- Please help me diagnose a problem or exorcise a demon.
Happy New Year!Posted 1 month ago
My road bike, fitted with Prime 35mm carbon wheels is noticeably slower than any of my other bikes. This is a perceived feeling as I don’t use GPS, bike computer or power meter. I can feel that it needs much more effort than my other bikes with the only difference being I have basic tubes in the carbon road wheels and my other bikes have Prime aluminium (I’m a fan of Prime wheels until this) tubeless set ups. Even the ‘cross bike is easier but I wouldn’t have thought it would make such a noticeable difference. It is clearly noticeable. I’m not imagining it. Honestly.
Sadly, there is only this bike with caliper brakes, the others are all disk so I can’t swap wheels to try it out. They seem to spin fine in the work stand and the BB seems fine as well.
Any ideas why this bike is such hard work? It’s full carbon and all things being equal, should be much quicker / less effort.
I’m going slowly madder around this. It’s becoming an obsession.
The road bike in question is at least 2lb lighter than any of my other bikes. The other bikes are all disc. The Phantom Bike is the only one with caliper brakes. All the road bikes and the ‘cross bike are set up the same. Within a few mm anyway, following a bike fit.
The drivechain has done around 1000 miles. No play in the bb. The chain length is good etc. This bike had the basic Shimano (circa £100) wheels which were replaced with the Prime carbons. I was expecting a significant increase in performance. I’m still waiting. It’s been around 3 months since they were swapped. Disappointing from the outset.
The only thing I can think of is that the carbon wheels have basic £5 inner tubes fitted as I couldn’t get the Hutchinson tyres to seal tubeless and I nearly broke fingers getting the tyres on and off where ALL of the other wheels are tubeless. Would tubes make that much of a difference?
edit: 35mm depth rims, not width, sorry. Everything feels fine in the stand. BB spins easily, as do the wheels. It is definitely harder work on the expensive road bike. I’ll move the pads even further out although they’re very ‘open’ as it is but it’s worth a go.
I’ll try running a stopwatch on the same stretch of road with different bikes.
That’s the size of it Matt. Hutchinson Fusion something or other. 25mm width. Cheap tubes in the tyres. All the other bikes are tubelessPosted 1 month agoTiRedMember
Geometry. I bet the saddle position isn’t the same so you are using slightly different muscles and may have different handling.
What is the head tube angle on the bikes? What is the seat tube angle? Are you in the same position over the BB? Is the reach the same if you are? Are the stems the same length if the reach is the same? Weight over the front wheel will influence was handling and change the feeling of the bike.
It’s probably perception btw. If you are as aero, and the geometry and position is the same, then tyres will account for up to about 10% at most. If you have high quality branded Kevlar beaded tyres then tubeless won’t matter. When I swapped some OEM wired Schwalbe Lugano tyres for some GP5000s there was a reduction in power of about 20 watts for the same speed. You won’t see that difference from tubes to tubeless, unless you have some seriously heavy nasty tubes (decathlon £1.99 for example)Posted 1 month ago
I hadn’t thought of geometry actually.Posted 1 month ago
The tubes are definitely from Decathlon and may have been less than £5 each….. is this the problem? It would be both great and not great if so. Great because it will be fixed but not great because I’m going to have to cut those tyres off. I have four different types of tyre levers, all proclaiming to be the lever that will work on any tyre…. it still took two burley blokes and a lot of pain to get the tyres on.
I sold the original wheels.Posted 1 month ago
From the first ride, I’ve been completely underwhelmed. A total contrast to the other three Prime disc brake wheelsets that I have. They’re considerably better than those they have replaced on the disc braked bikes.
I’m beginning to think it could be the inner tubes (would that really make such a difference?) but I also wondered if there was possibly a problem with the bearings or freewheel. Is there a way in which it would only cause issues when the bike is weighted and/or the drive train is under tension?
I doubt it is flex in the frame but I’ll definitely have a look at that over the weekend.
I’m tempted to sacrifice the tyres, buy new and see if I can set them up tubeless.
Doubt it’s the tubes personally.
Can you slam the stem on the new bike, that brought my old Defy to life after what had been a sluggish start feeling underwhelmed.
And do the Strava test suggested above before you start spending money based on what might be a misconception.Posted 1 month ago
From my racing days, the best single item upgrade for any bike for me was tyres. Go and buy some real racing tyres and ride it with them one. I’m out of the loop as regards really good tyres these days, but choose the top of the range race tyre from anyone and, as above, don’t go silly widths; 25 or 28 will be fine.Posted 1 month ago
Tubeless tyres….meh…. top of the range clinchers with decent tubes were good enough for racing on…NebSubscriber
Sounds obvious (surprised no-one has mentioned it yet?), but are you sure the gearing is exactly the same between bikes? Slightly different chainring or cassettes can make a huge difference in feel.
But the clock never lies, so you won’t know if it is actually slower until you measure times.Posted 1 month agosteve_b77Member
Tubes and tyres are too negligible, even if they are cheap tubes, the tyres are more than decent.
Are they the Prime SE’s with the very cheapest Novatec hubs? I reckon that as they all work fine in the stand, that when you’re on the bike the wheel bearings are loaded and are binding under load.
As you don’t do electronic recording, do you have a basic wheel on trainer? If so, check it all over in the stand and then mount it on the trainer and have someone ride it while you look for obvious binding of the rear wheel bearings.Posted 1 month agotheotherjonvSubscriber
Perception is of little value at this point, you need to go out over a timed circuit and see whether it really is slower or if your perception is fooling you. It’s been done many times with FS vs HT where HT feels faster but FS actually is, you need to do the same here.
After that it’ll either be proven or not; then perception becomes important. In the sense that it’ll either change your perception when you see the evidence that it is faster, or that it won’t and you still won’t enjoy riding it / them no matter what- and it’s about smiles, not miles after all?
Trying to find out why they’re slower when there may be nothing to find is a waste of effort at this point.Posted 1 month agosingletrackmindMember
I am wondering if putting a cheapo tube inside a TL tyre is not helping.
Tubeless tyre built slightly heavier to run with sealant , and add the weight of the tube
Now possibly add in the factor of slightly rubbing brakes on the rims, with possibly bearing drag once weighted.
How you check for bearing drag weighted? Oh a roll down test. Flat road. 15mph , reach line, roll to standstill and mark spot, get other bikes, rinse and repeat. see who goes further.
My 2p’s worth . Buy 2 x Michelin Power Race tyres and latex tubes to make the ride come alive.
and as for not having a bike you ride very far so wont need to fix a puncture , have a word with yourselfPosted 1 month agosquealerMember
I had a very similar thing on my road bike.
Swapped my synchros alloy wheels for a set of 50mm carbon ones. Ran the same tyres on both sets. The carbon ones felt slower from the start and very rough Strava data supported that. I ran them for a few months then swapped back and sold the Carbon wheels.
Maybe some frame and wheel combos just don’t work? Who knows.Posted 1 month ago
The reason I mentioned pad clearance earlier was that on my bike, I wound the pads in to just a few mm after changing them, and the next ride the bike was very slow.
After about an hour of riding around wondering what was going on, I wound them back out and it was immediately back to normal.
EDIT: this seems to be a thing, because carbon wheels are a lot stiffer than aluminium ones, so end up rubbing more.Posted 1 month ago
Thank for tall the tips, suggestions and advice apart from “and as for not having a bike you ride very far so wont need to fix a puncture , have a word with yourself”
There’s always at least one. 30 miles out and 30 miles back is about my limit on this bike. I can mitigate a puncture with a bit of a walk and a train ride home, should the need arise. If I’m doing my every other weekend 100 mile ride, I’ll take another bike. This is only going to be going on for a few more weeks because if I can’t sort it out, either in my imagination or in real terms, the wheels will be passed on with full disclosure.
Thanks anyway for your partially kind advice and thank you to everyone for your helpful suggestions.Posted 1 month agokcrMember
This is a perceived feeling
If it’s a “perceived feeling” all you can do is change your perception. I think the conventional solution to this is to buy an expensive upgrade. This will usually make the bike feel faster.
What tyre pressure are you running, a road bike with tubes should be up around the 100psi mark.
That’s very old school, especially with the wider tyres that most people are using these days. I’ve dropped my pressures significantly in recent years. The bike seems to roll fine, and it’s a more comfortable ride.Posted 1 month agoscott_mcavennie2Member
What tyre pressure are you running, a road bike with tubes should be up around the 100psi mark.
I run both my road bikes at around 70psi (25mm on one and 28mm on the other). Neither bike feels slow.
Advice on here has been to run 23mm tyres and increase psi to 100. Are we still in the 90s?Posted 1 month ago
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