fatman

Hi!

Ok let me start by saying that I don't have a road bike, actually it is a mountain bike, but since it is a 29er it allows me to use 700c wheelsets easily. Changing tires each weekend will be a pain in the neck so for convenience my idea is to have a second set of wheels to quickly make the bike more road worthy. I bought a pair of Mavic SpeedCity 700c wheels at an excellent price on eBay. The wheels are excellent for me because the hubs are disc brake compatible so I bought an additional set of disc rotors and now all what I need is the rear cassette and tires.

The bike currently has a 48-38-28 crankset. I noticed that road cassettes comes in combos that usually starts with 11, 12 or 13 teeth on the first ring finishing with 23, 25 or 27 teeth on the last ring. This is confusing for me because in mountain bike your choice is basically a 11-34 combo. So, what criteria do I have to use to select the right cassette?

I'm planning to use the bike on open roads and city streets for up to 40-50 miles. Sometimes I will have to dodge heavy traffic, go up and down sidewalks and over few potholes and bumps, resistant to puncture flats is required. For that kind of usage, what brand and type of slick tire do you recommend? Possibly a very narrow tire will allow me to go a little bit faster but I can trade width for durability, of course without going to extremes. I think that 1.5" is too wide and remember that this is going to be a 700 tire.

Any ideas?

Thanks!

slider

Road tires are measured in mm. I like to run slightly larger tires than most because I find them comfortable and they don't slow me down noticeably. I'd suggest a 26 for durability or a 23 if you have to go that 1/2 mph faster. I currently ride 25mm Soma Express' on my road bike

https://www.somafab.com/tires.html

and Rivendell Rolly Polly's on my commute bike

https://rivendellbicycles.com/webalog...bes/10033.html

I'd get the 11 tooth cassette to have the same top gear on each wheelset. Nothing says you can't run an 11/34 though. Are there hills where you live?

-s

brunning

26 is a hefty road tire.

a good starting point, as with many things, is the middle.

12-25 is an average casette and 23s are average width road tires.

go down to an 11 if you think you'll be riding faster or if you have a smaller "big" ring (under 50t, maybe?). move up to a larger tire if you're riding really rough roads.

demoncyclist

WHy don't you move the 11-34 to the 700c wheel and see how it goes before you decide what you should buy. Write down the tooth count of your cassette, and see what you use the most for a variety of terrains. Also, think about any combos that are missing that might keep your cadence where you like it. Remember that with the larger diameter wheel, the gear combinations will feel different than with the mountain wheels. Keep us informed.

tommy2pants

For street riding,you don't need as low gearing as for mtb. You need an 11 small cog for speed, and unless you have some killer hills, a 23 or maybe even a 21 large cog is likely good with that 28 small ring. 700c tire widths are cm, not inches. 20 cm is narrow,28 fairly wide.Cross tires are even wider. Something like specialized armadillos are pretty bulletproof, but are heavy and lack ride quality.

MichaelW

For utility commuting use, most riders would use a 25-32.

28 is a nice compromise between speed and durability.

wlevey

I recently made a similar change to my Specalized Sirrus Comp (originally a commutor with MTB gearing). I put an Ultegra 11/23 on the back. The bike came with 700x26 tires and I recently changed to 700x23.

With the lower gearing up front you will notice that you still will not be able to keep up with your Roadie friends (unless you have much stronger legs than them and spin a very high cadance. You will definately go faster though and the ride will be less jarring. Also, keep in mind that the crank length is different. You spin a smaller circle on a road bike. The cranks on a MTB are longer to give you more leverage on your down stroak for humping up rough hills at lower RPM.

After spending several hundred to add a new front deraillier and Ultegra STI road shifters (I also had to use "travel agents" for the V brakes) I found that I sitll wasn't getting the performance I wanted. So, I went out and got a real road bike! I now ride a Lemond Buenes Aris and the difference is ammazing!!

I suggest you evaluate your goals and go from there. If you want to go on FAST club rides or race get a road bike. If you are just looking to smooth out your ride the mods will probably be fine. Let me know if you need any more pointers...Bill

tommy2pants

A consideration here. If you keep the mtb deralier to shift the 34 on the other wheelset,a cogset with a 21 or 23 may not work well, as the mbt rear mech tracks a different path as it traverses the cassette from small to large. and can end up too far away from the smaller cogs in the above cassettes for proper tooth engaagement. That said,you may need to stick with a road cassette with larger rear cog like a 27.

wlevey

In reply to Tommy2pants -

No a problem for me when I made the conversion to 11/23. I just put the cassette on and rode away. I didn't even have to adjust the in/out travel! My rear derailler on the Sirrus is a Deore LX (or is that XL).

Bill

fatman

Hey Thanks to you all!!!

I'm going to be riding alone most of the time and using the bike mostly for utilitarian tasks. As I said I will be riding up to 40 miles but it will be 15 to 25 in average. Of course on the longer rides I will like to go faster than I'm going now. I haven't discarded to get a road bike in the future, but for now I'll be fine with the MTB and the mods and at this point I bassiclly have everything except the tires and cassette.

I think that I will follow your recommendation and set on a tire between 26-28 mm. I still have to decide wich brand. I did a search for 700x26-28 tires and this is what I found:

Michelin Transworld City
IRC Metro II
Continental Top Touring 2000
Panaracer Pasela Tour Guard
Panaracer Urban Max
Hutchinson Top Speed

Can I use the "Tiny Minnie Mickey Moe" selection method and go fine with any of those tires?

I'm still concerned about all those pot holes, speed reducer bumps and small shattered pieces of glass that I frequently encounter. Even with my MTB tires (WTB Motoraptor 29"x2.1") I got punctures and "snake bites" flats. Something that I also forget to mention is that it rains a lot here and riding while raining is unavoidable.

The bike have a Deore XT rear deralier. When combining gears I always try to keep the 48 ring with the 5 smallest rear rings, the 38 ring with the middle 5 and the 28 with the biggest 5. I use the 48 chainring most of the time and I use the 48x11 combination with frequency on the straight parts so I will like to keep an 11 teeth ring in the cassette. Now, as you ask, there are a lot of hills in my area where I had used the 38 chainring and few short but very steep hills where, due my physical condition, I have been forced to use the 28 chainring. Because of that and the possibility of shifting problems that you mention I think that I will go with a road cassett starting with 11 and ending with 25 possibly 27 if that exist. I can not move the curret 11-34 cassette because I will be swaping wheels frequently. In other words I'm too lazy, that's why I'm bulding the additional wheelset after all. :-)

Again thanks! If you cal tell me more on the tires or have any other suggestion please let me know.

tommy2pants

You did not find all the 28s. You may have to go to Specialized for the Armadilllos. If Shimano, 27 tooth 9 speed cassettes are available, and if 8 speed, there were 28s. Snakebites suggest the need for higher infaltion, and punctures, the need for something pretty bullet proof but relatively inexpensive like armadillos.

wlevey

Before you settle on anything take a look at the Specalized Armadillo!! you can get a 700x26 in that. They are virtually bullet proof tires that have a good amount of tread and last well. The BIG selling point for me is that they have a kevlar belt that runs bead to bead which reinforces the sidewall as well as the tread area of the tire. I have had a set on my bike for the past year and a half and have been very happy with them.

Bill

fatman

Got it! I will take a look to the armadillo tire.

I can not find an 11-25/27 cassette. There are cassettes with 25 or 27 rings but they start with a 12 ring, so it seems that I'm going to have to go that way.

tommy2pants

Sorry aout that 11/27 miscue. should have known better. Couple other things.Chain length,if sized right for the 34 may be too long for a 25 or 27. Probably no problem if as you say you avoid the small cogs when in the small front ring. Sometimes when switching wheels, the rear derailer may need readjusting due to slight differences in hubs. Sticking with the same make hub minimizes the potential for problems.Pay attention to locknut to locknut hub width. Current MTB stuff is 135, and standard road is 130mm.

fatman

Damm, chain length, hub size! This was supposed to be painless, Why is this getting more and more complicated?

Ok, SpeedCity wheelset hubs specs from Mavic web site:

HUBS
Free wheel mechanism: steel free wheel body
Axle width: front 100 mm, rear 135 mm
Adjustment, removable, sealed cartridge bearings

Also according to the web site the min/max tire size goes from 28 up to 37 mm. I check Specialized and they have a 28mm Armadillo tire. Thanks God!!!

I decided to buy the Shimano ultegra 12-27 cassette but for some reason is nowhere available until late January early February. I will check on eBay.

Something else that I have to do is either recalibrate the disc brake pads each time I swap wheels or shim the disc rotors so they match positions on each wheelset and I have no idea on how to do that. I will be posting this over the mechanics forum now.

wlevey

Make you r life simple!! Put an Ultegra 11/23 on the bake and go out and ride!!! Life doesn't need to be so technical!! Teh 11/23 will give you a noticable increase in speed and will give your bike more of a Road feel (especially if you do the mod I did and put a drop bar and STI shifter on it - see my previous response). At most you will need to make some small adjustments in the in/out travel, but I didn't even have to do that!!

All of this assumes you are using a 9 speed set up!!

By the way, my mechanic (Barnetts trained by the way) showed me how Barnetts figures chain length and mine didn't need any adjustment. He said I could take ONE LINK out, but it would make a negligable difference and would prefent me from swithing back to my 11/32 if I wanted to.

Just spend the $50 bucks and get the Ultegra. Trust me, you will be happy with the decision!!!

Oh, I just looked closely at you last post!! Are you using MTB wheels??? Looks like it from what you said (tire width 28-37). That doesn't sound like it will take a true ROAD tire!!

fatman

My mistake, the wheels accept tire from 19 up to 32 or 35 if you use disc brakes.

fatman

Just to inform that I bought the Specialized Armadillo 700x28 and the Ultegra 12x25 and everything is working fine. I had to buy that cassette because there where no other available at the LBS. Same thing with the tires.

wlevey

Patients my son! unless you like your tires fat I would have ordered the 700x26 and or looked around for them (Specialized may have them on the web). They are plenty wide enough. The 12/25 cassett will probably be fine, you just won't be able to get as low when tackling hills. As long as you have the legs you will be fine. Being an old geezer I like to have the opportunity to get a bit lower if I need it. Just for information sake the next to the lowest cog on the 12/27 is a 24! It goes 12,13,14,15,17,19,21,24,27. I think the 12/25 goes 12,13,14,15,17,19,21,23,25. As you can see, not a gigantic difference between the two.

Bill