I just got a 26’’ torker lx for bike path riding and a 3-mile, flat commute. I replaced the seatpost (kh forged), saddle (impact naomi), cranks (nimbus), and pedals. At some point in the future I would like to replace the wheelset for a lighter one. I was wondering if I could use a 26’’ road bike wheel set (ideally with a skinny smooth tire) built with a uni isis hub. I think I would prefer a roadbike rim over a uni rim because of how skinny and lightweight I could make it.
If this is possible, does anyone have any recommendations for a lightweight 26’’ rim? I was told this size is mostly used for mountain bikes, so I don’t even know if they make lightweight 26’’ narrow rims. I was also told uni hubs usually require more spokes than most road bike rims use.
Any suggestions?
P.S. The torker was free, hence the reason I have a 26’’ instead of a 29’’. I’m guessing a 29’’ wheelset will not fit on a 26’’ frame. If this IS possible, then I can just go back to the recent 700cc thread that was posted.
A 700C wheel with a skinny tire should fit in your 26" frame. If not a 650B (27.5") wheel will fit, again with a skinny tire.
700C originally meant a wheel 700mm tall with a “C” width tire, which was 1.5" or 38mm. The BSD of the rim is 622mm.
650B was likewise 650mm tall with a “B” tire - 1.25" or 32mm. The BSD of the rim is 584mm
To figure out what would fit you can calculate approximate wheel diameters by adding the BSD to double the tire width. If it is less than double your axle to crown height you are good.
EDIT: on the subject of spoke count; Are you planning on disassembling your wheel to re-use the hub? Personally I would suggest you leave your current wheel as is and get a new hub for your “second” wheel. If getting a new rim look for ones used on tandem applications, these tend to have more spoke options.
If you are re-using a hub and can’t find a rim with the right number of holes you can lace a 24 spoke rim to a 36 spoke hub or a 32 spoke rim to a 48 spoke hub by skipping every third hole on the hub. I would not go less than 24 spokes but that’s just me.
The best thing about ISO 559 is that you can get just about anything you want in that size. There are rims less than an inch wide made for things like racing wheelchairs, although sometimes they’re advertised as 25"x1" size. Look for the “559”.
I’ve got Sun Rhyno Lite rims on my 26" commuter bicycle and I’ve been happy with them. They’re somewhere close to an inch of inner width. A road tire in the 1 1/2" to 1 3/4" wide range sits well on that rim.
As saskatchewanian said, a skinny 700c tire isn’t a whole lot bigger than 26". “622” is just the nearest millimeter equivalent to 24 1/2", and adding two 1" high tire sections would give a 26 1/2" diameter. Since you have the frame, you’d could measure and see how tight a fit that would be. But keep in mind that you’d have the proverbial “bacon slicer” wheel with that, which are said to be a handful even by folks who like to ride them.
I re-use one of my old MTB 26"rim (559*18mm internal width) on my uni4city.
With k-rad 26x2.5" I have bigger external diameter than 700c skinny tire (but far heavier :D).
I have no problem with the narrow rim as I’m running between 3 and 3.5atm(aprox.40-50 psi).
In your case, I’m not sure it will be ok with 622 rim and slick mtb 29" tire on a 26" uni frame but give a try with your frame on a 29" bike if you would like to go fast.
I couldnt grow to my 700c build. they are quite twitchy and not a pleasure to ride specially due to the tyre pressures road tyres usually are run at.
so many 26 and 700c rims out there! Most 26er rims are narrow its a matter of sorting out through them and finding the correct spoke hole. most uni hubs being 36h. common mtb rims are 32h.
Only other consideration really is you need to calculate the new spokes and a mtb / 700c rim isnt designed for a full load of the rider and the forced on it riding a Uni are different to a bike so strength in some ways may be compromised depending on the quality of rim you find but there shouldnt be any issues unless your mounting curbs and doing drops
What are you actually trying to achieve with a light, narrow rim? If the answer is going fast on tarmac, then in general there are better ways to achieve that, wheel weight and even tyre rolling resistance not being the major limiting factors on a uni.
What made you choose the naomi saddle? Sounds like you might wanna find someone to trade it for something a bit thicker, KH street or Freeride. I haven’t done much riding on the naomi, but I know it is really slim and won’t end up being very comfortable for distances.
Also, more on topic, I’ve been thinking a lot about a jackshaft 700c uni. Does the extra twitchiness help overcome the large effective wheelsize, or make matters worse?
I did my longest ever ride on a stock Miyata saddle and it was pretty comfortable. It’s not the thickness of the padding so much as the shape and angle.
My new Freeride saddle (bought so I could fit the KH handle set) is the least comfortable saddle I have ever used.
Would you look at that. I knew that:
19" rims were actually 15 1/4",
20 = 16
24 = 20
26 = 22
but somehow never clued in that:
650B = 23
700C = 24.5
and 36 = 31
And to the OP:
I had a skinny road wheel for a while, it was a ton of fun since it was extremely manoeuvrable and a challenge to ride down erosion canals on partially melted streets etc. It also cut through mud and slush very well. It took a lot of concentration to ride though since it was very twitchy could easily throw you if you attention wanders just the slightest bit.
It was great fun but not something you can just relax and ride like a fatter tire unicycle.
If you’re going for light and skinny, the ISIS hub would be overkill. Like putting a trailer hitch on a Fiat 600. Square taper will be more than strong enough to go with a wheel you have to be nice to.
Speaking from zero experience with skinny 700c’s with jackshafts, I think the lighter wheel will definitely make the thing more responsive, and less sluggish. It would be worth it to try.
Note that the skinnier your tire, the harder you have to pump it up. This is great for high performance, but bad for ride comfort. Also a really hard tire can take more of a beating when you hit random potholes or other bits of road reality. Generally you can go to a little bit wider tire if you get tired of a super-skinny one–you might want to keep that in mind when choosing a rim.
Eureka! Yeah, a light bulb went on above my head when I realized the sham-metric basis for BSD sizes. I’ve also used ISO 571 650C tires that were (are?) fashionable on triathlon bikes, really 22 1/2". And there’s 650A = ISO 590 = 23 1/4", Schwinn S-6 = ISO 597 = 23 1/2", the larger ISO 451 20" size (folding bikes, recumbents, a few oddball BMX bikes) that’s 17 3/4", etc, etc.
Oddly, the 27" road bike tire that was standard on US ten-speeds in the '60s and '70s is ISO 630 BSD. My guess is that it’s supposed to be 24 3/4", but if so then they snuck an extra millimeter in because 629 mm is more accurate. The ISO 507 24" size is more puzzling because an inch is precisely 25.4 mm by international definition, so 20" BSD ought to be 508.
I’ve brought this up on a couple of bicycle lists and forums before and never gotten any responses. I never knew whether it went over everyone’s heads or if it was so obvious that it didn’t need to be mentioned.
glad you guys are good with maths lol your making my head hurt,
yeh the 700c guni looked the part but was better to look at than to ride.
80psi for a road bike tyre is low and still it was so rough and you feel every bump rock crack and peice of dust on the road… the road camber is still noticeable on a skinny too.
Honestly 700c tyres/ rims on a Uni are to me just ok. Mine ran in a Kh26 frame no issues at all and was a 700x28c. I wanted to see a 700c guni so i had to build one.
Now i done it, looked great but disappointing ride. i thought it would feel better and climb easier than it did. low gear is choppy and slow, high was good but constant swinging back and forth on the tyre is annoying and hard work. they are not a very forgiving Uni size.
I can see why so many people ride 36 Guni. 36er is a great size. climbs reasonably well, looks like a beautiful striking young lady with high heels in a crowd and as KH himself said a 36 guni has 2 useful gears.
Hence 700c Guni out, 36er Guni in progress
If any one is planning to run a 29 or 700 tyre try to get one with say 32c < air volume and keep your ungeared road Uni crank lenghts to a minimun. The 700 Guni was easier to ride 125mm than 150mm. Post pics when your complete your 700c please !!! Cheers
My 29er guni has a 50mm tyre and a lightish narrowish rim (for a uni) - I might go a little narrower when I replace the tyre, but probably not smaller than 40mm. I still find that hard enough work, but really need to get more practice at riding it. Currently using 125 cranks, but I think I’ll probably go back to 140 as I find those harder and don’t seem to get any speed benefit in high gear (it came with 150 but those were too long for me to change gear comfortably with my little feet).
Yeah, a light bulb went on above my head when I realized the sham-metric basis for BSD sizes. I’ve also used ISO 571 650C tires that were (are?) fashionable on triathlon bikes, really 22 1/2". And there’s 650A = ISO 590 = 23 1/4", Schwinn S-6 = ISO 597 = 23 1/2", the larger ISO 451 20" size (folding bikes, recumbents, a few oddball BMX bikes) that’s 17 3/4", etc, etc.