piit wrote:Hi and thx for the replies. Some backround, I have already CB1100R -83 box rear swing and brake, prolink front end with brakes and prolink comstars. Comstars are fitted currently my Â´79 and I am ready to go widened rear rim if cannot find other solution to have wider rear tyre (160-170 would be quite nice). I have been in contact to Kosman and 4.5" widened rim takes 525$+shipping to Finland. This is about the money I am ready to put this project. All the original parts I will store to possible later usage.
I have been tried to study and collect information about other possibilities for example CBR600 rims. A lot of rims available in ebay (germany). I am very open for all options, but as normally plans never keep in budjet so...you know other model front end (yeah, up and round), brakes, rear swing, 17" rims.
Does it sound bad to have only widened Comstar rear rim with 18"x160 tyre and in front 100/110x19"? Currently I am running with 130/80x19 rear and 100/90x19 front (after market rear shocks) and I am fine with the performance...I mean rear is now a bit lower, but I cannot "feel" problem. Regards,
I have a full 1100f front and back and Kosman widened my back 1100f rim to 4.5". This, plus a few other econo things I did transforms the CBX early model into what it should have been all along at all speed and in the twisties. Kosman also widens Comstars. I think I have seem pix of the welding seam on Kosmans ground off and it looks great. I dont know if you can do this on the widened Comstars or maybe even Kosman acn......ask them. I did not do this because I do not care that much about detail looks of things like this vs the overall outcome.... which in my case was ....improved handling.
Issues I see in what I think you said you might do
1. You could still keep your 19" front rim but you are going to have to do the math and raise the front forks to accomodate for the lower 160x17 on the back to keep your X near to stock specs. I am thinking ....take diff in diameter of the 160x17 and 130x18...divide this by two ....and this would be a good place to start raising your front forks to get the bike back to near stock. My guess is 11-15mm. If you do not do this your bike will be super steady on the straights, but require far more effort in the twisties to turn in and flick back and forth in tight twisties.
Note: Low theory here and I only have personal experience to back this up.....but I really do not think the contact patch of a 100 tire is quite up to improved braking that a four or six piston system can give. Also for fast street riding or track days and I think the 100 side tread angle is too steep and might be a mismatch for the wider rear tire tread angle....160...whatever, but you could try this and see how it works. After all if 100 series front tires were that trick and reallllly worked we would see them on new sport bikes and in WSB and MotoGP.
Finally I always thought that a wider 18" comstar rim off another period Honda could be bolted on an early model front hub........but to my knowledge no one ever did this. This would give you a 110x18 front and would be a cheap out for solving this.
Advantages of my conversion that apply to your components also
1. Bike is lower by 13mm or so due to 26mm less in diameter on front and back 1100f rims compared to stock CBX rims. Very big improvement in turn in and in the twisties in general
2. 1100f front brakes and the brakes you have are a big improvement over stock early model brakes. I do not know about 1100r brakes which I am guessing are equal or better than 1100f brakes, but in the end almost anything is an improvement over stock early model front brakes components.
3. 1100f forks have an early version of anti-dive that works....really works on hard braking. It works so well it took some time for me to adjust. If your 1100r front forks have anti-dive this will be a good improvement.
4. In my view, you have to go with a wider rear rim to ensure you get all the benefit out of your other improved components. I dont want to go into my views on wider vs narrow rims on heavy and powerful bikes but suffice to say there are few if any new bikes today with around 100hp or more with 130 rear tires............and for very good reason. Like I said I have a 160 and like it. It has a balanced look with the back of a stock CBX which in my view a 180 tire does not..........and the 160 does work great...right out to the edge on track days.
If you agree/approve, I will call Sandy Kosman and see if we can get a better price for you on the Comstar rim widening. No promises....but if we dont try we know the answer..right.
Best and happy to see you on line