Anyone running a 29" front tire on a 27.5" bike?

greeno

Active Member
Region
USA
City
San Diego
Seeing how I'm always ready to experiment with sports I am involved in I thought I would give swapping out my 27.5"x 3" front tire for a 29" a go.

So I pulled the front tire off of my hardtail bike ( which I barely ride anymore) and disassembled the wheel to use the hub and build up a 29'er. Same size front dropout (135mm) as my current bike so I ordered a WTB Asym i35 29" rim, 29" x 3" tire and some 14g spokes from Wheelbuilder. They arrived a few days later so I pulled out my wheel stand and build up the wheel, adjusted tension and trued it on up. I then applied the rim tape dropped the tire on, aired it up to preset it to the rim, removed valve stem and poured 5 oz. of Stans in. Installed valve stem and filled up to about 25psi, sprayed it down with soapy water to expose any leaks and then let it sit overnight.
Next day I checked on the tire and it was still aired up so I swapped it for the 27.5" and took it for a 30 mile ride.

First thing I noticed was it looked bigger in size and rode like it was bigger too.
It seemed to roll over bigger rocks easier but wasn't quite as quick on the turns as the original 27.5" tire.
Going down some steeper trails it seemed to be a hair more stable holding it's line.
Going through some twisty tight sections it felt kinda bulky.
Didn't really notice any changes in geometry as far as angles are concerned. Luckily I'm running a Wren 150mm on the front so there is no brace bar to deal with. Which allows me to use pretty much any size tire I choose as long as the spacing is the same.Which is one of the reasons I went with Kevin and his products. Don't want to have to purchase separate forks to try different tires.

Going to keep the 29 on the bike for a couple of weeks to better get a feel for it and see if it's a thumbs up or down. If I go back to the 27.5" I will break the wheel down again and rebuild back up the 26" tire for the old bike and chalk this little experiment up to curiosity. Regret the things you don't do, not the one's you do.
Thanks for listening.
IMG_1247.JPG
IMG_1249.JPG
 
Last edited:

JRA

Well-Known Member
I've been riding my bike like that for 3yrs. now. It has always made sense to me coming from my moto days but it wasn't until 27.5+ came along that offers a closer diameter that I really tried it. I have been riding 29" wheels since 1999 and become very used to the handling I can expect from one. I don't like wider tires on the front however as I like ginsu steering but do in the rear for traction/flotation, In order to get that effect using a smaller rim with a bigger tire was the only way to achieve my goal. So now like you I use WTB asym i35 rims with a 2.3 vigilante on the front and started 3 years ago with the first b+ tire a Trailblazer 2.8 that I had to crimp my cs's a bit to get in there. but now use a 2.6 Vigilante that also fits and is knobblier for winter riding.

At this time even some of the big players are shipping their bikes out "mullet" as it has come to be known but it seems to be a mixed bag of folks that it works for overall. Biggest disadvantage is it can lower your bb which can cause more chance of pedal strikes. I personally think pedal strikes are more a cause of human error and not reading the trail than bike error.
 

Ebiker33

Well-Known Member
What are the practical theoretical advantages and disadvantages of this set up?
I have seen some bikes come stock like that from the factory.
 

greeno

Active Member
Region
USA
City
San Diego
Not sure how it lowers the BB on a 27.5” bike with 29” front wheel. Going with a smaller than original tire in the back I could see that being true.
 

JRA

Well-Known Member
True that but I started with a 29" frame which others have done also but not in your case. In fact your diameter discrepancy is much more than what I have so it actually raised the bb and slackens the head angle more. You'll have to ride ti some to see if it works for you.

BTW curious as to what bike that is?
 

TomW

Active Member
I'm looking at the new Hydra frame and I was wondering if I should go Mullet (29" up front 27.5" rear) if/when I decide to build one up.
My brain is melting looking at the geo specs on the Watt Wagons Website lol. Trying to visualise possible build routes. I want to build it as a enduro/allrounder.
I think it may be to slack but its hard for me to work it out without the physical parts in front of me lol. I have been trying to compare geo and measurements to other popular enduro bikes like the Kenevo
But things like fork offset etc is confusing me even more tbh.
I will have to consult with Pushkah at some point.
 

pushkar

Well-Known Member
I'm looking at the new Hydra frame and I was wondering if I should go Mullet (29" up front 27.5" rear) if/when I decide to build one up.
My brain is melting looking at the geo specs on the Watt Wagons Website lol. Trying to visualise possible build routes. I want to build it as a enduro/allrounder.
I think it may be to slack but its hard for me to work it out without the physical parts in front of me lol. I have been trying to compare geo and measurements to other popular enduro bikes like the Kenevo
But things like fork offset etc is confusing me even more tbh.
I will have to consult with Pushkah at some point.

You absolutely can do that. Put that in the notes are when checking out.
 

greeno

Active Member
Region
USA
City
San Diego
Got 3 good rides in the last couple of days and I think I have an opinion for me at least as far as going with a 29" tire up front on my 27.5" frame bike.
Like I stated earlier it felt a little bulky on the tighter trails but going up and over large objects ( rocks, stumps, roots) it eased over the top just fine. Today we had some steep downhill sections with some big rocks thrown in for good measure. So I dropped the seatpost all the way down and all was good until I rolled over a couple of bigger dropoffs. It honestly felt like I was going over the bars a couple of times. Weird feeling. I'm guessing because of the bigger arc of the wheel it allows the rear tire to travel a bit more forward before it allows you to pull out of the drop. I would of thought that a bigger wheel up front would of had the opposite effect. Or maybe I WOULD of flew over the bars on the 27.5" tire on the same trail. What do I know? Leaning towards the 27.5" but will take a few more runs before I make the call.
 

greeno

Active Member
Region
USA
City
San Diego
Well the verdict is in on my opinion as to keep the 29" up front or swap out for the original 27.5". I'm going to stay with the 29". At first I was leaning toward going back to the 27.5"
This past week I got to ride the same trails where I first tried out the 29' and it felt great. I guess I'm use to the subtitles now on how it handles as I don't even notice it being a bit bigger anymore. I do find that I tend to go faster and seem to ride more aggressively than before. On some of the soft/rutty steep sections I just throw the tire in the main rut area and power right on through. The drop-offs that I almost beatered on didn't seem as bad either maybe because I was carrying more speed and not being so timid. Should of taken a few pics of the ride for contrast. Next time if I remember. Looks like were supposed to get a bit of rain so off the bike for a few days.
 

BarnBoy

Well-Known Member
Region
USA
City
Pleasanton, CA
Interesting topic for discussion @greeno! I was looking at a second set of 29’er in addition to the fatty (26x4.8) for my future Hydra to do the “Mullet” getting an additional comfort angle.... (IDK!)

Dang cool bike!!!
 

biruja

New Member
I like this discussion too. Seems like something you have to test yourself like different skis.
 

reed scott

Well-Known Member
I'm still getting used to the 'luxury' of 27.5 in. plus sized tires. I love em. I rode 26 in tires forever and kick myself for not really keeping up with the bike world the past ten years. It will probably be years before I think about 29" wheels and likely never.