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I’m looking to upgrade my rims and tires. I’m running 29mm rims with DHR II’s (2.3), front and back.
I ride slow, hilly tech (80%) with some downhill gnar (20%) thrown in. I’m looking at three options (Note: my frame maxes out at 2.4 on the back):
(1) Front: 2.4 or 2.5 DHF with 29mm rim / Back: 2.3 or 2.4 DHR II with 29mm rim.
(2) Front: 2.4 or 2.5 DHF with 29mm rim / Back: 2.3 or 2.4 DHR II with 35mm rim.
(3) Front: 2.4 or 2.5 DHF with 35mm rim / Back: 2.3 or 2.4 DHR II with 35mm rim.
Any help would be much appreciated.
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2.4 tires can reasonably be run on i20-35 rims but will be best on i25-30 rims. Putting a 2.4 tire on an i35 rim will make the tire widen out to about 2.5. Putting a 2.4 tire on a i20 rim will make the tire narrow down to about 2.3.
2.5 tires can be reasonably run on i23-37 rims but will be best on i27-33 rims. A 2.5 tire will be 2.6 wide on an i37 rim and 2.4 wide on an i23 rim.
2.3 tires can be reasonably run on i18-32 rims but will be best on i22-28 rims. A 2.3 tire will be 2.4 wide on an i32 rim and 2.2 wide on an i18 rim.
In all these tire/rim combinations, using the widest reasonable rim adds weight without adding much performance. While using the narrowest reasonable rim, reduces weight but also reduces performance. That is why it is best, if possible, to stay to the middle of the rim width range.
In the end, i23-32 rims will work for all 2.3-2.4-2.5 tires but i27-30 rims will likely be best. I wouldn’t use 2.3 tires on i35 rims. I think of i30 rims as the universal rim in that they work fine with 2.2-2.8 tires but best for 2.3-2.6 tires which are the tire widths most mountain bikers are most likely to use. And that’s why most Trailbikes come with i30 rims.
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Bike Nerd, Thanks for your insight, it’s greatly appreciated.
While the bike (Kona Process 134DL) came stock with i23 rims and 27.5 Ardents (2.4 front & 2.25 back), I upgraded to i29 rims a couple of years back and opted for the DHR II’s (2.3 – front and back) at that time.
That being said, my thought was to keep an i29 rim (either the current WTB Asym or switching out to a Stan’s Flow MK3) on the front with a 2.5 DHF and swap out the i29 on the back for an i35 rim (WTB Asym or Stan’s Baron) with the 2.3 DHR II.
Your thorough explanation helped me reach this conclusion: i29 rims w/DHF 2.5 front and DHRII 2.3 on back. I’m assuming that the 0.2 width differential will work.
What I’m not so sure about is whether upgrading from the stock 2.4 to a 2.5 tire will change the geometry and performance of the bike with a 140 travel fork. If it does, I might consider upgrading to a 150 travel fork.
I’m new to this forum and I really appreciate you taking the time.
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You could put a 2.6 tire front and 2.2 rear and you wouldn’t affect the geometry of your bike enough to matter. I wouldn’t worry about using any 2.2-2.6 tire front or back.
You could also put a 150 fork on your bike and not alter the geometry much. However, I don’t think you would get much performance advantage by adding 10mm of fork travel (and your bike is not designed for a 160 fork). Putting on a 150 fork would be a waste of money unless your old 140 fork is in very bad shape or of very poor quality and needs replacing. Otherwise, I would just keep the 140 fork.
The 2.5 DHF and 2.4 DHR are made specifically to go together and I think you will get the best descending performance by using this combo. However, I am not a fan of Minions for Trail riding. Minions are incredible for descending but terribly slow-rolling on the flats and climbs. Minions are best if most of your rides are winching yourself to the top of the mountain (or using a chairlift or shuttle) so that you can bomb down. If your rides are flatter, don’t get Minions. Minions might come stock on many bikes but I don’t think they are the best tires for most riders.
Instead, consider using 2.4 Maxxis Dissectors front and rear (or 2.6 front and 2.4 rear). Dissectors roll so much faster than Minions but still have a very aggressive tread pattern and descend almost as well as Minions. I just switched from Minions to Dissectors and they are so much faster rolling and more playful. For me, using Minions took some of the joy out of riding and switching to Dissectors brought it back. I’m even considering using lighter and faster-rolling Maxxis Rekons when I replace the Dissectors. Or maybe a Dissector front and a Rekon rear.
I favor wider tires and I would put the widest tires that would fit which would be 2.6 front and 2.4 rear on your bike (and would work fine on your i29 rims). I think that 27.5 wheels really benefit from 2.6 tires. In my opinion, 27.5×2.6 tires are equivalent to 29×2.4 tires in terms of performance.
Remember, tires are the most important component on your bike so choose wisely. If you get the the right tires for your bike, trail conditions, and personal riding style, your riding experience will be immensely enhanced. Get the wrong tires and you won’t like mountain biking nearly as much. I’ve learned this from personal experience. In my opinion, for Trail riding, 2.4-2.6 tires are best and tires that roll faster, like the Dissectors or Rekons, are best.
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The only concern I might have with Dissector’s and Rekon’s vs DHF or DHR II’s is traction.
I ride typical east coast trails (Connecticut). While there is some form of flow in some instances, the trails are predominantly slow rolling tech.
Most of the trails are undulating hills – constant up and down (100-200 yards either way) over the course of any particular trail and the climbs, more often than not, are as techie as the flats and downhill sections.
That being said, I am, like most riders in this area, trying to find the right balance between faster rolling tires and those that offer enough traction for the endless rock gardens and quick and constant sprint climbs.
You suggestions are well taken. A 2.6 front and 2.4 back seem like the best selection. When I do upgrade the bike (1×12 to replace the 2×10, new wheelset and new fork), I’ll absolutely upgrade the Rockshox Revelation to either a Rockshox Pike or Fox 34 (140) or Fox 36 (150).
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