Yet another Addendum:
New Tire Link:
http://www.conti-online.com Continental Tires
Expanding Search to Motorcycle Rims:
As an
alternative, decided to open myself up to more options as I began to have some serious concerns about having enough choice between rims and tires. The gating factors being:
Diameter,
Width,
Aspect Ratio,
Hole Count,
Product Type/Usage,
Quality of Workmanship,
Reputation,
Price, and
Availability. Failure to meet criteria of any one of these attributes could sink a potential match. Here are some
motorcycle rim manufacturers/suppliers that I reviewed:
http://www.mooseracing.com Moose Racing Rims (this official site is lame, so Google a supplier)
http://www.rkexcelamerica.com/mx_excel_rims.html Excel Rims (so is this one; other retailers do a better job)
http://www.prowheelracing.com/products/mx/rims Pro Wheel Racing Rims
http://www.buchananspokes.net/categories/british_style_steel_rims.asp Buchanan's Rims; supplier of several types - including
bare,
unpunched rims for custom orders. Spendy!
Suppliers:
There are a lot of sites out there to help us find the proper tires and rims. The problem that I had with many of them is that they want us to provide the
make,
model, and
year of the
motorcycle/scooter before offering a selection which in my mind is ass-backwards if I already know the diameter, width, hole-count, etc. Google, TheFind, Amazon, eBay, and their ilk were of limited value, and often frustrating as a utility when attempting to craft a proper search string. One gem though stood out:

http://www.tyres-pneus-online.co.uk
Pneus-Online finds the tyres we need in the UK! This gets the
Most-Useful Website award: Big time saver, a great tool for comparison, with up to date reports, and best price listing. I found this site at like 9PM last night and I am still on it this morning. ***
Picking a Favorite:
I have decided upon the
Continental Conti-Go! 2.75-18 M/C 48P TT (70-457) tyre mounted on an
Excel Takasago 18x1.85 (457-47)
36h Rim. I will leave the front and rear to be the same since I am crafting a 2WD bike.
I cannot begin to explain the challenge here in attempting to match a tyre and rim, it was a struggle until I found the very last link
Pneus-Online***. :? However by then I had pretty much figured out the math and formulas for converting the sizes on the fly and I was in the final stages of sorting out the suppliers.
Why Continental:
I have close to 9 months experience running the
Continental Contact Reflex both F and R on my current e-build; they are adequate and give me little trouble. That ended up weighing in during in the process of removing
unknowns from the calculus.
There are some great manufacturers out there, but most of what they offer is difficult to source, and if it is found, pray it doesn't cost your next-born child. The
Continental Conti-Go appears to be a decent modern all-weather road tire, though I will need to pick something else for snow or off-road.
Continental Conti-Go! New City tyre for light motor bikes.
Why the 18-inch Wheel Size:
The Excel 18-inch/457mm rim when combined with the 2.75-inch/70mm wide tire (and similar aspect ratio) should not exceed a total diameter of 24-inch/610mm - thus meeting the criteria to drop the overall bike height by at least an inch/25mm. Presently I have the Mavic EX 729 Disc Rim with the Hookworms pegged for install - effectively setting the wheel diameter to 27.5-inch/700mm and exacerbating the already tall-for-a-medium-sized frame (it's a Felt-Compulsion 1). Then I added Marzocchi 888 RC3 EVO DH forks which will raise the height even more.
As for why I picked 18-inch over 17-inch or 16-inch, I just thought that it might look a little odd if the tires were too small. The other problem is that the rear suspension framework is too narrow to load a 3-inch-wide tire; even if the diameter was smaller there's just not enough room. Once I gave up on the 3-inch-wide tire idea, another struggle ensued to find any tire narrow-enough to fit.
The last factor was based on selection and availability: There simply is not enough choice, and that can be easily proven by using the
Pneus-Online*** website. U.S Domestic supplies are limited: I had to go look across the pond to Europe before I finally found the tyre.
The 1.85-inch/70mm-wide x 18-inch/457mm diameter Excel motorcross competition rim, being machined from lightweight 7-series aluminum, is stronger than any bicycle rim, and as a 22-inch equivalent-bike size - it falls neatly between the 20-inch and 24-inch inch gap. Trivia: This size also called an
ISO 457mm standard, 22x2.125, and 22x1.75, and
impossible to reliably find in bike-size.
Excel Takasago Signature Series Rims, available in several colors.
Caveats:
- There is lots of poop about the Excel rims needing their own spoke kits; another work item.
- Need to source a tube and rim-liner as well.
- Then figure out how to get the tires balanced.
No doubt it will be a burly-strong setup though when complete! 8)
<pause to graze, looking for something to nibble on
Conclusions:
Q: Rhetorically, can we find and mount a 16-inch/406mm motorbike/scooter tire onto a 20-inch BMX wheel?
A: Yes, certainly. For example, mounting the Continental Conti-Go!
2.75-16 on say a
Bombshell BMX Revolution Pro 1.75-inch Rim would create a wheel that drops a standard MTB frame by more than 2 inches; a viable solution, it's lighter, less expensive, more bike-like, and exceedingly meets the criteria.
My choices however are constrained by many factors, beginning with the narrowness of the frame. Picking a slightly larger rim expands the selection, raises the load characteristics and the top speed, and I end up getting a more durable pairing.
In the end, I guess one could say
if you look hard enough, you will likely find what you're seeking, or...maybe it will find you.
Trouble always finds me; no need to look that.
Thoughts?
KF