having some wheel issues, seen a very good deal on a set of new carbon wheels... but they are 38mm internal.
I'm guessing this is a left over from when plus tyres were all the rage. my bike isn't a plus, but it will take 2.6 tyres with plenty of clearance.
are these suitable for 2.5 and 2.6 tyres?
historical data from 5-10 years ago varies from "definite death for exceeding the 30-35mm recommendation" to "nobody can feel any difference.
I normally go with 1.6 to 2.0 times the internal width. So 2.4" to 3.0" tyres in your case.
Many people will tell you that if you go too wide on rim width the knob profile will be too flat and you will lose traction catastrophically when you lean the bike over in corners as you've gone beyond the side-knobs and onto the sidewall. I've never experienced this so we can only assume I am simply not gnar enough and you shouldn't take my advice, what with me being an obvious mincer.
Bird were selling EX1700 and XM1700 wheelsets half price last week, I'd see if they have any of those left if I were you.
I’d suggest that list says it’s at the upper edge of “alright” at 2.6/65mm. dependent on the rim, your total tyre profile will be only ~18-22mm larger than the rim. That’s a pretty square profile and IME means that rock gardens will come into more frequent contact with the rim, especially if cornering at the same time. I use 25mm ID rims with 2.4s and 30s with 2.6.
My old Nextie Black Dragons were only 44mm ID and were for tyres from 3.0-3.5”. Even on those.a 3.0 tyre was pretty square.
What wheels are they, as good deal and carbon normally means you can find an alloy set cheaper and far better quality.
35mm internal is going to drive you to big floaty, flimsy tyres.
I’d normally say throw dhr2 2.6 on there and you’ll be sorted. But… as you don’t have the wheels yet… double check your frame clearance first.
My Ripmo came with 35s and 2.5 Assegais. Been happy running that combo, and also used a 2.4 DHR2 and 2.4 Tacky Chan with no complaints.
What is “alright” and what works optimally are two different things…
If you owned them already, and needed to transfer them onto a bike with 2.6” max clearance to get it going whilst you saved up for new rims, then fair enough… I absolutely 100% would not buy them though!
Anything over 30mm is too wide for modern MTB’s to be honest… 30mm is optimal with a 2.6” tyre, 25-28mm is about optimal with a 2.4” tyre. Larger rims might “work” with wider tyres, but you’ll lose a lot of the benefits of the tyre shape/profile by pulling it squared than it was designed to be… In fact, since the plus size thing has died a death, manufacturers have slowly been following the DH race scene again and experimenting with rims narrower than 30mm again and to good effect!
Theres a reason those 38mm rims are cheap… And as for carbon rims… Single worst thing you can spend money on on a mountain bike! Save your money, buy some decent 30mm wide alloy rims, and enjoy more grip, better ride feel, better tyre shape, far less concerns about smacking them into rocks as well as a whole lot more money left in your bank account…
right, you've put me off 38mm, will be sticking with 30.
also weighed up (literally) the rims vs (figuartively) the bank balance and ordered that discounded DT swiss set from the Bird sale
update next week when they have arrived and been fitted.
right, you've put me off 38mm, will be sticking with 30.
Since you've been convinced by the naysayers, where was this deal you found?
I've found wide rims (35mm to 40mm) and 'normal' tyres when combined with inserts allows me to run ridiculously low pressures that just behave so much more predictably than any combination I've run before.
But then I'm not a World Cup downhill racer so if you are a WC DH racer you're probably better off taking the advice of others on this thread.
40mm wtb rims here with 2.6 schwalbe tyres.
20 stone rider at 30psi in tubes............. best set up i have used.
no floaty flimsy bollax like stated above.
Since you've been convinced by the naysayers, where was this deal you found?
dt Swiss from bird as suggested by chakaping
dt Swiss from bird as suggested by chakaping
I meant the deal on the 38mm rims you now don't want.
I assumed you didn't post the link in your OP because you didn't want anyone else snaffling them up 🙂
roval 38 6fatties
this isn’t the only one
Update - 1 ride on the dt Swiss. Feel great, smooth and quick rolling. Unnervingly quiet hubs compared to hope too.
possibly the amazing feel is just because it’s new hubs and truer than I can manage rims… and possibly I’d just got used to riding my heavy spare/holiday wheels with soft supergravity tyres for the last 2 weeks so getting my trail tyres back felt so good.
thanks mboy for talking me out of carbon and chakaping for the link to the bird sale. (And everyone else for contributing to the discussion)