gen 7-speed trans and it's got a long and sordid reputation for this issue, and is one of the reasons I'm getting rid of the car. GLC63 is first on my list, and I thought surely with the new 9-speed this must have been fixed. Should I just get a Hellcat?
#42
The throttle response in Sport+ is very "touchy" and probably not the best setting for the street. I've experienced the "jerking" a few times and certainly wakes you up. You either need to mash the throttle or use the paddles to overcome...kinda how these vehicles are meant to be driven.
I agree it's annoying and can be frightening when it happens, but will live with it, as I'm not sure MB's "fix" will do anything other than neuter the car. These vehicles can take the abuse, so mash away. Just my .02.
I agree it's annoying and can be frightening when it happens, but will live with it, as I'm not sure MB's "fix" will do anything other than neuter the car. These vehicles can take the abuse, so mash away. Just my .02.
You hit the nail on the head. Not best setting for street and designed to be mashed like when you’re racing.
These dudes need to get a manual sports car with like power. If they’re sitting loose in their seats and gas it in 1st the car will jerk forward appropriately and their body will then move back and forth in their seat going from accelerate to engine breaking in gear and thus their gas foot will move back and forth and that’s being applied to the gas peddle and the car is responding appropriately. The dealership ‘fix’ to this is detuning first and second gear to limit throttle input and engine breaking from the gas peddle. Not a problem with the vehicle it’s a problem with the driver.
Last edited by BAMBAMODA; 05-30-2019 at 12:13 PM.
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Chrisk03 (05-30-2019)
#43
It's a throttle issue and you are crazy if you take it to a dealer and have them tear down the trans to find the "cause"...IMO. This isn't a Lexus LS. I believe in the manual it even states that you shouldn't be in Sport+ or driving like a bat out of hell until your trans warms up. The software is VERY aggressive in S+ and shifts aren't real smooth, even when warm, but they are quick and responsive. I agree the first time you experience it, you are like WTF, but it's all in probably millimeters of movement of the gas pedal on whether it happens or not and some can make it happen (or not) at will. If it's not to your liking, its probably not the vehicle for you...and that's ok. Some have been able to get a software update that helps fix it, but also neuters the vehicle from my understanding. Good luck.
Didn't read this. Just stated the same thing. Sucks because now I need to make sure the dealership doesn’t apply this ‘update’ and make my car less race like.
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Chrisk03 (05-30-2019)
#44
Senior Member
As far as updates go if it is anything like the one the W205 C63s guys got it just makes the car a little more refined. I don’t know exactly if there is a update or not. I stay in the w205 forums as well just because we are just about the same build
#45
Member
On another note.... For me, I've also found wearing flip flops really induces it bad. Pretty much every time I drive with flip flops now that it's warm out, boom! 100% driving time spent in Sport +, so I can't flip the dynamic switch back fast enough when it starts. I usually just lift off all together and sorta look to the side direction at something until it calms down to hide the embarrassment lol. The other problem.... I wear Piloti racing shoes the other 99.9% of the time, which I've done for the last 15+ years, so I think my foot movement and feeling has become habitual with the GLC and the aggressive nature of sport plus. Drove the Sportage the other day and I felt like I had to keep it to the floor in 1st to get any where. Checking it for throttle/turbo issues haha
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Chrisk03 (05-30-2019)
#47
I see people seemingly talking about separate issues. I haven't experienced the suspected "jerkiness" in Sport+ on my 43. Sport+ mode seems to always have you in the correct gear to accelerate. I prefer the feel of the car in Sport+, but don't use it all the time. Depends on whether I feel like driving aggressively at the moment. I do love the sound/feel of the backfires. Could that be what people are experiencing?
What I have experienced is, in comfort mode... I hit the gas and after a bit of acceleration, it seems to slowly switch to 2nd gear. It hits the gear and then after a little more throttle, goes to third. IIRC, this is all at sub 20mph speeds. If I have a slight turn on the wheel, it exacerbates it. I noticed this on the test drive, but it didn't really bother me. To be honest, it felt like some sort of adaptive driving that was tuned to someone other then me. I notice this at casual driving speeds. Not pedal pounding. If I'm pedal pounding, I'm in S+ mode.
What I have experienced is, in comfort mode... I hit the gas and after a bit of acceleration, it seems to slowly switch to 2nd gear. It hits the gear and then after a little more throttle, goes to third. IIRC, this is all at sub 20mph speeds. If I have a slight turn on the wheel, it exacerbates it. I noticed this on the test drive, but it didn't really bother me. To be honest, it felt like some sort of adaptive driving that was tuned to someone other then me. I notice this at casual driving speeds. Not pedal pounding. If I'm pedal pounding, I'm in S+ mode.
#48
I see people seemingly talking about separate issues. I haven't experienced the suspected "jerkiness" in Sport+ on my 43. Sport+ mode seems to always have you in the correct gear to accelerate. I prefer the feel of the car in Sport+, but don't use it all the time. Depends on whether I feel like driving aggressively at the moment. I do love the sound/feel of the backfires. Could that be what people are experiencing?
What I have experienced is, in comfort mode... I hit the gas and after a bit of acceleration, it seems to slowly switch to 2nd gear. It hits the gear and then after a little more throttle, goes to third. IIRC, this is all at sub 20mph speeds. If I have a slight turn on the wheel, it exacerbates it. I noticed this on the test drive, but it didn't really bother me. To be honest, it felt like some sort of adaptive driving that was tuned to someone other then me. I notice this at casual driving speeds. Not pedal pounding. If I'm pedal pounding, I'm in S+ mode.
What I have experienced is, in comfort mode... I hit the gas and after a bit of acceleration, it seems to slowly switch to 2nd gear. It hits the gear and then after a little more throttle, goes to third. IIRC, this is all at sub 20mph speeds. If I have a slight turn on the wheel, it exacerbates it. I noticed this on the test drive, but it didn't really bother me. To be honest, it felt like some sort of adaptive driving that was tuned to someone other then me. I notice this at casual driving speeds. Not pedal pounding. If I'm pedal pounding, I'm in S+ mode.
Someone above was saying the 43s have some sort of tq converter that the 63s don’t. So I can see that adding shift time and giving a user more car movement when the next gear takes. But again this is apart of any vehicle. Manuals have it bad if you’re shifting inside ideal RPMs but daily relaxed driving you can make it smooth just by easy shifting. Most transmissions are geared and mapped for fuel economy over performance. Not sure which transmission the 43 has but I’d bet the gearing was selected for a performance sports car and when you’re not super low to the ground, stiff suspension and flat with a performance sports car you’re gonna get more feel in your pants during shifting. I can’t think of any sport vehicle I’ve driven that doesn’t have this same effects. The large sport SUVs just carry so much weight they’re significantly more sluggish so the 1-2 gear changes are not the same. Only ‘fix’ would be to change the allowed throttle input max for the 1-2 gears which will slow it down and eat up your 0-60 performance
well it can also be regeared but that would take away from the 0-60 times.
Must be a 43 only thing with tq converter
Last edited by BAMBAMODA; 05-30-2019 at 04:27 PM.
#49
Been trying to tell em
On another note.... For me, I've also found wearing flip flops really induces it bad. Pretty much every time I drive with flip flops now that it's warm out, boom! 100% driving time spent in Sport +, so I can't flip the dynamic switch back fast enough when it starts. I usually just lift off all together and sorta look to the side direction at something until it calms down to hide the embarrassment lol. The other problem.... I wear Piloti racing shoes the other 99.9% of the time, which I've done for the last 15+ years, so I think my foot movement and feeling has become habitual with the GLC and the aggressive nature of sport plus. Drove the Sportage the other day and I felt like I had to keep it to the floor in 1st to get any where. Checking it for throttle/turbo issues haha
On another note.... For me, I've also found wearing flip flops really induces it bad. Pretty much every time I drive with flip flops now that it's warm out, boom! 100% driving time spent in Sport +, so I can't flip the dynamic switch back fast enough when it starts. I usually just lift off all together and sorta look to the side direction at something until it calms down to hide the embarrassment lol. The other problem.... I wear Piloti racing shoes the other 99.9% of the time, which I've done for the last 15+ years, so I think my foot movement and feeling has become habitual with the GLC and the aggressive nature of sport plus. Drove the Sportage the other day and I felt like I had to keep it to the floor in 1st to get any where. Checking it for throttle/turbo issues haha
Id take your flip flops to MB and say something’s wrong with the car but you have to test drive it with my flip flops on. Haha.
Never wore car racing shoes. They look cool. Had motorcycle shoes for a liter bikes.....because I wanted my ankles to look good in the coffin.
#50
Member
Id take your flip flops to MB and say something’s wrong with the car but you have to test drive it with my flip flops on. Haha.
Never wore car racing shoes. They look cool. Had motorcycle shoes for a liter bikes.....because I wanted my ankles to look good in the coffin.
Never wore car racing shoes. They look cool. Had motorcycle shoes for a liter bikes.....because I wanted my ankles to look good in the coffin.
Finally, a sense of humor. That flip flop idea would be priceless to video.
The racing shoe thing started back in the early 90's for me. Back then, a 11, or even a 12 second import was sort of a big deal and not common on the east coast, and honestly the ignorant techs really didn't know much about the imports, so they would just give stuff a quick look and go. It was more of a "your sh it all looks tight and straight, so roll on". Well, once I dipped into the 11's with my Eclipse, they said I would need some sort of fire retardant clothing, a helmet, 4-point harness, and laceless/velcro covered flame retardant racing shoes to match. The closest place I could find that next week, was some shop in Philly that had these nice looking Piloti "driving" shoes on display, and in my size. They were pricey(90's) at $140, but I didn't have a choice if I wanted to run the next weekend. So basically, I tucked the laces into the sides of the shoes, said they were flame retardant, and they became "Shoes that pass tech" so I stocked up lol.
Fast forward a few weeks, and they had become the most comfortable shoes I'd ever owned. It's like walking became easier, lighter, and holy hell could I feel the pedals, and heel and toe was like cutting air. So I bought every color and style they offered. I've accumulated around 20 pairs over the years.
If you guys have never used driving/racing shoes to well.... drive or race, then you don't know what your missing. Remember those rounded heel shoes they came out with a few years back that helped you walk easier and helped with back issues??? All based off of driving shoes.
Down side.... The soles are also very thin on racing/driving shoes by design, so wearing them on any surface(gravel etc) that's not smooth, will be some what annoying and uncomfortable. Now if Sparco would make some low cuts, I'd be a happy man lol