Nimbus Impulse 36 disk brake model

Sorry, we were a little behind with the spec’s and photos. The photos and spec change are up on the UK site.


My brake has started squeaking a lot over the last week or so. Is there something I can adjust to fix this?

Day one my Impulse disc brake was unbelievably smooth and quiet. Learning to use it (my first brake) was a dream come true. After 100 miles, the brakes (when firmly applied) started making noise. You might call it “squeaking” but it’s really the holes in the disc meeting the pad. It’s perfectly normal per my LBS. I bought a set of Hayes pads but haven’t needed them yet.

I have been told that the type of brake material has an influence on squeaking. If I recall, the softer synthetic stuff squeaks less and has a shorter lifetime (but I do not care.)

Ask a bike shop if switching brake pad material might help.


I fixed it. It started after I took the wheel off to change the tube. The disk didn’t go back in exactly the same way when I put the wheel back on, so the brake started rubbing. I just had to loosen the brake on the frame, move it a little so it doesn’t rub anymore, and then tighten it back up on the frame.

Impulse video

Here’s a little video of a practice session on the Impulse. What the guy on the bike says can be more or less translated as: “Golly! You dare to do that??!?”

Fashion a Tourniquet! My Magura HS33 is losing blue blood.

I still love my Impulse and I plan on keeping it fully intact as a back-up / loaner to my brand new geared (KH/Schlumpf) 36er. Florian has not given his blessing to using a disc brake with his hub so I was left with no choice but to use Magura HS33 hydraulic rim brakes. I just got my new rig yesterday and so far, I am not impressed with the brake. It appears to have been damaged (are these brakes really that fragile? Did I take the simplicity of my disc brake for granted?) in transit. Thanks UPS! What can brown do for you? They can beat the shit out of your package. That is what. By brakes are leaking hydraulic fluid (Magura calls it “Blue Blood” but any Kentucky Wildcats fan can tell you we bleed blue as well.) between the silver collar and the black bolt (see picture below). I’ve removed it and shipped it for repair. So, for the time being, I’ve got no brakes at all. On a positive note, I finally get a chance to ride a unicycle without a handlebar. I never bothered to scrounge up a scrap 5 inch piece of pipe on which to mount my lever (told UDC they should include one) and I didn’t want to cut either piece of my Shadow handlebar.

You should have seen me (before I knew my brakes were a bust) cruising down the road pulling on the spooner lever ever so gently (having learned on disc brakes and scared of rim brakes grabbing hold and launching me off the front) only to find I had zero braking (no tension whatsoever) power. It made me LOL.

Usually the plasmatic crossovers are pretty durable, but whats the force from the rear wheel of a UPS truck gonna do to a little part like that?
Bummer. Well, if you were here in Portland, I’d fix it for you while you waited.

Careful what you offer, I might show up on your doorstep. Then again, the United States Postal Service (USPS) only charged me $5 to ship the whole brake (from spooner to pads) kit for repair and rebleeding. Your tax $ at work. Can I ship them to you next time this happens? They are footing the bill on the new ones but next time is on my dime.

Looking longterm, even if I don’t learn everything there is to know about these brakes, I really need to learn how to reinstall them myself. In the last few days, I think I’ve read every thread you posted on. Then there is a ton of literature on the MTBR forum. Magura brakes have been around forever. They are “old as dirt” like you and me. BTW, I was also born in 1968 before Kennedy’s assassination and the moon landing. Face it man, 1968 was a long time ago.

Bronson suggested I have Scheller’s (my LBS) put them back on (hopefully, letting me watch) and I agree. I took lots of pictures as I was taking them off and I might be able to “wing it” but I really want them set up proper the first time so I know what they are “supposed to feel like” as I make the transition from the disc brakes I know and love.

Sorry for the threadjack. I will keep all my “brakes” questions confined to Brycer’s “Magura adjustment” thread. Back on topic, while my brakes are being repaired, I am taking advantage of this (my first) opportunity to practice without the Shadow Handlebar in place. Come to think of it, this might be better placed in the “Shadow Handlebar first impressions” thread. Sorry, I just don’t like starting new threads. In all my years on the forum I have only started one.

Here (see picture below) is my best attempt to protect my KH front saddle handle (new and improved for 2011) from getting too scratched up while I have my handlebar off because, once I put my Shadow Handlebar back on, it protects the front saddle handle as the brunt force is taken out on the end of the handlebar. After doing this I realized that I probably spent enough money in Bontrager grip tape and F4 Tape Self-fusing Silicone tape that I could have bought an extra KH front saddle handle. Hopefully, the minimum adhesive backing won’t leave too much sticky residue. I think it should be OK. It’s time to take her out and let her drop (When I UPD, I let the uni fly and focus on not getting myself hurt) a few times.

Lesson learned: I am really bad at wrapping handlebars! I used this same stuff to wrap the handlebar grips on my Impulse Shadow Handlebar (used my good grips on my new 36" guni) and it looks great out on the end where I could tuck the wrap in with the plug (very professional) but gets ugly at the bottom. I just can’t stop without it bunching up. I won’t even include a picture of it because it is really ugly.

I wrap my seat handles with old tubes for comfort. It’s pretty easy to get a clean wrap. I posted a description with pictures in the 36er thread a while back: Post Your 36er Here

Thank for the URL. I remember seeing it a while back (that used to be my favorite thread. my new favorite is the Schlumpf hub general discussion thread) but could not find it when I needed it. Besides, the new KH Saddle handle does not have a hole.

Yeah, I was bummed about that change for just this reason.

Yeah, I was bummed about that change for just this reason. For a hole-less handle I might try coating the entire thing with PlastiDip.

Hey Folks. I wanted to order an Impulse by tonight to save with the 10% discount but am only limited to a KH Street seat as an available option. Should I wait until Freeride is available as an option or stick with the Nimbus Gel? I have ridden street on my trials and freeride on my 29. I would like the freeride (just emailed josh) but was wondering if this is a deal breaker if I can’t get that substitution in time? davey

Christmas Special

The Nimbus Impulse is on sale at UDC:

Have a nice holiday!


hey 36 riders!
according to the shipping info, my impulse should arrive on monday! I got it during the 12 days sale with additional white studded pedals, white clamp, and a white saddle cloth (to give it a white/black scheme). I am so excited!!

Anyways, how much of the seatpost do i need to cut? I just realized I am not the tallest person (5’10.5) and my inseam is like 30’-31’. I’m fine right? I will be riding on 125mm cranks. additionally do i need to make any modifications to the shadow handles???


also, are there any saddle bags you guys reccomend that would work for the impulse to carry the basics? Thanks!

To start off leave the post as long as possible.

How I figure out how long my post should be is to measure the distance from the pedal (in to lowest position) to the top of the saddle on another unicycle that you ride often. Use that as your baseline measurement.

When you get the 36 do the same measurement with the seat all the way down. The difference between the baseline and the measurement on the 36 is how much you should cut off.

Start out with the post as long as possible. You can always cut a bit more off but can’t make it longer again.

thanks for the help! the only problem is the two unicycles i ride regularly were recently sold so i can purchase this one. im sure i will be able to figure it out. i was just hoping that i wasnt to short to ride one! should i do anything with the shadow handles? Thanks