Building my first gravel bike and having a hard time deciding the rim width.
I'm leaning more towards light gravel and road so I think I'm better off with 700c for now. I've found DT Swiss GR 1600 wheels which fit my budget. They have internal rim size of 24 mm, now I am thinking whether they are too wide for 35 mm to 40 mm tires, or should I go a step narrower to 22 m wide rims? What do you think?
Also if anyone can recommend wear-resistant reasonably fast tires I am listening for tips. Currently considering Pirelli Gravel H tires.
I ride 25mm road tyres with 21 internal rim width and that is perfect (expand to 29mm). I am looking to build a gravel/road bike too and would not go narrower than 24 internal (considering 24-26 internal rims myself). Tyres would be those pirelli's in a size 40 or continental terra.
I would say that you're good with either inner width, 22mm or 24mm for those tire sizes. If you truly don't plan on ever going wider than a 40mm tire; I'd get the 22mm inner width rim. You'd save some weight and the tire would have a more "ideal" shape than with the 24mm inner width. But again, both would work. It really depends on if your tire width would more likely skew towards the narrow side (would you ever use 28mm road tires?) or the wider side (would you ever use 2.2" mtb tires?).
clarksonxc wrote:It really depends on if your tire width would more likely skew towards the narrow side (would you ever use 28mm road tires?) or the wider side (would you ever use 2.2" mtb tires?).
My frame fits max. 42mm in 700c, but yeah 28mm slicks could be an option as well for tarmac. I plan to get a 650b wheelset for rougher surfaces in the future, with which I can go as far as 2.3".
I have heard wider rims support wider-end of tires better so maybe I could get a pair carbon wheels optimized for 28c for tarmac when as my third set of wheels. So many choices...
Aesch wrote:I ride 25mm road tyres with 21 internal rim width and that is perfect (expand to 29mm).
Expanding could be a problem for me because 40mm tyre on 24mm rims could possibly go wider than 42mm which is the maximum for my frame.
Aesch wrote:Tyres would be those pirelli's in a size 40 or continental terra.
I considered Terras as well but they seem to wear out quite quickly, just after some hundred kms showing serious wear: https://youtu.be/J2E-W_AtqSE?t=233
In addition to whether a wider rim could make the tire too wide for your bike, it can depend on your riding style. I tend to prefer the ride, handling and feel of a “rounder” tire profile (“C”) over a more square profile (“U”). For this I choose rims narrower than the current fashion. The 24mm rims will be fine for the 35-40mm tires, though I would choose 20-22mm rims.
I have used narrower tires on >28mm rims and tires up to 2.6” on 16mm rims. They all worked. Still prefer relatively narrower rims.
I have the 1600 and 1800 you mention. My tires are about 1mm wider on the wider rims. I put 28mm tires on the 1600 rims and found (at the limit) I was riding on the sidewall rather than the tread, and I have some wear there. So, nope, I wouldn't put anything smaller than a 32mm tire on the 1800 rims. Really, a 22mm internal rim will do just about anything, where the 24mm internal rim may work slightly better for larger tires, its gonna limit you on the low end.
Thanks for everyone's input. Reading your responses I might actually go as low as 20mm inner width rims, DT Swiss ER 1600. They come in two variations: 23mm and 32mm rim height. Supposedly the latter are more aero but the former are a bit lighter. So yet another choice presents itself, but I doubt there's not much difference. The 32mm looks better in my eyes though.
On 20mm rims I could fit anything from 28mm to 40mm or so, so probably the better choice for my frame.
krovikan wrote:Thanks for everyone's input. Reading your responses I might actually go as low as 20mm inner width rims, DT Swiss ER 1600. They come in two variations: 23mm and 32mm rim height. Supposedly the latter are more aero but the former are a bit lighter. So yet another choice presents itself, but I doubt there's not much difference. The 32mm looks better in my eyes though.
On 20mm rims I could fit anything from 28mm to 40mm or so, so probably the better choice for my frame.
You can go much wider than 40mm tires if you like. 20mm rims have been my go-to on my MTBs for 15-20 years with 2.0”-2.6” tires.
FWIW I wouldn't go with the 32mm option. To me, it adds too much weight without enough aero benefit, so you might as well go with the shallower hoops. Alloy has a really bad weight to aero ratio compared to carbon, and I think if aero is important to you than carbon is the only path that's worth it.
clarksonxc wrote:FWIW I wouldn't go with the 32mm option. To me, it adds too much weight without enough aero benefit, so you might as well go with the shallower hoops. Alloy has a really bad weight to aero ratio compared to carbon, and I think if aero is important to you than carbon is the only path that's worth it.
Agreed. I'd go so far as to say aluminum works a better on gravel than Carbon. On my gravel rides, I appreciate the compliance and I'm not too worried about a little aero or weight (I sure don't dress aero).
I throw carbon rims on the bike with my road tires (where weight, stiffness, and aero do make some difference), but they don't feel as nice.
I've got 22mm IW DT Swiss wheels (hand built all road RR 481 rims with 350 hubs) and I've run tires ranging from 32-45 on them with no issues. I believe they are 25mm deep.
If you're limited to one wheel set and it's a gravel bike that can accommodate larger tires, 22mm is nice and what I went with but I've really gotten used to larger tires and really like the comfort and am willing to give up a little rolling resistance.
First, I don't think you'll notice a 1 or 2 mm rim width difference unless you're right at the edge of safety.
Second, if you plan to use tires with tall side blocks I suggest you follow the tire maker's rim width recommendations. Rims too wide or too narrow will mess up the intended contact patch.
Third, if you'll use round section tires with low or no blocks the rim width won't matter much. I've used tires down to 35 mm on 25 mm (inside) rims with great results. Note those are hooked rims with proper flange height and bead seat diameter run with tubes at pressures around 70% of tire maximum. FWIW newer charts from DT and Mavic allow tires down to 28 mm on a 25 mm rim but I wouldn't go that far.
Going the other way I did notice some directional stability issues on pavement with 48 mm tires on 21 mm (inside) rims. I wouldn't want to ride with a rim narrower than 50% of the tire width on pavement.
stu wrote: Going the other way I did notice some directional stability issues on pavement with 48 mm tires on 21 mm (inside) rims. I wouldn't want to ride with a rim narrower than 50% of the tire width on pavement.
That is more of a pressure issue. Need to run higher pressures to support the tire sidewall.
shiggy wrote: That is more of a pressure issue. Need to run higher pressures to support the tire sidewall.
You could be right. The tire was a Soma Supple Vitesse EX which has a very flexible casing. I noticed the problem running 40 to 45 psi and thought going much higher would to some extent defeat the purpose of such a wide tire. My theory is the lateral instability was due to a combination of flexible sidewalls, low pressure, tall section, and narrow rim. I couldn't try a wider rim because frame clearance was already marginal.
Those 21 mm rims were fine with a variety of flexible tires from 38 mm to 42 mm. I've also used very flexible Rene Herse Snoqualmie Pass tires on 30 mm rims. Those 44 mm tires measure between 46 and 47 mm on the 30 mm rims. I've had no problems running them between 30 and 35 psi so I think rim width does have some effect.
I wouldn't recommend 30 mm rims to the OP. I think 22 or 23 mm rims would work well with anything from 45 mm knobby gravel tires to 32 mm fast road tires. I ride a lot on broken-up pavement so I prefer wide tires with slick treads and flexible casings. I'm sure 25 mm rims would work for me but I couldn't resist trying something different. 🙂
My frame fits max. 42mm in 700c, but yeah 28mm slicks could be an option as well for tarmac. I plan to get a 650b wheelset for rougher surfaces in the future, with which I can go as far as 2.3".
I have heard wider rims support wider-end of tires better so maybe I could get a pair carbon wheels optimized for 28c for tarmac when as my third set of wheels. So many choices...
krovikan wrote:
Expanding could be a problem for me because 40mm tyre on 24mm rims could possibly go wider than 42mm which is the maximum for my frame.
I'm running Maxxis Rambler on 23 ID rims, true 40mm and great tire. Set up tl. Have 1000 miles on them and I'd say rear is 1/2 cooked and front less than that.
stu wrote: You could be right. The tire was a Soma Supple Vitesse EX which has a very flexible casing. I noticed the problem running 40 to 45 psi and thought going much higher would to some extent defeat the purpose of such a wide tire. My theory is the lateral instability was due to a combination of flexible sidewalls, low pressure, tall section, and narrow rim. I couldn't try a wider rim because frame clearance was already marginal.
Those 21 mm rims were fine with a variety of flexible tires from 38 mm to 42 mm. I've also used very flexible Rene Herse Snoqualmie Pass tires on 30 mm rims. Those 44 mm tires measure between 46 and 47 mm on the 30 mm rims. I've had no problems running them between 30 and 35 psi so I think rim width does have some effect.
I wouldn't recommend 30 mm rims to the OP. I think 22 or 23 mm rims would work well with anything from 45 mm knobby gravel tires to 32 mm fast road tires. I ride a lot on broken-up pavement so I prefer wide tires with slick treads and flexible casings. I'm sure 25 mm rims would work for me but I couldn't resist trying something different. 🙂
Jan explains it pretty well, but not completely IME.
A wider rim can “support” the tire sidewall, letting you run lower pressure, it also REQUIRES a lower pressure to get the same “cush” feel. When you combine this with Jan’s observations on casing collapse, the risk of poor handling and pinch flats increases. Similar to stiff casings needing lower pressure than a supple casing for the (sort of not really) same feel. The keys being, a round tire profile lets it flex uniformly, and a supple casing lets it flex more easily. Air pressure supports the casing.
I'm running Maxxis Rambler on 23 ID rims, true 40mm and great tire. Set up tl. Have 1000 miles on them and I'd say rear is 1/2 cooked and front less than that.
Been there, done that. You are right, it is a similar tire, but lasts maybe twice as long as the Terraspeed. They both weep similarly half way through their tread, but that never really bothered me (It doesn't hurt anything). My Ramblers started blistering after 2 seasons, so I quit using them before the tread was done.
If you want to know the correct size, use the ETRO chart. This is what tire mfgs target. Go to wide a tire and your tread/carcass won't be optimized. Pinch it too much and you can get some stability issues.
Back in the day I used to mountain bike on rims that were not much wider than road rims. But when low pressure got fashionable, I found the sidewalls of my tires would just collapse when I pushed on them hard.
(ETRO is very conservative - a better match might be if your tire mfg has a chart based on wheel, tire, and weight ENVE does a great job with this on their web site).
chas wrote:(ETRO is very conservative - a better match might be if your tire mfg has a chart based on wheel, tire, and weight ENVE does a great job with this on their web site).
IMHO ETRTO is still living in the last century when most bicycles had 23 or 25 mm tires on 13 or 14 mm rims. Things have since changed with mountain bikes, gravel bikes, and 20 mm rims on road bikes. I can understand their attitude because of safety. If you put a tire with an oversized bead diameter on a rim with an undersized bead seat diameter you risk blowing it off the rim at high pressure. A wide rim will exacerbate the problem because more of the sidewall tension is in the radial direction, pulling the bead away from the rim, and less of the sidewall tension is in the lateral direction, pushing the bead into the flange.
Mavic has recently published recommendations which also consider rim shape (straight or crochet hook) and tire pressure. There's a chart near the end of this page: http://engineerstalk.mavic.com/en/the-right-tyre-width-on-the-right-rim-width/ Notice with rims up to 25 mm they say you can safely use tires just 3 or 4 mm wider than the rim.
On topic I've never really noticed a difference between rim widths. On various gravel bikes I've gone from 17mm to 25, but in 2 or 3mm jumps. 1mm or 1.5mms on each side is such a small increase that unless it's the same bike, tire, pressure, and back to back you probably won't pick it up.
I'd find something with the price, weight, durability, and aero benefits you're looking for first. A few mm here or there won't make or break a ride.
