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People normally convert either 700c or 27" bikes to 650b to increase clearances and allow a wider tyre to be used, perhaps with fenders. Slightly longer reach brakes can be used to allow this.
Converting the other way, from a smaller wheel size doesn't really make sense, as mtbs already have clearance for wide tyres, and putting a larger size like 650b on will reduce clearances.
Your idea that you got beaten because the other bike had bigger diameter wheels maybe not the whole reason. There is a lot of hype now about 29" and as you have noticed, also 650B. But the evidence is not as conclusive as they claim. If you want to speed up your own wheels, first try a lighter tyre, a smoother tread and a higher pressure.
As to the question of whether the 650Bs will fit, I think not if you have rim brakes. Your 26" rims are 559mm from side to side and 650Bs are 584. So if you have rim brakes you have to move the pads out 12.5mm. No problem with discs. Mudguards you don't have. But you still need an extra 19mm below the fork crown and at the rear stay bridges. Check if you have 20mm space plus a bit.
How wide are the 650B tyres you are looking at? Much narrower than 2.3" I think.
You will be more efficient on narrower tyres so if you baulk at the wheels at the last minute, just get som XC 1.7 tyres. You'll be faster.
The connection for us tourers is that we have even more reason to be concerned about efficiency. Why drag a brick behind your bike?
The marathon involved was from Jalkhad to Babusar top and return. Myself and 3 Pak riders were turned around with approx 2k to go as we were too slow.
The fastest guys on the day were Pak riders on older style mtb, a slovakian who competes in road races around the world,a english solo 24hr champion and their partners.
Aasd Mehmood(Pak army rep),Mohammad Sabir(current Pak time trial record holder) and Mohammad Ibrahim( riding a ancient rigid mtb bought from a US soldier in Afghanistan) were all at the front, and lovely guys to boot.
I am interested in 650b as I enjoy all cycling and being able to cover more ground in a day would make touring on my days off more feasible.
Cheers Matt
Its important to check out your front fork if you are converting. Most standard 26 inch suspension forks will take 650 wheels as there is usually plenty of room below the stanchion, but with some the crown (i.e. the part just under the headset) actually moves below the stanchion at maximum compression (i.e. when you make a big hit), and the crown may hit the tyre at precisely the moment you don't want it to hit. You should check out the manufacturers website, most have information on this.
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1
Why?People normally convert either 700c or 27" bikes to 650b to increase clearances and allow a wider tyre to be used, perhaps with fenders. Slightly longer reach brakes can be used to allow this.
Converting the other way, from a smaller wheel size doesn't really make sense, as mtbs already have clearance for wide tyres, and putting a larger size like 650b on will reduce clearances.
5
We are not only touring riders we are cyclists. So let's help a bit.Your idea that you got beaten because the other bike had bigger diameter wheels maybe not the whole reason. There is a lot of hype now about 29" and as you have noticed, also 650B. But the evidence is not as conclusive as they claim. If you want to speed up your own wheels, first try a lighter tyre, a smoother tread and a higher pressure.
As to the question of whether the 650Bs will fit, I think not if you have rim brakes. Your 26" rims are 559mm from side to side and 650Bs are 584. So if you have rim brakes you have to move the pads out 12.5mm. No problem with discs. Mudguards you don't have. But you still need an extra 19mm below the fork crown and at the rear stay bridges. Check if you have 20mm space plus a bit.
7
Yes, you will have higher top tube and you will be higher off the ground. But you are already a bit higher on 2.3" MTB tyres.How wide are the 650B tyres you are looking at? Much narrower than 2.3" I think.
You will be more efficient on narrower tyres so if you baulk at the wheels at the last minute, just get som XC 1.7 tyres. You'll be faster.
The connection for us tourers is that we have even more reason to be concerned about efficiency. Why drag a brick behind your bike?
11
With all due respect, at 50 I am aware you need to get the motor right before blaming the bike.The marathon involved was from Jalkhad to Babusar top and return. Myself and 3 Pak riders were turned around with approx 2k to go as we were too slow.
The fastest guys on the day were Pak riders on older style mtb, a slovakian who competes in road races around the world,a english solo 24hr champion and their partners.
Aasd Mehmood(Pak army rep),Mohammad Sabir(current Pak time trial record holder) and Mohammad Ibrahim( riding a ancient rigid mtb bought from a US soldier in Afghanistan) were all at the front, and lovely guys to boot.
I am interested in 650b as I enjoy all cycling and being able to cover more ground in a day would make touring on my days off more feasible.
Cheers Matt
13
The top riders are mostly on 29ers and 650 wheels now, but the pro teams still (if they can afford it), use 26 inch bikes as well for certain types of course. I don't think there is much doubt that on long, undulating and rough ground the bigger wheels roll better and significantly faster. But on twisty technical courses, 26 inch wheels may still have an advantage (especially for smaller riders). As a cheaper alternative to changing your whole wheel, you might want to check out some superfat tyres, they offer some of the advantages of big wheels (although there may be clearance issues with some bikes).Its important to check out your front fork if you are converting. Most standard 26 inch suspension forks will take 650 wheels as there is usually plenty of room below the stanchion, but with some the crown (i.e. the part just under the headset) actually moves below the stanchion at maximum compression (i.e. when you make a big hit), and the crown may hit the tyre at precisely the moment you don't want it to hit. You should check out the manufacturers website, most have information on this.
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