the 700c slim tyre riders thread

Here’s links to threads/photos of the kind of machine I’m talking about-

('hell on wheel with a really nice photo of the kind of extreme slim road tyre I’m talking about)

(Mike Fules ‘Bacon Slicer’ thread with pictures)
(Bacon slicer)

Basically the old style 28"- precursor to the modern ‘29-er’ which is the same but with a fatter (and heavier) tyre, probably on a fat rim.

My recent thread-

described how I switched from a fat 29er tyre (WTB stout 2.3") to the thinner (but still 29-er) Kenda Klaw and found that it was much easier to pedal up a hill.

Of course, there’s a price to pay- the cushiness of the fat 29-er tyre makes rolling over bumps in the road straightforward- the thinner the tyre, the more you have to be careful what you’re riding over.

And, the thinner tyre tends to need higher pressure and therefore the ride is less comfortable.

In a world of diversity encompassing 20" trials/hockey, 24/26" muni, 29-er muni/road riding and the mighty 36"coker variants, the category of the 700c slim tyre seems to be by far the smallest category.

But there is an appealing aesthetic to the slim, light 700c with racing tyre, Mike Fules many posts on his ‘Road Razor’ and 'Bacon Slicer’made he clear that he was aware of the lower ‘practicality’ of the ride, but that the purity and extra focus required, made it a worthwhile machine.

Previously, several years back I did try a 700c racing tyre on my 29" Nimbus- and vowed ‘never again’ :slight_smile:

But, my recent experience with the Klaw and it’s benefits on uphills has got me interested- today I’ve just bought a 40mm 700c tyre, installed it on my old Nimbus and, am looking forward to trying it out over the next few days.


  1. are there any 700c slim tyre riders out there?
  2. if so, what do they think are the pros/cons compared to the modern 29-er and, why do they prefer the 700c?
  3. does anyone know if the slim 700c tyres work on the modern wide 29-er rims?
  4. do you feel that many of the modern advances in unicycle technology actually have an adverse effect when it comes to 700c’s?

(I ask that because I think that the old-style square taper hubs which are now unobtainable, are better suited to the 700c as they’re lighter and the strength of the splined hub is superfluous in that context)

We’re just approaching the season when the skinny tyre comes out again. 700c x 23mm at about 120 psi.

As you remarked, the appeal is mainly aesthetic. I like the purity of riding the narrowest hardest circle of tyre. It’s me against the terrain without any help from the uni.

Longest ride ever on it was about 56 miles (90 km). A typical ride is 10 miles. It’s OK for undulating cross country unless the ground is soft.

I ride 125s for versatility, or 114s for comfort. Shortest cranks I’ve tried were 80mm - and the uni ended up in the canal.

When funds and stupidity combine, I will try a 19mm tyre.

I just replaced the stock knobby tire on my KH 29 with a Schwalbe Marathon Supreme HS 382 and am amazed at the difference. I ride exclusively on the street and try to ride up any hill I can find. The new tire is quite fast.

I would love to try something thinner like a road bicycle tire but don’t know how to determine what will fit on the KH 29 rim.

Thanks for the thread! I hope we get more replies.


Wow, I didn’t realise when posting this thread that ‘skinny tyre season’ was officially almost upon us :slight_smile:

Having put the slim tyre on the Nimbus (only a 40mm @ 50 psi I’m afraid, but at least a step in the right direction) I’ve not managed to get out on it- hopefully tommorrow.

What I’d like to do is invite a variety of big wheel riders up to Sheffield and try out a selection of 29-ers/700c slims/cokers/26-ers etc on the wide variety of sheffields terrain (including many useful hills).

I think it would be really useful in terms of direct comparisons and, also, possibly shatter some myths (in particular I’d like one of the 'coker with 110mm brigade to tackle some Sheffield hills :slight_smile: )

Anyone interested?

Nothing extreme- probably just a couple of hours riding for the first one.

I expect wheel sizes could go down to 24x3, but 20"-ers definitly wouldn’t work.

Currently I’ve got the KH29-er, a 700c Nimbus with slim tyre and a 24x3, so I could lend two of those out- it would be excellent if Mike could bring the “bacon slicer” and “road racer”.

Let me know if anyones interested and,if so, I’ll put a new thread up on the ride to try and get more interest.

That’s a coincidence, the slim tyre I’ve just got is a Swalbe Marathon 700x40c.

I also wondered if such a tyre would go on the KH,with the rim being so thick.

I decided to put it on my old thin-rim Nimbus, leaving the KH with the Kenda Klaw,as I know that tyre works OK on the KH.

Is your tyre a 40mm one?

I might like to bring the Bacon Slicer.

The Road Razor was sold a season or two ago to someone from this forum.

Whoops. sorry- a genuine slip of the finger- I did get the name right in the first post :slight_smile:

Do you know how they got on with the Razor?

Am I aloud in the club? I used to ride a 27x1-1/4 (about 32mm wide and a bit taller than 700c) I think the wheel is still around somewhere and I will definitely break it out once the snow melts since I don’t have the 36er anymore.

On second thought I think I re-used the hub for a freestyle I built up last year. I still have the tire/rim and don’t ride the freestyle much… I might have to put that hub through its 4th wheelbuild :slight_smile:

Skinny wheels are fun but I love my fat tires too.

I met the guy once a few months later in the forest on a different uni. He seemed reasonably pleased with the Road Razor, but I haven’t really had any contact since.

I must admit that in some ways the 28mm Continental tyre on the Road Razor was more suitable for a uni. I have a very tall 23mm on at the moment, and it can be tiring to keep it going straight. Roger had a quick go on it at a hockey meet in Derby and wasn’t dead keen on the handling. For the pure 700c experience, I ought to go for a round section 19mm or something daft like that.

Oh they were the days, when cycle wheels were
27 x 1 for hardcore racers
27 x 1 1/8 for pretending to be a hardcore racer
27 x 1 1/4 for fairly fast riders
27 x 1 3/8 for everyone else.

Eggs were fourpence a loaf.

I originally built the Lotus mark 2 as a pure road machine, with a 700x23c tire, and whatever cranks I could find - I think as long as 150s and as short as 85s. I truly love this unicycle and have ridden it a lot. Right now it’s got a Serfas 700x38c cyclocross tire on it, 150mm cranks, Odyssey Twisted PC pedals, and an old-style Schwinn air saddle conversion.

The thing that I like the best is the feeling of just being able to “float” my feet on the pedals and let the wheel take care of itself. It tracks straight and true, and I’ve even done some Muni on it.

The tire I bought is the only true 29er they carry for the Marathon line and it only comes in a 50mm size.

I believe I’ve read in this forum that the 700c tires don’t fit properly on the KH 29 rim because the lip on the tires isn’t substantial enough to sit in the rim and could lead to blowouts.

Can someone with direct experience comment?

I just measured my stock KH 29 rim with the Marathon Supreme 29"X2.0" and the tire bulges out about 8mm on each side so I think it would definitely be possible to run a 40mm wide tire. I’d love to lose another 10mm. Let me know!

Today, during a gap in the wet and windy weather, I managed to get out for my first ride on the 700c.

Rim is the old style, narrow, non-eyeletted Nimbus rims, tyre is a 700c 40mm, cranks 150mm- tyre pressure was 45 psi (tyre states range of 50-85 psi, but I wanted to ease myself in gently)

Years back, when I went for a ride with such a set-up (my 29-er tyre had died), I vowed never to use such a tyre again, as I found myself thrown off by minor road imperfections.

Today I went out with a good attitude and the understanding that a 700c shouldn’t be ridden like a 29-er- road imperfections are to be spotted in advance and avoided, not ridden over with brute force.

Even so, i was expecting more UPD’s than usual (on the 29-er I’m usually at zero UPD level)- so I took the unusual precaution of putting knee-pads and elbow pads on under my clothes.

I was very pleasently surprised- the uni tracked well (possibly better than the 29-er Kenda Klaw I’ve got on the KH29) with no road crown issues.

A total of zero UPDs on a ride of (guessing here) around 40-60 mins.

As expected, it’s really good on the uphills- I was tired before I started, but ended up seeking out climbs more than I tend to on the 29-er.

Obviously this set-up isn’t the kind of hardcore super skinny set-up like Mikes ‘Road Razor’ and ‘Bacon Slicer’, but, it’s also definitly not a 29-er- certainly a good first step to moving to a narrower tyre and, IMO, quite a practical vehicle.

It felt, overall, not as fast as the 29-er (apart from the uphills of course) but, that’s purely my perception (I long ago gave up on the hassle of using speedometers on unicycles)- and, I fully expect that speed will increase after more rides.

I decided to follow Mikes example and (a first for me), name the unicycle- I choose ‘Close shave’, partly cos it seems like a appropriate name for a uni in the ‘slim 700c’ tradition, but also because I recently came very close to selling the nimbus at a super-low price, purely cos it wasn’t being used and was just taking up space.

After todays ride, I’m glad I didn’t- the ‘Close Shave’ lives to ride again :slight_smile:

I ride a 700c x 23 on my sun unicycle, with 127-mm cranks. I had 102-mm cranks on it before but it was really difficult to ride. I plan on trying out 114-mm cranks to see if it is between the speed of 102-mm and the control of 127-mm cranks.

Randonneur Touring

Has any one tried the Vittoria Randonneur Touring tire? It look like it might have some ‘shoulders’ instead of a full round tire. I think this may allow it to track straighter. None of the local shops have one in stock. I hate to order one and then not like it.

I thought that generally round was better than square for road crown?

Though there are multiple factors- 2 tyres which seem considered very bad with road crown are the 2.3 big apple 29-er and the 24x3 Gazz- one is round and the other square.

Then again people also say the smaller big apple is good and that the 2.3 big apple can also be OK if the tyre is pumped up hard.

As for ordering the tyre and then not liking it-

  1. someones got to be first :slight_smile:
  2. the opinions of others aren’t everything- despite the fact that many strongly dislike the 2.3 big apple 29-er tyre, others love it- I remember when it first entered the unicycle market that it got rave reviews

Today’s rides involved both the 700c x40 and the KH 29-er, so I got a chance to compare the two.

I decided to ride up to a friends house, which normally I don’t do on the uni cos this it involves, right from the start, several ‘almost-extreme’ hills- not the steepest that Sheffield has to offer, but, not far off and,they’re also quite long.

Last time I went that way I was on the KH with it’s origianl WTB 2.3 tyre and, I was appalled by how hard the ride was.

So the new set of of 700c with 40mm tyre was a logical choice- as a further variable I put more air in the tyre- last ride was at 40psi, today I pumped it up to 60 psi.

The hill climbing was hard but doable, certainly easier than with the WTB stout, so I was happy with that result.

Riding again felt slower than it did on the 29-er and i feel this was made worse by the extra air in the tyre.

Having ridden up and finding out my friend was not home, but had gone into town to juggle/spin in the park, I decided that, with the day being so nice, I’d go home, swap unicycles and meet up there.

Ride to town involves no major hills, so I took the KH 29 (with Kenda Klaw tyre) and, in the interests of experimentation, also pumped that tyre to 60 psi (previously I’ve never had it above 40 psi).

Two things were quickly apparent-

  1. when riding the 700c I’d had the strange feeling that the wheel was smaller than it should have been, and assumed I was probably imaginging it- on mounting the 29-er, it was undeniable that it felt bigger than the 700c- the mount required more push to get my centre of gravity over the wheel.

I guess the size of the bigger tyre really does add sufficient inches on both sides of the wheel, to make a perceptable differnence

  1. when riding the 700c, I’m looking down, on the alert for bumps, holes, gashes, potholes in the road (which, on many of sheffields side roads, are extremely common), whereas,on the 29-er, I’m looking way ahead, scanning the horizon, feeling very little need to be looking at the road cos I know that the tyre will roll over minor obstacles.

That leads to two noticably different feels to the rides.

My thoughts on the tyre pressure change were that, in both the 700c and the 29-er, 60 psi brought more negatives than benefits- it made the ride more uncomfortable, little drops harder, required more having to scan the road- the only possible benefit I can think of,is that it may have helped going uphill, if the roads were smooth and perfect- but, they’re not.

I’d be interested in hearing views from those who ride skinny tyres at 100+ psi- do they have such high tyre pressure cos it’s necessary for the tyre to work properly, or, are there any other benefits to the higher pressure?

So, 2 good rides in one day- using the 700c has certainly lead to a greater appreciation of the 29-ers good points.

I’m thinking that it might be good to get hold of a tyre that’sbigger than the 40mm swalbe, but smaller than the Kenda Klaw- which could the the perfect compromise in terms of balancing weight with cushiness.

Also, i’d like to try the smaller Big Apple- despite the fact that it actually wieghts more than the Kenda Klaw.

For future rides I’ll definitly be going lower on the tyre pressure, possibly try both at sub 40 psi and see what that does to the rides.

I’ve also been considering building a slim 700c from scratch and have it as a dedicated lightweight super-elegant uni.

One issue with that, is that seems to have totally abandoned supporting the old 28" uni technology and parts- there’s no narrow 700c rims and 99% of the hubs are the splined ones (heavier)- it looks like the square taper hubs will soon be extinct.

That’s a real shame, IMO- while it’s obviously good that there’s plenty of support and advancement for the hardcore muni-ists- I do feel that, to some extent, it’s been at the expense of those of us who have no intention whatsoever of doing ‘drops’ of even 1 foot, never mind 3/4/5 foot.

As we’ve seen from this thread, some of those who wish to try the slim tyres are reluctant because it’s not clear that the wide KH type rims can actually support such tyres.

I really don’t need a ‘bomb-proof’ hub, or a ‘super-wide’ rim, or cranks that can survive 6 foot drops- all those things merely add weight, cost and, often, complexity.

And while it’s good that the extreme equipment is available for the extreme riders, surely I’m right in thinking that many, possible even most, unicycle riders, just like to ride around, or are into distance, or fitness etc, etc.

Snakebite punctures: pinch flats caused by both sides of the rim to make two parallel punctures, sometimes through both the outside and inside of the tube making a total of four holes.

The skinny tyre is designed to have a small contact patch, and this can only be maintained with high pressure. Remember that most tyres are designed for bicycles which spread the weight over two wheels. Even then, road riders often ride at 120psi or more.

Use the skinny tyre as a precision rapier; the fatter tyre is a broadsword. Outwit the trail by finding the optimal route through, over or around the obstacles that you would ignore on a fat tyre.

As you get better at cross country riding, you have to try harder to find difficulty. On a skinny slick high pressure tyre, you can take your own difficulty with you.

Here’s a good fat tyre!


Yup like Mike said you pretty much need higher pressures when riding skinny tires. On my 27 X 1 1/4 i would usually ride between 120 and 100 PSI I would like to keep it at about 110 but it lost pressure really fast due to crappy tubes. If the pressure fell below about 80 it would start to feel like crap and it would be really easy to damage the rim, tire and tube if you hit a pothole wrong.

At over 100 PSI these tires have extremely low rolling resistance and you can get going pretty fast with short cranks.