Raven Sport Tour Tyres Fitments

[RSTRG]

I have been riding a 2009 RST with 26 X 1.75 Panaracer Pasela Tyres since new. At the time this was the largest tyre fitted using mud guards. I am wondering if larger tyres would improve my riding comfort. I have read that 26 X 2  Schwalbe Marathon Supremes were sometimes fitted on later models. Has anyone any experience of using 2" tyres on a RST? Any actual measurements to access the practicalities of using 2" tyres would be very useful. My bikes current tyre fit measurements are tyre width 41.5mm, tyre to chain stay clearance 5.3mm each side.
Thanks Ron

[JohnR]

I've just fitted a pair of 42-622 Supremes on my non-Thorn bike. I was concerned, given the nominal size, that they would be a tight fit in the mudguards but I did some research and discovered that Supremes tend to come up smaller than the size. Mine measure 38mm wide at about 38psi (39mm wide when inflated to 80psi to seat the beads). I also compared the total width of a flattened Supreme tyre with a 40mm G-One Speed. The Supreme was 4mm narrower. Rim width, however, will be a factor. My rims are 23mm external width. Wider rims will increase the width of the inflated tyre.

The evidence suggests that 50mm Supremes will be a bit narrower than the nominal size. This may not apply to other 50mm tyres. If you want to try a pair of Supremes then SJS have some. They may not stay around as they have been discontinued.

[martinf]

I don't think 50x559 Supremes will fit with mudguards on a Raven Sport Tour.
I have these tyres on my Raven Tour, the height of the tyre above the rim is about 42 mm.

I have 42x559 Supremes on my Raven Sport Tour, the height of the tyre above the rim is about 33 mm. The mudguards are mounted as high as they will go under the fork crown. There is plenty enough clearance, but not enough for the extra 9 mm of height. I reckon a true height of 38 mm would be about the limit on my Raven Sport Tour, but with rather tight mudguard clearance.

50x559 Supremes would probably fit on the Raven Sport Tour WITHOUT mudguards, as it looks like height rather than width is the limiting factor. But as I live near the Atlantic coast I am not going to try.

For what I consider a sporty bike, I reckon 42x559 Supremes are a very good compromise for adequate comfort combined with good performance on a mix of decent roads, bad roads and good unsurfaced paths and tracks.

32x559 Continental Grand Prix (less difference between claimed dimensions and measured dimensions than the Schwalbe tyres) were very slightly faster on smooth tarmac roads, but significantly less comfortable on bad road surfaces and for mild off-road riding on towpaths and the like.

[RSTRG]

Thanks to JohnR and martinf for their information, using this I have remeasured the clearances for the  1.75" Paselas and estimated them for the 2" Supremes.

Current setup as measured
26 X  1.75 tyres actual width 41.5mm and ht above rim 38mm. SKS mudguards fitted using hex hd screws and 2 washers.

Clearance at fork crown 8.5mm & 8.5mm at blades.

Clearance at brake bridge 8.5mm & 8.5mm at seat stays.

Clearance at bottom bracket bridge 11mm & 5.3mm at chain stays.

Replacing the hex hd screw and washers with a button hd screw increases the tread dia clearance by + 3mm.

Estimated clearance for 26 X 2 tyres assuming  SKS mudguards fitted with button hd screws to give maximum clearance, would be.

Tyres width 46/47mm (est) & ht above rim 42mm measured.

Clearance at fork crown 7mm & 5mm at blades

Clearance at brake bridge 7.5mm & 4mm at seat stays

Clearance at bottom bracket bridge 10mm & 2.5 - 2mm at chain stays*

*Based on my measurement of the chain stay spacing at the 2" tyres widest point being 51mm.
51-46/47 = 2.5 or 2mm each side. 2.5mm  is probably the maximum clearance achievable.

I might get away with using 2" tyres at the forks but it would be unlikely at the rear.

Another possibility would be to use the 853 forks but that's another question!

Thanks again
Ron