Inner-rim width and affect on handling

[csermonet]

Looking to upgrade my Azonic Outlaws and it seems that the most value for money would be the Hope Hoops that come with Pro 2 Evo's with Mavic ex721's. I will be going from 25mm inner rim width to 21mm. What sort of affect will this have on handling? I will be remaining with 2.5 maxxis tires. Curious to know if there is a certain width that is ideal, and any other information one should know about this when building a wheelset. so please feel free to school me

[gurp]

I went from a 325 to a 721 on my rear wheel running a HR2 2.4 3C and didn't notice a difference in handling. Maybe I would have felt the change on the front, not sure.

[pinkrobe]

OP, you might want to repost in the wheel and tire subforum. The consensus is that wider rims give more support to the sidewall, reduce tire "squirm" and make your junk bigger.

[SHIVER ME TIMBERS]

OP, you might want to repost in the wheel and tire subforum. The consensus is that wider rims give more support to the sidewall, reduce tire "squirm" and make your junk bigger.

you also get hot 20 year old chicks that pose with Don

[derby]

OP, you might want to repost in the wheel and tire subforum. The consensus is that wider rims give more support to the sidewall, reduce tire "squirm" and make your junk bigger.

Yes, this!

Way back in the early days, 30 years ago when I got my first trail bike, all the rims were around 44mm outside width. The widest tires, Ground Control, were 2.1.

It was in the later 80's and 90's when pro roadies came in to poach pro mountain bike race wins, they brought new narrower and narrower rims, and smaller lighter semi-slick tires, to loose a lot of rolling weight. The trend to narrow rims began then, and only recently with the "AM" growth have trail bike rims began to gain width.

Some tires, such as Minions are designed to be pretty square in profile on a narrow rim, and a wider rim could be too sharp edged for these and others having square profile. But current narrow rim round profile tires become a little more squared with wider rims, and improve their cornering bite and traction.

For the last couple years I ran a 35mm front with 28mm rear Velocity rims, using the same tire front and rear. I think it balanced the handling better, since the front turned better without washout as easily.

Recently I am trying 30mm carbon-fiber rims front and rear on my 6" travel bike with the same tires as before. The much lighter weight is noticeable, especially while steep climbing, the bike feels more nimble. But I miss the greater stability and more positive turning grip of the 35mm front rim, however, dropping almost 1/2 pound of front rim weight is nice. Now I want 40mm wide carbon-fiber front rim with my 30mm rear now, or matched with a 35mm cf rear would be even better..

[csermonet]

Thanks for the responses guys. The hope hoops with ex721's seem to be a good deal, think ill get those eventually and maybe replace the front with a 823 when the time comes.

[mbell]

you also get hot 20 year old chicks that pose with Don

Is that Dom's lame cousin?

[rhynohead]

This:

Tech Tuesday

[eurotrash666]

On one bike, I switched from a 19 mm inner channel to a 25.5 mm inner channel using the same 2.4" tires on back-to-back rides. That test made it amazingly obvious that wide is the way to go. Next for me: Syntace 40mm wheels!

[frango]

I've been thinking about getting Syntace MX 35 wheelset, coz I think 40mm rims are a bit of overkill, but... even with a discount I could get, I couldn't afford them, currently.
Moreover, there are no real life reviews, yet.
So, I've decided to reduce wheels' weight but replacing local Dartmoor Raider rims (inner width: 24mm, outer: 31,4mm) with WTB Frequency i23 hoops. I don't think 1mm width difference will make noticeable difference. At least when we talk about tire shape.
With new spokes my wheels will drop about 250-300g.

[csermonet]

I've been thinking about getting Syntace MX 35 wheelset, coz I think 40mm rims are a bit of overkill, but... even with a discount I could get, I couldn't afford them, currently.
Moreover, there are no real life reviews, yet.
So, I've decided to reduce wheels' weight but replacing local Dartmoor Raider rims (inner width: 24mm, outer: 31,4mm) with WTB Frequency i23 hoops. I don't think 1mm width difference will make noticeable difference. At least when we talk about tire shape.
With new spokes my wheels will drop about 250-300g.

I dont know **** about wheels, what sort of spokes are you using to save weight? I think I will hold off on the Hope Hoops with 721's, on account that the 21mm inner width will create an undesirable tire profile for DH use. My past 2 bikes have both had Outlaws so i dont have anything other than 25mm inner width to compare to. From what ive read and the responses ive gotten in this thread, sounds like i wouldnt want to go any smaller than that, bigger if possible.

[frango]

My current set is Hope Pro II hubs with DT Competition spokes and mentioned Dartmoor Raider rims (570g each rim). Complete wheelset weighs 2010g.
I am going to shave 100g on each by switching to WTB Frequency i23 (450-470g per rim) and the rest on Sapim CX Ray spokes with 14mm alloy nipples. The set shout be at 1700g mark.
This upgrade will cost me more then twice less then Syntace MX 35 wheelset.

[eurotrash666]

Don't get me wrong, I have 3 sets of Hope hubs, five pairs of hope brakes, three hope stems and a triple crown... I love me some hope parts but there is a big difference in the Syntace hubs, which are between DT and King by design. As far as no real reviews, I gotta laugh! Wheel reviews are so extreme, it is like fanboys and morons going on about how their wheelsets are either diamonds or turds, with little in between! Seriously, the 8" bike is getting the mx40s this spring.

[frango]

I don't need to swap hubs, so however you say Syntace hubs are better than Hope has no importance for me.
As for real world reviews, I will wait till I can read more about Syntace wide rims. Coz, as just proven by PB, Enves are not so bombproof.

[eurotrash666]

I only said it because you made the comparison between your wheels being half the cost of the Syntace. Your wheels have no importance to me, either. The Hope is a nice hub, and the i23 is a good, strong, light rim. I think the Syntace is a better freeride wheel due to width and engagement points, and comparing the two based on price as if they are equal is apples and oranges.

No wheel is bombproof, and no review is objective. Wheel reviews are either nightmare stories of failure, where the reviewer declares the wheel as crap for a reason that is often no fault of the manufacturer, or they are short-term reviews from somebody who rode the wheel for a day and took lots of nice pictures. Both types of review are worthless and are bad to base a purchase decision on. I need to find this "real world" you speak of.

[frango]

Maybe you misunderstood me and maybe I was a bit too picky
I only said that the wheels upgrade I plan will be much cheaper than getting new wheels.
I didn't only compare my future wheels to Syntace MX 35 on base of price. I also took into consideration the way I use/wear wheels.
WTB i23 rims have been at least a year on the market. I kinda like I-beam idea for the rim.
Syntace rims are brand new. Few people had a chance to use them. They are one chamber rims. I am not sure if a "secret/proprietary alloy" provides enough strength to "counterbalance" simpler rim profile.

PB review is fair, IMO. This is the type of review may convince you or not to buy certain product.

[eurotrash666]

No worries. You've got a fair point.

I'm thinking I'll pull the trigger on the MX 40 wheels. The diagram below is the Syntace profile. It has the shelf in the inner channel like the Flow, and the profile is wide and low. With the offset spoke drilling and the tension you can get with the CX-ray spokes, I think it will be plenty strong. I'm still about 20kg under the rider limit, too!

[Saul Lumikko]

Wider rims also reduce rolling resistance, because the contact patch becomes wider, which causes it to shorten as well, when pressure is the same. Shorter contact patch = better rolling.

Unless you overdo it and the transition and side knobs - with worse rolling resistance - come into play, but you'd need seriously oversized rims and narrow tires for that to happen.

I was very happy going from 19 to 21 mm already, and will probably go even wider on my AM trail bike.

[frango]

No worries. You've got a fair point.

I'm thinking I'll pull the trigger on the MX 40 wheels. The diagram below is the Syntace profile. It has the shelf in the inner channel like the Flow, and the profile is wide and low. With the offset spoke drilling and the tension you can get with the CX-ray spokes, I think it will be plenty strong. I'm still about 20kg under the rider limit, too!

I may consider MX35 as my future wheels, ones near future set give up. But it may take few years
I am way below weight limit... like in the middle of it So, in general, I am pretty sure MX35s would hold up well. My only concern is the rims' tendency to get dings and flat spots, like Flow.
I hope, you will be able to tell more in the of the season

[The Grimmer]

Got the hope hoops with 721's and they're great. The fact is 721's are DH rims. They wouldn't make them that 'narrow' if they were useless for DH. Think about it. A lot of pro's use Deemax which is only 23mm internal. That's 2mm difference from the 721's. I use minions and i love it, great traction, and the hope hoops are freaking cheap, pretty darn strong and also quite lightweight!

[Saul Lumikko]

2 mm makes a surprising amount of difference, and I don't think "they wouldn't make them if they were useless" is a good argument in an industry that brought you these:

[The Grimmer]

Wider rims also reduce rolling resistance, because the contact patch becomes wider, which causes it to shorten as well, when pressure is the same. Shorter contact patch = better rolling.

Well yes ..unless your tyres are very square, in which case the intermediate or even side lugs will touch the ground and dramatically increase rolling resistance.

Also regarding the cranks you pictured. 721's are regarded as very good rims, and I see a lot of people riding DH with them. They would not be as popular, and therefore a company as big as mavic would not bother making them if they were useless.
How many people do you see riding those cranks? The answer: None.
That is because they ARE stupid. 721's are good rims for DH.

[Deerhill]

Some tires seem to bottom out/pinch less on the 21mm rims than the wider ones

[Saul Lumikko]

Well yes ..unless your tyres are very square, in which case the intermediate or even side lugs will touch the ground and dramatically increase rolling resistance.

That's almost the same caution I gave in the original post. "Wide rims - reduced rolling resistance" is not true in all cases:

Unless you overdo it and the transition and side knobs - with worse rolling resistance - come into play, but you'd need seriously oversized rims and narrow tires for that to happen.

Also regarding the cranks you pictured. 721's are regarded as very good rims, and I see a lot of people riding DH with them. They would not be as popular, and therefore a company as big as mavic would not bother making them if they were useless.

I'm sure 721's are good rims, no doubt about that. I only meant that "they wouldn't make it, if..." isn't a very good point. And 2 mm in rim width makes a surprising amount of difference. In the case of the OP the difference is 4 mm, from 25 to 21 mm. In my opinion that's downgrading and will be noticeable.

[Deerhill]

The bike def likes the bigger junk