Schwalbe Racing Ralph 36x2.4

General
1

A few weeks ago I sewed two RR2.4s together to make a lightweight XC 36” tire. Used the tire for almost two weeks commuting to work and while it was a whole lot lighter than my modified TA tire I was not all that impressed with the tire on the road. It had a bit of a buzz to it making the unicycle vibrate a bit and while it wasn’t bad it did pull a bit more on road camber.

The commuting was mostly to test my latest tire joining method and the joints were great.

Yesterday I finally got out to the trail I had in mind when I built the tire. It is a marathon length loop that includes loose sand, rock fields, mud, short steep rolling hills, longer gentler hills, dirt 4X4 track, gravel road, an amazing view, and finishes with the option of 7km of highway or about 9km of trail. I am sort of out of shape so rode the pavement at the end.

Preparing for the ride I re-configured my 36 for the trail. Swapped out the long/low handle for a medium/short handle, took the magura rim brakes off and threw my 150/125 cranks on.

Once I got on the trail the tire had no problem meeting and exceeding my expectations. With the lightweight, high volume tire I was able to ride stuff in 125mm that I had not been able to ride with 137s in the past. It floated on sand better than a 26x3 and worked flawlessly rolling over fist sized rocks and small logs. Cleared mud better than my modified TA, had less rolling resistance and let me ride further, faster, and on looser terrain than ever before.

I was riding with lowish PSI, probably around 25 pounds (can’t find my pressure gage) and the tire did fold on me once on a one foot drop that I took a bit crooked and it was definitely bouncier than I was used to on a 36. I spun out a couple times climbing in sand with the cranks in the 150mm setting but I was able to go further before spinning than ever before. The tire also picked up the odd stone, which would ping on the frame, but all and all I am really happy with the tire.

The tire measures in at 61mm (2.4” just like the sidewall says) and leaves about 4mm of clearance over the tire. I will throw up some pictures as soon as I find my camera. I would also love to find out the actual weight of this tire (my scale must be with my camera and pressure gage) but judging on the weight of the tires I used to build it I would guess about 830g.

2

Wicked!

Looking forward to seeing some photos Sas. The 29X2.4 racing ralph is my favorite XC tyre, a 36er version would be awesome! :slight_smile:

3

Love to see pictures! glad to hear i worked good :slight_smile:

4

Man, that would be the 36er muni dream tire!

I love that tire on my 29er, if only they’d build it for 36ers, I’d snap one up for sure.

So is it staying together okay?

What’s your process for blending the two treads together?

5

Thanks guys, never found my camera but figured out to get pics off my iPod. Who would have thought that gimmicky little camera would come in handy?

Here is the “wheel deal”

600×800 83.4 KB

The join

and clearance on a KH36 frame

Ben: I sewed the two beads together really well and am mostly using glue to hold the casings together. The single line of stitching is mostly to hold everything in place while the glue was drying. I did all the stitching first, gooped up the seams real good (about 4cm overlap) and then installed and inflated the tire until the glue set.

The RR was the first tire I have encountered that no matter how careful I was I could not peel back the tread so it is just a simple join with a full casing/tread on top of a casing with tread removed on the bottom. Ideally I would peel the tread back and sandwich one casing with tread removed between the other casing and corresponding tread rubber.

6

Nice result!

Nice work Eric! That tyre looks great, maybe you should send the photos to Schwalbe so they get the hint and make a run of 36X2.4" RR’s! I think they’d be snapped up super quick! Also good to see Petes (Lunicycles) handlebar setup is getting some love! His handlebars must have a thing for racing ralphs, as I also scored one of his bars during his firesale, and it’s on my 29er with a racing ralph.:slight_smile:

7

question…

Saskat/Eric,

Your 36 x 2.4 RR experiment is genius. I hope UDC or Coker is taking note and making plans for revisions to the present line of 36er tires. They are beasts to speed up or slow down, and it sounds as if you found a much more attractive alternative for 36er XC.

I was a bit confused by the passage quoted above: did you mean to imply you were not impressed with the modified TA or the 36 x 2.4 RR on the road? Either way, I wonder if the buzzing could be reduced or eliminated by spacing the center knobs in a somewhat varied (or slightly irregular) pattern. Of course that would make for uneven wear without some sort of compensation.

I was also curious whether or not you tried running the 36 x 2.4 RR at higher pressures on the road so that it might spend more time on the more closely spaced center knobs?

Looking forward to your answers…

Cheers,

UPD in Utah

(a.k.a. Bert)

8

yah I didn’t really like the tire on the road. I generally like lower pressure but did try pumping it up to around 40 PSI. Higher pressure helped a bit with road camber but it was still more noticeable than with my TA tire. With more pressure the buzzing got worse and the vibration is annoying.

I didn’t build it for road rides though. On soft and irregular surfaces both of those issues go away and the tire really shines.

I plan to build a light road tire, probably something like 36x1.5 for when I want to use the 36er for road rides/commuting.

9

Your modified tires are great. I think you said the lengthwise joins took about 40 hours (much more stitching required). How long do these shorter joins take?

10

That’s really nice (could have lined the logos up though ;))

Interestingly I find the RR on my 29er is far less affected by road camber than my TA on the 36er (both at about 25psi). The TA at higher pressure (anything over 30psi) I find almost unrideable if there’s any camber on the road at all - by far the worst tyre I’ve ever ridden for camber problems.

As for the chances of convincing Schwalbe to produce 36" tyres, I suppose we can dream…

Rob

11

You should do tires for people and they send you in tires and you do them for a price.
How long does it take to do one?

12

Since this one was done sporadically over a couple weeks it is hard to say how long it took but maybe 20h. What took the longest was getting the tread rubber off the casing since it would not peel worth a crap.

I could have lined up the logos but decided to do it this way so I would have a usable chunk leftover if I decided to make a second one without having to cut two more tires.

I have another new RR2.4. I might be talked into making another tire for $300 ($100 for the tires + $100/join) It is really labour intensive.

13

:slight_smile: I was joking…

14

This, again, is awesome! It is so cool that it works out well for riding.

What kind of glue do you use? It must stick really well to provide the strength of the joins. When I tried I used Bostik Contact, but that was useless - just didn’t adhere to the rubber at all, but peeled straight off when dry. Are there various types of ‘contact cement’? Because I thought that was what was suitable.

Look forward to a slick-tread one for road use. I may have another go with folding beads some time…

Sam

15

I would have thought vulcanising rubber glue (like in puncture repair kits) would work. I stuck a lump of old tyre to the inside of my torn RR and it’s held up for a year (tubeless). Not quite as extreme as sticking two tyres together, but it was a fair size rip.

I’m sure Eric will answer when that side of the world gets up…

Rob

16

Like you guys I thought that rubber cement would work but on previous attempts I found out that it just doesn’t do the trick. I experimented with about half a dozen different glues when I was working on my current 32" tire and settled on “Marine GOOP” being my glue of choice (it also works great gluing rubber soles on moccasins)

I am curious if I can run the sewn together tire tubeless but Stans is scarce in these parts. Not really sure if there would be much of an advantage anyway since I rarely get flats in summer and it freezes in the winter.

EDIT: I have been commuting with the wheel the last few days with the pressure the same as I had on the trail. You can still hear the tire buzz but the vibration is gone, which is a relief. I guess this tire likes lowish pressure.

17

Marine Goop eh? I’ll have to try some of that. It looks like it is mostly available in north america, but can be got hold of in UK too (http://www.rcgroups.com/forums/showthread.php?t=727303).

I guess that as you’ve not mentioned it, you don’t have any trouble with bumps or dips at the joins, even with overlapping casing?

Sam

18

At the tread there is no bump or dip but the sidewalls stick out about 1mm further on each side at the join. I could have avoided that by sewing the edge of the seam all the way across but decided not to sew the sidewalls as they are quite thin and didn’t want to make too many holes incase I wanted to go tubeless.

On my first 32" tire I have broken beads at the joints and it causes dips in the tread, on my second (current) 32" tire there is a bit of a bump in the tread and sidewall from the overlap, but that casing is much thicker with kevlar anti-flat layers. It is also only 32mm wide instead of 60.

19

Your joins are starting to look really clean. Thanks for posting.

20

One more query: did you cut the tires ‘square’ with the bead, or at an angle to compensate for the change in bead/tread length ratio at different wheel sizes?

It looks from your pictures that it is simply a square cut, but it is hard to tell for sure. I’m going to have another go myself soon so want to have the best chance of your level of success!

Sam