Rim Width and Tyre Width

[Jb123]

Hello There

i have a question, i am currently running 2.6 Magic Marys on my Kenevo from New (didn't like the idea of 2.8's) has anyone put say 31-35mm internal rims on their bike and run 2.5 Tyres, if so how does it feel ?

 

[Hasse Birkmose]

Hello There

i have a question, i am currently running 2.6 Magic Marys on my Kenevo from New (didn't like the idea of 2.8's) has anyone put say 31-35mm internal rims on their bike and run 2.5 Tyres, if so how does it feel ?

Only on a regular mtb. 2,5 tyres on 35 mm internal rims and really liked it. Less tyre roll at low pressure.

 

[Jb123]

Only on a regular mtb. 2,5 tyres on 35 mm internal rims and really liked it. Less tyre roll at low pressure.

yes i have run that combo on a normal bike many times, i was wondering how it would be on an E-bike i am not a fan off these big tyres was thinking i would have more rolling speed and less resistance on the motor with a smaller rim and tyre combo, but i don think i could run 2.5 tyres on 38mm internal rims it might upset the tyre profile

 

[Eckythump]

I have successfully run 2.6” tyres on 40mm internal rims on my ebike. Not quite the same but not far off.

 

[Jb123]

I have successfully run 2.6” tyres on 40mm internal rims on my ebike. Not quite the same but not far off.

Hello Mate what i mean is effectively running normal size wheels and tyres like a non e-bike would have but running them on a E-Bike I.E 31-35mm inner rims with 2.5 tyres on as apposed to 36-40 mm inner rims with 2.6-2.8 tyres

 

[Eckythump]

You said 2.5” on 38mm internal that’s virtually the same as 2.6” on 40mm isn’t it?

 

[Eckythump]

2.6” & 2.8” profiles on same rim width.

 

[Jb123]

View attachment 16521 View attachment 16522

2.6” & 2.8” profiles on same rim width.

Thanks mate

 

[Jb123]

View attachment 16521 View attachment 16522

2.6” & 2.8” profiles on same rim width.

what i mean is has anyone got a normal bike rim and tyre combo not all these wide rims and plus tyres

 

[Eckythump]

My buddies Level RR came with standard width rims and a 2.5/2.4” minion combo, his previous Haibike came with 2.35” tyres, you are good to go??

 

[Jb123]

My buddies Level RR came with standard width rims and a 2.5/2.4” minion combo, his previous Haibike came with 2.35” tyres, you are good to go??

is there any benefit to running them apart from a small weight saving, i did think about in the winter they would cut through the mud better rather than sit on top off all the mud like the plus do

 

[Kiwi in Wales]

Read this post, it should give you loads of good info

Ebike tire showdown. - EMTB Forums

 

[Eckythump]

To me the benefit of narrower tyres is getting away from tyre squirm when cornering really hard.
Dropping to 2.6” tyres cured that for me anyway. Another buddy with an ebike here has gone the other way and stuck a 2.6” on a 23mm internal rim as he prefers the extra forgiveness over a 2.35”. A 2.35” tyre will cut through sludge better but once you get down to 2.5/2.6” tyres it is diminishing returns.

 

[Mabman]

I like a narrower tire in the front that probably is a result of using them for the last 35 years. After trying fat bikes years ago I hated the way the front end grabbed and self steered so I never understood the appeal of running a fatter tire in the front, especially at low psi.

What I have settled on is a 700c 2.3 mounted on an i35 rim. Precise steering control that I am used to and the ability to run 1bar tubeless, which is the same as the 650b 2.8 I use on the back.

 

[33red]

I ask some questions directly via email at the manufacturer. Here people meaning well might be wrong. A 2.5 2019 might be different than 1 or 2 year before. Many manufacturers started to modified their construction. There might other appellation but some use WT like wide thread.
- You might also consider BB height to avoid hitting rocks.
- You might also use shorter arms to avoid pedal strikes.
My bike came with 40mm and 175. I switched to 165 and a bit smaller tire but i like not hitting stuff so i would not forget that.

 

[HikerDave]

Hello There

i have a question, i am currently running 2.6 Magic Marys on my Kenevo from New (didn't like the idea of 2.8's) has anyone put say 31-35mm internal rims on their bike and run 2.5 Tyres, if so how does it feel ?

I run a 2.6 Butcher, actual width 2.5 on the front with a 30mm internal-width rim and it’s great. On the back I’m running a 2.3 Slaughter on a narrower rim and that combination is giving me very balanced traction. If I pull the trigger on a custom wheelset I’ll be sizing up to 35 front, 30 rear though because I prefer a more square profile; I’m normally a slow rider except when I’m not.

For a given tire size, a narrower rim makes the tire wrap around more angle which means the bike needs more lean to engage the side knobs; it’s the opposite on a wider rim where the side knobs engage with slightly less lean. So probably in loose stuff with marginal traction wider rims are better but on ego hardpack after a rain the narrower rim would be better, on the theory that more g-force in the turn means more lean.

You just need to avoid an extreme lightbulb shape which could make the tires blow off the rim at high pressure.

 

[HORSPWR]

So what’s the general consensus, 2.8 on the front and 2.6 on the rear or the other way around?
I come from a motocross background where the front tyre is skinny and the back tyre is wide.

 

[33red]

So what’s the general consensus, 2.8 on the front and 2.6 on the rear or the other way around?
I come from a motocross background where the front tyre is skinny and the back tyre is wide.

There is no answer because first to get a good answer you would need to be more precise. I weight 130 ponds, my first Ebike came with 3.0x27.5 on 40 mm. I just started enjoying expert trails. I do benefit from the extra grip of 3..0 and it keeps my BB as intended by the designer so i will not go way smaller on this bike. Maybe a real expert does not need that much grip thanks to better technique, maybe an heavier rider prefers thinnier tires, maybe i would prefer them too if i did not have to deal with wet roots. Also some tires are not available in all sizes.
I would go starting from nothing with a 27.5x3.0 rear on 40 mm for extra grip(i like to climb) and i am on hardtail so extra cush with a 29x2.6 on 30 mm for roll over but that is just me. Many are on full suspension go for thinner rear for less drag but is this wise on an Ebike? Sometimes people act on habits. Just like arms i switched from 175 to 165 and will never use 175 in trails that comes from road bikes.

 

[Rusty]

So what’s the general consensus, 2.8 on the front and 2.6 on the rear or the other way around?
I come from a motocross background where the front tyre is skinny and the back tyre is wide.

That is actually something often argued. I guess it really depends on what sort of terrain you are riding. For many years XC racers ran a 2.0 or 2,1 on the front and a 1.9 on the rear. The argument was that the skinnier tire cut through the muck better and because it was lighter (say what?) was easier to get up to speed where the fatter front tire gave better grip in corners. I can agree with the 'cut through the muck' thought but the lighter argument doesn't hold unless you are weighing every tire at purchase as I have had 1.9s heavier than 2.0s of the same pattern.
On the eBike I am running either 2.5 or 2.6 (29er) front and rear.

BTW - I ran a 3.25 x 21 front knobbie on a 125 back in the 70's during a test session and besides making it difficult to loft the front wheel it made the bike feel like a modern day fatbike when trying to corner.