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Running a smaller rim up front?

Old 01-25-21, 07:17 AM
  #26  
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Next get some longer forks and make it a chopper (think of the motorcycles in Easy Rider).

That's what we did when we were kids, Well, I never did, but a few kids did. Extra-long fork, small front wheel, tall sissy bar in back.... I have no idea what they did for brakes, but who knows, maybe they were coaster brakes. But I have to imagine the steering felt awkward, at best.
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Old 01-25-21, 09:30 AM
  #27  
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I am continually surprised this is all really happening. Its just such a caricature.
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Old 01-25-21, 09:36 AM
  #28  
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And now you will begin to notice that the brakes won't reach...

Plus, didn't you say somewhere you wanted to put 180mm crank arms on? Better check the pedal strike with a smaller wheel too.
Experimenting is fun, and a good way to learn about bike design.
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Old 01-25-21, 09:48 AM
  #29  
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Originally Posted by Happy Feet View Post
Experimenting is fun, and a good way to learn about bike design.

Usually the hard way
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Old 01-25-21, 10:04 AM
  #30  
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Not sure if your bike was originally 27" or 700c, but an example of changing wheelsize for better traction/handling (gravel) would be a 650b conversion as some have noted. Changing only the front end seems odd but to each their own I suppose. I just did this both wheels). A couple of points:

1. Converting the front wheel will be easier than the rear for your bike as you don't have disc and an older sprocket design. In my case I went 10speed cassette to 10 speed cassette, disc to disc.
2. Make sure you find brake calipers that reach each rim before converting.
3. Look at conversion charts to see what tire sizes match up. 700x28 is pretty close to 650bx42, 700x32 is pretty close to 650bx48.


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Old 01-25-21, 01:46 PM
  #31  
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Originally Posted by Happy Feet View Post
Not sure if your bike was originally 27" or 700c, but an example of changing wheelsize for better traction/handling (gravel) would be a 650b conversion as some have noted. Changing only the front end seems odd but to each their own I suppose. I just did this both wheels). A couple of points:

1. Converting the front wheel will be easier than the rear for your bike as you don't have disc and an older sprocket design. In my case I went 10speed cassette to 10 speed cassette, disc to disc.
2. Make sure you find brake calipers that reach each rim before converting.
3. Look at conversion charts to see what tire sizes match up. 700x28 is pretty close to 650bx42, 700x32 is pretty close to 650bx48.


I was well aware that the brake would not reach. I simply decided to try this out for fun.

Switching to a 650b front sounds like a good idea actually. I want a wider front rim and tire.

I tried out the setup. The slight change in angles, most notably the change in fork rake seemed to look agreeable before my first test ride. During the ride, I was surprised how much the behavior of the bike changed. I didn't like it, and realized why some of you veterans claimed it to be a bad idea.

I think the biggest problem was my super tall stem. It was also slightly off centre. It did not track straight as stable anymore and required corrections. After gradually getting used to the big change in sensitivity to inputs, I began to enjoy it. Its definetely not going to stay like this for more than a few rides though but I was enjoying the wider rim as well as the noticeable change in response to input.
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Old 01-25-21, 07:02 PM
  #32  
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According to a tire size chart, the 27x1.25 tire my bike is designed for measures at around 694mm.

my front tire i typically use (700x38) measures at 698, which isn't far off, but my rear, (700x28) is at 678. I think part of the reason why I thought my handling was slow was the front tire being larger. My current front 26x1.75 is 648mm.

In reality these numbers are not perfectly accurate, as tire diameter is dependent on how it fits on the rim.

How did you get brake levers which work with your 650b rims when you converted? If i use 650b for the front, since I can only fit maybe up to 1.9 wide max, that would make the tire diameter between 672 and 680mm, which is relatively close to the factory standard.

I think, that going a little smaller in diameter is fine, as long as the sizes are more or less equal front and rear. But according to my experiment using 26x1.75 rear, going significantly smaller in the rear actually proved to work really well for me. It was just enough of a difference to result in the faster handling I wanted when pushing the bike hard, but there is no discernable difference in handling when turning normally.
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Old 01-25-21, 07:19 PM
  #33  
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Originally Posted by Moisture View Post
According to a tire size chart, the 27x1.25 tire my bike is designed for measures at around 694mm.

my front tire i typically use (700x38) measures at 698, which isn't far off, but my rear, (700x28) is at 678. I think part of the reason why I thought my handling was slow was the front tire being larger. My current front 26x1.75 is 648mm.

In reality these numbers are not perfectly accurate, as tire diameter is dependent on how it fits on the rim.

How did you get brake levers which work with your 650b rims when you converted? If i use 650b for the front, since I can only fit maybe up to 1.9 wide max, that would make the tire diameter between 672 and 680mm, which is relatively close to the factory standard.

I think, that going a little smaller in diameter is fine, as long as the sizes are more or less equal front and rear. But according to my experiment using 26x1.75 rear, going significantly smaller in the rear actually proved to work really well for me. It was just enough of a difference to result in the faster handling I wanted when pushing the bike hard, but there is no discernable difference in handling when turning normally.
As noted, I didn't have to worry about rim size because I have disc brakes (on this bike). The rotor/caliper position remain the same regardless of rim size.

The rest of what you wrote is confused. You didn't go 26x1.75 rear according to your experiment, you went 26 up front. Varying tire size front and rear, within the same rim diameter, is a pretty established practice in mtbing, usually a wider front tire. Some will even go one rim size higher ala mullet (example 29r front, 27.5 rear).

But mostly, I think you are trying to get that bike to do something the frame size was never intended to do. No matter what you do to the wheels, the telescopic steerer and short stem make for a very awkward ride. If it's the only bike you have you may not notice it but as soon as you ride a purpose built trail bike in your size you will see what is possible.

I read that you can't find a decent bike for your price range but even a used large size rigid mtb would give you a better platform to build a trail bike off of than an old school ten speed. And I like old school ten speeds - I use one as a FG. But there are simply limitations to what geometry and size can be made to do well.

Another idea would be to look for a decent used 90's era hybrid to use as a platform, within your size. While they get a bad wrap by some, there were some well made frames that have the benefit of accepting quite wide tire sizes. Here's a step through Trek Multitrack that I picked up for free and did a drop bar conversion to (it came with flat bars). A 3x drivetrain and canti brakes that could be converted to V's for better stopping power. It was my first "gravel" bike beyond converted 26" mtbs.

I would expect to pay 100-300 bucks for a diamond frame variation of it online with some patience. They make good budget gravel / easy offroad bikes.






Last edited by Happy Feet; 01-25-21 at 07:40 PM.
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Old 01-25-21, 08:11 PM
  #34  
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What if you just skipped all the weird tricks and just bought a new bike? You'd notice a bigger difference that way.
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Old 01-25-21, 08:57 PM
  #35  
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Originally Posted by UCantTouchThis View Post
What if you just skipped all the weird tricks and just bought a new bike? You'd notice a bigger difference that way.
Or he could just poke around in a better class of dumpster.
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Old 01-25-21, 09:09 PM
  #36  
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Originally Posted by Happy Feet View Post
As noted, I didn't have to worry about rim size because I have disc brakes (on this bike). The rotor/caliper position remain the same regardless of rim size.

The rest of what you wrote is confused. You didn't go 26x1.75 rear according to your experiment, you went 26 up front. Varying tire size front and rear, within the same rim diameter, is a pretty established practice in mtbing, usually a wider front tire. Some will even go one rim size higher ala mullet (example 29r front, 27.5 rear).

But mostly, I think you are trying to get that bike to do something the frame size was never intended to do. No matter what you do to the wheels, the telescopic steerer and short stem make for a very awkward ride. If it's the only bike you have you may not notice it but as soon as you ride a purpose built trail bike in your size you will see what is possible.

I read that you can't find a decent bike for your price range but even a used large size rigid mtb would give you a better platform to build a trail bike off of than an old school ten speed. And I like old school ten speeds - I use one as a FG. But there are simply limitations to what geometry and size can be made to do well.

Another idea would be to look for a decent used 90's era hybrid to use as a platform, within your size. While they get a bad wrap by some, there were some well made frames that have the benefit of accepting quite wide tire sizes. Here's a step through Trek Multitrack that I picked up for free and did a drop bar conversion to (it came with flat bars). A 3x drivetrain and canti brakes that could be converted to V's for better stopping power. It was my first "gravel" bike beyond converted 26" mtbs.

I would expect to pay 100-300 bucks for a diamond frame variation of it online with some patience. They make good budget gravel / easy offroad bikes.





I know that some people like to use their road bikes on singletrack, but with the drop bars and long stems you are practically getting the reach of a aingletrack bike anyways

I M well aware that a bike like mine with the short cockpit will not work well on real singletrack. As such, it is strictly for road and gravel duty , which makes up for the majority of my riding.

Worst case, I will revisit my XL Zaskar and use that for singletrack this season.

I meant only the 26x1.75 front tire, my mistake.

How do the 650b rims stack up to your old 700c setup? Pros and cons?,
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Old 01-25-21, 10:59 PM
  #37  
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Originally Posted by Moisture View Post
...How do the 650b rims stack up to your old 700c setup? Pros and cons?,
Horses for courses.

My 700c 28mm GP5000's are pretty fast road tires. On pavement they are what I would use.
My 650b 42mm WTB Resolutes are slower, but not unreasonably so, and have better traction for dirt/mud. On gravel/trails they are what I would use.

I can swap wheelsets in about two minutes so I decide what terrain I'm riding and choose accordingly.
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Old 02-03-21, 12:38 AM
  #38  
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Originally Posted by Happy Feet View Post
Horses for courses.

My 700c 28mm GP5000's are pretty fast road tires. On pavement they are what I would use.
My 650b 42mm WTB Resolutes are slower, but not unreasonably so, and have better traction for dirt/mud. On gravel/trails they are what I would use.

I can swap wheelsets in about two minutes so I decide what terrain I'm riding and choose accordingly.
Which cassette are you using on your 650b wheelset versus your 700c?

its awesome to be able to switch wheelsets like this. Im sure the 650b set is helpful in snowy conditions.

my thin road tires perform mostly well in slippery or gravelly conditions for the time being.
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Old 02-03-21, 06:01 AM
  #39  
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Originally Posted by BlazingPedals View Post
Going to a smaller front wheel will make the bike twitchier by increasing the head tube angle, if that's your goal. You can also accomplish it by getting a fork with more rake. Do you have a disc brake on the front, or are you planning on losing a front brake?
Trail can be decreased by both methods, true, but the change in flop won't be the same, so they won't necessarily handle the same.
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Old 02-03-21, 06:57 AM
  #40  
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Would you happen to be on Strava or some other ride-tracking app, @Moisture? I'd really like to get a better idea of the kind of riding you do, because your bike design experiments are all over the place.
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Old 02-03-21, 10:28 AM
  #41  
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Originally Posted by Steamer View Post
Trail can be decreased by both methods, true, but the change in flop won't be the same, so they won't necessarily handle the same.
A small increase in head tube angle would be offset by slightly less fork rake. But from initial impressions, the twitchy front end definrtly did take some getting used to.

Originally Posted by mack_turtle View Post
Would you happen to be on Strava or some other ride-tracking app, @Moisture? I'd really like to get a better idea of the kind of riding you do, because your bike design experiments are all over the place.
Which bike tracking app do you recommend?

I do mostly sub 30 minute commutes, almost everyday, not many dramatic or long hills where I live, or at least not in the areas I ride regularly. I use my gearing a lot and focus on always maintaining a specific cadence and a nice steady pace. I only sprint when the wind is light (almost never)

I'm pretty spirited around turns and will occasionally do some hard sprinting bursts in the right areas. This is when I feel like I do need to get slightly more aero. I'm going to lower my stem a little
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Old 02-03-21, 10:34 AM
  #42  
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Strava seems to be the most popular but it's heavy on the "competition" side. RideWithGPS is a little more laid back. you can track rides with your phone but it drains the battery pretty fast and is not very accurate. a smart watch or GPS bike computer tends to be more accurate. for your purposes, it probably does NOT need a high level of precision, just enough to give you a general idea of where you've gone, how far your rode, and approximately how fast you're riding.

I save my stuff on Strava to share with friends and use RideWithGPS (on a desktop computer) to pre-map routes if I want to ride somewhere new. I use the free version of both. I have a relatively cheap Garmin Vivofit 3 watch to GPS track my rides and runs. on that note, I need to run some more because laziness has killed my legs.
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