Max tire size for ST-500
- Thread starter tjkilbane
- Start date
yes, it is.
letsbike
Well-Known Member
If you want to keep those original wheels, you are going to be severely limited in tire choices, since 27" is almost extinct. Especially if you want a quality tire, which I assume you do. For what purpose do you want a large tire? A 27×1-1/4 will certainly fit, I think, although there is always variation depending on the manufacturer. (1-1/8 being the original size) I have used the metric equivalent (700×32) on a touring tandem that had a combined rider weight of over 300 pounds plus small panniers and a trailer, riding dirt trails and occasional gravel roads, with no problems. Your biggest limiting factor will be the brake caliper clearance.
You may consider buying a new 700c wheelset. It would be of better quality, if you plan to use the bicycle a lot, and give you way more tire options. Plan B could be to have your current hubs re-laced to 700c rims, strong ones, if you plan to tour or ride gravel routes.
There are members here who own these early ST's. Maybe they will reply with a answer that has been tried out in the real world.
The ST on your bicycle's model designation stands for Sports Tourer, and that is what your bicycle was designed to do.
You may consider buying a new 700c wheelset. It would be of better quality, if you plan to use the bicycle a lot, and give you way more tire options. Plan B could be to have your current hubs re-laced to 700c rims, strong ones, if you plan to tour or ride gravel routes.
There are members here who own these early ST's. Maybe they will reply with a answer that has been tried out in the real world.
The ST on your bicycle's model designation stands for Sports Tourer, and that is what your bicycle was designed to do.
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Buddman66
Well-Known Member
Hi , have a look on sidewall of tyre , I’m sure you’ll find it’s 700 x 23c or 700 x 28c which is 28 inch
Buddman66
Well-Known Member
I’ll take that back you could have 27 x 1 1/4
Best way to get wider tires will be to switch to 700C wheels. Let me know if that's an option and I'll see what will clear on your frame. I have a couple of mid 80s touring frames here. I'm running 32-35 mm tubulars on two of them, haven't tried anything wider. Note that switching to 700C is likely going to require longer reach brake calipers also.
Trailmix
Member
Your bike appears to be a 1985 model, post a pic of the serial number and I can tell you. Anyway, the answer to your question is not an easy one. Early ST frames did not have the dimples on the inside of the chainstays so the condition of your rear wheel and variances in brand/model will be important. Make sure your rear wheel is as true as possible.
I have successfully used 1 1/4 Panaracer Paselas (standard version with no puncture protection) on non-dimpled frames with a very true rear rim. The standard Pasela, in my experience, tends to run 1-3mm larger than the TourGuard/PT version which runs 1-2mm larger than the UrbanMax/TServ/Somafab NewExpress-(basically all the tires running a Hypertex casing) so if the standard Pasela fits then chances are good that the other versions will fit too.
Now for the frames. IIRC, the dimples appeared around late September-early October of 1987 for the 1988 production year. I have a few 88s with the non-dimpled stays but most will have them. On these frames I have used 1 3/8 tires like the Swift Sand Canyon or the Kenda knobby (can’t remember the model) with no problem.
Just a note, the last time I ordered from Swift Tire I never received the items. I had to dispute the charges through my credit card company and Swift refunded my money at the last minute (months later) to avoid penalties from the credit card company.
If anyone has an 88 ST (or any other model Cannondale from 1983-1999) and would like to share the serial number, I would love to add it to my S/N database that I am compiling to learn more about these mid-year production changes. I have around 850 numbers right now and these changes are just now becoming easier to track and will probably get easier as the numbers increase.
I have successfully used 1 1/4 Panaracer Paselas (standard version with no puncture protection) on non-dimpled frames with a very true rear rim. The standard Pasela, in my experience, tends to run 1-3mm larger than the TourGuard/PT version which runs 1-2mm larger than the UrbanMax/TServ/Somafab NewExpress-(basically all the tires running a Hypertex casing) so if the standard Pasela fits then chances are good that the other versions will fit too.
Now for the frames. IIRC, the dimples appeared around late September-early October of 1987 for the 1988 production year. I have a few 88s with the non-dimpled stays but most will have them. On these frames I have used 1 3/8 tires like the Swift Sand Canyon or the Kenda knobby (can’t remember the model) with no problem.
Just a note, the last time I ordered from Swift Tire I never received the items. I had to dispute the charges through my credit card company and Swift refunded my money at the last minute (months later) to avoid penalties from the credit card company.
If anyone has an 88 ST (or any other model Cannondale from 1983-1999) and would like to share the serial number, I would love to add it to my S/N database that I am compiling to learn more about these mid-year production changes. I have around 850 numbers right now and these changes are just now becoming easier to track and will probably get easier as the numbers increase.
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letsbike
Well-Known Member
Why are you stopping at 1999? The original company went through 2003. That is a great project however.
I once put a 700×38 (40-622) tire on the front of my 2001 T2000 just to see if it would fit. No clearance problems at all, I just had to ditch my fender. I never put one on the rear, I was just curious if I could do a gravel tour with the bike, and was playing around.
I once put a 700×38 (40-622) tire on the front of my 2001 T2000 just to see if it would fit. No clearance problems at all, I just had to ditch my fender. I never put one on the rear, I was just curious if I could do a gravel tour with the bike, and was playing around.
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Trailmix
Member
Great question. There are a few reasons and I will probably expand the scope to include those at some point.
When I first started compiling these, I was only interested in the 1986-1993 versions because this is my favorite era of Cannondale bikes and these are the numbers that make sense as there are no unknown numbers in this style of number. It was the unknown that eventually led me to expand to the pre-85 and the 1993-1999 styles in an attempt to make sense of those. I haven’t really been able to add sufficient numbers to those databases to justify expanding further but it seems inevitable.