ruirui

i have a redline team conquest and i find it harder to keep up with the group who's riding road bikes. but when i ride my road bike i can keep up just fine. any reason why CX would be slower even when i'm using 23c tires on the CX?

knobster

Only thing that would make it any slower in my opinion would be your road bike puts you in a position where you're more aerodynamic. Do you sit more upright on the Redline?

ruirui

the geo between the two frame is fairly close, so i would think i sit about the same. however, the BB on the cx is higher than my road bike, which might be the reason why i might be sitting higher up.

2014 redline conquest - size 51


2009 scott addict r1 - size 52


also, my redline is currently setup with SRAM XO 38/24 crank & SRAM XO RD + Ultegra 12/30t.

if gear ratio is same, will MTB group be slower when compared to using road group; besides the weight difference?

AK404

Same tires?

ruirui

yup.. same 23c tires.

CharlyAlfaRomeo

What kind of speed is this group ride maintaining? 38/24 are tiny chainrings for road riding.

ruirui

they were maintaining 18-19 mph speed. tops got up to 21, which i was still able to hang.. but noticed i'm more worn out. it's the same route we usually take and usually i just ride my addict, but last sunday decided to take redline out for a spin and immediately felt the difference in speed.

i'm also wondering what if i change my crank from the current SRAM XO 38/24 to a FSA 50/34 crank and still using the current 12/30 in the back.. would i get the same speed as my addict?

tFUnK

Maybe you can get another set of wheels/cassette/tires that is better geared towards road riding?

I think a few different factors might be in play here. The bike could be heavier than a road bike. The geometry is not as responsive (maybe chain stay length?). The large gaps in the wide range cassette might be messing up your cadence when riding in the group.

Kopsis

I occasionally take my steel CX bike on the weekly group ride instead of my CF road bike. Same wheelset in both cases and similar enough geo that there's not a big aero difference. At normal pace I find virtually no difference in effort between the two bikes. At 30 MPH I'm pretty much spun out on my 1x10 drivetrain, so I do find myself pretty beat up after sprints (but I consider the forced high cadence work good training).

The 38 big ring is certainly small for road, but you can almost hit 25 MPH in your 12t cog if you spin 100 RPM cadence. Unless you're "masher" and don't like to break 80 RPM, going bigger on the crankset shouldn't make much difference if the group's top speed really is limited to 21 MPH.

I can't help but wonder if you have a brake dragging. When you put the road wheelset on the CX bike, did you check brake alignment? It's not unusual to have to make some adjustments when switching between road and CX wheelsets.

CharlyAlfaRomeo

Kopsis is right, 21 MPH should be in easy reach with that gearing. Sprints and downhills may be a problem but it doesn't sound like an aggressive ride.

Weight shouldn't make much if any difference unless you're climbing for long periods at steep grades and the geometry should have no effect on keeping up the pace so something must be going on.

ruirui

tFUnK: i ordered a FSA compact crank 50/34 so gearing will be same like my addict to test out.

Kopsis: yup i checked to make sure there's no brake rub. even though the shorty ultimate on there is a PAI to setup properly. ordered a pair of TRP CX8.4 to replace and see... cuz i also had some stopping power issue even when the shorty was setup with narrow stance coming down a 15-18% grade.

CharlyAlfaRomeo: yup.. that's what i'm hoping to find out. i thought i sit upright on CX but probably cuz BB is much higher compared to my addict, but overall seems to be fine. so maybe after changing the gearing to be like my addict then we'll see if it still slow. but i think maybe cuz of different crank, my cadence is off, so maybe that's why i feel cx is slower. on my road bike i have no problem keeping up with a group ride of 21mph pace.

knobster

I don't care what people say, the difference between riding a Scott Addict and a Redline Conquest is going to be pretty measurable. Just riding at a easy pace no, but trying to keep up with a group like that it's going to quickly show you the differences between the two. It's going to require a lot more energy to keep that same pace on the Redline than the Scott. Based off what you said about the geometry, the main thing that's probably holding you back on it is the weight and possibly wheelset.

ruirui

Knobster, I was thinking probably the weight is what's holding me back on the Redline. My Redline is about 16.5lbs with pedals and my addict is 13.65 lbs with pedals. Both are running the same CF wheelset.

knobster

Wow, 16.5 seems very light for that Redline. My Moots is closer to 20 but thats a guess. 13.65 is quite a light bike. I can't imagine 3 lbs would make that much difference though. Stumped.

AK404

I'm thinking that the posture on a CX bike would be different. Would be a little bit more upright, wouldn't you?

Number400

I ride my CX bike a lot on pavement and have caught up and mixed in with road bikes. All I know is when I get the CX bike moving on the road, I can hear the wind whistling though my mini v's and my stout wheels with 32c tires. Even with your 23c's the CX bike is much less efficient in the wind and once you get over 20mph or so, it takes a lot more work to keep it there for longer rides over a real road bike. What shoes and pedals on the CX bike vs the road bike? Stiff soles make a huge difference too. That and it's an aero thing for sure.


Donnie says it's vacuum!

Soundtallica

I realize this thread is old, but I still want to throw in my opinion. Like you, I have a Redline Conquest (albeit the highest end carbon model) that I put 23c tires on and intended to ride road on it when it's not CX season. My road bike is a pretty fancy Focus Cayo Evo with Di2, and both bikes weigh the same. Well, as much as I want to believe otherwise, the Conquest feels slower than the Cayo, even with identical wheels and tires. It holds speed as well as the Cayo does, but the Cayo just feels a lot sprightlier when accelerating and on steep climbs. The Conquest also actually is slower, by less than 0.5 mph, and I'm not saying this lightly as I rode both on the same loop while averaging the same amount of power on my power meter (I have a Stages so I can swap it between bikes).

I really don't know why this is. The longer chainstays and wheelbase shouldn't make a difference, since both have the same contact patch with the road. Both bikes are set up exactly the same in my road position, and both feel brutally stiff in the BB. The only reason I can think of is aerodynamics. I am a strong Cat 3 racer that spends most of the time above 20 mph on the flats, and the Conquest is considerably less aero with big fat frame tubes and canti brake arms that stick out. Still, I don't feel that that alone should slow me down that much. As for climbing, I can only reason that the Conquest's frame is a bit heavier, but we all know that wheel weight makes a bigger difference. So I'm really stumped here and have no idea why my CX bike is slower than my road bike, even on the same wheels. Maybe Focus knows something about snappy road feel that Redline doesn't?

Either way though, I won't bash the Conquest for not being something it wasn't designed to be. It is still far more responsive than any MTB on mildly technical trails while still providing 95% of the performance of a true road bike, so it's still my best all-rounder and the bike I would keep if I had to narrow my stable to 1 bike. Horses for Courses!

SlowJoeCrow

Have you compared gearing? CX bikes typically come with 36-46 chain rings instead of the 34-50 or 39-53 found on most road bikes. This will make your CX bike seem slower because your top gears are lower. Also CX bikes tend do be designed with a bit more "give" in the frame to handle rough surfaces so they often feel "softer".
Redline makes excellent CX bikes and has a lot of history so I doubt Focus knows more than Redline.

Soundtallica

Yeah, the Redline is a lot more comfortable even on the same wheels as the Focus. But I have it set up with a 34-50 compact, which shouldn't feel that different from the 39-53 on the Focus. I run both with 11-28 cassettes.

SlowJoeCrow

It might be worth trying a 36-52 mid-compact setup, you still lose some high gear with a 50 instead of a 53, also the 36T inner will feel snappier.

NormanF

Traditional CX bikes were meant for bursts of short, aggressive riding and portaging by hand over obstacles. They're not meant for long distance riding in the way of a road bike.

Modern gravel road bikes/adventure bikes on the other hand, are built around endurance road bike geometry and they're comfortable for all-day rides on multi-terrain.

I would leave a CX bike for CX pursuits and a role as a townie bike, not to ride a long distance.

Kopsis

At the speeds you're riding, aerodynamics will have a measurable effect. Combined with the weight difference (which still affects acceleration and climbing even though it's not rotating weight) a 0.5 MPH difference on the average is not all that surprising.

snow_echo_NY

sub.

i don't have any answers for you. these past couple of weeks i've been slow and i thought it was the heat. i checked my road tires on my cyclocross and i was running on 60 psi. i pumped it back to 100 psi and i'm back and fast.

could be saddle height and bar height and reach as others have said. (i've been watching lots of GCN global cycling network and their vids on cyclocross-road bike differences - perhaps this could help you?)

fietsbob

Air resistance of the rider is a Huge % of It. no matter what the bike ..

Number400

As a complement to my post above, I have since put a set of ultra light tubulars on my CX bike and are running Conti training tubulars. The gearing is not ideal but with 25mm tires, it's a fast bike on pavement and it rolls. I still use a fairly soft mountain shoe and SPD's so I will not get my most efficient performance but I can climb well on it and almost grab a KOM on it here and there and I barely ride a bicycle anymore.