# PSA: Don't Put Bike Rack Too Close to Exhaust



## Tyrone Shoelaces (Nov 6, 2006)

....or risking melting your carbon fiber rim as I did this weekend.

In 20ish years of cycling and driving I have never heard of this, so perhaps my mistake will prevent it from happening to you.

Car is brand new to (to me) for about 2 weeks and a week ago I got a 2" receiver hitch installed and Kuat NV hitch rack. Stuck the rack in the receiver, snugged it down, boom nice and tight solid and done...or so i thought.

Then yesterday after about 75 minutes of freeway driving to the trailhead I got out of the car and as we were getting ready I noticed that my front tire was completely flat and Stans was dripping out. I was confused because I knew the tire was solid and there was plenty of air in there in the morning, then upon closer inspection I saw that my carbon rim (the stock Giant P-XCR0 that came with my Trance) had a big crease in and was kind of folded. I went to touch it was HOT. Nearly too hot to touch. Then i realized that my car exhause basically melted it

If it was an alu rim i'm sure the tire would have blown or something. My tire in this case seems fine (WTB Vigilante TCS)

So anyway, head's up. Pass it on. Don't let it happen to you.

This is what the rim looked like as i took off the bike rack








14 inches. Direct in line of fire is no bueno. Car/rack combo in this case is a 2011 BMW X5 with a Kuat NV. I've since noticed that Thule racks might sit up a little higher so i guess my options are 1) find a rack that places wheel further away or higher than exhaust, 2) divert exhaust away, or 3) make some kind of heat shield for existing rack. 








What rim looks like today. It kind of split after the heating and cooling. That crap in the split is dried up Stans. Stan's didnt seal the crack! Wtf!!? Hahaha ;-)








Some of you might be saying "well no ****, you got what you deserved"...but honestly, the thought of this happening never even entered my mind. Nor had it entered into the minds of the 8 other experienced riders that I was riding with yesterday. So hopefully my expensive lesson learned will prevent this from ever happening to some of you.


----------



## PauLCa916 (Jul 1, 2013)

Depending how much room you have in your car couldn't you just remove wheels ?
Sorry to hear this happened to you there was a post in the forums about it awhile back.


----------



## rox (Aug 30, 2008)

learned this the hard way too on a trip to northstar. was using a trunk mount rack that let my front tire hang kind of low. noticed it but didnt really think that much of it because there was a good 1-1.5 foot clearance between the bike and car. wondered what that loud pop sound was around auburn, found out when I reached the parking lot. this was before carbon rims so the wheel seemed ok but the tire was another story.


----------



## gsa103 (Sep 1, 2014)

Bummer though. I've definitely heard of that happening, so I made sure to check it with my rack. 

I think the main issue isn't the horizontal distance, its the vertical distance. My rack (Raxter) comes out and then sits up ~8" inches from the hitch point. It looks like your tire mount is only up ~3" putting it directly in line with the exhaust. Two steel plates bolted to the round bar should fix it, but the simpler solution is probably to get a different rack.


----------



## LJ0913 (May 28, 2004)

PauLCa916 said:


> Depending how much room you have in your car couldn't you just remove wheels ?
> Sorry to hear this happened to you there was a post in the forums about it awhile back.


His rack requires the wheels to be on.

That sucks!


----------



## thickfog (Oct 29, 2010)

Deserve it? Why? That's surprising.


----------



## Tyrone Shoelaces (Nov 6, 2006)

thickfog said:


> Deserve it? Why? That's surprising.


Ha. I dunno. Just being hard on myself


----------



## Procter (Feb 3, 2012)

Wow thanks for tips. Surprised by this I'll keep an eye on my bikes on short drives and see if there's any heat buildups. I have a new hitch rack but I have only used it for one of my bikes without carbon rims, so I'm wondering if this would be a problem for my other bikes.

If you're willing to risk it again you might try with an 8in extension like this one:
Hitch Extender for 2" Trailer Hitches - 8" Long Hidden Hitch Hitch Accessories 80307

But I agree the issue looks more like the fact that its the direct line of fire, not necessarily the distance.

So you could also try one of these - use it to either raise or lower, your choice - raising probably safer overall:

Hi-Low Hitch 10" 10,000 lb - By Roadmaster


----------



## pwu_1 (Nov 19, 2007)

Enve has an article about that. It says the wheel has to be at least 18 inches away from the exhaust and must not be directly in the path of the exhaust, even if it's more than 18 inches away. 
Here is a link to the article --> https://enve.zendesk.com/hc/en-us/articles/201458669-Exhaust-Heat-Warning


----------



## Tyrone Shoelaces (Nov 6, 2006)

Procter - hey that Hi-Low Hitch you linked might be the ticket for me. I will look into it more.

What is slightly strange is that this is not the longest drive I have taken with a carbon rim sitting in the "line of fire" position. Last weekend on my rack's maiden voyage I transported road bikes with carbon rims to and from Folsom and Napa. Which is a further drive (twice) than my Folsom to Strawberry drive that caused the damage yesterday. Looking back, why didn't the carbon road bike rim melt (a Reynolds) on longer drives but my MTB rim did on a shorter drive? Any theories?


----------



## Buzzaro (Jan 27, 2008)

Tyrone Shoelaces said:


> Looking back, why didn't the carbon road bike rim melt (a Reynolds) on longer drives but my MTB rim did on a shorter drive? Any theories?


Ambient temperature? More rubber on the MTB tire to catch and hold more heat?


----------



## Tyrone Shoelaces (Nov 6, 2006)

Buzzaro said:


> Ambient temperature? More rubber on the MTB tire to catch and hold more heat?


I thought of ambient temp as well, but it was lot warmer when I drove home from Napa to Folsom with the road bike last Saturday afternoon (90's?) vs Sunday morning from Folsom to Strawberry (upper 60's?).

More rubber on MTB theory could be true.

The ENVE article that was linked above mentions that it's the resins and not the carbon itself that breaks down. Perhaps there is a difference in the amount of resin in the Reynolds road bike rim vs the Giant MTB rim (ie less in the road rim so it doesn't heat up as much).

The only other notable difference in comparing both situations is that the road bike was tubed and the MTB was setup tubeless. Not sure if that means anything though. Hell, maybe the Stan's in the MTB rim started to boil heating it up even more from the inside....hmmmm?

Just spitballing..


----------



## BStrummin (Nov 17, 2009)

Maybe there was more hot exhaust coming out of the tail pipe on the way up 50 than going across the valley to Napa? Did you have them both installed at the same place? I'd make sure they knew about this. Not for compensation necessarily but sheesh, a big fat exhaust pipe can put out some warm air. I've seen at least two coolers on those steel hitch mounted trays have large holes melted right into them.


----------



## Tyrone Shoelaces (Nov 6, 2006)

BStrummin said:


> Maybe there was more hot exhaust coming out of the tail pipe on the way up 50 than going across the valley to Napa?


Could be....I was most certainly on the gas more during the drive up 50 and into the mountains as compared to relatively steady highway driving across the valley.



> Did you have them both installed at the same place?


Nah I had the hitch installed at a local U-Haul place that does these installations all the time. Then bought bike rack at my LBS and put together and installed it myelf


----------



## Buzzaro (Jan 27, 2008)

Tyrone Shoelaces said:


> I thought of ambient temp as well, but it was lot warmer when I drove home from Napa to Folsom with the road bike last Saturday afternoon (90's?) vs Sunday morning from Folsom to Strawberry (upper 60's?).
> 
> More rubber on MTB theory could be true.
> 
> ...


Does the road bike have rim brakes? If so those wheels are likely engineered for higher temps.


----------



## Tyrone Shoelaces (Nov 6, 2006)

Buzzaro said:


> Does the road bike have rim brakes? If so those wheels are likely engineered for higher temps.


Good point. Yes. Rim brakes on the roadie.


----------



## Sean Allan (May 4, 2005)

Ron,
How do you know the road wheel isn't compromised? I'm not an engineer, but I've had plenty of carbon stuff fail that looked perfectly fine. Check that thing over real good.


----------



## Tyrone Shoelaces (Nov 6, 2006)

Sean Allan said:


> Ron,
> How do you know the road wheel isn't compromised? I'm not an engineer, but I've had plenty of carbon stuff fail that looked perfectly fine. Check that thing over real good.


I was just thinking the same thing Sean. Thx.


----------



## mbmtb (Nov 28, 2013)

this was def. something i checked when getting a hitch rack. don't remember if it was discussions here or in the instruction manual for the bike or what. i've definately melted reflectors in the past with exhuast in a different setup.

the kuat goes straight back from the hitch? some others go up, partly for clearance, partly for this. and i think you can get some heat deflectors.


----------



## fgiraffe (Aug 30, 2004)

Bummer man, that sucks. I'm honestly surprised that with 14" of clearance the resins still melted. Was there a lot of stopped traffic? Seems like at freeway speeds there would be enough airflow to cool the exhaust temp down. 

Sorry you found out the hard way.


----------



## Tyrone Shoelaces (Nov 6, 2006)

fgiraffe said:


> Bummer man, that sucks. I'm honestly surprised that with 14" of clearance the resins still melted. Was there a lot of stopped traffic? Seems like at freeway speeds there would be enough airflow to cool the exhaust temp down.
> 
> Sorry you found out the hard way.


Yeah none. No stopped traffic at all. Just a straight interrupted shot up 50. Think I slowed for one of the Placerville lights and that is all


----------



## fourarm (Jan 6, 2004)

Tyrone Shoelaces said:


> Yeah none. No stopped traffic at all. Just a straight interrupted shot up 50. Think I slowed for one of the Placerville lights and that is all


I have the same car and have been using a Yakima Hold-up for 3 years with no problems. Just curious, is it a diesel...the exhaust may run warmer than regular gas. Also, I think I remember reading somewhere that if you aren't boosting it most of the exhaust comes out one side.

Edit: pic attached

View attachment 929421


----------



## Brewtality (Jul 25, 2007)

Much higher loads required for driving up 50. Elevation and road gradient combine to create significantly higher exhaust temps. Napa is a comparatively easy cruise.


----------



## Tyrone Shoelaces (Nov 6, 2006)

fourarm said:


> I have the same car and have been using a Yakima Hold-up for 3 years with no problems. Just curious, is it a diesel...the exhaust may run warmer than regular gas.


Nah not diesel. Just the regular inline 6.


----------



## Passenger13 (Oct 17, 2006)

Great, right after I make up my mind to go with trailer hitch/bike carrier over roof rack, I have to read this!?! I am going to measure the vertical distance on my exhaust before I make a purchase.


----------



## cwix (Nov 25, 2008)

Thanks for the heads up on this. Am so sorry about your rim. I wouldn't have given that a thought either!

I'm right in the process of choosing a Kuat rack to put on a BMW x1- just about your same set up. It looks like the Sherpa (as opposed to the NV) may ride a little higher out of the heat zone. The x1 has two exhausts right next to each other -though the engine's smaller. A little heat shield sounds like the ticket if needed.

I don't even have carbon rims. Still, someday, perhaps. 

Thx again for the post about this Ron. Hope you found a way to get in a good ride that day.


----------



## TahoeBC (Apr 11, 2006)

The impressive part was he finished our planned Sayles Canyon ride manualing the whole thing


----------



## rox (Aug 30, 2008)

its definitely from engine load. just cruising on a flat highway doesnt get the rack/rim hot enough with all the air cooling and low throttle. but under load on a long sustained climb like going to tahoe the exhaust is much hotter and will eventually heat the tire or rim to failure


----------



## Tyrone Shoelaces (Nov 6, 2006)

cwix said:


> .
> 
> Thx again for the post about this Ron. Hope you found a way to get in a good ride that day.


Thanks and I did. Thanks to some quick thinking by Tahoe BC, he immediately called up Watta Bike in Myers explained the situation, and they hooked me up (on very short notice and at a great price) with a demo Rip9 for the day. It was a size too big but it worked out. Ken from Watta Bike even was happy to come back to the shop after closing hours because he knew we'd be on an all day adventure. Long live this great LBS!

Photo Credit: Empty Beer


----------



## Axe (Jan 12, 2004)

Yikes.

Off to check how far away my 1-up is... but so far so good, my r-class exhausts is kinda low..


----------



## cwix (Nov 25, 2008)

Ironic; I ride a Rip9.

From those two prime photos it's clear to see you had a boom great ride, right there.
Comrades to help ya out, find a way through. The essence of MTB.

Sayles Canyon looks awesome. Props to Empty Beer on the camera!


----------



## ancient rascal (Mar 2, 2010)

*Happy Tuesday !*

This thread reminds me of a really bad joke ... Did you know that Dan White is not really dead? :drumroll: ... He's just exhausted ! :nono: Off to Half moon Bay with the GF now ... carry on! :thumbsup:


----------



## mtbne1 (Apr 7, 2008)

Oh crap Ron.....I have a 2014 X5 and I just bought and assembled the same rack. I have not used it yet but will be driving up to the Weaverville 9 to 5 in a couple of weeks with two bikes attached. That is a long drive so this has me concerned. Time to take a close look at the clearances between the two tail pipes and the rack. Crap!


----------



## TahoeBC (Apr 11, 2006)

Maybe something like this will work? try it out with your new carbon wheel and report back 

Dual Purpose 2 Hitch Adapter


----------



## mtbne1 (Apr 7, 2008)

I like that and it looks like an inexpensive alternative rather than worrying if I'm going to fry my bike......and certainly waaaay less expensive than a carbon wheel. Thanks for sharing that.....


----------



## 06HokieMTB (Apr 25, 2011)

I melted a large Kelty duffle bag AND a hard plastic coffee travel mug (as well as some other assorted camping gear) on a way to Moab 2 years ago. It was in a hitch mounted cargo rack.

Like the PO, I didn't even think about the possibility of stuff melting.

Both of my bikes have carbon wheels, but my Thule rack sits high (both hitches are in the middle of the bumper)


----------



## ziscwg (May 18, 2007)

I know it's ugly, but a piece of cheap ceramic or porcelain tile (the right size) right in front of the wheel could mitigate this to some degree. It would have to be angled correctly for the hot air flow down and away from the bike.


----------



## 1WD (Sep 4, 2014)

You could buy some metal flanges that mount onto the exhaust ports and re route the flow of air to the sides or the ground. It would be relatively cheap to find the parts to make the routers. The hardest part would be figuring out the best way to mount the system.... Magnets perhaps.


----------



## Axe (Jan 12, 2004)

Ain't all those exhaust tips just a decoration? Any way to make one that points downwards?


----------



## nov0798 (Nov 27, 2005)

Make a heat shield.


----------



## OCDKV (Jul 7, 2014)

Just a suggestion, Turndown Exhaust Tips. I use them on my Harley to blow the exhaust heat away from my fat back tire.

A quick Google search turned these up:

Gibson Turndown Exhaust Tip, Gibson Turndown Exhaust System Tips

Borla Turndown Exhaust Tip, Borla Turndown Exhaust System Tip

MBRP Turndown Exhaust Tip, MBRP Turndown Exhaust System Tips

Sucks that this happened. Thanks for sharing.


----------



## tigris99 (Aug 26, 2012)

Being ur vehicle, turn down tips imo would be bad (risk heat transfer to bumper).

An old thread like this saved me, but my car isn't affected by a turn down tip. Also ran into the melting stuff on cargo rack a few years back....wasnt pleased then definitely feel for u.

In this case, price of sheet aluminum and a couple pieces of aluminum 1/8 or 1/4x 1 flat stock, fab up a heat shield to deflect exhaust down under the rack. As long as there is an air gap between aluminum sheet and anything that can melt, problem solved. Its what I did for my cargo rack back then with suv I had. Simple, take extra time and easy too look clean and like it belongs there.
Sent from my Nokia Stupid Phone using Tapatalk


----------



## RTM (Sep 17, 2005)

Thanks for sharing this as a warning. That's good karma. Sorry it happened to you though. For what it's worth I'm thinking the heat shield on the rack is a good idea. Either that or an extension to push the rack back a bit. 


- Rob


----------



## hatake (Jul 16, 2004)

I don't think it is the same hitch rack - it has quite a lift. My 1Up has similar lift and I've driven plenty (with boost) with no issues. So look for the rack with some lift. OP's rack looks totally horizontal. Sorry for what happened, I feel your pain nonetheless.


----------



## MrEconomics (Aug 23, 2004)

Tyrone Shoelaces said:


> Ha. I dunno. Just being hard on myself


Because there is always a troll that would say you deserve something like this. Good to get that out before they get a chance to massage their internet balls.

I put a chrome extension that points down. I have a Subie Outback so no issue, but wasn't going to risk it.


----------



## Bacons (Nov 10, 2011)

nov0798 said:


> Make a heat shield.


I was thinking the exact same thing. Kuat is a nice flat/wide platform that would allow you to easily do this. And it's a better fix than moving pipes, extensions, etc.


----------



## Gordon Shumway (Sep 17, 2012)

That stinks, does the rack instructions/info warn about this? I would think about returning the rack if you still can to get one that sits higher. A heat shield is a great solution but IMO you should not have to do that to make a product work correctly. 

When I first signed up on here I read a thread about this problem with racks and exhaust but luckily my 4Runner exhaust tip points down a bit and my Thule T2 sits the bikes up higher than the exhaust. It definitely had me worried at first but I have made several long trips with mine up mountain roads with no issues.


----------



## Harold (Dec 23, 2003)

I have seen plenty of tires melted by hitch racks placing the tires too close to the exhaust, so this is no surprise to me, though I've not seen it before.

I will certainly be warning customers about it, though.


----------



## Bailey44 (Dec 30, 2010)

The exact reason my wife's bike goes closest to the bumper...


----------



## tjchad (Aug 15, 2009)

hhhhhhhhhhhhhh


----------



## terrasmak (Jun 14, 2011)

Going to look when I get home, never paid attention to my rack on the grand Cherokee or when I use the cargo basket.


----------



## GelatiCruiser (Oct 11, 2012)

Thanks for the heads up, I just committed to buying a Thelma 2...I'll make sure I pay attention to this.


----------



## techt (May 12, 2014)

I have a Diesel and haven't had any issues so far, of course I don't use a frame adapter and my bikes go in an angle.


----------



## shwinn8 (Feb 25, 2006)

happened to me once... had green slim all over bumper that never came off


----------



## OldZaskar (Oct 18, 2007)

Thanks (!) for bringing this to out attention. As it happens, tomorrow morning, I'll (probably?) be putting a bike on my 1Up rack... with Enve wheels.

Can you tell if the 1Up is higher than your Kuat - it looks like it. But, it's tough tell from your pics.

The tray is 14" from the exhaust tip. But, it's also about 10" higher... wonder if that makes a little, or a lot of difference.

UPDATE: Just back from riding. Two bikes on the rack. The inside bike actually had Enve wheels. After 1 mile, we checked the temp of the tray - still cool/cold; same temp as other end of outside tray. 45 minutes later - same result, e.g. the tray closest to the exhaust was cold. Guessing it's because the rack is about 10" higher than the exhaust and 14" behind it.


----------

