Building a Cyclo Cross bike

[NotSoBigBen]

Pimped my Monster's fork a bit today ....

 

[igg]

Needs a wash now...

[skadonk]

Thanks for the contribution Skadonk... post some more about your adventures please.

 

That Mercer... hmmm. 

 

http://tdaglobalcycling.com/

 

We take fully supported tours all around the Globe. The 'main' tour is Tour 'd Afrique. 12000km Race from Cairo to CapeTown.120 days.fully supported. Gravel Grinder Bikes are perfect, plenty open tarred roads in Africa,but also plenty chronic Gravel Sections.

Other Tours also vary in length and Time, but you sure as hell get fit and strong.

[LOOK695]

Needs a wash now...

Please give as a ride review on how the bike rides

[Fat Boab]

I'm new to all this cyclocross/gravel-grinder etc stuff, but this looks kinda fun!

 

http://www.bicycling.co.za/bikes-gear/tested-2016-cannondale-slate/

[igg]

Please give as a ride review on how the bike rides

I don't really have a whole lot to compare it to, but here goes.

 

Basic specs:

PXLR XL Frame

SRAM Rival 22 HRD groupset (50/34 compact + 11-32 cassette)

Spez Tracer Pro 33c tyres

Spez Romin Evo saddle

Overall weight ~10.3kg

 

The first 15km of my ride involved quite a bit of grinding coming from the drive-train as the RD went out of whack. This was resolved by hopping off a few times and turning the barrel adjuster, thereafter the ride was excellent and about as smooth as you'd expect from a rigid frame doing a bit of offroad.

 

There's a bit of frame flex, but the majority of the bump compliance comes from the higher volume tyres. Staying seated over bumps or through dips would see me getting kicked off the saddle; I wouldn't want to take this bike on washboard gravel. I've ridden a previous CX bike on washboard, it's absolute hell, and I suspect this bike would behave similarly. Hardpack & gravel were effortless, however, loose sand presented a few problems for me as I almost got spat off the trail at one stage. This I believe is largely to do with my setup and the forward weighted position.

 

I can safely say the PX is significantly faster than my MTB on the same trails as I picked up a pile of PRs on Sunday; this would not be true on more technical single track. Lower weight, improved gearing, a much smaller "granny" gear (can't cheat as much) and improved riding position are all contributing factors.

 

The disc brakes are potent as hell. This inspires a lot of confidence in knowing that the brakes are there if you need to stop in a hurry, however, caution and modulation are required as I discovered how exceptionally easy it is to lock a skinny tyre on a loose surface. As long as they were dry, the centreline rotors appeared to be doing what they advertised to do: no turkey warble. The few times they got wet they started squealing like a stuck pig, but it only takes 1 or 2 hard brakes to get everything dry and return to blissful silence.

 

One thing that is a cause for concern is the large flair on the left chainstay to accommodate the disc brakes. The problem is my foot has to be dead straight or I get heel strikes. There's only about 5mm of clearance when my foot is straight so it's very easy to contact the frame here. I've tightened up my pedals (Shimano XT) to reduce float, this helped with the heel strikes. Even so, I stuck a piece of tape there to see how bad it would be, I chewed right through it in a single ride

 

Other thoughts:

Shifting is exceptionally crisp and fast.

The shifters are quite large but I didn't find them or the master cylinder to be an irritation.

I need to adjust the shifters as I can barely reach them from the drops.

I'll likely take it for setup next week, so I can chop the fork steerer and replace the tired bartape.

The rear hub is quite loud when coasting; more pedaling required!

That seatpost is a giant pain to adjust tilt; I think it matches the bike really nicely though!

Overall the ride was fun! I'll probably take it on the road this weekend and see how it goes.

[LOOK695]

I don't really have a whole lot to compare it to, but here goes.

 

Basic specs:

PXLR XL Frame

SRAM Rival 22 HRD groupset (50/34 compact + 11-32 cassette)

Spez Tracer Pro 33c tyres

Spez Romin Evo saddle

Overall weight ~10.3kg

 

The first 15km of my ride involved quite a bit of grinding coming from the drive-train as the RD went out of whack. This was resolved by hopping off a few times and turning the barrel adjuster, thereafter the ride was excellent and about as smooth as you'd expect from a rigid frame doing a bit of offroad.

 

There's a bit of frame flex, but the majority of the bump compliance comes from the higher volume tyres. Staying seated over bumps or through dips would see me getting kicked off the saddle; I wouldn't want to take this bike on washboard gravel. I've ridden a previous CX bike on washboard, it's absolute hell, and I suspect this bike would behave similarly. Hardpack & gravel were effortless, however, loose sand presented a few problems for me as I almost got spat off the trail at one stage. This I believe is largely to do with my setup and the forward weighted position.

 

I can safely say the PX is significantly faster than my MTB on the same trails as I picked up a pile of PRs on Sunday; this would not be true on more technical single track. Lower weight, improved gearing, a much smaller "granny" gear (can't cheat as much) and improved riding position are all contributing factors.

 

The disc brakes are potent as hell. This inspires a lot of confidence in knowing that the brakes are there if you need to stop in a hurry, however, caution and modulation are required as I discovered how exceptionally easy it is to lock a skinny tyre on a loose surface. As long as they were dry, the centreline rotors appeared to be doing what they advertised to do: no turkey warble. The few times they got wet they started squealing like a stuck pig, but it only takes 1 or 2 hard brakes to get everything dry and return to blissful silence.

 

One thing that is a cause for concern is the large flair on the left chainstay to accommodate the disc brakes. The problem is my foot has to be dead straight or I get heel strikes. There's only about 5mm of clearance when my foot is straight so it's very easy to contact the frame here. I've tightened up my pedals (Shimano XT) to reduce float, this helped with the heel strikes. Even so, I stuck a piece of tape there to see how bad it would be, I chewed right through it in a single ride

 

Other thoughts:

Shifting is exceptionally crisp and fast.

The shifters are quite large but I didn't find them or the master cylinder to be an irritation.

I need to adjust the shifters as I can barely reach them from the drops.

I'll likely take it for setup next week, so I can chop the fork steerer and replace the tired bartape.

The rear hub is quite loud when coasting; more pedaling required!

That seatpost is a giant pain to adjust tilt; I think it matches the bike really nicely though!

Overall the ride was fun! I'll probably take it on the road this weekend and see how it goes.

Shot, thanks????. What is your shoe size? Could this be a contributing factor?

[igg]

Shot, thanks. What is your shoe size? Could this be a contributing factor?

 

Size 44. So it's certainly not small, but I suspect even smaller feet may have this issue. I'll see if I can take a pic tonight to see what's going on.

 

One thing to note is that my left knee is very mobile. This is clear as day when watching the vids from a bike setup, so it's contributing to a slight rotation on my foot. Tightening up the pedals really helps reduce this, but there's a point where I can no longer unclip safely.

[LOOK695]

Size 44. So it's certainly not small, but I suspect even smaller feet may have this issue. I'll see if I can take a pic tonight to see what's going on.

 

One thing to note is that my left knee is very mobile. This is clear as day when watching the vids from a bike setup, so it's contributing to a slight rotation on my foot. Tightening up the pedals really helps reduce this, but there's a point where I can no longer unclip safely.

I am wearing 46. Can your cleats still be adjusted to give more clearance?

[igg]

I am wearing 46. Can your cleats still be adjusted to give more clearance?

They can, but I'm weary of doing this as I use the same shoes on my MTB. The QFactor on my MTB looks to about about 5-10mm wider.

[Fat Boab]

Size 44. So it's certainly not small, but I suspect even smaller feet may have this issue. I'll see if I can take a pic tonight to see what's going on.

 

One thing to note is that my left knee is very mobile. This is clear as day when watching the vids from a bike setup, so it's contributing to a slight rotation on my foot. Tightening up the pedals really helps reduce this, but there's a point where I can no longer unclip safely.

 

A couple of thoughts:

 

1. Maybe your mobile knee won't like having its foot clamped in more? Not all at once anyway?

 

2. I had the same problem when I used a very broad-heeled MTB shoe on a roadie (I know, it's a rule breaker....), so bought a narrow-held pair of shoes, still MTB, and problem solved. Don't know how 'extreme' your stays/shoes are though... 

[Paul Ruinaard]

Ok guys so heres some info from the frontlines.

 

1) You get full carbon CX bikes (look at Colnago, Trek, Specialized etc) and then you get more the classic look of Steel frames like Ritchey (www.bicicletta.co.za) or Cotics.

 

2) a CX bike is purpose built with more clearance for wider tires. a typical CX bike will use 35mm tires (again Ritchey does an awesome CX tire)

 

3) a CX bike will typically have a slightly different geometry with a raised BB for more clearance over obsticles.

 

4) You can go Rim brake; disc brake manual or disc brake hydraulic.

You will have to choose your frame accordingly as the mountings are different.

 

5) then you can really mix it up and go Di2 Electronic Hydarualic group.

 

6) You would need to choose your wheels carefully too. HED Ardennes CX rims have a 25mm wide rim so allows for the tire to be set much better. they are also super light and strong.

 

Cyclocross bikes are very capable but not recommended for technical mtb riding (unless you have skill like Martin Ashton)

 

A top end Ritchey CX bike with HED wheels, Ritchey Carbon Components and Ultegra Di2 Hydraulic group will set you back R65k.

Carbon Frames you can add an additional R20k to that.

 

Some pics to follow

Where can I get Ritchey CX Tires?

[Yusran]

Hey.

I have just seen this thread and read all the guys getting a buzz off Gravel grinding...great to see.

I have done a fair bit, infact alot i guess. I crossed Africa (cairo to Capetown) on a Cinelli Bootleg CycloX, and i currently have an Avanti cycloX bike that i have crossed South East Asia, China, Australia and Europe on.... they amazing! any road,any speed.

( i did try Oak Valley 24hr race,but withdrew after 13 hours of solid riding and raw hands! - shocks may have helped)

My brother works for the same company, he had Local Legend Frame Builder Dave Mercer build him a Gravel Grinder for the Trips.  Steel is Real!

 

Thought I'd add a few pictures just for the hell of it.... maybe it will inspire some of you?!

I work for a company that crosses Continents by bicycle, fully supported. Once a year on the trip through Africa, they pass through Namibia and through the Cederberg just before reaching 'home' in CapeTown. - for any gravel grinder, its the best off road road racing you can dream of! Fast Gravel Roads of Namibia is an adrelanine rush all day on these bikes!!!

cheers..happy sweating and suffering.

 

image(8) kopia.jpg

image.jpeg

 

Very nice!

 

I am in the queue for a handbuilt frame... can't wait to meet David and get my own Mercer bike going!!!

 

(laughing and squirming like a child)

[Fat Boab]

Where can I get Ritchey CX Tires?

 

I think Monark was selling some 2nd hand? (Commission!)

 

New, I think Bicicletta have?

[igg]

A couple of thoughts:

 

1. Maybe your mobile knee won't like having its foot clamped in more? Not all at once anyway?

 

2. I had the same problem when I used a very broad-heeled MTB shoe on a roadie (I know, it's a rule breaker....), so bought a narrow-held pair of shoes, still MTB, and problem solved. Don't know how 'extreme' your stays/shoes are though... 

 

My shoe heel is quite narrow, so changing shoes is unlikely to make a difference. I'm honestly more worried about wrecking my shoe than removing the paint on the frame.

 

Tightening up the pedals has reduced knee/pedal movement. This was done during my MTB setup, and I prefer the reduced float. I've also built up the soles of my shoes (using shoe goo) to have better contact with the pedal. This was suggested during bike setup and has really stabilised my foot. I use the same pedals on both MTB and CX.

 

I have bad ITB in my left leg that the above changes have helped with. The main issue really is my left foot is slightly pronated so the heel has a tendency to drift inboard, and that's when I get the strike on the chain stay.

[Fat Boab]

My shoe heel is quite narrow, so changing shoes is unlikely to make a difference. I'm honestly more worried about wrecking my shoe than removing the paint on the frame.

 

Tightening up the pedals has reduced knee/pedal movement. This was done during my MTB setup, and I prefer the reduced float. I've also built up the soles of my shoes (using shoe goo) to have better contact with the pedal. This was suggested during bike setup and has really stabilised my foot. I use the same pedals on both MTB and CX.

 

I have bad ITB in my left leg that the above changes have helped with. The main issue really is my left foot is slightly pronated so the heel has a tendency to drift inboard, and that's when I get the strike on the chain stay.

 

Sounds like you've dug deep into what makes your body tick. I'm not a medical person, so am not trying to diagnose at all; just sharing for info.

 

I also pronate, am prone to ITB, patella tracking issues, my knees used to splay like I was communicating in semaphore. But I found that modifying my squat, heel raise etc gym routine in the following way has helped enormously. Recruit ones hip flexors by squeezing a small ball, or rolled-up towel between your knees when doing most gym exercises. Eg squats, heel raises, relevant core work where your knees are positioned close together. Now my knees track much more vertically, and the tendency to splay is much less when I'm tired consequently I get far less ITB, knee pain etc. But none of that will bring back the paint I rubbed off with my heel