Results 1 to 32 of 32
  1. #1
    mtbr member
    Reputation:
    Join Date
    Feb 2004
    Posts
    295

    Anybody go from 30mm internal rim width to 25?

    I've been running Blunt 35's for a few years and finally discovered cracking around the spokeholes in the back, so... time for a new rear rim. These rims have been more prone to sidewall bends/dents than any other rim I've run. I'm sure at least some of that is due to operator error but I'm also sure that the aluminum is on the soft side. I've tried to straighted out enough sidewalls in my day to know the Blunts feel softer than average. But anyway, I love the volume I get with 2.4's on these rims. The traction is great and the suspension the provide for my rigid SS is appreciated. But, instead of jumping right back at the Blunt 35, I started shopping around a bit and discovered a nice weight savings if i were to drop back to a 25-27mm internal width rim. I'm worried though about ride quality and durability.

    Has anyone here gone from a rim like the B35 but then switched back down to a narrower rim like the WTB KOM i25, the Blunt SS, the DT EX471 or a Stans Arch MK3? If so then what were your impressions?

    FWIW, i ride in central VA, lots of roots on technical oldschool type single track no big drops, lots of punchy climbs. I'm 150lbs and ride pretty hard.

    Thanks for the input!

  2. #2
    mtbr member
    Reputation: watts888's Avatar
    Join Date
    Oct 2012
    Posts
    6,267
    Going from 30 to 25 isn't that bad on some 2.2" tires I had. Not sure about 2.4". Only thing I really noticed was a little less traction in corners, but that could also be because I added an extra 3 psi to account for the narrower rim under my 240lb. You might not need that. There's a guy that rides on trails I ride that's rocking 3.0's on 30mm rims, and he loves it. If he can do that, you can roll 2.4's on 25mm rims.
    And unless you absolutely need the light weight, avoid the blunt SS. I hear they ding like crazy.
    "a hundred travel books isn't worth one real trip"

  3. #3
    mtbr member
    Reputation:
    Join Date
    Oct 2015
    Posts
    1,902
    I guess it depends on the rear tire and how hard you lean the bike. But 2.3 maxxis tires are better on 25i

  4. #4
    Elitest thrill junkie
    Reputation: Jayem's Avatar
    Join Date
    Jul 2005
    Posts
    30,458
    I like 2.3s on I25, works well and gives a good profile for the tires I use (29er). Keeps things fast.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Sep 2018
    Posts
    203
    Quote Originally Posted by Jayem View Post
    I like 2.3s on I25, works well and gives a good profile for the tires I use (29er). Keeps things fast.
    Is this because the tire is taller (instead of wider) and has less contact area with the ground?

  6. #6
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    12,381
    Some tires will work better on 25mm rims because they were designed back when 19mm was common. Put them on wide rims and the tread profile gets squared off unless you keep the pressure up. If you like those tires a 25 could be the right choice.
    You'd have to try higher volume more rounded tread profile tires to see if they would give you better performance.
    And most forks will take a 29 x 2.6 tire even without Boost spacing for a front. Most 2.6 tires should be designed to perform well on wider rims than 25mm. Some work well on 40mm rims. Lower pressure, flattened footprint you don't get with the old tires on 25mm rims. You can get a slower more controlled slide-out when you lose traction.

    Blunt 35 is a hooked bead rim. You could get more strength from hookless with a thicker bead.

  7. #7
    since 4/10/2009
    Reputation: Harold's Avatar
    Join Date
    Dec 2003
    Posts
    24,418
    my wife's bike came set up with 2.35's on 24mm rims. works well for her

    Quote Originally Posted by SqueakyWheel73 View Post
    Is this because the tire is taller (instead of wider) and has less contact area with the ground?
    less rotating weight, rounder tire profile for predictable cornering

  8. #8
    Turns right to go left
    Reputation: 410sprint's Avatar
    Join Date
    Oct 2012
    Posts
    578
    If you are sticking with a 2.4 tire or below, I say try something less than 30mm. Riding my hardtail all over North Carolina (probably similar to your trails in VA), I found the Arch MK3 (26mm) to be a better match with 2.35 and 2.4 tires vs the Flow MK3 (29mm). Cornering and braking were better with the Arch, and running the same PSI, I could not detect any difference in shock absorption between the two rims.

  9. #9
    mtbr member
    Reputation: jimarin's Avatar
    Join Date
    Mar 2005
    Posts
    614
    If youíre in the 2.3-2.5 range I donít think youíll notice a huge difference. I can see wider for 2.6 and up but 25 is fine for most tires. Plenty of World Cup Dh guys still ride 471 which are 25. Obviously you can go to narrow but in general I think the wide rim thing is hype.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jan 2018
    Posts
    68
    I'm your size and live in the same area (west of charlottesville). Went from e13 trs i30mm to arch mk3, both using dhf 2.3 and aggressor 2.3. Approx 21psi f&r. I've noticed zero negative impact and having the snappier feel is nice.

    I still ping off the occasional root/rock but only have one small dent to show for it. The e13 wheels actually may have bottomed out a little more frequently and definitely have a few extra dents. Quite happy with the arch mk3.

  11. #11
    BOOM goes the dynamite!
    Reputation: noapathy's Avatar
    Join Date
    Jun 2008
    Posts
    4,000
    I see you mention the WTB KOM, but not the Frequency Team? The ~50-100g extra weight is worth it IMO.

  12. #12
    mtbr member
    Reputation: vikb's Avatar
    Join Date
    Sep 2008
    Posts
    12,361
    Quote Originally Posted by head View Post
    Has anyone here gone from a rim like the B35 but then switched back down to a narrower rim like the WTB KOM i25, the Blunt SS, the DT EX471 or a Stans Arch MK3? If so then what were your impressions?

    Thanks for the input!
    I've run a few sets of Blunts. They are soft. I have tried other rims like carbon Light Bicycle or AL DT Swiss, but all at ~30mm internal width. I wouldn't want to narrower as I like wide tires and the support they get from this size rim.
    Safe riding,

    Vik
    www.vikapproved.com

  13. #13
    mtbr member
    Reputation: JoePAz's Avatar
    Join Date
    May 2012
    Posts
    4,836
    This is for a rigid SS application right? No big enduro machine?

    If that is the case then 2.4 should work all the way down to 21mm internal wheels. I routinely have run 2.35 tires (Ikons) on 21mm and 24mm internal wheels for a front tire and 2.2 for the rear tire. For a lighter bike I don't see the need for super wide wheels if you not running big tires too. Now I did convert my 29er SS from 2.35/2.2 on 21mm wheels to 29x3.0 on 35mm wheels. I also pulled off the 100mm fork for carbon rigid. Very different ride, but 3.0 at 11/14 psi are very different from 21/28 in 2.35/2.2 Incidentally i run 20/26 on my 24mm wheels on my FS 29er. So far that is as low as I want to go in the rear, but I might get away with 19 front.

    Personally If I had a rigid SS I would 3.0 like I do now or if I had 30mm internal wheels run 2.6 and the 3.0 did not fit. One thing I have seen is guys runing 3.0 in front and 2.3/2.5/2.6 rear depending on fitment on rigid SS. It is actully pretty cool how 29x3.0 rolls on a singlespeed. Takes work to get it rolling, bu once you do they are hard to stop. Faster overall than normal 29? Not really sure, but fun in a different way and faster in some areas for sure.
    Joe
    '18 Specialized Epic 29", Vassago Verhauen SS 29", '13 Santa Cruz Solo 27.5", XC, AM, blah blah blah.. I just ride.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Feb 2017
    Posts
    30
    Wondering a similar thing myself. I plan to use 2.35 tires. I'm partial to dt swiss wheels, which only come in 25mm or 30mm. Nothing in between, so not sure which to go with. My current tires are 27.5 2.8. Bike came with 32mm rims. I upgraded to 35mm rims and I can't tell any difference from the width whatsoever, so it probably doesn't matter all that much.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Aug 2015
    Posts
    424
    My '17 6 Fattie has 30 mm rims.(true is 29mm) Ran the 27.5x3.0 Ground Control tires that came on the bike just fine. Tubes and tubeless.

    Sent from my SM-G930V using Tapatalk

  16. #16
    mtbr member
    Reputation:
    Join Date
    Sep 2017
    Posts
    172
    I went from wtb sti 29mm inner to dt Swiss ex471 25mm inner for my rear and maintain 2.3 hdf- definitely felt snappier. Tire definitely looks skinnier though. Actually went wider to 30mm front with 2.5 wide trail tire - love the combo.
    Kona Process 153 29er

  17. #17
    Barely in control
    Reputation: Schulze's Avatar
    Join Date
    Feb 2007
    Posts
    2,034
    I use ooo25mm on 2.4" tires and everything works out well.

  18. #18
    Keep on Rockin...
    Reputation: Miker J's Avatar
    Join Date
    Nov 2003
    Posts
    5,674
    Ride quality...

    I do feel wider rims let you run a lower air pressure for a given tire size. That gives you a nicer ride for sure. But I've found that to be the case on larger tires like 2.5 and 2.6" tires. You are likely not going to get away will very low pressure on a 2.4" tire IMO, on a wide rim, without rim dings. If you got away with it, good for you. I tried and can't.

    If I knew I wouldn't run anything larger than a 2.4 I'd likely be on an i25 rim, i27 max.

    For years I ran 2.3 tires on i19 rims and did just fine.

  19. #19
    mtbr member
    Reputation:
    Join Date
    May 2018
    Posts
    84
    For that weight i25 for 2.4 seems pretty optimal to me.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Jul 2011
    Posts
    7,874
    I'm late to this but I went from 30 to 27 and run bonti tires 2.3 XR 3 and 2.4 XR4 and they are fine.
    OG Ripley v2

  21. #21
    mtbr member
    Reputation: vikb's Avatar
    Join Date
    Sep 2008
    Posts
    12,361
    Moving from a 25mm rim to a 30mm internal width rim on a tire with a 2.4" measured casing I was pretty amazed at the changed in steering precision with the better supported sidewalls. I had not noticed an issue when I was on the narrower rims, but it was pretty startling how much better the wider tires performed in that respect on the wider rims.
    Safe riding,

    Vik
    www.vikapproved.com

  22. #22
    mtbr member
    Reputation: global's Avatar
    Join Date
    Apr 2006
    Posts
    177
    Went from 30 Id rims 1440 gram wheelset and 2.35 tires front and rear fast trax.
    To 25 Id rims 1240 gram wheelset and 2.1 rear racing Ralph. In front 2.25 racing ray. Also tweaked my rear suspension reduced sag to 18% and slowed rebound 3 clicks. Feels like I picked up a ton of free speed everywhere. Iím really happy with the change.

  23. #23
    mtbr member
    Reputation:
    Join Date
    Feb 2018
    Posts
    162
    Quote Originally Posted by global View Post
    Went from 30 Id rims 1440 gram wheelset and 2.35 tires front and rear fast trax.
    To 25 Id rims 1240 gram wheelset and 2.1 rear racing Ralph. In front 2.25 racing ray. Also tweaked my rear suspension reduced sag to 18% and slowed rebound 3 clicks. Feels like I picked up a ton of free speed everywhere. Iím really happy with the change.
    It would be awesome to have 2 sets of tire/rims/cassettes to swap as needed! Probably cost me around $2500 though lol.

  24. #24
    Barely in control
    Reputation: Schulze's Avatar
    Join Date
    Feb 2007
    Posts
    2,034
    Quote Originally Posted by global View Post
    Went from 30 Id rims 1440 gram wheelset and 2.35 tires front and rear fast trax.
    To 25 Id rims 1240 gram wheelset and 2.1 rear racing Ralph. In front 2.25 racing ray. Also tweaked my rear suspension reduced sag to 18% and slowed rebound 3 clicks. Feels like I picked up a ton of free speed everywhere. Iím really happy with the change.
    All that stuff depends on the terrain....

  25. #25
    mtbr member
    Reputation: socal_jack's Avatar
    Join Date
    Dec 2008
    Posts
    1,366
    Quote Originally Posted by vikb View Post
    Moving from a 25mm rim to a 30mm internal width rim on a tire with a 2.4" measured casing I was pretty amazed at the changed in steering precision with the better supported sidewalls. I had not noticed an issue when I was on the narrower rims, but it was pretty startling how much better the wider tires performed in that respect on the wider rims.
    Yeah, same experience here. As a clyde 25mm rims on 2.4 tires required 27+ psi not to roll to some degree. Now can run down to 20 psi and still be planted.
    ROS9+ SS
    ROS9 SS
    GT Peace 9R SS

  26. #26
    mtbr member
    Reputation:
    Join Date
    May 2018
    Posts
    84
    Quote Originally Posted by socal_jack View Post
    Yeah, same experience here. As a clyde 25mm rims on 2.4 tires required 27+ psi not to roll to some degree. Now can run down to 20 psi and still be planted.
    OP is 150lbs. I would be surprised if he can not run 2.4 down to 20 psi on i25.
    What's your weight?

    And can you run 20 psi without pinchflats?

  27. #27
    mtbr member
    Reputation: vikb's Avatar
    Join Date
    Sep 2008
    Posts
    12,361
    Quote Originally Posted by krumme View Post
    What's your weight?

    And can you run 20 psi without pinchflats?
    I'm 200lbs ready to ride and run my 2.4" tires at ~19 front and ~20psi rear. No pinch flats or other problems. Great traction. Which is nice as I live in Coastal BC.
    Safe riding,

    Vik
    www.vikapproved.com

  28. #28
    mtbr member
    Reputation:
    Join Date
    Aug 2004
    Posts
    397
    On rim softness, Velocity blunts and wtb rims are so soft. I29 rim lasted me 1 ride, it had 8 dents. I replaced with a stans flow, at the DH park I hit a rock super hard with a 2.6" tire it cut the bead and casing of the tire and there was barely a mark on the rim. The WTB rim would have caved in.

    3 years ago when the wide rim thing started to take off I got some velocity blunt ss 26.6mm ID I think. I dented the hell out of them. Went back to 22-23mm rims and the bike was so much better. All the tires I use don't like wide rims.

    I'm 170 pounds and have a low CG I'm 5'7". I've only ever had tire roll over when I took a corner just wrong. I also run my 2.25's on 23mm rims @ 18f/20r to 20f/22r depending on the terrain. So I say skinny rims on XC style bikes.

    Trail and Enduro bikes running sticky 2.4-2.5 tires where people rail machine built corners at 30mph can benefit from wide rims for sure.

  29. #29
    mtbr member
    Reputation:
    Join Date
    May 2018
    Posts
    84
    Quote Originally Posted by vikb View Post
    I'm 200lbs ready to ride and run my 2.4" tires at ~19 front and ~20psi rear. No pinch flats or other problems. Great traction. Which is nice as I live in Coastal BC.
    Yeaa makes sense. My take would be you can do the same on i25 if you are 150lbs.
    At least that's my experience with 150lbs but havnt had so much time yet on my 29 2.35 i25 wheelset.
    My i30 wheelsets and i21 wheelset seems to indicate the same.
    Last edited by krumme; 2 Weeks Ago at 02:27 PM.

  30. #30
    mtbr member
    Reputation: socal_jack's Avatar
    Join Date
    Dec 2008
    Posts
    1,366
    Quote Originally Posted by krumme View Post
    OP is 150lbs. I would be surprised if he can not run 2.4 down to 20 psi on i25.
    What's your weight?

    And can you run 20 psi without pinchflats?
    225 no pinchflats tubeless spez butch/purg 2.6 but really 2.4 on i29 asym wtb. Came from Goma 2.4 f/r both are tall tires.
    ROS9+ SS
    ROS9 SS
    GT Peace 9R SS

  31. #31
    Barely in control
    Reputation: Schulze's Avatar
    Join Date
    Feb 2007
    Posts
    2,034
    Quote Originally Posted by vikb View Post
    I'm 200lbs ready to ride and run my 2.4" tires at ~19 front and ~20psi rear. No pinch flats or other problems. Great traction. Which is nice as I live in Coastal BC.
    Depends on your terrain, riding style, bike type. You guys are throwing out these numbers and they are meaningless without context.

  32. #32
    mtbr member
    Reputation: vikb's Avatar
    Join Date
    Sep 2008
    Posts
    12,361
    Quote Originally Posted by Schulze View Post
    Depends on your terrain, riding style, bike type. You guys are throwing out these numbers and they are meaningless without context.
    Coastal BC - Vancouver Island, Sea to Sky Corridor, Moab, Sedona and the like. I've used the same pressures and tires across many different bikes 26er, 275er and 29er. 150-160 travel up front. 130-160mm travel in the rear. Style?...neo-impressionist?
    Safe riding,

    Vik
    www.vikapproved.com

Similar Threads

  1. Bomboloni Width on 30mm Internal Rim?
    By mopes in forum 26+/27.5+/29+ Plus Bikes
    Replies: 19
    Last Post: 02-15-2017, 07:17 AM
  2. 26" rims between 22-30mm internal width?
    By Juz1970 in forum 26er Bikes
    Replies: 8
    Last Post: 09-05-2016, 06:18 PM
  3. Replies: 3
    Last Post: 05-01-2016, 04:11 PM
  4. 30mm internal width rims + 2.3" tires?
    By sgtrobo in forum Wheels and Tires
    Replies: 19
    Last Post: 04-16-2016, 07:41 AM
  5. 30mm width rim an upgrade from 24mm width rim?
    By metrotuned in forum Wheels and Tires
    Replies: 3
    Last Post: 07-22-2012, 07:30 AM

Members who have read this thread: 315

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.