New frame 2025 : TFSA JH-35

[Takiyaki]

Why would you want big balloon 32s on such a light frame? Seems contradictory

[Gloopann]

Why would you want big balloon 32s on such a light frame? Seems contradictory

Because they are faster and more comfortable?

[jonathanf2]

I'm running 25c tubeless. Less weight, accelerates faster especially uphill and still absorbs a lot of road chatter. For a lightweight road frame, 30c max tires is plenty.

[TidyDinosaur]

I'm running 25c tubeless. Less weight, accelerates faster especially uphill and still absorbs a lot of road chatter. For a lightweight road frame, 30c max tires is plenty.

I guess it all depends on your weight also... For us lightweight riders on wide rims 28mm might be plenty... But when you are 100kg things might be different.

[jonathanf2]

I guess it all depends on your weight also... For us lightweight riders on wide rims 28mm might be plenty... But when you are 100kg things might be different.

If I weighed 100kg, I'd be scared to ride a 700g bike frame! 

[Takiyaki]

Because they are faster and more comfortable?

They either have less rolling resistance or more comfort, not both at the same time.

https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison

And in my experience, albeit clouded by frame material etc, the road comfort going from even a 28c road bike to a 42c gravel bike is marginal. We're still talking about zero suspension frames and bumps being handled by a few mm of tire. Narrower tires are lighter and more aero. I think for decent roads 28c is the sweet spot. 32c makes sense more for flat insurance than comfort IMO. I have 28c and 32c on some of my bikes and don't feel a huge comfort difference.

[Gloopann]

They either have less rolling resistance or more comfort, not both at the same time.

https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison

And in my experience, albeit clouded by frame material etc, the road comfort going from even a 28c road bike to a 42c gravel bike is marginal. We're still talking about zero suspension frames and bumps being handled by a few mm of tire. Narrower tires are lighter and more aero. I think for decent roads 28c is the sweet spot. 32c makes sense more for flat insurance than comfort IMO. I have 28c and 32c on some of my bikes and don't feel a huge comfort difference.

The link you showed clearly states that the rolling resistance goes down as tire size goes up, and we know that wide tires are more comfortable because you can run lower pressures and have the same air volume in the tire. Whether you feel that difference is up to you, but the physics doesn't lie. Wider tires have less rolling resistance and are more comfortable.

Now, it's possible that after a certain size we start losing speed again, but 32s aren't that size (NorCal Cycling tested 28, 32 and 34 and found that the 34s were slightly slower than 32s, they were on par with 28s, with the 32s being the fastest ).

[Takiyaki]

The link you showed clearly states that the rolling resistance goes down as tire size goes up, and we know that wide tires are more comfortable because you can run lower pressures and have the same air volume in the tire. Whether you feel that difference is up to you, but the physics doesn't lie. Wider tires have less rolling resistance and are more comfortable.

Now, it's possible that after a certain size we start losing speed again, but 32s aren't that size (NorCal Cycling tested 28, 32 and 34 and found that the 34s were slightly slower than 32s, they were on par with 28s, with the 32s being the fastest ).

Yes, RR goes down as tire size goes up if you keep the pressure the same. Nobody is running 32cs at 100psi. You buy bigger tires to run lower pressures, which the link shows makes RR worse at recommended pressures and about equal for equal comfort. So by extension, to actually improve on comfort from a smaller tire you are getting more RR. Along with more weight and aero drag at any pressure setting.

Plus in my experience the comfort improvement isn't huge, or at least not big enough to warrant the sluggish feel and losses. There aren't many wheel choices to get a 32c tire to hit the 105% rule for example. They straight up balloon on the 29-31mm wide wheels I have.

Im not saying people shouldnt buy 32c etc, do whatever you want........ just saying to temper expectations and have a full understanding of the costs and benefits.

[RasmusWH]

Maybe you are gonna build it up with 25-28c tyres now for a light weight climbing build, that's fine, but if I were to buy a new frame in 2025 I would like the opportunity to go wider than 30 mm in the future, even if I build it up narrower now. As rims are getting wider to, you also risk that even the stated 30c max width is getting problematic with a 30c tyre on a 25 mm internal rim width, and I don't see what you lose with a 28 mm tyre on a frame that max out on 32 and not 30 mm, so why limit the frame to max 30 mm?

[TidyDinosaur]

I think TFSA might be very conservative with that max size. I have the SL6 clone (JH-19) that has a max of 28mm according to TFSA and can easily fit 32mm tires.

[jonathanf2]

Maybe you are gonna build it up with 25-28c tyres now for a light weight climbing build, that's fine, but if I were to buy a new frame in 2025 I would like the opportunity to go wider than 30 mm in the future, even if I build it up narrower now. As rims are getting wider to, you also risk that even the stated 30c max width is getting problematic with a 30c tyre on a 25 mm internal rim width, and I don't see what you lose with a 28 mm tyre on a frame that max out on 32 and not 30 mm, so why limit the frame to max 30 mm?

I agree it doesn't hurt to have slightly wider tire clearance. Even my latest bike build has 32c max clearance, despite running only 25c tires on that bike. I think what gets overlooked is that wider tire clearance also opens up these frames as lightweight endurance bikes.

On another topic, I'm surprised no one has mentioned the built in camera/light fixture on the seat post! I run my lights all the time for safety reason. Having that mount in place would be very convenient for me. 

[Takiyaki]

Maybe you are gonna build it up with 25-28c tyres now for a light weight climbing build, that's fine, but if I were to buy a new frame in 2025 I would like the opportunity to go wider than 30 mm in the future, even if I build it up narrower now. As rims are getting wider to, you also risk that even the stated 30c max width is getting problematic with a 30c tyre on a 25 mm internal rim width, and I don't see what you lose with a 28 mm tyre on a frame that max out on 32 and not 30 mm, so why limit the frame to max 30 mm?

I mean I already tried 32c and didn't feel like it was worth it over 28c...... for road bikes not sure why that would change, and if it does it will be far ahead enough in the future to change frames anyway.

The issue with a frame like this is more clearance = longer forks/stays = more weight. Which comes back to my original point. If someone is willing to run 32s, there are probably better frames available for them, since weight doesn't seem to be a priority.

[BalticSea]

They either have less rolling resistance or more comfort, not both at the same time.

https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison

And in my experience, albeit clouded by frame material etc, the road comfort going from even a 28c road bike to a 42c gravel bike is marginal. We're still talking about zero suspension frames and bumps being handled by a few mm of tire. Narrower tires are lighter and more aero. I think for decent roads 28c is the sweet spot. 32c makes sense more for flat insurance than comfort IMO. I have 28c and 32c on some of my bikes and don't feel a huge comfort difference.

Weight difference between 28mm tyres and 32mm tyres are literally 100% irrelevant.