| Author | Message | ||
     Mr_grumpy |
Or for the culturally challenged among you "tires" For those of you who haven't yet discovered this (and I only became aware quite recently myself), Darksiding is running a car tyre on the back of your motorcycle. I don't mean sidecar outfits either, talking about solo mc's. Why? cost, availability, tyre life, traction, off road grip, wet road grip. I've read lots of reasons on various sites including advrider & seen videos on youtube. Now I'm not particularly thinking of doing this myself, but wondered if any on here had done it, & if so on what & why? | ||
| Hybridmomentspass |
I dont see how it'd work well for street applications, with car tires being pretty squared off | ||
| Hammer71 |
You will mostly find that the touring crowd is big on it for the mileage | ||
| Moxnix |
A current discussion on a land speed racing thread denotes rules that square shoulder tires are for sidecars, solo bikes cannot run them. Back in the 60s, chopper guys put car tires on the rear of their bikes, but they always tended toward the bad handling kit. On the salt flats, some have done well over the years with drag racing front tires on the read for speeds well over 200, but always in a straight line. Narrow car tires are something we are not seeing outside the low production classic and restoration games, but, there must be some round profile series of skinny tire, like the 16-inch Michelin radials on my Morgan +4, or a narrow tired for VWs or such that could have a bit more rounded profile for "touring" rather than heavy-handed sport bike riding. The new steel belted Michelin bike tires may well offer higher tire life in addition to more resistant to puncture in the carcass. | ||
| Skntpig |
No thank you. | ||
| Teeps |
I rode customer bikes with CTs, back in my M/C mechanic days. Didn't feel safe; so I stopped test driving them on the street. Today's cruiser crowd like CTs because it's a cheap way to get that "fat tire" look without having to modify the wheels of the bike. And, they will insist that the bike handles and stops better with the CT on the back. | ||
| No_rice |
when we built one of the first wide tire Bourget bikes back in the day, it used a corvette rear tire. cant remember the dimensions now, but it was very squared off. to turn left you had to turn quick right, which would tip the bike up onto the left side of the tire edge, and then you could do your left turn running on the edge of the tire... took some getting used to. especially when you were trying to do any maneuvering underpower with the high compression, high boost turboed vtwin. but in a straight line that thing would light that tire up at any speed you felt like. | ||
| Arcticktm |
I would suggest renaming it from Darksiding to Darwinism. | ||
| Ducbsa |
The Cycle World forum has a long running thread on this that is pretty entertaining. | ||
| Akbuell |
Not something I would choose to do. I can understand the reasons, but I would have to be very careful on a cruiser on I-40 between Asheville and Knoxville, for example ... On thing I have not seen discussed about CT usage - Good luck with the insurance company/companies should you be involved in a traffic incident, your fault or not. | ||
| Azxb9r |
An old friend of mine used to run one on his drag bike. The major down side is that it makes the bike a biotch to turn as it does not want to lean with the car tire. The other down side (with drag slicks anyway) is the low pressure you need to run in order to get full tread contact causes o lot of sidewall flex and makes the rear of the bike "pogo" on decel. Since street tires have stiffer sidewalls than drag slicks, this may or may not be a problem on the street. | ||
| Jramsey |
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| Fast1075 |
There is a particular technique to shutting down a "car tire" drag bike. I ran a 1428 Kawi 10" slick bike for years. Shutting it down and getting it stopped was at times "interesting". At my local track, no big deal. Nice and smooth, 1/8 mile. Some of the "outlaw" tracks in Georgia were frightful. | ||
| Bob_thompson |
Back in the day a friend of mine running a low 11 second drag Harley ran a low pressure road race slick and did not have much traction problems if heated first with a burnout. Harry (Fast1075), what are you running to get those low 9,s? Others? Interesting drag race thread. | ||
| 6gears |
I am pretty sure all those designers at the motorcycle tire companies have been doing it wrong all these years...... | ||
| Mr_grumpy |
What got me interested me about this whole thing was reading about somebody who was running to Alaska from the midwest then back through Canada, a trip he'd done before & always took & used a spare rear tyre due to all the slab on the way. This time apparently he was going 2-up so no room for a spare, & did the whole trip on a car tyre. I've also read about the running pressure needing to be reduced to allow the tyre to deform enough so that the tread stays in contact with the road when leaned over. I know all about the square profile & sidewall flex etc etc, I'm a qualified motor mechanic & have spent most of my life on the road. And yes I do understand about tyres being designed for different fitments, I'm not a complete moron. However I'm always intrigued by cross-over usage, things being used successfully to do something they weren't designed to do. In this case, I can see the reason & how the compromises work out. With a touring bike that's not going to get huge lean angles anyway I don't think it's unreasonable for a longhaul tour, but I wouldn't be trying to poke it hard through the mountains. Using different tyres than original is nothing new, back in the 80s I had a few friends that were taxi drivers, they of course ran huge mileages. Most used to run commercial van tyres as they lasted nearly twice as long as car ones, the ride was a little harsher but a trip to the scrapyard for some softer springs sorted that out. Also a number of years ago when 16 inch rims were popular, it wasn't uncommon to see tyres destined for pre 1960 Citroen 2CV mounted on bikes, they were a 125 x 16. Now it's the other way round, I've seen off-road Deuch's with bike knobbies on. Also the road tyres are so expensive now due to the low demand that there's no economy to be made. Here's a couple of vids. http://www.youtube.com/watch?v=PZ_d5IIdRZI http://www.youtube.com/watch?v=qoNDo7o1d6Q | ||
| Fast1075 |
I "retired" and sold all my drag bike stuff when the economy took a dump. The big tire bike, with the throttle stop turned off and the nitrous at 100% on a good track could go 7.96 My small tire bike (1075cc) would run 8:60 unleashed. I usually ran it at 9.90 with throttle stop and progressive nitrous. | ||
| Kyrocket |
This is a hot topic on Vulcan Forums especially with the VN2000. One reason of course is cost, I think some of them pick up a CT for around $35 - $50 and can go 20K miles on them which is another factor. I fall in line with 6gear, if they were meant to be on there then the manufactures would be installing them themselves. I won't be doing it, but hey, whatever floats your boat. | ||
| Hr_puffinstuff |
when my dad gave me his old CB750, it had the rim from an FLH laced onto the stock hub w/ a Goodyear Super Eagle 100 on the back. i always assumed it was for the launches, (Dad and his buds were drag racers) but Uncle Maury, who did the mod, told me it was because you could use a VW Bug tire in a pinch. That was the set-up i learned how to ride on. a couple summers later, when it FINALLY got bald, i changed to a round-profile tire, i had to learn how to corner all over again. to this day, i'm still "early on the brakes, early on the gas" kind of guy. | ||
| Bienhoabob |
It's funny that this thread would appear on a Buell forum, where cornering is the biggest attribute. I happen to be one of those that went to the Darkside. I have a Kumho 205 mounted on the rear of my Yamaha FJR. I was preparing my FJR to do an IronButt 48+. (all 48 states plus Alaska in 10 days) I was after longevity not cornering. After 11,000 miles, I can say that I might never go back to a MC tire for long distant traveling. The only drawback I can see is, as mentioned, the cornering. Cornering is different, you have to work a little harder at it. It takes a little getting use to it, but not a big deal. I wouldn't advice using the CT on a road track, but anything less than knee dragging would be fine. One of the pluses with a CT is that it likes to track straight. At times I ride in strong cross winds. I find that I'm not leaning into the wind as much when going down the highway. Ditto with Semi's on the highway. I've also ridden in 500 miles of straight rain, tire felt well planted the entire time. I'm looking to get 40-50,000 miles out of the rear tire. Not for everybody, but CT's are for me. | ||
| Sifo |
I'm looking to get 40-50,000 miles out of the rear tire. Impressive mileage, no doubt. I just don't see the need when modern sport touring tires will give about half that distance and still maintain the handling (and safety) of the bike. I would think there must be some touring tires that would allow for even better mileage than the sport touring tires. I've gotten 25K out of a Pilot Road 2. Another set was changed at 21K simply because I was heading off for a long trip in the mountains and felt better about having new rubber. I think I'm at around 20k on another set now on my Triumph. I just wouldn't want to hurt what I find to be the best part of riding a bike; Twisty roads! | ||
| Mr_grumpy |
It's funny that this thread would appear on a Buell forum, where cornering is the biggest attribute. Lol, that's my fault, I'm interested in all sorts of stuff, & find that generally somebody on here has the experience I'm looking to to investigate. Thanks Bob, it's nice to have somebody who's actually done it give their view. | ||
| Azxb9r |
If you were planning a long ride, especially if you were going to be in places where service/parts availability was an issue, I can see how the added durability of the car tire might be desirable. I would think that the car tire would dry rot long before you wore it out  | ||
| Datsaxman |
Lots of misinformation, voodoo, and old wives tales out there. Here too. If you have less than 10,000 miles on a CT, you are just guessing or telling funny stories. Some tyres on some bikes it actually works very well. Others, not so much. Yes, I have a CT on the Concours and even one on one of the Ulysses. I really expected it to be awkward when I first had the 175/78R16 on the Concours. I have 15 miles of mountain road at the beginning and end of every ride (!) and the first week I was SOOOO cautious. A little more lean each day, then pretty soon I was hustling through the corners with real confidence. Fabulous fitment on the Concours, dragging the pegs riding solo and all that. Rain, 130F in Death Valley, whatever. Not so great on the Ulysses, but not terrible either. Contact patch is my favorite topic about CT. Contact patch has NOTHING to do with traction, except in the case where a wider tyre would get you some clean contact going through oil, sand, etc. NOTHING. Retired University Professor in Physics here, so pick a fight about that if you want. Not recommending a CT to anybody. Just saying that you don't know if you don't know firsthand. saxman | ||
| Britchri10 |
Datsaxman: Are you referring to the "principle of moments" re: contact patch? (I'm not a physics guru but my brother is & I remember him saying something along these lines many moons ago. I didn't understand it then but I remember the phrase) Genuine question. I'm not trying to be a S/A! Chris C | ||
| Buellhusker |
Datsaxman What size and brand CT did you fit to the Uly? | ||
| Bob_thompson |
If this thread is mostly about longer mileage from a tire, and it seems so, due to having to accommodate the ill handling characteristics of a car tire, why not just go to a high mileage touring tire, like a nice Conti road attach or something better, but in a true MC profile and still retain the great handling of our Buells? Seems like a no brainer and if you're doing an extended tour of the whole lower 48 states for a long time, just plan on a nice layover and get a new tire along the way. A great chance to see the local color. 1/4 mile, high H.P. run a 6-8" car slick. The rest of the time MC profile and have fun carving the twisties. Or is this thread just about controversy? | ||
| Rick_a |
We used to have guys come by the shop all the time to try to get a CT put on their big cruiser or on a loose MC wheel. Hell no! Anyway, I've given up on high mileage tires for the Buell. I've found sport touring tires last marginally more due to deeper tread/harder compound. On the flipside is reduced grip and having a terrible profile due to wear at the end of it's life. No thanks. If I decide to improve tire wear I'll purchase a bike that can take a heavy bias ply cruiser tire. | ||
| Datsaxman |
Husker: I have tried two on the Ulysses...a Bridgestone G019 Grid and a Kumho Ecxsta LX. Both are 205/50R17. This was done as an experiment to see how it would ride, and out of frustration because the tyre life has been so awful. Stocker: 4800 miles. Cord started showing 200 miles from home on a one day trip. Got lucky and found a replacement Full Bore brand. Which lasted 2400 miles. Just over ONE MONTH of gentle riding. What a lousy tyre all around. Put on a Shinko because I had it already as a spare for another bike. Got 3200 miles. I found myself constantly wondering if the tyre I had just put on was worn out already and going to fail suddenly. So...drop some more dough for one of the brands that folks around here say they get a lot of miles from...and be ready to replace in a few weeks or months...or try the CT. Remember, the Concours CT is really working well. Thompson, there is nothing ill-handling about the Concours with the CT. With all due respect, do you have any actual CT experience, or just looking for some controversy? I can't help you with that, sorry. Just saying what my experience has been. No evil handling so far. Just takes a bit of extra effort to initiate a turn from center on the Ulysses. The Concours I don't even notice any more. And I have tested the CT back to back with the stock tyre on another wheel. Not very different at all. But the CT on the Concours is narrow, and that helps a lot IMO. Recap: 4000 miles into the Bridgestone, the tread is about 10% worn - yes, I measure the depth, not just eyeballing - and the thing is a little strange to ride. Not dangerous, not anything unpredictable or squirrelly, no matter what your friends tell you. 205 is the narrowest 17" size I have found, and it is just too wide for good handling IMO. The Kumho is on a spare wheel, but I expect it will be a lot the same. Experiment cannot really be called a success, since the handling is quite a bit more deliberate than with the stock Dunlops, but it is not a failure either, as the Ulysses works just fine with the CT on. MUCH more secure feeling in the rain, on loose surfaces, fully loaded and two up, etc. Chris, calculating "Moments" is fine, but what I am talking about is even simpler. Friction, especially static friction, depends on ONLY TWO THINGS: 1) Coefficient of friction between the two surfaces that are in contact. This is just a number, typically between 0...1 that describes how well the materials adhere to each other due to their surface roughness. Big for rubber on rough pavement, small for wet rubber on smooth concrete, for example. 2) The contact force pressing the surfaces together. The weight on the tyre in this case. Nothing else matters. Most folks expect that the size of the contact patch is important. It is not. This has been well understood for hundreds of years, but does not seem to appeal to people's "common sense" prejudices. Amontons in about 1700 was the first that I know of to have figured this out, restaed and elaborated on by Coulomb in 1780 or so. Ancient history, then? Why yes. So if you think "That CT will not hold the road when the contact patch gets small in a corner", you are mistaken. It sticks EXACTLY as well, so long as the surface is uniform. That narrow contact patch DOES follow cracks, grooves, and seams in the road, though! The first trip up a driveway at an angle was not comfortable, but that has been the only trouble so far. Mileage thus far: 40,000 miles on the Concours + 4,000 miles on the Ulysses. An interesting experiment so far, with more to test. Disclaimer: Not recommending a CT for your MC in any way. You should only put approved Buell and H-D products on your Buell. I mean, you should have the Certified Technician at the Franchise Dealer install only OEM and Official Licensed parts. | ||
| Mr_grumpy |
Thanks for that, very informative. That's exactly what I was after finding out when I kicked this thread off. |
