[Closed] 2.25 or 2.35 for XC; much difference?

19 mm rims are bit on the narrow side.

If 2.35 matches to 19 mm internal bead - then, maybe good for your bike:

2.35 front, tire with lots of grip

2.2 rear

Have a similar setup on one of my hardtails (29").

2.35 / 2.2 is a great combo. But I run 25 internal bead width rims.

XC rather than XC racing? In fairness I think even Schurter is on wider race tyres now.

I wouldn't think the small width difference alone will make much difference. A fast tread pattern and a compound chosen to reduce the drag is probably where you would notice a difference over a big soft trail bike tyre.

I'd guess you might get a slight weight reduction too, but as you're South Downs based, the flints mean you can forget super light tyre carcasses!

A 2.35 is going to be very ‘bulb’ shape on 19mm.  It won’t catch fire and you won’t die, but you won’t be experiencing the best possible results from the tyre - although the degree of this will vary with tread design.  Tyres intended to present a ‘round’ tread will be less negatively impacted than ‘squarer’ designs.

No reason you shouldn’t do this, but it’s another layer of personal circumstances to consider if you’re ever inclined to ask other riders about tyre choices.

Same situation as you, 19mm rims.

Tbh, I think 2.35 can be pushing it a bit - ok for a tyre with evenly spaced tread, like a Bontrager XR4  but increases gaps between rows of tread  on a more open tyre like a High Roller which for me makes them feel odd.

Smorgs are just about ok - not tons of feel but they don't let go. Huge volume so really comfy.

Edit -  What he said!

I've got 2.35" G-One Speeds and 2.3" BSC Tpye 1s (basically PX re-badged Vee Speedsters), that I sometime use with my ~20mm internal rim width 29er wheelset for the Wazoo with tubes.

Due to the relatively extreme teardrop shape the tyres conform to on a narrow wheel, there's not a chance in hell you would catch me risking tyre pressures below ~35/45PSI (front/rear), for fear of the tyre bead detaching from the rims.

For a squarer, less teardrop shape that could relatively safely use lower pressures for a bigger contact pacth with more grip in a tubeless setup, I would look for tyres in the ~30-45mm measured width.

XC rather than XC racing?

the plan was general riding plus racing but gorrick seem to do three races a year now. I've missed the first, can't make the second and the third is in november!

Grassroots XC has died in the south! I guess i shouldn't complain as I haven't raced for 5/6 years!

Seriously it's 0.1 of an inch or 2.54 mm dependent on tyre manufacturer, if that's really going to impact on you're riding so much I think you're over thinking things.

Tread pattern, compound and weight are going to have far more impact than 2.54mm irrespective of internal rim width twaddle where a 2.25 will be ok on a 19mm internal, but a 2.35 may be pushing it!!

the plan was general riding plus racing but gorrick seem to do three races a year now. I’ve missed the first, can’t make the second and the third is in november!

what about all these races, showing on the Gorrick website?

8 Feb 18 Skedaddle XC Spring Classic 1 Crowthorne Wood »
Bracknell Road, Crowthorne, Berkshire RG45 6AR
04 Mar 18 Skedaddle XC Spring Classic 2 Area 51 Frimley Green »
near Frimley, Surrey GU16 6HT (follow roadsigns to private land)
22 Apr 18 Gravity Trail Enduro Area 51 Frimley Green »
near Frimley, Surrey GU16 6HT (follow roadsigns to private land)
06 May 18 Kawasaki G100 XC Enduro Challenge Minley Manor (north entrance) »
Minley Road, Yateley, Hampshire GU17 9LP
20 May 18 Hot MTB Challenge Vernham Dean Playing Field »
Vernham Dean, Hampshire SP11 0JY

For the record, I'll be racing them on 2.25 rocket ron rear with a Nobby Nic 2.35 up front 21mm internal width rims!

I ran 26” Schwalbe 2.4s on 719s for years down to low 20s psi and never had any issues of stability.