Wide tyres with v-brakes

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dondelion
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Joined: 13 Sep 2014, 10:48am

Wide tyres with v-brakes

Postby dondelion » 2 May 2018, 3:27pm

Afternoon,

I'm building an expedition tourer from a Surly Troll frame and would like to run v-brakes with very plump tyres. I've had more faff with discs than I've had with v-brakes (bent rotors, pads not lasting) and as I'll be heading into some remote areas, v-brake parts are easier to source. The frame has clearance for 3 inches so the Surly Extraterrestrial tyres at 2.5 inches look they'd be fun.

Am I going to run into clearance issues with the brakes? I presume mountain bikers used to ride v-brakes with pretty big tyres. From this little database https://www.gravelbike.com/v-brake-arm-lengths/ the longest v-brakes are Tektro 849AL. I suppose rim width is a big factor too. What are people's experiences?

Thanks

Brucey
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Re: Wide tyres with v-brakes

Postby Brucey » 2 May 2018, 3:50pm

since the tyres may not come up to size anyway (and the size will vary with the rim you use), V brakes are not expensive and clearance also depends on exact boss position on the frame, my suggestion is to 'suck it and see' . You need only buy one tyre and brake to try it out, swapping parts around to try both ends.

Worst case is that you have a tyre and a brake that don't work in the intended application. This might count as cheap knowledge.

cheers
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wbm1874
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Re: Wide tyres with v-brakes

Postby wbm1874 » 2 May 2018, 4:17pm

I had 55mm tyres with v-brakes on my troll. Loads of room at the front, but the rear tyre barely cleared the brakes at the back. If the tyre was any wider, I would've had to deflate the tyre to remove the wheel.

mercalia
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Re: Wide tyres with v-brakes

Postby mercalia » 2 May 2018, 4:45pm

with my dawes 1-down and 1.75" Marathon tyres to get wheels off I have to disengage the V brakes cables & pull the arms right out, and in the past deflated the tyres a bit. Well if you have to deflate the tyres atleast you have a simple security feature, any thief will have to deflate the tyres first? which means more time they are exposed. 19mm exal rims

Fill the Surly Extraterrestrial tyres at 2.5 with Helium and you might just float away :wink:
Last edited by mercalia on 2 May 2018, 5:18pm, edited 2 times in total.

dondelion
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Re: Wide tyres with v-brakes

Postby dondelion » 2 May 2018, 5:05pm

I quite fancy the Paul Motolites https://paulcomp.com/shop/components/motolite/ but am sceptical that a £250 brake is going to be 10 times as good as a £25 brake. 4 inch long brake arms and 'tons of vertical adjustment' suggests they'd fit the Surlys. Anyone every used them? Is it worth just putting one on the front to save a bit of money? Are they as good as lots of people seem to say they are?

peetee
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Re: Wide tyres with v-brakes

Postby peetee » 2 May 2018, 5:14pm

Clearance for tyre removal is one issue but more important is the arc of travel of the brakes. Wide tyres and narrow rims combined can result in the tyre bulge fouling the brake pad. Often the pad adjustment that is necessary results in poor pad to rim contact producing premature and uneven wear and poor feel at the lever.
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mercalia
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Re: Wide tyres with v-brakes

Postby mercalia » 2 May 2018, 5:14pm

dondelion wrote:I quite fancy the Paul Motolites https://paulcomp.com/shop/components/motolite/ but am sceptical that a £250 brake is going to be 10 times as good as a £25 brake. 4 inch long brake arms and 'tons of vertical adjustment' suggests they'd fit the Surlys. Anyone every used them? Is it worth just putting one on the front to save a bit of money? Are they as good as lots of people seem to say they are?


I thought the virtue of the V brake design was they were cheap solid engineering, no need for fancy stuff?

Brucey
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Re: Wide tyres with v-brakes

Postby Brucey » 2 May 2018, 6:01pm

if you want a fancy cantilever brake then the VO ones seem like pretty good value; £100 for a bike's worth (silver or black)

Image

Image

http://freshtripe.co.uk/velo-orange-grand-cru-zeste-cantilever-brake/

BTW whether the brake blocks are likely to tickle the tyre or not varies with a lot of things, but the brake type isn't really one of them; unless you were thinking of 'parallel push' V brakes, it makes no difference if they are Vs or cantis, (provided we are talking the same depth of brake pad etc). Both brakes swing the pads around the exact same arc....

cheers
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horizon
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Re: Wide tyres with v-brakes

Postby horizon » 2 May 2018, 6:08pm

mercalia wrote: and in the past deflated the tyres a bit. Well if you have to deflate the tyres


Given that the likeliest scenario for having to remove the wheel is that the tyre has deflated itself already, maybe that isn't so much of a problem ... :wink:
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dondelion
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Re: Wide tyres with v-brakes

Postby dondelion » 3 May 2018, 5:22pm

So it looks like the sensible thing to do is just buy a large cheap tyre and see if it fits with the old Avid Single Digits I'm sure I've got somewhere. I haven't actually got the frame yet and am waiting for it to arrive from Germany where it was £300 cheaper than here. I just can't wait...

Hadn't even really thought about canti brakes as I've not had much experience with them. V-brakes are more powerful no? Or is it the pads and the setup that makes the most difference? And aren't cantis a bit of a faff?

The bike is going to be used for loaded off road touring in the likes of Mexico, the Andes and the Himalayas (if we get that far) so I'd like to be able to stop with a heavy load on a steep gravelly hill. I'm heading off for a couple of years and brakes are quite important hence the possibility of investing a bit of money in something well built like the Paul's Motolites. If they're not worth it, I'll just slap on some Shimano or Avid instead. The Motolites seem to be rated as the most powerful v-brakes you can get along with Shimano XTR. Anyone actually used them?

Brucey
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Re: Wide tyres with v-brakes

Postby Brucey » 3 May 2018, 6:52pm

dondelion wrote:...Hadn't even really thought about canti brakes as I've not had much experience with them. V-brakes are more powerful no? Or is it the pads and the setup that makes the most difference? And aren't cantis a bit of a faff?...


well V brakes are a simpler, less adjustable form of cantilever brake. Cantis can be less, as or more powerful, varying with the model of brake, and the setup. As for them being a faff I don't think there is much in it.

IMHO a significant difference is that cantis are less likely to be damaged if the handlebars flop round; by contrast very may V brakes are instantly bent/broken by such happenstances.

Don't get too worked up about how powerful others think various V brakes are; it varies with the bike, and on any given bike the maximum power is very simply dictated by the arm length and the boss placement; after that it is stuff that you can easily change like brake blocks. Cantis can vary in power a bit more than that, and (of course) are more adjustable. If you think you are going to run into tyre clearance problems, the right cantis are likely to offer better clearance than any Vs.

BTW if you are going for two years you might be doing well to avoid the rims wearing out in that time.

cheers
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elPedro666
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Re: Wide tyres with v-brakes

Postby elPedro666 » 3 May 2018, 7:52pm

I use XTR (m951 & m970 parallel push) with 2.4 Mountain Kings on 17mm and wider rims with no clearance issues at all. Stopping power is absolutely fantastic - to the point where you have to warn anyone unfamiliar who takes a spin on the bike! Avids should have more clearance I should think, certainly wouldn't expect any issues.

Only thing I would double-check - as mentioned above - is the boss spacing, as it's possible it could be narrower than usual MTB spacing... which someone will know I'm sure! 85mm I *think*...?

You can make cantis work as well as Vs, but it takes black magic whereas Vs are a doddle, especially the XTR where the quality of the parts makes adjustment a pleasure.

Hope that helps!

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Brucey
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Re: Wide tyres with v-brakes

Postby Brucey » 4 May 2018, 12:58am

just an illustration of how boss position can affect MA and clearance, even with the same model brake in use;

this brake has very high MA (about 4:1) and you can fit a fat tyre beneath it;
Image

this bike has bosses at a different height, has a different MA (a little under 2.5:1) and won't fit the such a fat tyre under a similar brake;
Image

cheers
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Gattonero
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Re: Wide tyres with v-brakes

Postby Gattonero » 4 May 2018, 10:17am

dondelion wrote:Afternoon,

I'm building an expedition tourer from a Surly Troll frame and would like to run v-brakes with very plump tyres. I've had more faff with discs than I've had with v-brakes (bent rotors, pads not lasting) and as I'll be heading into some remote areas, v-brake parts are easier to source. The frame has clearance for 3 inches so the Surly Extraterrestrial tyres at 2.5 inches look they'd be fun.

Am I going to run into clearance issues with the brakes? I presume mountain bikers used to ride v-brakes with pretty big tyres. From this little database https://www.gravelbike.com/v-brake-arm-lengths/ the longest v-brakes are Tektro 849AL. I suppose rim width is a big factor too. What are people's experiences?

Thanks


Your problem are going to be the rims, too.
A 2.5" tyre, let alone a 3", isn't great on a rim that is less than 25mm wide. For a start, you won't find many 29er rim-brake rims in that size, and with the pivot stance you have on that frame you will still have the v-brake arms getting very close to the tyre even with the pads set with the thickets spacers, there's only so much throw you can have there.
Perhaps you better try with cantilevers as you can get a longer throw with them.
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gregoryoftours
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Re: Wide tyres with v-brakes

Postby gregoryoftours » 4 May 2018, 9:42pm

You could maybe try Cane Creek direct curve v brakes. I THINK they should provide plenty of clearance for wide tyres. They don't require the use of a noodle. I used to run some and they have really nice modulation, but they need different spring tension on each side and can go out of balance easier than other brakes.