Max tire size for DTSwiss RC46 C

[stormur]

Hi & Hello my 1st post here .

I'm bit confused… DT Swiss recommends for their carbon clinchers ( rrc46 c NOT DICUT / pre-dicut / ) tire size 19-23mm ( rim is 15c , and exactly 15mm inside ) , however everywhere for given(15c) rim size , and even Reynolds manual ( rim manufacturer ) MIN size is 23mm…

Installed 23mm Veloflex , looks on the rim bit narrow-ish for me… ( like 21mm tubular on 21mm rim ) - basically rim and tire are equal in width.

From the other hand, mounting bigger ( my "normal" is 25mm ) tires risking damaging rim ?

Max tire pressure on rim is estimated at 9bar, bit low for 23mm way low for 19mm….

Any thoughts ?

[mattr]

9 bar is actually rather high.

[stormur]

Pressure doesn't bother me at all, on Conti 4000sII 25mm I use 7,5R/6.5F on Veloflex Corsa 8R/7F - my only issue is 25mm on these rims - is it "safe" or absolutely not ?

I know that some manufacturers are very restrictive , just "in case" , some give real limits, some do not at all ( for wieght f.e. ), …

Logically, I should follow "standarts" ( 23-28mm for 15c rim ) , but instruction attached to wheels and even decal on rims says "19-23mm"… In alu - I don't hesitate to use 32mm on 13c rim , but carbon clincher is different "animal".

So, I asked here, maybe someone has experience with these ?

[bm0p700f]

19-23mm tyres will be for aerodynamic benefit. A 25mm tyre will fit fine.

[stormur]

Thnx ! but ( ) are you sure ? DT says "Max tire width 23mm" not like "recommended" or so ….

[mattr]

I would imagine that the max tyre size is closely linked to the maximum pressure. So a 23mm tyre at 9 bar is the edge of the envelope, plus a significant margin. Much like stans rims. Narrower tyres = higher pressures.
If you are below the max pressure and above the max size, as long as you aren't doing anything daft (CX tyres at 8 bar) I'd not lose any sleep.

FWIW, the relatively low max rated pressure is probably thanks to the tendency for carbon clinchers to let go of the tyre/tube under prolonged vigorous braking and the related heat build up. (Descending mountains, badly)

[stormur]

Thank you. I thought same, but good to have "confirmation"

I live in relatively flat area ( about 1% (1500-1600m) average climb-descent on 150km ) and wheels will be used only for road, which aren't so bad .

On CX open tubulars I'm like 2,5 rear and 2.0 front - being 85kg fortunately no flats yet ( grifo ).

Anyway, I think topic can be closed.

Thanks again.

[stormur]

Asked DtSwiss for info , received answer :

Thanks for your mail and that you are riding on our DT Swiss wheels.
I would and I cannot recommend wider tires than 23mm. We did not test these wheels with wider tires than 23mm, there fore we cannot warranty for the good function and the long live of the rim, when you are using other tire dimension, than DT Swiss officially recommend.

Sorry for not giving better information for you.

Thanks for understanding

Freundliche Grüsse / Best regards
Daniel Wyder
International Service & Customer Support Manager
DT Swiss AG

[fa63]

That is an idiotic, cover-your-ass response from DT.

Run 25 mm tires, the wheels will be fine.

[Grill]

Considering I've seen these rims used in CX races, I don't think you'll have any issue with 25mm.

[mattr]

Which basically means, "we are bone idle and couldn't be bothered to test properly, Fredrik in marketing has run a pair with 23s, so you should be ok"

[stormur]

I'm after 1st "test" ride on Conti gp400sII 25mm (26mm on these rims) and all looks/feels fine pressure F:6,1 R: 7 bar . Tires are easy to install on these rims ( however has about 1000km so are bit strechted already ) - what a change after Vision