Riding on the Darkside
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Greetings from the Farside

Go down

Greetings from the Farside Empty Greetings from the Farside

Post  cruisinTx on Thu May 18, 2017 5:17 am

Good morning,

New user from Fritch, Texas here.  I have been contemplating switching over to the dark side with my BMWs.  The first bike is likely to be my R1200C as it is the one closest to needing new treads.  Thanks to other postings I have already discovered sources for a few brands and models that will fit the rear at 175/55 15 (OEM is 170/80).  One of those is the Hankook Ventis V4 ES H105 as the tread pattern caught my attention.

Are there any other beemer riders out there who have tried this?  I also have an R1100RT that I may try a CT on if all goes well on the C.

Another thing I read on the K1600 web site last night is using a narrower rear tire on the front with the rotation reversed.  One owner who already uses a CT on the rear seems to be extremely happy with an Avon Roadrider AM26 turned backwards on the front.  The tire currently has 8700 miles on it and still measures 9mm in tread depth. Anyone with experience on that?

Thanks for letting an old fat guy in; looking forward to learning how to do this properly and safely.


Number of posts : 7
Location : Fritch, Tx
Registration date : 2017-05-17

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  cruisinTx on Fri May 19, 2017 5:17 am

Things seem to be a little quiet around here. I'm beginning to wonder if an apocalypse happened and I missed it.

Either way, while waiting on some replies, I guess I'll ramble a little bit with hopes of getting some questions answered.

First off I was looking through a lot of these threads to see it any one brand and model is most preferred when going to the dark side.  I have noticed here and a few other websites the Pirelli Run-Flat seems to be a popular model but my limited research certainly does not establish it as a "most preferred."  I've been surfing a lot of websites to find sizes that will fit my BMWs and really like the way Pirelli has their sizing charts set up where there is sort of a table showing all sizes for you to pick from.  Once a size is selected, the page shows which of their tires are available in that size.  If none are available, it tells you that as well.  This is much easier to use than the brands that only provide a box to enter your desired size and if it's not available, you draw a blank.  It make you guess what sizes they may or may not have.  One thing I am having trouble finding on the Pirelli format is understanding which of their models are considered run-flat and which are not.  Is there some code in the name that clues you in as to run-flat or not?

The next thing I am wondering about is tread design.  A few years ago I saw a You Tube video where a camera was mounted under a Gold Wing pointing back at the car tire mounted on the rear.  The tire design was such that there was a significant tread groove right down the middle.  As the bike leaned over the tire flexed at that center groove keeping half the tread pretty flat on the pavement.  I really liked the way that happened and am wondering if tires of that design might be preferable over those without a distinct separation of tread left to right.  During my research the past few days, I have noticed a few tires with center grooves and few with a very narrow center tread  having grooves on either side and a somewhat smaller tread cut into that center stripe like the Pirelli P4.

Since I am needing smaller rear tires than a lot of the big cruisers, this search is proving to be pretty difficult.  Any help on sizes, side-wall stiffness, brands and models would be greatly appreciated.

OEM size for the:
R1200C is 170/80 R15
R1100RT is 170/60 R17 or R18 (I have two sizes of rear wheel to choose from)

thanks in advance for any feedback.


Number of posts : 7
Location : Fritch, Tx
Registration date : 2017-05-17

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  bandito_two on Sun May 21, 2017 6:20 pm

Some have preferences for some bikes, some are still experimenting with different brands/makes of tires (they do take longer to wear out  thumbup )and some are limited to a very few choices. The important thing is to find tires that can fit on the rim and then onto the bike. After that, then one can decide among the available tires for brand, style, cost, availability or whatever criteria one uses in their tire selection decision.

With that said, for your R1200C, a 175/65R15  may be a better choice and a 185/70R15 may even be better than that so that the sidewall height will have it be closer to the bike tire overall diameter. It will still be smaller than the bike tire diameter, so if the speedometer is determined by the rear wheel speed, your speedometer will be even more optimistic; that is your actual speed will be lower than indicated and will also show your mileage to be more than actual. The thing is, a 195/70R15 per the specs would have a sidewall only 0.5mm taller than the bike tire sidewall. But the section width (tire at its widest point... at the sidewall which is probably going to be sightly wider than the tread face) of the 195/70R15 car tire might not fit into the space normally occupied by a 170/80-15 bike tire. At the tread face, the 195/70R15 is close enough to call it 1 inch wider (0.984 inch wider) than the 170/80-15 bike tire. It just might fit though. If you can measure the space on the bike, here is a link to dimension specs on the 195/70R15 and there is a handy tire size calculator on the site as well. From searches there are some tires available in that size... hard to find initially, but I did find 6:

Not that it is indicative of fitment, but my small scooter stock rear tire size is 130/70-12. It now uses a 145/70R12 car tire and has had a 155/80R12 mounted but needed a slight modification for it to fit. The point of this is that for a bike as small as that, a tire 11.5% wider than stock fit without issue and the other was 19% (nearly 1/5) wider with only a small modification.

Some sources for 15 inch tires:
Sometimes hard to find sizes can be found on ebay... It is where I found difficult to source 165/65R13 tires for my Silverwing 600 scooter.




All I could find for 17 inch tires were compact spares which are speed and weight limited and not really safe or useful for your need. Ditto for 18 in tires as well. The narrowest 17" tires I could find started at 205mm widths with low profiles... figured looking for 18 inchers would be just futile. Sorry, no luck with those.

FYI, here is this regarding runflat type tires: (make sure you copy the whole link to paste in your browser)

About the "double DarkSide"; Below this link is a brief excerpt from the item in that link. That whole item is pretty long and it was done in regards to twist and go scooters 250cc and up, but a lot of it applies to motorcycles as well.
=  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =
From a message of mine from silverwing600.com (edited)
I originated the use of a car tire on the Honda Reflex scooter and the use of a 150/70-13
scooter rear tire up on front of the Reflex for the "Double Dark Side" treatment. Some of
my comments on the subject of Dark Side can be found on the Yahoo hondareflexowners group
(as bandito_two) and on the advrider.com/forum (as bandito2) mostly in the "battle scooter"
sub-forum. There are other forums where I post, but these 2 are where most of my comments on
the Dark Side subject can be found. I consider them to be informative, logical, reasonable,
and worthwhile. I'm just a regular guy...with scooters... and (different) ideas. So, FWIW...

Being the pioneer type, I also run a Silverwing rear tire up front on my Honda Reflex
scooter. (rear tire up front along with car tire on the rear is known as DOUBLE DARK SIDE)
My bike had an episode of head shake once but that problem got resolved. It sticks like glue
to the road, barely shows any wear after several thousand miles of use and, well... it just
looks better too along with the taller car tire on the rear. Some big bikes do this too.

There are differing opinions as to which rotation direction to mount the rear tire up front.
I had mine mounted in the normal direction as the tread is designed to evacuate water best
in forward rotation. Remember even when mounted on the rear of a bike, that there are also
forces acting on that rear tire in braking which is in the opposite direction of forces from
acceleration. Even more so on a larger heavier bike, especially if it is heavily laden with
a passenger and extra gear.

The bike I have it mounted on is much smaller and lighter and I don't carry a passenger.
Still I don't think even that matters that much. On the rear, the forces work the tire in
both directions, on the front it is freewheeling and only gets force put to it when braking;
and that is mostly after the engine and rear wheel have already slowed the bike down. The
point is that the front tire does not get stressed as much as the rear tire. This becomes
evident if you stop and think about it; front tire even if slightly taller is narrower,
probably with tread not as deep as the rear yet typically lasts twice as long as the rear
tire which is much wider and usually has a deeper tread.

So, on the much larger, heavier bikes, mounting a rear tire up front in reverse rotation
makes sense to some of those guys. Then there are others who mount it in normal rotation for
many of the same reasons I did.
=  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =

I did have an episode of head shake wobble with my double DarkSide scooter, but that got resolved. But after thinking about it, I'm not 100% sure one way or the other whether the larger tire up front did or did not have something to do with it. Scooters are much lighter than motorcycles and so very well may be more sensitive to such an application... I did like how it worked though while pulling my single wheel trailer with that double DarkSide scooter.


Number of posts : 45
Location : Rochester Hills, Michigan
Registration date : 2008-07-11

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  cruisinTx on Mon May 22, 2017 6:58 pm

Thanks for the feedback.  Your input is greatly appreciated.
With the BMWs the biggest limiting factor on tire width is the space between the tire and the drive shaft housing.  On the R12C, I’m pretty sure a 185 will fit without rubbing.  I currently have a Metzler 180/70 and have about 5/8” between it and the shaft housing.  Unfortunately, the RT is another story altogether.  It currently has a 160/70 x 17 with only about a ¼” to spare between it and the drive shaft housing.  The only thing I found that will clear the housing in either 17” or 18” are spares with a very low speed rating.

Once I wear out the current tires on the cruiser, I will report back here with which car tire I chose for the rear. It will likely to be the Bridgestone Ecopia EP422 as I like the fact it has a center groove that should allow for easy flexing to help keep half the tread flat on the pavement.   After seeing good reports about the Avon Roadrider AM26 rear tire being used on the front of BMW K1600s with great success, I will likely use that on the front of the C.

Anyway, that link you sent on tiresize.com was exactly what I needed—thanks again!!


Number of posts : 7
Location : Fritch, Tx
Registration date : 2017-05-17

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  Danodemotoman on Fri May 26, 2017 2:44 pm

Beginning the 10th year of using the rear dark tire on the C10 Kaw Concours.
I endured ridiculous comments by several COG club members the first year. None of the negative comments have occurred to me or other riders. Of course none of the individuals had ANY experience using the dark side tire.
I continue to mention that the DS advantage is tire mileage and ALSO improved traction. Falls on deaf ears. Most are in wonder that I am still using DS as if they had not heard anything I aid about the benefits. LOL.
The conversion is limited in tire choice in the case of older mc's like the C10 (using 165mm tire width) that have limited swingarm width. I have not found a tire with more than one ply sidewall like modern performance tires.


Number of posts : 37
Age : 70
Location : Graham WA USA
Registration date : 2008-09-05

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  dcotop on Fri Jun 02, 2017 11:48 am

Yes indeed, it does seem to be quiet here. Nuther new guy here looking for the real info on how it works.


Number of posts : 5
Location : Texarkana, TX
Registration date : 2017-06-02

Back to top Go down

Greetings from the Farside Empty Detailed update

Post  cruisinTx on Sun Jul 08, 2018 9:12 am

Greetings again all. I first posted newbie questions here last May and would like to provide a detailed update in the event there are other BMW riders out there thinking about going DS. I initially thought I would be converting the R1200C to darkside first. It turned out the R1100RT needed new tread before the C. I did a considerable amount of measuring and searching for a tire that would fit without rubbing the driveshaft housing. I had switched my first RT from an 18" to 17" wheel way back in 2002 in order to take advantage of greater tire selection in 17" and to lower the bike just a tad as I am vertically challenged with a 27" inseam. I took a chance on a 175 fitting this bike knowing it would be very close to the shaft housing. Luckily, it fit with about 2mm to spare & a close friend who has been DS for about 15 years and over 200K miles said, "that's 1.9 (mm) than you needed." LOL, he is correct I suppose. In the end, I am so happy I had that 17" rim on the back as it is next to impossible to find an 18 in a suitable size. The tire I eventually bought and had mounted (in August) is an Achilles ATR-K Economist in175/55 x 17. I experimented with tire pressure for several weeks starting at 26 then changing it every couple of hundred miles and finally felt that 32 was ideal for this bike and my riding style. I absolutely love the DS tire on this bike. I now have 6105 miles on that tire and shows almost no signs of wear. Taking this DS thing a step farther, I have also put an Avon AM26 Road Rider on the front in a size that yielded an almost perfect correction to the typical speedometer/odometer error most companies build into their speedometers.

So that is the run down on the RT. The C was up next, but it needed a front tire before the rear wore out so I actually converted the front to the Avon AM26 before I did it to the RT. It turns out Avon makes one in the exact same size as my OEM so it was an easy choice. That tire is showing just minute signs of scalloping but has not become a huge annoyance yet. I'm keeping a close watch on it though. I first started out thinking a Bridgestone Ecopia EP422 in 185/65 x 15 would be my choice for the rear tire on the C. Then as I did more research and read more on the facebook page Rolln' on the Darkside, I decided something closer to the OEM size of 170/80 would be much better as this better as this bike's speedometer pick-up is on the rear wheel. I read on the FB page about a couple of guys who were using the Federal SS657 165/80 and were very happy with it. I put the size in my Excel spreadsheet to compare the circumference to the OEM and the Bridgestone; turns out the Federal is only 1.21% smaller while the Bridgestone is 4.82% smaller, a change I did not want to deal with. The next larger size that might have fit with minimal circumference change was a 205 that would have been only 0.87% smaller gave me enough doubts about hitting the drive shaft housing, so I went with the SS657 just a few weeks ago. I started with pressure at 28 and that seemed to be perfect. OH MAN; this tire gives that bike a feel like I've never had on it or any other bike since I started riding in 1968. I have already logged 1344 miles on the C with that tire since getting it mounted June 13 and have been very pleased with it.

That's it; now running double dark on two BMWs (R1200C and R1100RT) and highly recommend other beemer riders consider doing the same.


Number of posts : 7
Location : Fritch, Tx
Registration date : 2017-05-17

Back to top Go down

Greetings from the Farside Empty Re: Greetings from the Farside

Post  Sponsored content

Sponsored content

Back to top Go down

Back to top

Permissions in this forum:
You cannot reply to topics in this forum