Wheel size questions

[G-Man]

You normally specify the spoke angle by providing the hub dimensions and offsets as shown here. Those are the settings they feed into the dimpling / drilling process.

http://www.central-wheel.co.uk/rims/rim ... edure.html

G

[richmondzb]

Kellie, Did you ever pull the trigger on those rims? I am going through the same situation. I have bought so many parts that turned out being the wrong I am becoming gun shy.

[rrietman]

the correct rim size for the ca77 is 1.85x16. I have used two sets of the Union cycle rims with dream hubs and they CAN be made to work by drilling and reaming but it is a PITA. unfortunately these are the only NEW rims available for the 305 dreams unless you can find someone with some very old stock (Nick?). I have quite a pile of old dream rims that need rechroming, but that =$$$$$.
Randy

[KellieLyyne]

Yep Randy I know what you mean about PITA. I did pick up the Union Cycle rims and there's a local guy near me, who relaces vintage rims. So I met with him and showed him my situation. He was able to get them laced, but the angle and the spokes being a little shorter than he usually likes made it a little more difficult than it should have been. I have one good original rim, and I am looking for another decent one to have rechromed. But I am being pretty picky on the rim I choose to rechrome. Since I have some rims for now, I will run these and keep my eye out for a good candidate. Isn't building things fun????

[conbs]

While this thread has discussed what is the "correct" size rim for a 305 Dream, it might also just be a question of what will "fit".

In his "Everything you ever wanted to know about 250-305cc Honda Twins" piece, Bill Silver says:

"Visually, the front and rear rims and [sic] seem identical, but there were some subtle
dimensional differences between the front and rear hub, so there are separate part numbers
for the two different rims."

It is not only a question of width 1.85 vs 2.15, but what angle you need for the spokes to line up depending on whether it is a front or rear hub. With due respect to Nick, I think Bill deserves some deference on the correct rim size at 2.15". I have read that the 1.85" rim is correct for a CA95 which uses a 3.00x 16 tire.

As Bill also noted, "...I have seen more than a few 250-305 Dreams running around on 3.00x16” tires, which were designed for the much lighter 154cc CA95 “Benly” machines." I have seen that myself as well. Those 3.00 tires just look wrong on a 2.15" rim. It flattens out the side wall. I also suspect 3.00's would tend to have a lower load rating as well.

Irrespective of what is "correct", the 3.25x16 tires will probably mount on either size rim, but will fit a little differently. And, though the 3.25's may "fit" on a 1.85" rim, it seems like it would make the sidewall too rounded. Maybe it wouldn't matter, but I would be interested in what the engineers have to say about that.

Not having tried to lace up any of these different combinations, I can't speak to spoke angle issues, but it would seem to me that starting with the "correct" parts would surely make life easier. In the end, if you can get your wheel put together and you're happy with it, then that's probably all that matters.

If anyone takes exception to any of the above, I hope you will add yout knowledge to this thread.

[rrietman]

I have dissasembled quite a few original 305 dreams and I'm pretty sure that the original rims were 1.85x16. most of em are stamped "D.I.D."1.85X16. I'm not sure but I think the CA95's use the same.
Randy

[KellieLyyne]

I know first hand what Bill Silver was trying to explain to me about the "angle" differences with the rims. Its not just the rim size that causes an issue but the angle of the dimples and holes drilled in the rims themselves. When you lace up the rims, with the spokes you need to bend the spokes at steeper angle to get them to fit. Due to the narrower hubs on the CA95 it is not an issue. However when you put the wider hub of the CA77 into a rim that was originally drilled for the CA95 you start understanding the real problem. The spokes that "should" have worked were a little short. Next time I do a set of wheels for this bike I will use my originals and have them rechromed and then I will send them to Buchanans to have spokes made for the application and have them lace them up for me as well. This bike build has been an educating experience.