road wheels too big, will mtb wheels be too small?

hypersonic

I'm thinking of fitting 26" wheels to many flat bar road bike which has disk brakes, but I can't work out the difference in sizes between the wheels with the tires fitted? 26" = 660.4mm. so is there only 4cm between the two tire sizes or have I missed something?

Laundry_Hamper

Whatever your problem is, I doubt that this is the solution to it. Why do you feel road wheels are too big?

hypersonic

Laundry_Hamper wrote: »

Whatever your problem is, I doubt that this is the solution to it. Why do you feel road wheels are too big?

there is no clearance for mud guards, this is my utility bike so I'd like to fit a decent set of mud guards.
I'm hoping that moving to 26" wheels will give me a cusher ride.
A mate of mine has offered me a 26" rear wheel for free. so if I want to go with 26" wheels I just need the front wheel.
does anybody know if the spacing for disk brakes is the same for road and mtb wheels?

DirkVoodoo

Might want to be careful. Axle spacings might be different for the rear wheels (maybe even the front? Shows how much I know mountain bikes).

Have you considered crud catchers or race blades? Fatter tyres run at the right pressure for your weight will give a cushy ride, as will wearing the right clothing.

hypersonic

DirkVoodoo wrote: »

Might want to be careful. Axle spacings might be different for the rear wheels (maybe even the front? Shows how much I know mountain bikes).

Have you considered crud catchers or race blades? Fatter tyres run at the right pressure for your weight will give a cushy ride, as will wearing the right clothing.

I have tried moving from the original 23mm tires to 25mm, probably should have gone to 32mm as there's plenty of space width wise.
thanks for the heads up on the axles, I'll check this.
I've seen race blades on a bike in work, and I'm not sure they will really keep the surface water off, any advice on this would be appreciated.

Coronal

What kind of bike do you have? It would be strange if you could fit 32 mm tyres, but not 25s with mudguards... Also, raceblades are pretty decent at keeping crud off you. At the very least you don't get a nasty stripe all up your back. Full mudguards with mudflaps are the way to go if you want total protection, though.

niceonetom

650b

Lumen

http://sheldonbrown.com/tire-sizing.html

hypersonic

Coronal wrote: »

What kind of bike do you have? It would be strange if you could fit 32 mm tyres, but not 25s with mudguards... Also, raceblades are pretty decent at keeping crud off you. At the very least you don't get a nasty stripe all up your back. Full mudguards with mudflaps are the way to go if you want total protection, though.

I bought it second hand and I don't recognise the brand but it's got a G-shock label on the top tube. I've Google this but I've had no luck getting more details.
Like niceonetom, I think it might have started life as a cycle-cross frame and some how got fitted with 700c wheels.

hypersonic

Lumen wrote: »

http://sheldonbrown.com/tire-sizing.html

wow there are a lot of 26" wheels sizes. I'm not surprised I'm so confused!

Lumen

hypersonic wrote: »

wow there are a lot of 26" wheels sizes. I'm not surprised I'm so confused!

Basically, 26" MTBs are all 559mm BSD, and 700c road wheels are 622mm BSD. So that's 31.5mm difference in rim radius. It's a lot.

The other important thing is rear spacing. Normal road wheels are 130mm, MTB are 135mm. If you have a metal frame you can probably just bend it. You can of course have a MTB rim laced to a your existing hub to retain 130mm spacing with a smaller diameter wheel. Maybe you have 135mm already since you have disc brakes.

The other important thing is rolling diameter. If that changes, you will have different pedal clearance and different steering geometry. Smaller tyre = less trail = less stable handling.

el tel

G-shock you say? I think that's a Casio

hypersonic

Lumen wrote: »

Basically, 26" MTBs are all 559mm BSD, and 700c road wheels are 622mm BSD. So that's 31.5mm difference in rim radius. It's a lot.

The other important thing is rear spacing. Normal road wheels are 130mm, MTB are 135mm. If you have a metal frame you can probably just bend it. You can of course have a MTB rim laced to a your existing hub to retain 130mm spacing with a smaller diameter wheel. Maybe you have 135mm already since you have disc brakes.

The other important thing is rolling diameter. If that changes, you will have different pedal clearance and different steering geometry. Smaller tyre = less trail = less stable handling.

thanks very much for the info, sometimes I wonder how bikes got so complicated!
if I took the plunge and just got new wheels would 650b work?

reallyunique

It sounds like you have the wrong bike for you.
Trying to engineer a solution with new wheels is unlikely to be cheap or as effective as you'd hope.
Sell the current bike and get a 26" bike with discs, second hand. No way that's more expensive/difficult than fitting 650b wheels to a no-name frame. 650b tyres and rims are uncommon here and the increase in clearance may not be enough if you're really into fat tyres.

If this is just a hobby then maybe 26" is a plan. Check your spacing, you may find you've 135mm hubs to begin with, if not then lace new rims to your current hubs. The discs won't have moved so everything should be fine. The whole bike will be closer to the ground leading to possible pedal strike when cornering but beyond that I wouldn't worry about geometry changes too much.

Seriously, there are enough bikes out there to be able to get one closer to your needs without building a Frankenbike. I, however, want to build a 650b version of my favourite Audax bike but I'm a looney

hypersonic

reallyunique wrote: »

It sounds like you have the wrong bike for you.
Trying to engineer a solution with new wheels is unlikely to be cheap or as effective as you'd hope.
Sell the current bike and get a 26" bike with discs, second hand. No way that's more expensive/difficult than fitting 650b wheels to a no-name frame. 650b tyres and rims are uncommon here and the increase in clearance may not be enough if you're really into fat tyres.

If this is just a hobby then maybe 26" is a plan. Check your spacing, you may find you've 135mm hubs to begin with, if not then lace new rims to your current hubs. The discs won't have moved so everything should be fine. The whole bike will be closer to the ground leading to possible pedal strike when cornering but beyond that I wouldn't worry about geometry changes too much.

Seriously, there are enough bikes out there to be able to get one closer to your needs without building a Frankenbike. I, however, want to build a 650b version of my favourite Audax bike but I'm a looney

I''ve thought about selling, but the closest replacement I can see is a giant seek 0, which is 1200euro and 2kg heavier, although it does come with gears.
I.'ve taken a look at the hubs on the bike at the moment to see if there 130mm or 135mm but they are formula 32h, which came in both specs, along with some terrible reviews.

Lumen

You can get a decent second hand hybrid with mudguards for about 400 euros.

Is your current bike singlespeed? Do you want gears?

hypersonic

Lumen wrote: »

You can get a decent second hand hybrid with mudguards for about 400 euros.

Is your current bike singlespeed? Do you want gears?

single speed with a belt drive, really like the belt drive, not sure why as a chain works just as well, but it's probably the reason I am slow to sell, and the disk are much better in the wet.
I'm thinking maybe I should have a dry weather town bike and a wet weather town bike.

rab!dmonkey

Could you post some pictures of your bike? If I were you I would probably sell up and try some other bike, rather than messing about relacing wheels.

Lumen wrote: »

If you have a metal frame you can probably just bend it.

Do not do this with an aluminium frame!

studiorat

hypersonic wrote: »

single speed with a belt drive,

Take it to a shop and get new rims built onto the hubs.

hypersonic

after a Lot digging on internet I think I've found the frame. I think it was an early version of the kinesis he9010 single speed frame.

http://www.kinesis.com.tw/frames/he9010-2011.php

so I have the frame geometr, but I don't see the rear axle spacing.

hypersonic

rab!dmonkey wrote: »

Could you post some pictures of your bike? If I were you I would probably sell up and try some other bike, rather than messing about relacing wheels.

Do not do this with an aluminium frame!

I'll throw up some pics when I get home next week.

just wondering why you shouldn't bend aluminum, even a little bit?