I’d be up for a lighter road tyre for my 36’er. At the moment it’s stock Nimbus Nightrider 36" x 2.25" multi surface that came with the Nimbus 36" Impulse Disc Unicycle with Shadow Handle.
What sort of weight saving do you imagine could be achieved with new tube and tire?
I would leave you to choose the tyre(s) as sending over to you seems first would add to the cost. I trust your experience and judgement . . .
I only ride distance on it.
Tom. I guess I got ahead of myself posting about making tires for others.
I am not saying that I won’t do it but I want to ride on mine for at least a month to see how it holds up before accepting money to do this for other people.
As for how light the tire could be…
I searched Jenson USA’s catalogue and came across the Panaracer T-Serv Protex Road Tire If their weights can be trusted I could make a sub 670g 36x1.75 road tire out of a couple of the fattest 26" tires.
Current 36" tires are about 1800g
I learned a little more in my own experiments today. I tried making a 36" tyre out of two 700c ones, but the joins failed when inflated to high pressure.
So I was making a 700c out of the remaining good sections of tyre to test better join technique; with a good 6cm of overlap at each of the two joins.
Unintentionally I made it a test of thread strength. One join I sewed with linen thread (used for carpets, buckles etc. - probably this is what Sask’s mum’s white thread is) and then I found some heavy duty polyester thread (similar to normal clothing polyester thread, but twice as thick, and unbreakable with my bare hands (ouch)) in a shop nearby, so used that for the second join.
When I pumped up the tyre to a good pressure it escaped the rim at one join… followed seconds later by the gunshot of a blowout (sorry neighbours, it was 7:40am!). Looking at the remains, it was only the polyester thread that had failed (shredded - it snapped on every stitch). The rubber walls of the tyre hadn’t torn, and the linen thread join was OK.
In short: good thread matters. Linen worked, my thick polyester didn’t!
Sam
P.S. We should start a Frankentyre (/tire) discussion thread really…
how is the tire holding up?
The tire is holding up great but the dip at the seam isn’t going away. I have somewhere around 2-300km on it so far an really like the size. Way lighter and faster than any of my smaller wheels and much less awkward than my 36. Yesterday I just finished drilling and tapping a few holes in the SINZ crank I have on there now and it feels great with the pedals in the 102mm hole and using a disk break on the descents.
I am gong to take the wheel apart, fix the bump at the rim seam, use longer brass nipples for joining the spokes (had a couple of the short aluminum nipples pop) and make a new smaller tire so the wheel will fit in a 2007 KH29 frame so I can put the fat 29 back in the Triton and keep this thing around for short road rides. I think it is going t become my commuting wheel.
i am thinking about sewing up some tires
Sometime in May I built up a new tire to fit in a KH29 frame, freeing up the Triton frame for bigger and badder tires.
The new tire was built out of cheep 27x1-1/4" tires from wallmart. I thought that they had kevlar beads since they were folded up in a little box and said “KEVLAR” on them but the really had a kevlar flat protection belt and some sort of steel cable bead.
I built the tire in a similar fashion to the 24" tire I posted earlier in this thread but no stitching in the casing, only around the beads. I could not go through the beads so had to basically just wrap them tightly together. I glued up the joins (or at least I thought I did), glued down the flaps, wrapped some tape around them and inflated to let the glue set.
There was maybe a 1mm lump at each join from the double layer of re-enforced casing. I don’t think I ever took a picture of it while it was in one piece.
With the new thin tire it wasn’t even 31" so I sort of stopped calling it my 32" wheel and started calling the wheel size 700X*
Anyway the new tire was 32x700 and had 3-4mm clearance with a 2007 KH29 frame. Perfect as far as I am concerned.
I have ridden a 32mm tire before on a 27" wheel and it was pretty rough. It is still a bit rough on the larger wheel but definitely felt smoother. Perhaps we can get a way with skinnier tires on larger wheels.
Anyway I have been using the 700X for commuting off and on, basically when I didn’t have the 36 set up for the road. Played with pressure a bit and really felt that the tire needed more pressure than I use in other tires (duh). I would mostly ride around 80 PSI. Today when I got to work the tire felt a little soft so I went to the air compressor and put some more air in by sound. The big tank usually sits at slightly over 100 PSI so I filled until the air wasn’t really “rushing” anymore. Figured I had just under 100 PSI, the original tires were rated to 90 PSI, figured I should be OK anyway.
Rode the thing home for lunch, then rode back. When I was rounding a corner in the yard I hit a rock that I usually miss, fell off the front and BANG! the bead blew out at one of the joins. The steel cable bead had slipped at the join.
Latter on in the day I happened to look at the pressure gage on the air tank and it was sitting just under 130 PSI, I guess I put a bit more in than I thought. Probably at least 120 PSI.
When I got home I took the tire off the wheel and inspected the damage. I was surprised to find that the casings weren’t glued together on the join where the bead went, and there was no evidence it ever was glued.
I cut the threads that were wrapping the bead and peeled the tread off the join. The Marine Goop I used held the tread on very well and I actually left little bits of rubber behind on the glue.
Looking at the rim I was surprised to see how much stretch 120PSI inflicted in the fibre reinforced packing tape I used for a rim strip. I think I will do a double wrap next time I am using pressures that approach 100PSI.
The other join was still perfect.
I could re-build the tire with the chunk I have left from the original build but I don’t think I want to deal with a cable bead again.
Time to start looking for a nice Kevlar/Aramid bead tire in 32mm width.
*700C is 622mm BCD, 700X is 700mm BCD
