# Winter project done: Bontrager race-cx-explorer-frankenbike



## KDXdog (Mar 15, 2007)

Objective: convert my Bontrager Race to a 700c cross/adventure bike. Challenge: use as many existing parts that I already own, buying the minimum of new parts. Why? I have the itch to try CX again, and jump on that newfangled "Gravel road" bike kick that's the rage these days. Plenty of old New England dirt roads and paths to explore round here.

Yes, I know, I could just buy a used CX bike for cheap money, but where's the fun in that?

Details on the build to follow, if anyone wants to know. Better pictures also.


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## joeinchi (Jun 19, 2010)

Congrats! Looks great!

Would love to see details. Was that originally a 26er?


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## KDXdog (Mar 15, 2007)

yes, 26. I'll detail the build soon. Originally this:


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## hollister (Sep 16, 2005)

Recycled housing even?

Interesting use of a noodle


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## KDXdog (Mar 15, 2007)

hollister said:


> Recycled housing even?
> 
> Interesting use of a noodle


All new housing, except the rear derailleur section. It's a sealed Avid unit. V-brake noodles make good "last loop" to derailleur.

But VERY sharp eyes Hollister!


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## colker1 (Jan 6, 2004)

How is that rear brake set up treating you?


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## KDXdog (Mar 15, 2007)

Details:
The Bonty chain stays are bridgeless, so tire clearance is no problem. 1st challenge: brakes. Canti bosses are for 26” wheels, so the bosses are low. I searched for a “converter”, Mavic made one, but once I flipped the pad holders on my tall Avid tri-aligns...ureka! Yes they work. No, they are not super strong. 

Wheelset: old Araya rims, Shimano hubs. I had 9 speed bar end shifters, so I figured I’d use a spare new 9 speed mountain cluster (Sram). But, I didn’t realize the old 7 speed cassette body was shorter. Solution: unbolt and take off the largest gear, converting a 9 speed to an 8, that fits a 7 speed cassette hub, and works with 9 speed shifters. Yes, it indexes. Friction mode shifts very quickly too.

Didn’t like “squashing” the stays together. 130 rear axle replaced with 135 for the frame. Donor wheel (taco-ed rim) finally served a purpose.

Old Tioga Bottom Bracket with lock rings on both sides allowed me to adjust the chainline so the 48/36 Ritchie rings would clear. I installed 3 BB before finding one that worked.

What I had to buy: Surley Cross Check 1” threadless fork, cx brake levers, Conti CX tires (35mm) & tubes. 9 speed Sram chain. Bar tape.

What I had “new” on the shelf: Kelly Stem, Salsa Bell-lap bars, Tektro levers, cables & bits.

Re-purposed: XTR derailleurs, Cane Creek headset, Ritchey cranks with NOS rings, old mountain pedals, Ritchey front canti’s and front hanger, Tri-Aligns, Avocet saddle, Ringle seatpost, Avocet saddle...

I can convert it back to it’s mountain wheels, Bomber fork, stem, controls, etc pretty quickly. 

Not a show bike, built to ride. So far so good, it handles just fine. I wasn’t sure what would happen with the fork, but no weird steering. Climbs better than I expected. Rolls fast. This will be a work in progress for sure!


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## Jak0zilla (May 16, 2010)

How well does the rear brake work? And does the BB height feel weird?

I've noticed in my travels that Xtracycle make a 26 to 700c brake adapter. (I think the Mavic one is no longer made, but I could be mistaken.)


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## yo-Nate-y (Mar 5, 2009)

I can see rationalizing away the rear brake weakness if the front is what it should be and you can get them to feel fairly balanced in practice (like a single pivot Campy rear!).....but it would totally bug me aesthetically. 

Fun project. I also wonder about handling, etc, and look forward to (on/off-road) ride reports!


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## KDXdog (Mar 15, 2007)

Rear brake: I had new Kool Stop Eagle claw ll's on at first, and on my shakedown ride, they worked as well as dragging my foot on the ground. Maybe because they were new...so I put on the ol' Scott's and I'm able to lock up the wheel, with a FIRM squeeze. 

An adapter may be in my near future. As well as in-line adjusters for the shifter cables.

Handling: Been riding it on local single & double track, it feels good. Between the fork and the bb height, I was expecting handling "issues", but in reality, it's working just fine so far. But I really need to log a lot more miles in.

I have bar-end shifters on my Bridgestone RB-2 road bike, so I'm used to them.

It certainly rolls a lot faster on the road to get to the trails!


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## LARRYJO (Aug 7, 2007)

You can try these for the rear brakes:
https://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=1709
I bought them thinking they would help with my Bonty 650B project but realized they are for 700c.


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## joeinchi (Jun 19, 2010)

On the handling, it sounds like the stem and fork were a good match for your frame and 700c's. 

On my 26" drop bar conversion, I found that the original stem put too much weight over the front wheel after installing drops. I had to slide the saddle forward on the seatpost about an inch ... almost to its forward limit. Generally, it was barely noticeable but steering inputs were somewhat amplified. It was heavy.

I switched to a shorter stem, moved the saddle back near the clamp center and, now, the steering feels "normal."

Thanks for sharing.


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## KDXdog (Mar 15, 2007)

LARRYJO said:


> You can try these for the rear brakes:
> https://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=1709
> I bought them thinking they would help with my Bonty 650B project but realized they are for 700c.


Thanks, those look interesting!


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## Jak0zilla (May 16, 2010)

KDXdog said:


> Thanks, those look interesting!


They do look interesting! You'd need to source some new brake posts with the 9mm threading on them, and some bolts to fit the female threads on the Bontrager frame, but they are much sleeker than the other adapters. (And are apparently available.)


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## 1 cog frog (Dec 21, 2004)

LARRYJO said:


> You can try these for the rear brakes:
> https://www.jrbicycles.com/storefront/index.php?act=viewProd&productId=1709
> I bought them thinking they would help with my Bonty 650B project but realized they are for 700c.


I am having a hard time seeing how those work. Do you need a set of brake post studs to thread into the top hole, and a bolt to hold them onto the original brake posts? If they don't work for you, I may be interested in them.


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## GMF (Jan 10, 2004)

The thing I don't get about those adapters is that it looks like they would twist outboard when you hit the brakes. It seems like a brake booster would be essential for their effectiveness.

Aside from that, I do dig the frankenbike and the creative use of recycled components!


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## namkrad (Jul 22, 2009)

Very cool.
What a great way reusing a nice frame, kudos!
/J


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## Sizzler (Sep 24, 2009)

Nice work, looks really good! The race frame lends itself very well to a 700c conversion, on my similar build I used the adapters available through xtracycle:


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## Jak0zilla (May 16, 2010)

Sizzler - you used an xtracycle adapter on your fork as well? Can we see a pic?


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## Sizzler (Sep 24, 2009)

Jak0zilla said:


> Sizzler - you used an xtracycle adapter on your fork as well? Can we see a pic?


Sointenly!

Here's a link to the build thread in case your interested: http://forums.mtbr.com/vintage-retro-classic/sailin-814449.html


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## Trower (Apr 27, 2009)

Nice bike!! I have really been enjoying my Peugeot gravel bike a lot, surprising amount of fun How are you liking the Salsa Bell-Lap bars? I really love mine.


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## KDXdog (Mar 15, 2007)

Sizzler said:


> Nice work, looks really good! The race frame lends itself very well to a 700c conversion, on my similar build I used the adapters available through xtracycle:


Sizz, how the heck did I miss your original post? Nice work! The xtracycle adaptor looks a bit nicer than the Mavic one.


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## KDXdog (Mar 15, 2007)

Trower said:


> Nice bike!! I have really been enjoying my Peugeot gravel bike a lot, surprising amount of fun How are you liking the Salsa Bell-Lap bars? I really love mine.


I do like the Bell Laps, but now that I'm getting used to them, I wonder if I'd like a wider flair like the old WTB bars. I've been riding this bike every day, road, singletrack, gravel bike rail-trails... I'm really liking this version of the bike. Rear brake is working "ok", but I'm still planning on another mod to make it better.


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## KDXdog (Mar 15, 2007)

Been meaning to update this, been too busy riding it!

Rear brake: I went with the Sinz BMX u-brake adaptor. It's a nice little piece of machining, featuring a tiny "roll" that fits into spring hole, to prevent the "rolling" mentioned earlier. I found a pan head screw at hand, that fit perfectly in the cavity that bolts to the frame. I've now changed it to an allen head, the screw head pictured looked too K-mart for me.

Anyhow, you can see how much it moves the brake stud up. Works for my Avid and Gravity, but NOT for the Suntour pictured. So it won't work for all canti's, but for those with tall adjustments. Maybe they would be perfect for a 650 conversion. Don't know for sure, I don't have a 650 wheel...

YES, it now works well! I can lock up the brake with the road levers, with ease, instead of just "ok" braking before.
Pictured is the Bonty (coincidence) hybrid tire I've swapped with the cross tires I started with. I love the CX tires, but with the road/bike path riding i've been doing, didn't want to wear the xc out so fast, and in the spirit of doing this on the cheap, I had the Hybrids in my tire pile. I friend gave me them years ago, i never thought i'd have a use for them!

Overall, Frankenbike has worked out very well, and my other bikes are gathering dust this season.









Bonty original bolt on post, vs standard thread in, vs the larger thread in you'll need for the adaptor.


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## KDXdog (Mar 15, 2007)

The short bolts that come with the Adaptors (that attach the adaptor to the frame) didn't work on the Bonty frame, different smaller thread size.

I went to 6 local BMX shops, no one had them. Only 2 ever heard of them. Easily found on the web.

I ended up using the Gravity brakes, as I had a bushing issue with the Avids, and was in a hurry to try the bike. Gravity's worked so well, i left them on.


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## mrjustin007 (Jul 22, 2008)

Thanks - This thread has just given me some inspiration for my next project. I have a Bontrager or Kona Hot to work with.


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