I just bought my Strada and seeing it IS a strada whet I would really like is a 17" ROAD front wheel. Please no comments about " Why didn't you buy something else then". I chose VERY carefully a bike that I could ride on the relatively close roads in the area when I don't want to distance tour on the hiways on my BMWF800R. The local sealed roads are quite rough and lumpy and the extra travel and lighter weight are what I need ( plus I love singles) My real question is : Is it possible to get a 17" front wheel that will fit AND still have the ABS work properly. Want ABS. I saved my life in a North Queensland wet season downpour when following a semi. Please no half baked answers. I have been racing bikes for years and build them myself so I know I can fit a 17 easily enough. The problem is how the ABS actually works. I can't seem to find out if the wheels read individually and calc. their velocities/accellerations OR they use a direct comparitor ( eg. they check to see how far out of phase one wheel is from another) Any accurate help would be appreciated. BTW I am hopeing to post a thread on shortening the front and rear suspension as soon as I get time for shorter riders ( eg my girlfriend) and more road orientated riders. Anyone know where I can get a cheap stock seat or seat base.
First thing would be to find another 17" road wheel from another bike that has an ABS tone wheel with the same number of teeth. It sounds like you know what to do about getting the rotor to fit, correct offset, axle size, etc.
Greg, check the price on a stock seat from the dealer. I've been amazed at how inexpensive parts are for this bike compared to others that I own. The factory seat might be cheaper than you think. As for getting ABS to work, all you need to do is sort out the brake rotor with the ABS ring. That is what makes the ABS work, not the wheel itself. You may have to just get custom spoke wheels laced around a Husky hub. The Terra hubs are actually very reasonably priced from the factory.
Piece of cake. Only a matter of money. I would grab a front wheel off of a 2000 up BMW F650GS or G650GS, as long as it is the single cylinder one. You really only want the front hub. You can have the wheel re-laced by Bucanon's or Woody's wheels using a 17inch rim and the ABS will function properly as you will be using the stock ABS ring. These are all the same on the BMW's and on the Husky Terra and Strada. Rotor same too.
Thanks ridingdonkeys. I now live in a town where the nearest husky dealer is a very long way away. Much easier to get parts via the net. As I said I don't have a problem matching and finding a 17' wheel. The problem is ensuring the ABS will work as it is one of the reasons I bought the bike. The reluctor ring is what determines what the ABS sees from the wheels. I can get the existing ring to works with any wheel I choose to put on.My problem is HOW the ABS "brain" reads and interprets , then actuates the ABS. MY BMW F800R has the same ABS unit but front and rear reluctors are of different sizes ( and number of slots). You can't just put the ring on a different sized rim ( or even tyres size ) IF the ABS requires the SAME ROLLOUT per wheels to read correctly. The Strada has one slot difference between the front annd rear rings and there is 3mm difference between the stock front and rear wheels diameters ( of stuff all). There must be some tolerence built into the system as the front and rear diameters will wear at different rates and the rear will eventually become much smaller than the front. What I need to know is if the ABS uses the difference in acc. between the two wheels to actuate the system or if it reads each wheel individually and controls the pressure for each wheel individually. It may be possible to fit another ring from something else or maybe reprogram the ABS??? to work with a new rollout . I can lace up hubs myself but I am looking for a solid wheel for tubeless reliability, lateral stiffness and better tarmac tyres. As I said , I can get something to fit. May even buy a BST carbon or a Marchesini alloy.
I get what you're asking, and probably no way to know without getting one of the engineers to chime in. The ecu isn't exactly an open system. I'm more curious as to why spend the money on that change. Part of the reason the bike is so stable is that geometry. Dropping the front that much will make it turn in quicker, but it's going to be twitchy without squatting the back to compensate. Assuming you get it all sorted out suspension wise, you now have a 410 lb supermoto. I'm not sure I could rationalize that with the desire to keep the ABS functional, as really for the type of riding I want a supermoto for, the ABS is downright dangerous. My Strada is the first motorcycle I've had with it, and I'm not at all fond of how it decides to take control away from me if I'm screwing around without first disabling it. That aside, be sure to post up once you figure it out. Oh, and look into the BMW parts numbers for the HP4 and their other sport models. Looking at pictures they all have the rings on there and I bet they are properly tuned for a 17 inch rim. If the ABS all use the same brain and base it on the correct ring for the wheel size, that would be your best bet.
My wife owned a BMW F650CS Scarver. They were made in the early 2000s and were a street version of the F650GS which then evolved into the G650GS. The F650CS had 17" wheels and ABS. I would not be surprised if these wheels were a direct replacement.
My understanding of BMW ABS is that the system calibrates the difference in front and rear wheel rotation rates every time you start your bike. The ABS light flashes for a few moments as the system calibrates. A good number of people have put 21 inch front wheels on GS's in place of the stock 19 inches, and the ABS still works. You should google up Woody of Woody's Wheels, as he has lots of experience on changing wheels on ABS bikes.
Right, so the ABS reads the speed of wheel rotation based off the rotation of the sensor ring. It has to have an internal self-calibration to account for variances in wheel size. If it didn't, then ABS would cease to funciton as your tire wears. The question is how much wiggle room is in the firmware coding. Pure assumption, but firmware is expensive to make. If I'm BMW, I'm not going to design a separate ABS system for every model. That is far too expensive. I would design a firmware for universal application. It appears that is what they have done, as they use like hardware and sensors on most of their bikes. That being said, if there is a BMW running a 17" wheel with the same ABS system, then more than likely a 17" front will work on a Strada. Keep in mind that they are using the same ABS system on the Terra and Strada in Europe with varying wheel combinations. In Europe, a Terra can be ordered with a 21" front and 17" rear with ABS. That alone could stand to prove 2" of front variance in one direction.
As the bike doesn't have traction control, the ABS module probably doesn't need to see a relationship between the front & rear required to determine wheel spin. Number of teeth on the tone wheel would still be important because it will need to self calibrate itself to register a correct number of pulses for one revolution of the wheel. You could probably simulate ABS operation with some handheld frequency generators mocking wheel rotation to check the affect of non-standard wheel/tyre combos. Would be a interesting exercise.
MS Smith: I don't want a supermoto. I want a road bike with longer travel suspension to cope with the local roads and a little OK quality dirt road. I can ride ( race) a motard but that isn't the idea. I find the front wheel of the Strada way too slow turning anyway. Really fights hard turning ( mainly due to larger radius heavy wheel/tyre) and head angle. Husky tried to reduce the trail a bit by having a leading axle but I ( personally) feel it is still too hard to turn. I want to fit lighter front and rear tyres as well as the dual purpose tyres are VERY heavy and lack carcass compliance on the bitumen. Also easier to get better gripping front in 17. Nev: thanks for that lead I will chase that up. The size of the husky ring leads me to believe it may be a early developed one so this could be a possibility. Firmware is reasonable expensive to design ( flashing the existing hardware has to be done so different firmware versions will not incur an EXTRA cost there). The reluctor counts per revolution or roll out distance would be all that the program would have to have changed and that would almost certainly be an accessable constant. ie the existing algorithym would be the same , only that variable would be changed to account for different wheels/tyre. Bear in mind I am quite prepared for the fact that it can't be changed. Like the F800R hand grip heaters for which the fault code cannot be removed because they are disconnected. I live in the tropics and the heated grips are plain dangerous as the on button is on top of the bars and has a hair trigger. If I accidentally hit it when riding the grips get too hot to hold. Seeing as it hasn't been below 4deg C since the ice age here , the heated grips are useless, but cannot be removed. It may simply be that Husky put a 19 on it's ROAD version because it was too difficult to fit a 17 with ABS working and use the parts bin bit. On the other hand , it may not actually be a problem at all. That is what I am trying to find out. Ridingdonkeys: I can make/ get a frequency generator easy enough but this may be a time to see if the BMW canbus reader works for the Husky. Would be worth a try but probably need 2 people unless I can find an app for my motorcycle laptop that I can program to give me varying dual frequency outputs. Looks like time to connect my 911 reader and see if it will work for the husky. At any rate thanks everyone for the ideas input. Anymore constructive input is welcome particularly from people with specific engineering info on this topic
Short of having them send us the source, the only thing you can do is really try it. I think if you get the ABS light to go off your are all set. How bad you want to know without getting the 17" wheel? You could take your stock strada wheel, remove the tire, tape the heck out of the rim, and run it down some really smooth road long enough to see if the ABS light goes out. You only need 5mph, and not for long at all. If that worked, you could be pretty confident a 17" wheel with a tire on it would work.
Posted a little further up, nobody commented, so will try again. BMW made the G650X series. They had a 21 wheel on the X Challenge, 19 on the cross country and a 17 inch wheel on the G moto. All use the same ABS pump, ring, pick up. I sucessfully went from 21 to 17 with no ABS issues. I am not an engineer but I have the benefit of experience or trial and error. I can tell you that multiple people have put 17 inch wheels (via Woody's) on the X challenge and ABS worked fine. I took 12 RT front wheels and put them on R1200GS 19 inch wheel bikes. It works. Build the wheel install and ride!! IF you want it to turn quicker instantly, slide the forks up in the trees a quarter to half inch in the interim.
I've written a lot of firmware and understand your concerns. Even more importantly - I am cheap. If it were me I would find some place to ride in the dirt and at least let most of the air out of the front wheel to simulate it being smaller and see how the abs works out. That might come close to emulating the 17" rim.
Sorry Toyboy I missed you comment ( too much skimming). I think I can make some spacers to fit the f800r wheel and a bracket to mount the std ring to try an experiment, but if what you say is true on this bike then it possibly only references itself . It does have the latest model ABS unit though and may be differently configured. I have just moved 1000km and sold ALL my race bikes and spares before the move or this would be a breeze to experiment. Had 17' wheels and spare tyres of all sorts of sizes coming out my ears, but all gone now. No doubt to begin accumulating again in the new place. I might see if I can get one of those cheap chinese wheels to play around with to get reference points. Luckily the TR has a cheap solid disc on the front so easier to fiddle with. Coffee: I think to get a relevant decrease in rolling dia. would mean the tyre was so deflated that solid stops would be a bit dangerous. We used to race with 20psi in the smaller bikes and it only made about 13-15mm difference in radius loaded and rolling. Much less than that and the tyre prob won't stay on the rim.
I would be surprised to see the ABs work properly at that speed ( I stand to be corrected) . The sampling would prob. too far apart to get a meaningful correction. I have notice the ABS doing funny things at slow speeds anyway. Still... easy to do and worth a try.
Just thinking if different tyre diameter could be an issue. On a Terra with ABS, the rear tyre is 140/80/17 & non-ABS is 140/80/18 even though it still has a tone wheel for the speedo. Seems strange that they would have different size wheels for the two bikes. I'm wondering if it could be an issue with your Strada front wheel resize?
It works fine at that speed based on my experience on several bikes. Not sure there is a lower limit.
