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Tire width on 5.5 inch wide K-bike rim

glenfiddich

TravelsWithBarley.com
As part of my sidecar rebuild project I'm looking at changing from the 19/17 GSA spoked rims to 17/17 cast rims. That would let me put a 130 tire up front which in the world of sidecars is a good thing. On the front a cast R/RT/S rim is a nearly perfect fit. On the rear I'd need to go with a K12/13 rim as it has less offset than the R. The problem is the normal 180 tire would rub a bit unless I either relocate the exhaust 10mm or go with a smaller slip on. Of course my first thought was to swap the 180 for a 170, but in a pdf file that details converting the GSA to a supermoto it says the 170 is too narrow for the 5.5 inch rim and I'd have too much sidewall flex.

Has anyone tried this? How was the fit?

Pete and Glenlivet
 
Have you considered a smaller and relocated slip-on coupled with a car tire? Unless you’re planning on serious off-roading in your travels, I’d think the car tire would work well. There are a lot of sidecarists and two-wheel “darksiders” running car tires on the rear; the difference in cost and longevity is huge. I run a 155/80-15R BF Goodrich on the rear of my rig—I quickly tired of $175 bike tires that only lasted 3.5k on the rig. Just something to think about.

Best,
DG
 
Have you considered a smaller and relocated slip-on coupled with a car tire? Unless you’re planning on serious off-roading in your travels, I’d think the car tire would work well. There are a lot of sidecarists and two-wheel “darksiders” running car tires on the rear; the difference in cost and longevity is huge. I run a 155/80-15R BF Goodrich on the rear of my rig—I quickly tired of $175 bike tires that only lasted 3.5k on the rig. Just something to think about.

Best,
DG

I ran a 15" car tire on a VW rim (with adapter) on the ride from Vermont to the Salem OR rally but had a blowout in Oregon from a jagged chunk of volcanic stone and had the devil's time finding a tire shop willing to sell me a replacement for fear of liability. It soured me on the car rim option. I also ran an Achilles 175 car tire mounted on my stock GSA rim and while I loved the longevity, it tended to hydroplane in moderate to heavy rain. But at least that gave me the option of swapping back to a bike tire in the event of fatal tire damage so I might still go that way, but on a cast rim.

Frankly, a big part of the driving force here is aesthetics. I'm in the middle of renovating and modifying the hack, and the cast rims would look great with the new look.

Pete
 
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