Topic: How will it affect handling/ride going from stock 18 " rear to 17"???

[amattel]

My rear wheel has a flat spot according to the guy who tightened and trued it for me.

It seems to work fine (haven't had it past 90), but I intend to replace it when I come across an affordable rear wheel in decent shape.

I am looking at a 17" wheel on ebay which the seller says will lower the rear by 1 inch.

Could someone tell me the pro's and con's of going from 18" to 17inch in the rear?

I really don't have a problem with the 18" rear .  I am only considering the switch since it seems (so far) to be affordable.

thanks,

Adam

[Gordon]

Going from an 18" to 17" will lower the rear 1/2", not 1". 

Lowering the rear, or raising the front will have the effect of slowing the steering responsiveness because the center of gravity will be shifted slightly toward the back of the bike.  How noticeable this is depends on the individual rider and riding style. 

[amattel]

hmmmmm...  well I actually like it's responsiveness, so perhaps I will wait for an 18" wheel to come available.

What about all the cafe's that put 16" wheel on the back...do they drop the size of the front wheel as well to maintain good handling?

Adam

[Gordon]

What about all the cafe's that put 16" wheel on the back...do they drop the size of the front wheel as well to maintain good handling?

You can push the fork tubes up in the triple tree to bring the front down the same amount as the rear.

My opinion on the rim, though, is if you have no specific reason to switch to a 17", then stick with the stock size.  It shouldn't be too hard to find some.

[nteek754]

WOW guys I been running 16 inch rear no mods to front and she handle like a dream and this is on a 1973 750Kand oh yeah just put an 836 power plant into her frame and  oh man  isnt she sweet maybe you guys are like race ready I dont know to each their own have fun seven fifty four ever

[amattel]

WOW guys I been running 16 inch rear no mods to front and she handle like a dream and this is on a 1973 750Kand oh yeah just put an 836 power plant into her frame and oh man isnt she sweet maybe you guys are like race ready I dont know to each their own have fun seven fifty four ever

hey qtrhoss7...  what size tire are you running on that rear rim?

[ProTeal55]

I got a 16'' in the rear, and a 21'' up front, so I must be all messed up 

Gots a 130/90/16 out back, and a 100/21 up front.
To be honest, it handles pretty much the same from when the stock sizes were on it..

[oldbiker]

Hi Proteal, if that suits your eyes and riding style, stay with it. It looks OK to me.

[Gordon]

Settle down guys, I never said it would negatively affect the steering, just that it would have an effect, and it does.  If that works for you, then that's fine.  I have the rear of my 750 dropped almost 2" from stock, and it works great for me.  Stop being so sensitive!

[eurban]

As to the original question . . .Stock rims on the later 750s (77 on or so) were 17"  . . . . Why does switching to a 17inch rim necessarily lower the rear? Tires come in different profile dimensions so if you are worried about lowering, simply find a tire size (taller sidewall height) that replicates the original outside circumfrence  of the tire on your stock 18inch rim . . . . .

[nteek754]

prtril sorry for the late respose  130 90 16

[dusterdude]

adam,if the rest of these guys scare you away from the 17,please point me in the direction of that auction.

[cafe75-550]

Going to a 17" rear won't necessarily do anything to lower the bike, it all depends on the profile of the tire. On my CB550 I went to a CB650 rear, also a 18" to a 17" swap, but with the change in width in the rim I also went from a 100/90 rear to a 120/90, which lowers the back less than a 1/4", and when I put the new 130/90 on it the back end might actually be a touch taller, so a lot of it also depends on the tire...

[Jay B]

 

Lowering the rear, or raising the front will have the effect of slowing the steering responsiveness because the center of gravity will be shifted slightly toward the back of the bike. 

Not to be nitpicky here, but the change in COG would be very very small if you lowered the rear a bit. What slows steering is by lowering the back of the bike, you effectively increase the steering head angle, increasing both rake and trail. Real small changes in either make a big difference.

[BobbyR]

My 78 750K has a 17" rear as stock. Turns fine and stable on the highway.