[Fster]

As the title states I'm curious what the benefits and disadvantages of changing the wheel sizes from 21 front and 18 rear to 19 front and 17 rear.

 

[Dazzle]

Is yours normal or DCT i was wondering to get tubeless tyres, but I'm waiting for a DCT, and i did think the ecu and transmission might flipout due to different rolling radius ??

 

[Fster]

I don't have mine yet but I am waIting on a DCT. That's what I was getting at, if someone would won't to motard one, would it work on a DCT. Is it a feasible way of lowering one for a smaller rider or for better tire choices.

 

[True Ad Venture]

The whole point of the AT is its dirt friendly wheel sizes. You might want to check out NC750 series if you want a DCT road bike with smaller wheels. Or wait for Honda to release more 1,000cc DCT bikes, I have a feeling it won't be long.

 

[JustPlainBill0]

Is yours normal or DCT i was wondering to get tubeless tyres, but I'm waiting for a DCT, and i did think the ecu and transmission might flipout due to different rolling radius ??

The DCT shouldn't be affected by wheel/tire variations from factory sizes - the computer is watching speed (probably measured inside the transmission) and RPM to select the next gear. And whether the speed is accurate or not wont make a difference to the DCT, but it might to the rider as it could result in speedometer error.

ABS and traction control could be affected - it will depend on your tire size choices. At the rear, the OEM tire is a 150/70-18 with a (calculated) diameter of 26.6 inches and at the front with a 90/90-21 and a diameter of 28.3 inches you end up with a ratio of 1:1.07. If you can stay near that ratio with 17 and 19 inch wheels/tires (say with a 110/80-19 - 26.2" front and rear 170/60-17 - 25.3" with a ratio of 1:1.05) that might be close enough for the computer to manage without going crazy. (Assumes there is room between the swingarm sides for a 170mm wide tire.)

I calculate tire diameter by computing the height of the tire by multiplying the width by the aspect ratio (150 x 0.7 = 105mm) then converting to inches (105/24.5 =4.3") times 2 = 8.6 plus the wheel size 18" += 26.6 inches. Actual tire diameter will vary somewhat between manufacturers, tread style, street or dirt, etc.

As for benefits/disadvantages - 17/19" sizes will only lower the bike by one half the measured diameter (about an inch) and you can usually do a lot better than that with lowering links and dropping the triple clamps down on the fork tubes - at a much lower cost than changing wheel sizes and tires. You will have a greater selection of tires (TT and TL) with 17/19's.

As for me, I'm inclined to agree with True Ad Venture: look at the NC models (if you can deal with 50 HP). Or wait for Honda to bring out street oriented variations of the Africa Twin the way Yamaha has done with it's brilliant FZ/MT-FJ/XSR/MWT family.

 

[Fster]

Very informative response BillO. Despite the AT's height and my lack of it I will be taking delivery of this AT. I have pondered the notion of Honda coming out with multiple DCT models one that might be more suited to my needs but I want this AT. If Honda does come out with a 700cc or 800cc AT type DCT well maybe I will just have to buy one of those too.
Thanks

 

[JustPlainBill0]

As the (recent) former owner of a 605 ATK DS with a 36" seat height while I have a 32" inseam, I can assure you there are times when not being able to get solid footing makes parts of your anatomy pucker tightly. So I am very sensitive to the problem of being vertically challenged - especially off-road.

If the issue is primarily "seat height", there's plenty of information on the interweb on how to lower motorcycles without giving up too much in the way of functionality or safety. Get that AT and you will probably either adapt your riding style to the bike or the bike to your riding style.