The Wheel Modifications & SuperMotard FAQ
Please read the Disclaimer before attempting any work in this FAQ.
compiled & edited by Kristian #562

See also the Wheels General FAQ

Can I Fit Wider Rear Rims & Tyres to my GS ?
Iceman #975

Yes you can, a 160/60/17 will fit between the swingarm, but you need to remove, replace, or modify the OEM chainguard.

This particular tire requires a wider rim, pictured is a 4.25 x 17 with Pirelli MT60RS.

On the front is pictured a 120/70/17 Pirelli MT60R on a 3.5 x 17 rim. 


This Super Motard set-up makes for a lower seat height and quicker steering.

Rim-Width/Tyre-Size Chart

Anyone considering using non-homologated tires on their bike, particularly those doing a super motard conversion might be interested in consulting this chart:  Flash #412

Is there any way to convert the GS/Dakar to a Supermono.?

Report #1
by Iceman#975

Here's the list for all that's not factory OEM on our '01 GSA.

The primary reason I did the Super Motard set up was to lower the seat height for Icewoman. With a low Wunderlich seat, she's nearly flat footed at 5'4" and without shortening the suspension. With two sets of wheels, I can run the 17/19's with Metzler Karoo's and a Dakar tall seat and use the bike myself (I'm 6'2") off road and not worry about bottoming out a shortened suspension. It's about an hour to swap the wheels and the seat. She already has a more suitable trail bike (a lowered Yamaha XT225) that gives her more confidence when the trails get tougher.

The bike handles like a dream on the street with a steeper fork angle, Race Tech fork modifications, and an Ohlins rear shock. The bike is a GSA with Braking rotors (floating front) and stops on a dime, so I didn't feel it necessary to go to a larger front rotor.

Her ability off road with this heavier bike is limited, so we haven't really lost any usable performance when she's riding it. The Pirelli tires I'm using have an aggressive tread pattern, so the bike does fine on fire roads and easier single track without any muddy conditions. On the street, it's made her a more confident rider. The wheel swap gives me another off roads bike. For us, it's all a win win deal.

The signals are from KTM, extras from a previous bike I sold so I don't know what the cost from KTM would be. The Buell signals are the best buy, but I don't know if they have the flexible stalks like the KTM's do.

The bars are Renthal's for a Honda CR80 that I shortened by an inch off each end after fitting machined ends to be able to use the heated grips. If I did the bars again, I would have left the length alone, as shortening them gives the controls the ability to barely touch the windshield at full lock.

It's not fast enough to really be a Super Motard, but it looks like one. It gives us a bike that's a one of a kind and draws lots of questions, mostly from other riders who know it didn't come that way from BMW.

The bottom line is that Icewoman loves it, and when she's happy, everyone's happy.

As far as a Super Motard conversion goes, I am VERY happy with the way Icewoman's GSA handles. It's been a while since I had the stock wheels with Metzeler Karoo's back on the bike, but we just finished a 65 mile fireroad run through the Tahoe National Forest on Thursday using the 17/19 combo. The handling with the wide 17's was a bit quick steering at first, but after a year or so it now feels like there's something wrong with the handling with the stock 17/19's. The suspension is at stock GSA height/length but has Race Tech emulators up front and an Ohlins out back. When I first started the Super Motard conversion, a few had commented how the handling would be compromised by dropping the front height by the smaller front wheel, and that modifying the "factory engineered" angles would be somehow "unholy". I have found the opposite to be true with a great improvement in street handling, while the bike is still fire road worthy with the aggressive Pirelli's. It won't do much trail work and is worthless in mud or slick surfaced off road, but has been a excellent compromise for a street biased "explorer" bike. Another benefit with the Super Motard wheels is the lower seat height without losing any suspension travel. This is Icewoman's primary bike (she's 5'4"), but with a tall Dakar seat and stock wheels, it works for me too (I'm 6'2"). As far as what to lace up and by whom, I used Wheelcraft in Hayward, Ca. with very poor service results. A wrong sized front tube led to a pinch flat, and the rear directional tire was mounted backwards. After numerous promises to reimburse the $15 for re-mounting, I still haven't seen a refund. I used heavy duty spokes and polished Sun rims that were stamped "Buchanan", the supplier of the pieces. If I were to do it again, I'd use Buchanans, which I believe is also in the east bay (also Hayward?).

I think the conversion is a fantastic improvement in the handling of Icewoman's GSA. If there's a speedo error, it's so slight that I don't notice it. I run with a one tooth smaller counter sprocket, so the performance is good. When I swap to the 17/19 wheels with Metzler Karoo's, I'm riding off road at slower speeds, so I can't notice any performance change with the smaller wheels. The rotors are from Braking, the front is floating, and both are better ventilated than the stockers. It turns out the dimensions are the same as the Classic's, so the application is from the older F650's, since they don't show a listing for the GS's. I've found many parts that interchange, like the Race Tech emulators. Probably only because no one had looked closer to se if there were any differences in dimensions. 

Report #2

by Chainsuk

These are the Metzler Karoo's on stock wheels and Avon SS Pro 120 and 160 on the 17"

I just put the 17" wheels from Touratech on my 2001GSA. Excel rims and BMW hubs all included in the price. Excellent quality!!! I run Avon Distanzas 120 and 160 and they are great. Just did a 2500 mile road ride last week and yesterday did creek crossings and fireroads. Bike handles awesome (suspension still crappy), but the geometry is way good. I rode with hard bags, tank bag, and the tail loaded at 80+ on the interstate. Some buffeting, but not much.

The sidestand works fine (With the Touratech wheels) and the 160 Avon Distanza is within 1/2" circumference of the stock rear tire (I measured them), so the speedo works pretty close.

Motard Feedback:

Is there any way to convert the GS/GSA to a Dakar.?
by Iceman#975

Q. I want to make my GSA like a DAKAR. Or close to it. Is there a place between going all out (new swingarm, new rear suspension, new chain?, new front forks, new front wheel, new front suspension) and trading in my GSA for a DAKAR?

A. The bare minimum to make your GSA into a Dakar would be to re-lace your front wheel with a 21, use your fork legs to build Dakar forks by buying fork tubes, damper rods, and choice of springs (I used Race Tech's). In the rear all you need to change is the shock, upgrade to an Ohlins or buy someone's takeoff OEM shock. You'll need a kickstand, and will need to weld a chain wheel bracket to the frame. Or, if you don't want to spend so much, throw on a set of knobbies and only upgrade suspension components as needed. You may not need more travel, just better suspension, which is what I did to ours. Ohlins rear shock and for the front Race Tech springs, emulators, and 10 wt fluid.

Note the Dakar has a 2.15 inch wheel rim whereas the GS's is a 2.5 inch rim, thus the GS Tyre is not only smaller it is wider, more like a Supermono.

Off-Road Wheels