26" 27.5" and 29" Wheels and mtb's.

[Zac.A]

Excuse my ignorance but if a 650b wheel fits straight into a 26 inch frame and fork how much clearance is there? And when it rains won't it clog with mud?

 

I might try it out on my Cannondale flash, there is about 1cm of clearance at the back if you use a racing ralph, the front is fine because of the lefty.

[Caerus]

_{After watching guys on the first day of Sani2c 2 years back hitting the mud, we came to the conclusion, fox forks had the most clearence while the rock shox had the worst. If it was bad for 26inch wheels I can't imagine wanting to use a 27.5 inch wheel on a 26inch fork. It was taking guys 20 min to clear the mud.}

I hear you on the mud clearance issue, how much clearance would actually be needed, is there an optimum? The right tyre choice will also make a differance. When I look at my Fox fork with the current wheelset on, I'm only closing that gap by 12mm. This I'm basing on using a set of 650B Stans rims, and the current tyre I have on the front(Maxxis Crossmark)

 

In all honesty while riding through the whole of summer I've not had any issues with mud while riding with my 26" wheelset, certainly not enough to even worry if I had put a 650B wheelset on. So how much time will I actually spend riding in the mud, possibly not much. It will also depend where you are riding, and the type of mud I suppose. Yes it will have its issues and limitations, but don't all wheel sizes each have there own limitations.

[rouxtjie]

I hear you on the mud clearance issue, how much clearance would actually be needed, is there an optimum? The right tyre choice will also make a differance. When I look at my Fox fork with the current wheelset on, I'm only closing that gap by 12mm. This I'm basing on using a set of 650B Stans rims, and the current tyre I have on the front(Maxxis Crossmark)

 

In all honesty while riding through the whole of summer I've not had any issues with mud while riding with my 26" wheelset, certainly not enough to even worry if I had put a 650B wheelset on. So how much time will I actually spend riding in the mud, possibly not much. It will also depend where you are riding, and the type of mud I suppose. Yes it will have its issues and limitations, but don't all wheel sizes each have there own limitations.

Not to the point where you cannot ride. Clearance is a biggie, and the main reason I won't consider 650B. I get that we don't always ride in wet conditions but when you do you might as well put your bike on your back and start running.

[Caerus]

Not to the point where you cannot ride. Clearance is a biggie, and the main reason I won't consider 650B. I get that we don't always ride in wet conditions but when you do you might as well put your bike on your back and start running.

Fair enough, but still does not anwser the question, how much clearance is actually optimum? Is there a set distance between fork arch & tyre, as well as the back. When the design fork/ frames for either 26" or 29" wheelsets, do they have a clearance measurement all manufacturers work around, an industry standard so to say. This is where the particular frame and fork make a differance, certain forks & frames will just not work, some will certainly work.

 

Do you think there would be such a following of 650B wheelsets if this was such a huge issue?

Edited March 27, 2012 by Caerus

[rouxtjie]

Exact numbers I don't know but like swift01 said fox seems to have a little bit more than RS. There are also a number of factors like how well your tyres chuck mud type of mud etc etc so I dont think its an exact science.

 

All I know is it is already tight in there when the mud starts packing in the wet, I don't want to make that even less

[Caerus]

Exact numbers I don't know but like swift01 said fox seems to have a little bit more than RS. There are also a number of factors like how well your tyres chuck mud type of mud etc etc so I dont think its an exact science.

 

All I know is it is already tight in there when the mud starts packing in the wet, I don't want to make that even less

Thats the thing, it can work, but as I also said, it might not. It depends on a few variables, get these right and its happy days. I've been doing a lot of research into this, if it works for me, which I think it should, then its happy days. If not, not a problem as well.

[rouxtjie]

Thats the thing, it can work, but as I also said, it might not. It depends on a few variables, get these right and its happy days. I've been doing a lot of research into this, if it works for me, which I think it should, then its happy days. If not, not a problem as well.

Go for it

[nickelass]

think the answer is to use a 650b on the front wheel only,if you really like it go the extra cost and get a fork designed for 650b.

I may go this route with my anthem.

There is a mub clearance issue on the back.

I have only once encounted a mub issue(last year trans lesotho)it was so bad any wheel clearance will still be and issue.What happens is the mud /clay forms a layer which continualy gets bigger.

This reaches a point where you are now pushing your bike with neither wheel turning.so you resort to carring your bike only to find its 3 to four kgs more.

The only answer is to find a stream and use a scrapper to remove the mud.It does not come off easy.

I ended doing a complete strip down of my bibe on my return,as I all the lower suspension bearing were clogged up, and replaced my bb.

[Wyatt Earp]

Not to the point where you cannot ride. Clearance is a biggie, and the main reason I won't consider 650B. I get that we don't always ride in wet conditions but when you do you might as well put your bike on your back and start running.

Spoken like a true and honest man

[Wyatt Earp]

Exact numbers I don't know but like swift01 said fox seems to have a little bit more than RS. There are also a number of factors like how well your tyres chuck mud type of mud etc etc so I dont think its an exact science.

 

All I know is it is already tight in there when the mud starts packing in the wet, I don't want to make that even less

No exact science.

Inaugural S2C, we hit the Umko valley in the bottom, after 10 meters of trying to ride the stuff, it was tickets.

Next year we were taken along the foothills, the year thereafter they introduced Nicks Pass.

[NotSoBigBen]

Hopefully they don't come up with a 750.73 or 31.5 standard cause there's very little 'clearance' on my standard 29r Momsen with Specialized Captain Control tyres

 

[Kranswurm]

Hopefully they don't come up with a 750.73 or 31.5 standard cause there's very little 'clearance' on my standard 29r Momsen with Specialized Captain Control tyres

 

 

I think you have mud problems....crikey!

I have 3" clearance on my SC rear triangle so a 27.5 is feasible

[Caerus]

No exact science.

Inaugural S2C, we hit the Umko valley in the bottom, after 10 meters of trying to ride the stuff, it was tickets.

Next year we were taken along the foothills, the year thereafter they introduced Nicks Pass.

So I ask you, what is the optimal amount clearance actually needed? If you gonna hit bad mud it will clog up no matter what you are riding. Just quicker with less clearance. If its gonna be a really muddy ride, you can always just switch wheelsets.

[Caerus]

Hopefully they don't come up with a 750.73 or 31.5 standard cause there's very little 'clearance' on my standard 29r Momsen with Specialized Captain Control tyres

 

That pic says it all doesn't it. may as well stick 26" wheels on there

[scotty]

Hopefully they don't come up with a 750.73 or 31.5 standard cause there's very little 'clearance' on my standard 29r Momsen with Specialized Captain Control tyres

 

How many 29'ers have you got.

[rouxtjie]

No exact science.

Inaugural S2C, we hit the Umko valley in the bottom, after 10 meters of trying to ride the stuff, it was tickets.

Next year we were taken along the foothills, the year thereafter they introduced Nicks Pass.

I got so gatvol at breedts the one day(after some good rains) that I turned around halfway. It was one of the most frustrating days of my life...ride 100m clean...15min, ride 100m...clean 15min...wash rinse repeat till you are back at the garage. I can see the application for XC cats but not for me. Also think you have been around the block enough(literally) to see it's biggest downside...you cannot ride when its wet and muddy...Sabi...Sani..etc etc, I defnitely don't want to run day 2 of S2C