This theory crops up every once in a while. While it seems to have some merit, it goes against the physics. The one thing you will notice from using a 29er tube is more air bleeding through the rubber. As a result you will need to fill your tire more often, but to be honest with the volume held in a 36er it’s still quite a long time between fill ups.
Tubes blowout because they aren’t supported by the tire/rim. To be more specific; if a tire or rim support a tube in all but one small area, that area can blow out. This can be a sidewall weakness/cut, the wrong kind of rim tape, a poor fit of tire to rim, or the tube seating between the tire an the rim. This last scenario is the one that is more likely with a 29er tube in a 36er. Because the tube is smaller it is harder to get it to sit completely inside the tire, and as a result you may be more prone to installation blowouts.
If a tire blows off of a rim it can cause damage to the bead that can prevent the tire from ever seating again. If this happens with a new tire it is normal to assume it to be a defective tire. If it happens to a tire that has proven itself it is usually due to installation error. I have never seen a tire blow off of a rim because of the choice of tube.
I have had a single 29er tube in my 36er for the past couple of years. It has been through a half dozen flats (goat heads ), and it’s in its second tire. I have no regrets switching. The Coker tube was three times the weight, and 10 times the price of my 29er tube.
I’m going to replace my steel rim and 12G spokes soon. The Nimbus Stealth rims seem to be the only option out there, at least for the U.S. I thought I could get an alloy Coker rim, but I can’t find it on their site.
It looks like Coker no longer has the wheelset on their site. It’s too bad as it was by far the best deal going in large wheels, $125 shipped. You may be able to call them and see if you can get one. Keep in mind that the original Coker frame was for a standard “wide” hub, and the new hub (if you can get the wheel) is a “super wide” hub. It’s a pretty easy thing to spread the fork blades on the frame to fit the new wheel.
With 48 spokes I think there is no reason for a super wide rim though. If you can still get the wheel you can buy a 48h Nimbus or UDC hub and re-build it to regular width.
I have a Coker wheel on a Nimbus hub in a KH frame and think that it is the best combo you can have.
I have the same coker setup and am really happy with the unicycle.
I would have to agree that this unicyle is pretty close to as good as any other non-geared model as well. I ran this coker up to 15mph once, and this
fast enough. Any faster and I don’t think I would feel safe.( A UPD at this
speed would be a disaster.) So a geared 36 is probably not in my future.
Coker now has a video clip on the coker website of some dud doing some hops and drops. Coker seems to be promoting this
type of usage even though the Big one has a square tappered hub.
Wow, nice video clip! I think I recognized Jeff Groves and possibly Ben Plotkin-Swing. Looks like filming was done in Toronto, maybe? Yes, people did all kinds of stuff like that before there were splined hubs for 36ers. My 2002 Coker Deluxe from UDC is still on its original (narrow) hub, and has been used for plenty of MUni, though not as extreme as what’s shown in the video.
This is the most fun I have ever had on a wheeled device. My 36 is a 2007 Nimbus. It came with a handlebar and a cycle computer. So far, I have had the confidence to max out at 13.5 mph.
I literally freemounted and rode off on my second try , which was extremely surprising. I haven’t had a failed freemount since.
Congrats AustinLee, the 36er is an epic machine. Wish I would have known about them years ago, but didn’t ever see one until I found this forum the end of 2009. Now I’m making up for lost time.
I have a new generation Coker wheelset, in a Nimbus Titan frame, with the T7 handlebar, and the Mountainuni disc brake rotor with Sinz cranks and an Avid Juicy 5 hydraulic brake. It’s perfect. The Mountainuni rotor inspires a lot of confidence when attacking steep downhills.
It used to be that at around 14mph I could feel that “I think I’m starting to spin a little too fast feeling…what if I had to slow down in the middle of this downhill ???”. Then I would start to slowly apply the backpressure on the pedals before I went any faster. Now, I just go for it, knowing I can begin to lightly apply that sweet disc brake if I can’t maintain the spin.
My max speed of 20.7 mph was attained about two weeks ago, heading down a steep hill with the pedals in the 125mm position on my Sinz 125/150 cranks (now deceased - see picture). My new cranks are Sinz 140’s. I seriously thank God that the crank didn’t snap when I was going that speed down the highway They broke a few days later climbing a hill doing some mountain bike trails.
So anyway, if anyone else has Sinz cranks that have been drilled aftermarket, I would just be careful and keep an eye on them, or better yet, make a small compromise and just pick one size. Having a crank arm break on you is scary. I’m glad I didn’t break any bones!
The second pic is of the 36er with the new Sinz 140’s, and a new Coker button tread tire (I wore out the Nightrider tire - did too many 180’s without doing enough tire rotations to spread out the wear).
Also in the pic is my new Nimbus 26er with: Kris Holm seat and dual-holed Moments, and Magura HS33 brakes from Brycer1968. Just got the brakes on today, and they worked great on the trails. Thanks for the quick turn-around time and customer service Brycer! The neon yellow looks great with the black frame too
Rhino, Glad to hear that the SINZ dual hole failed in an area that wasn’t catastrophic for you. We’re not abandoning the multi-hole idea, but we definitely are not drilling/tapping the SINZ beyond the one that’s cast specifically for the crank size. And TY for the nice endorsement for Mountainuni Disc Brakes and it’s inspiriing Big Wheel confidence!
I still ride an “historic” Coker (bought in 2003) but many things have changed : T 7 handle, rim, nightrider tire, and a 26" tube ! (YES! I have had it for nearly 2 years now!).
my big problem is crank choice: the 140 appears to be the best suited for me but are hard to find!
now how to set up a brake on this old thing?
I had a pedal with bad bearings come off my recumbent bike when I was pedaling hard and going about 25 mph down a hill. In hindsight, I realize that if I’d kept my cool it wouldn’t have been that big a deal on two wheels. However, the feeling of having your foot suddenly and inexplicably fly off from spinning at ~95 rpm (I was clipped in) was terrifying; the emergency skid stop shredded my rear tire.
A broken crank on a 36er, particularly at speed, could be truly devastating. Glad to hear you survived yours!
Okay so I need to figure out how to post quote snippets when replying to people…maybe when I have more time.
Yes Mountainuni, the Mountainuni brake system has been great, and the Sinz cranks broke at a perfect time when I think about it. I probably shouldn’t have been using that particular set-up offroad as it was I feel a lot more confident with just the single hole cranks now, although it’s surprising how much easier it was to climb steep hills with 150’s versus 140’s. I really love the way the 36er feels on the swoopy singletrack trails, even when it’s partially rooty and rocky.
Sounds like a scary ride uniShark, I am very grateful my break was uneventful other than a walk back through the woods
Yep wobbling bear, you could always do the Mountainuni system on your Coker I would think? Maybe the UCM mount with the Sinz square taper cranks,(they are still available online in many sizes if Mountainuni isn’t stocking them?) Or, like uniShark mentioned, a caliper brake would at least give you some braking besides using your legs. On big downhills I would not want to be without my brake - No way!
you can see from the attached link, that a small shim (which we have) and a Uni-Caliper Mount (UCM) 2, 30mm M6 bolts and nuts retrofits the MountainUni Disc Brake System to Cokers nicely. We have 140mm Sinz in stock…
BMX calliper brake is the cheep no-hassle way to go, they work great on 36ers. I know what you mean about it being hard to find cranks in 140mm size. The two square taper cranks I have seen in that size are schlumpf and SINZ.
Adding a disk would be sweet but you can do the BMX brake for about $10
thought I’d bring this thread to life, rather than start a new one. I have a Coker V2 with the standard Coker vee brake. The wheel is powder coated aluminium and the brake grabs like nothing else on the powdercoat, making it near useless for anything other than very rapid dismounts. I’ve already got the pads toed out a lot to try to keep them from grabbing, but they still do.
Anyone had this experience and found a cure? I’m thinking about abrading, or even removing the paint from the rim, but I hate to go through all that effort only to discover it glazed right over again and I had the same problem.
Alternatively I could go the Sinz pedal/MountainMuni brake path. I like discs a lot, but I’m not sure I’m ready to throw ~$250.00 at this right now, which is what I’m guessing a disc setup would cost me. Are there options I’m missing?
The rim brakes on my Coker are very “grabby” also, and the wheel has machined side walls. The brakes on my 26" with Maguras aren’t as sensitive, so I was thinking it might be good to try a different pad material. (Although I’ve been practicing applying the brakes gently, I’ll probably get used to it over time.)
But I would also be interested in hearing other people’s experience.
On a side note, I’m using the brake pretty much every time I stop now (on the 36). It makes rear dismounts way easier to control, IMO.
), and it’s in its second tire. I have no regrets switching. The Coker tube was three times the weight, and 10 times the price of my 29er tube.
, which was extremely surprising. I haven’t had a failed freemount since.
They broke a few days later climbing a hill doing some mountain bike trails.
